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Edwin Way Teale, one of the mid-20th century’s preeminent nature writers, repeatedly traversed the US and chronicled his observations and reflections in his “American Seasons” books. In his later years, though, Teale settled into a New England home on 168 acres of land, and his focus shifted more locally. The resulting volume, A Naturalist Buys an Old Farm, has long inspired me, and it continues to provide a valued perspective: there is much to learn and appreciate right in one’s own backyard!

Lucky for me, my backyard happens to be Bill Yeck Park. In recent years, I have tried to attend more closely to the diversity of life in those 200 acres. Insect life—by far the most diverse animals—has been a big part of that. So, my routine has been to combine my daily excursions in the park—usually with my dog—with my enjoyment of photography and of biodiversity. What’s out there?

It turns out that taking pictures has a benefit beyond just enjoyment. That is, I could post my sightings to the website iNaturalist.org (“iNat”), the public database for recording photo-documented observations from nature. iNat now includes about 4 million observations from Ohio, a quarter of which are insects, and so it provides substantial context for one’s own observations. Here, I briefly recap a few findings for 2025. Perhaps there are some lessons to be learned.

Over the past decade or so, I have documented about 55 butterfly species in Bill Yeck. In 2025, I saw 44 of those. Of the 10 or so “missing” species, a few are uncommon in any year; checkered white and harvester are good examples. However, others were noticeably down in numbers from what I had come to expect. For example, Bill Yeck usually has a good number of four yellow “sulphur” butterflies in late summer. This year, two of those (orange and clouded sulphurs) were abundant as usual. But two others, the cloudless sulphur and the little yellow, were virtually missing. In fact, Bill Yeck was the top place in Ohio for reports of little yellows in 2024 (20 reports, out of 120 statewide), but there were 0 in 2025. Other species “missing” from Bill Yeck in 2025 included giant swallowtail (Ohio’s largest butterfly), wood nymph, and fiery skipper. Those local findings were mostly consistent with statewide patterns. Cloudless sulphurs, little yellows, and fiery skippers, for example, were down in numbers across Ohio.

On the other hand, some species had really good years. Black swallowtails were abundant, and monarchs surged in late summer. Likewise, zebra swallowtails, which are near the northern limit of their range in Ohio, were unusually abundant in 2025. For all those species, the banner year extended state-wide, with two or three times as many sightings in 2025 as in 2024.

The pattern was somewhat different for bumble bees. Historically, 20 bumble bee species have been recorded from Ohio. Only about a dozen have been seen in recent years, though, and just nine of those—the nine most common—were reported in 2025. Of those, seven were seen in Bill Yeck. For one species, the golden northern bumble bee (an attractive species with a yellow abdomen and a long tongue), Bill Yeck was the top locale in the state for reports. On the other hand, just a single black-and-gold bumble bee was reported—up from 0 the previous year—and perplexing bumble bees—a fuzzy, all-yellow species—were not seen at all, as has been the case in Bill Yeck and in local counties for several years.

What lessons can we draw from these findings? The most obvious is simply that there’s a lot of diversity out there! Even a relatively small suburban park like Bill Yeck Park, with its combination of mixed deciduous forest, meadows, and creek, can be home to lots of critters.

Documenting that diversity is a challenge. Even for well-known groups with relatively modest species diversity, like butterflies, it takes a lot of wandering to capture what’s out there. That’s even harder for groups like bees, where many species are smaller, harder to photograph and identify, and more restricted in time and place. I photographed about four dozen identifiable bee species in 2025—but that’s just 10% of the number in Ohio, and no doubt there are lots yet to find. Similarly, I had to learn how to look for ichneumons—parasitic wasps, many with long wavy antennae and flashy, patterned bodies—but once I did (sunspots in autumn woods were productive sites), I saw about 30 varieties, many still not identified. iNaturalist brings the power of the community to both the documentation and the identification of all this diversity.

What do we make of the changing and differing patterns of abundance? Why is Bill Yeck so good for some species while others disappear? And for those latter: will they return? The fact that patterns in Bill Yeck substantially mirrored those across the state suggests that causes are widespread, not local (though certainly park management practices are important). Maybe 2025’s cold, wet spring affected some species more than others, for example. But even if so: was it a direct effect of temperature and/or water (and if so, at what life stage), or might it reflect some other ecosystem interaction like parasites or disease? Unraveling answers to those sorts of questions could provide critical insights into preserving biodiversity, including for critical groups like pollinators or for specific species. As the human impact on natural systems continues to change, these issues become ever more salient.

Beyond scientific and practical intrigue, exploring local biodiversity is simply fun and interesting. Among the insects are many species with amazing body forms, colors and patterns, and life histories. And there’s always the chance of discovering something entirely new. Even just the names are fantastic. I saw elephant mosquitoes, lunate longhorn cuckoo bees, oblong woolcarder bees, dragonhunter dragonflies, antlered flutter flies, blotchwing spider wasps, and tufted globetail flies. Right out of Dr. Seuss!

Almost exactly 50 years after Teale’s “Old Farm” book, renowned global explorer Alastair Humphreys published his reflections on a year spent wandering the British countryside near his home. The message of that book (Local) is similar to Teale’s: if you explore with an open mind, then even your backyard is full of wonders. I understand that not everyone gets excited by butterflies and bumble bees, never mind wasps and flies. But our natural areas provide critical functions, from ecosystem services like pollination and water purification to a sense of well-being, wonder, and refreshment. We need our parks, and we are more likely to value what we attend to. Take a closer look at the critters in your backyard and neighborhood; you might be amazed at what you see!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Perfect for birthday parties, graduation parties, family reunions and more, large group shelters are available in eight of the Centerville-Washington Park District community parks. Reservations for the 2026 calendar year may be made beginning at noon on Friday, January 2.  

View the large group shelters and reservation fees >

Shelters can be reserved with a credit card payment online or by cash or check in person during office hours (Monday – Friday, 8 a.m. – 3:30 p.m.). Reservations are not available by phone; however, please call us if you have any questions! We can be reached at 937-433-5155.

Shelters are available for use on a first-come, first-served basis when not reserved.

Parents sending their kids out to explore the meadows and woods of Greene and Montgomery Counties can take comfort that we don’t have alligators, mountain lions, or poisonous snakes. But still, there are a few natural hazards out there. Among those, poison ivy is probably somewhere near the top of the “do not touch” list. “Leaves of three, leave it be!”

Poison ivy is a member of the cashew plant family Anacardiaceae, which also includes such well-known edibles as mangoes, cashews, and pistachios. Cashew-family plants take a variety of forms, including bushes, trees, and vines. Poison ivy itself can grow in several of those forms, ranging from a weedy ground cover to a rather robust shrub or a lengthy vine. Traits shared by most members of this family include small five-part flowers, fruits with thin skin and a single central seed (technically, drupes), and leaves with an alternate and compound arrangement. The simple characteristic usually used to identify poison ivy is its compound, smooth-edged, triplet leaves, with the central leaflet on a longer petiole.

Many members of the Anacardiaceae produce sap containing allergenic compounds. In fact, the scientific genus name of poison ivy, Toxicodendron, literally means “toxic tree,” and the offending chemical is an oil called urushiol. Urushiol also occurs in some human food crops from Anacardiacean plants, but in structures that can be avoided. In mangoes, for example, urushiol is substantially localized to the skin, which sensitive individuals should take care to avoid; for cashews the urushiol is removed by discarding the outer husk before marketing the nuts. In contrast, poison ivy contains urushiol throughout the plant, including roots, stems, branches, leaves, and fruits.

Despite the name “poison ivy,” urushiol is not really a poison. In other words, it is not directly responsible for harming human cells and tissues. Instead, urushiol initiates an allergic reaction. As an oil, urushiol can pass through the skin to enter underlying tissues. There, urushiol is modified (oxidized to its quinone form) and then binds to a protein (CD1) located on cellular surfaces. That molecular combination of quinone with CD1 is recognized by T-lymphocytes—cells of the immune system—as a foreign agent. Activated T-lymphocytes work to destroy targets like virus-infected cells and some cancerous cells. But in this case, they direct their destruction against skin cells, and the result is a type-IV hypersensitivity reaction—in other words, the allergic poison ivy rash.

Poison ivy unquestionably is irritating, potentially even dangerous. Nevertheless, it does have some attractive features. The first is that in autumn, the green leaves turn a beautiful array of colors, from yellow and orange to red and purple. A meadow full of poison ivy—and we have lots of those!!—can be a beautiful sight to behold in the fall.

As an additional benefit, poison ivy produces clusters of small, white fruits that ripen in autumn and can persist well into winter. Those fruits feed many animals, especially birds dealing with the cool-season lack of insects. Chickadees, yellow-rumped warblers, and downy woodpeckers are among local consumers. Poison ivy’s colorful autumn leaves probably help direct birds to the fruits. In exchange, birds provide the plant with dispersal services, as they digest the pulp but excrete the seeds unscathed.

So, how is it that birds (and also mammals like deer, rodents, and raccoons) can eat the fruits without suffering adverse reactions? The first answer to that question is simple: feathers and fur limit access of urushiol to the absorptive skin surface. No contact, no rash.

But why no reaction to taking the fruits internally? As noted above, the trigger for the human allergic reaction is the binding of urushiol to CD1 protein. It turns out that mammals have several CD1 genes, each resulting in a different variant of the protein. And the version responsible for urushiol binding in humans, CD1a, is absent in most mammals. Birds have even fewer CD1 genes and lack an urushiol-binding variant. As a result, birds and most mammals—with the exception of a few primates and, for some reason, guinea pigs—are unreactive to urushiol.

Those positive attributes of poison ivy are great, but they aren’t likely to add it to many people’s list of favorite plants. Don’t make a bouquet out of those beautiful fall leaves, and don’t decorate your dessert with those white fruits! Leaves of three: leave it for the birds!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.
 

It’s November, and Ohio’s migratory summer-breeding birds have left the state. That list of migrants includes the turkey vulture, which, as recently as a few decades ago, was southwest Ohio’s only vulture species. November used to be the beginning of the “vulture-free” time of year for Greene and Montgomery Counties. Not anymore.

Historically, turkey vultures, Cathartes auratus, were widespread across Ohio. They bred in counties across the state during warmer months but mostly migrated south in the fall. (In northeastern Ohio, the springtime return of those birds is celebrated each year in Hinckley on 15 March as Buzzard Day.) A second vulture species, the black vulture Coragyps atratus, also has a long record in Ohio, but restricted to the unglaciated southeastern counties. Though less migratory than turkey vultures, black vultures typically moved a bit southward for winter. The 1984 book The Birds of Dayton by the Dayton Audubon Society lists the black vulture as a “very rare visitor” to the Miami Valley and notes that this species “doesn’t seem to wander into the Montgomery County area.”

In recent years, those scenarios have changed. According to eBird, the public database of bird sightings with more than 1 billion logged observations, turkey vultures are now observed year-round — though still somewhat less so in winter — in both Montgomery and Greene Counties. (Check out the “explore/bar charts” link at ebird.org.) Black vultures, too, though generally less common than turkey vultures, now produce a steady stream of local reports in every month of the year, with no apparent cycle of abundance.

Both turkey and black vultures feed primarily on carrion, though black vultures are the more aggressive species and may be more likely to seek live prey. The two species are often seen together, both in flight and while feeding on the ground. While both appear as large, black birds, they do have distinguishing features. The larger turkey vulture has a red head as an adult (gray in juveniles) and solid black wings that are held in a noticeable “V” configuration in flight. In contrast, black vultures have gray heads and in flight hold their wings more horizontally, showing off distinct white patches toward the wingtips. In a mixed feeding group, black vultures tend to dominate, with turkey vultures taking a more peripheral position around the carcass.

What accounts for the changing abundances of the two vulture species in southwest Ohio? Two factors are likely important for both species. The first is the increase in human impact on the landscape. Both the increase in road-killed animals from vehicular traffic, as well as an increase in domestic carcasses as agriculture expands, are enhancing the food supply for vultures. (At the same time, cars pose a significant risk to vultures feeding on roadkill.) The second factor is also human-generated, though less direct. That is, climate change is creating warmer winters, which supports the notable increase in year-round residency for Ohio’s vultures.

One additional factor — a difference between the species — may be significantly responsible for the northward and wintertime expansion of black vultures. It turns out that among birds, turkey vultures have one of the best-developed senses of smell. Rotting corpses emit sulphur-containing ethyl mercaptan, and turkey vultures can follow that odor to its source. (Ethyl mercaptan is also added to commercial natural gas to facilitate leak detection. Humans can detect leaks at home, but vultures can be used as an indicator of leaks in supply lines.)

Black vultures, though related to turkey vultures, lack their olfactory capabilities. That difference is reflected in their anatomy. Turkey vulture brains are 20% smaller than black vulture brains. However, the brain structure responsible for processing the sense of smell — the olfactory bulb — is four times larger in turkey vultures. They also have more mitral cells, which relay olfactory information to the higher brain, and larger nasal cavity surface area. The result is an elevated sense of smell.

A consequence of that sensory disparity is that turkey vultures have an advantage in locating carcasses, even those that are visually concealed. And so black vultures do the next best thing and follow turkey vultures, often flying higher than their larger cousins so they can watch from above.

In the scheme of ecological communities, scavengers are critical contributors, as they remove dead organisms from and recycle organic matter to the landscape. This November, perhaps you will be giving thanks for the turkey providing sustenance to your family. At the same time, those other large birds with bald heads — the turkey vulture and its black vulture cousin — might warrant a moment of appreciation, too.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

It’s probably fair to say that, despite our fondness and admiration for the title character from Charlotte’s Web, most people are happy to keep spiders at a distance for most of the year. But now it’s October, and, for a little while, houses and yards are decorated with spiders and their webs. The classic Halloween spider is long-legged and sits in a radiating web. Out in the local fields and meadows, the spiders that best exemplify that form are the garden spiders in the genus Argiope.

Two species of Argiope call our area home. The yellow garden spider, Argiope aurantia, has a black central band down its dorsal (upper) surface, with yellow bands extending down the animal’s sides. In contrast, the banded garden spider, Argiope trifasciata, has narrow white, black, and yellow stripes running laterally across the entire dorsum. Other differences include the coloration on the legs (more banded in trifasicata) and the darker underside of aurantia. The two species seem to be roughly equally common.

Two features of Argiope spiders immediately impress. The first is their size. These are among Ohio’s largest spiders, with leg spans up to about three inches (5 cm). Females are larger than males, so it’s the girl spiders that are most likely to trigger arachnophobia!

The second impressive feature is the silken web, which is an engineering marvel. Argiope webs, with their classic spoked-wheel pattern, can span 60 cm (2 ft) or more. Spider silks (spidroins) are proteins, encoded by a diversified set of genes. They are produced as a liquid emulsion in specialized abdominal glands, then extruded through valved spinnerets. That extrusion process concentrates the spidroins, which induces the proteins’ amino acids to align and form a fiber.

Argiope spiders generate seven varieties of silk, each from a separate gland and with properties corresponding to its uses. For example, the silk from the major ampulla gland is used to construct the framework of the web and to attach it to supports like stems and branches; it is strong (high tensile strength) but relatively non-extendible. In contrast, the web strands used for prey capture are stretchier and stickier; they derive from two glands, the flagelliform gland that produces a fibrous thread for weaving the capture spiral and the aggregate gland that produces a sticky liquid coating.

In the center of the Argiope web is an obvious variation in weaving pattern, a dense zig-zag element called a stabilimentum and structured from “actiniform” silk. Theories abound about the function of this structure. It may reflect ultraviolet light in a way that attracts potential prey items; it may provide visibility to birds so that they can avoid the web; it may even make the spider appear larger so that potential predators are deterred. Those possibilities are not mutually exclusive.

Once an insect is trapped in the sticky strands of the web, the process of subduing it begins. Garden spiders have a relatively poor visual sense, and so they locate ensnared prey primarily by sensing web vibrations. Sensitive sensory structures (lyriform organs and trichobothria), primarily on the legs, help to identify the size and location of the prey item, and to distinguish ensnared insects from disturbances like wind gusts. Upon detection, the spider rushes to the insect and injects a combination of paralytic toxin (to subdue movement that might damage the web) and digestive enzymes (so that the spider can eventually “drink” its liquified prey).

Spiders often store their prey items while the digestive enzymes take effect. To facilitate that storage, the spider wraps the captured insect in silk derived from the actiniform gland, the same as used for the stabilimentum. Several strands are extruded simultaneously, and the spider uses its front legs and limb-like pedipalps near the mouth to wrap the silk around the prey, forming a tight cocoon.

Adult Argope spiders do not survive the winter. As well described in Charlotte’s Web, female Argiope spiders die after laying their eggs, typically around the time of the first hard frost. So, just as Halloween spider decorations are disappearing from homes, so too adult garden spiders are disappearing from the landscape. But the next generation is ready to go. The eggs are encased by a cocoon (also spun from silk, of two varieties), and they hatch in late fall. The spiderlings don’t emerge from the cocoon until the following spring, though. The newly hatched Argiopes climb to a tall perch, toss a fine silk line into the breeze, and float off to a new home. Garden spiders and their spiderling babies might not be quite as endearing as the characters in E.B. White’s story–but surely they are worth celebrating with a greeting. Salutations!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

There’s no mistaking a praying mantis! Praying mantises are named for the front-facing, folded forelegs that give the appearance of an animal in prayer. Really, though, the series of spikes along those “arms”, along with their lightning-fast movements, are a major element of the mantis’s success as a fearsome predator. “Preying” mantis, perhaps?

Praying mantises are members of the insect order Mantodea. There are nearly 2,500 species of mantises worldwide. Oddly, though, just a single species is native to Ohio. By comparison, Ohio is home to approximately 150 species in the order Odonata (dragonflies and damselflies) and something like 3,000 in the order Lepidoptera (about 150 species of butterflies, the rest moths). Our one native mantis is the Carolina mantis, Stagmomantis carolina.

Carolina mantises present all the standard mantis features. Mantises hatch out of the egg as nymphs, basically miniature versions of the adult, though without wings. They are predatory from day one, though the size and identify of their animal prey changes as they grow. Contributing to that predatory prowess, praying mantises have large, laterally placed eyes that generate high resolution, stereoscopic vision. Along with a head that swivels through 180 degrees, mantises can track prey without moving their body. So, praying mantises adopt a “sit and wait” hunting strategy, pouncing on any potential prey that wanders within reach. Mantises mostly eat arthropods — grasshoppers, flies, bees, butterflies, spiders, etc. — but they might occasionally grab a small frog, lizard, or other animal. Larger mantises (not Carolinas) have even been known to capture unsuspecting hummingbirds.

From a human (and maybe insect prey!) perspective, mantis predation is rather horrific. As noted above, mantises have extremely fast reflexes, and their serrated forelegs create an inescapable grip. The consequence is that mantises do not need to further subdue their prey; there is no stinger, no venom, no death blow. The mantis simply holds on while it devours its prey, one small bite at a time. The unfortunate victim eventually dies during the process.

Although the Carolina mantis is Ohio’s only native mantis, a few other species have been introduced to the state. One of those — the Chinese mantis Tenodera sinensis — is probably more common and more often encountered than the Carolina mantis. The two species are relatively easy to distinguish. Both are colored some combination of green and/or brown, but the Carolina version is smaller (5 vs 10+ cm in length as adults), has shorter wings (typically failing to extend to the end of the abdomen), and lacks the striped facial markings characteristic of the introduced species.

Adult female Carolina mantises lay eggs in the fall, forming a flattened egg case (ootheca) that hardens to a Styrofoam-like consistency. Adults do not survive the first hard frosts of autumn, but the egg case overwinters and babies emerge in late spring. Hatching success and survival of juveniles can be low, and hatchlings grow slowly, so relatively few eggs end up producing new adults by late summer. Their smaller size also makes them more vulnerable to predators than the larger introduced species. Together, all these factors create the generally low population densities of Carolina mantises.

Two aspects of mantis biology are widely held but open to question. The first is that the female mantis consumes the male during mating. It is true that mantises (both male and female) are fairly non-selective predators; they will eat anything they can catch, including sometimes other mantises. Moreover, female mantises are larger than males and so have the advantage as predators. Nevertheless, while sexual cannibalism has been observed occasionally in captive Carolina mantises, it remains unclear how often, if ever, it occurs in the wild.

A second holding about mantises is that they exert significant impact on the diversity and/or amount of insect life in their habitat. In other words, it seems reasonable to suspect that mantises are effective enough predators that they reduce the abundance of other insects. However, actual evidence for that impact is not compelling. Studies of Carolina mantises have found little effect on other insect populations. Perhaps that is because of the low density of Carolina mantis populations. However, even the larger, more abundant Chinese mantises may, by themselves, have relatively low impact on their insect communities. Clearly, many other factors, including other insectivores, are important, too.

That ambiguity about the impact of predation by mantises applies to a more practical setting as well. Mantis egg cases (usually of Chinese mantises) can be purchased commercially, and it is not uncommon for home gardeners to place them among the plantings, hoping they will suppress insect pests. That might be true — but mantises are just as likely to prey on beneficial insects, including a variety of pollinators. So, the net benefit of “mantis supplementation” remains an open question.

Be that as it may, mantises never fail to intrigue. Give one a long look and those big eyes will return the stare right back! September is the optimal time to find mantises among the late season wildflowers. Be on the lookout!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Game on! The Centerville-Washington Park District (CWPD) has added two new pickleball courts at Yankee Park, meeting growing community demand for the fast-paced, social sport.

The upgrade came during a planned resurfacing of the park’s three tennis courts this summer. One court was converted into two pickleball courts, while the remaining two tennis courts were refreshed. The project took about 10 weeks to complete.

“Pickleball has become one of the fastest-growing sports in our community,” said Kristen Marks, Centerville-Washington Park District’s Executive Director. “In our most recent community survey, residents told us they wanted more pickleball. We’re thrilled to offer this new space for people of all ages to play, connect and have fun.”

The new courts join CWPD’s six existing pickleball courts at Activity Center Park, giving local players a total of eight dedicated public courts to enjoy. All courts are open during daylight hours on a first-come, first-served basis.

Yankee Park is located at 7500 Yankee Street in Washington Township.

Media inquiries? Please contact Carrie Dittman, Marketing & Communications Supervisor at 937-433-5155.

Flowering plants (angiosperms; as opposed to other land plants like evergreens, ferns, and mosses) are characterized by flowers that produce seeds encapsulated within a fruit. Those flowers provide the beautiful displays of color that adorn our parkland woods and meadows for much of the year. But, of course, the color that dominates those habitats is green.

The green color of plants derives from chlorophyll, a pigment molecule that captures energy from sunlight. Chlorophyll absorbs blue and red light most strongly, and so we see the reflected, unabsorbed green light. That absorbed solar energy promotes a series of chemical reactions—photosynthesis—that ultimately result in the formation of plant sugars. Flowering plants evolved about 125 million years ago, but chlorophyll and photosynthesis arose much earlier. In fact, the cellular structures—chloroplasts—that contain chlorophyll in flowering plants are understood to have evolved about a billion years ago, when photosynthetic bacteria (cyanobacteria) were engulfed and then retained inside the cells of what became green algae. Those green algae eventually gave rise to land plants. That early evolutionary step—the incorporation of free-living bacteria into algal cells—is an example of biological symbiosis, the sustained interaction of two species of organisms in nature. Symbiotic relationships take many forms, ranging from mutualistic (in which both partners benefit) to parasitic (in which one partner suffers), and they underlie the great web of interactions that form ecosystems.

Photosynthesis allows an organism to create its own food, which is a great advantage. So, it might be surprising to consider that some flowering plants have given up that benefit. But indeed, something like 1% of angiosperms produce little or no chlorophyll; they are not green, and they are incapable of photosynthesis. As such, those plants need another method to obtain nutrients and energy. Two local examples illustrate how that is accomplished.

Dodder (genus Cuscuta) is represented locally by two similar-looking species, field dodder and common dodder. Dodders are related to morning glories, the green stems of which form tangles of vines and support showy colorful flowers. Dodder is “viney” too, but it is immediately recognizable in our meadows from its stringy orange stems climbing over and around a variety of other plants. That appearance is responsible for dodder’s many alternative names, including devil’s hair, strangleweed, hellbine, and others. Dodder is an annual, growing anew each year from seeds. As the young stems elongate, they sense chemicals emitted by favorable host plants and grow in that direction. Once contact is established, the dodder stem produces small protruding structures called haustoria, which penetrate into the host. Those haustoria then absorb nutrients that are circulating in the phloem fluid of the host (phloem distributes products of photosynthesis from the leaves to the rest of the plant). In other words, dodder is directly parasitic, not so different from a vampire, or a vampire bat, sucking blood. Dodder can substantially reduce vitality of its host, to the point that it can become a significant crop pest when that host has agricultural value. Eventually, dodder’s original roots disintegrate and the dodder becomes entirely dependent on the host for nutrition. In later summer, the stem supports a large number of small white flowers, and the subsequent seeds are shed to start the next generation.

Ghost plant (Monotropa uniflora, formerly called Indian pipe) take a less direct approach. Many of ghost plant’s relatives, like azaleas and rhododendrons, have vibrant flowers, but ghost plants themselves have a single wax-white stem that curves downward at the top to support a single wax-white bell of a flower. Given their lack of photosynthesis, ghost plants do not need to be in sunlight, and they typically grow in the shade of woodland trees. Those trees are photosynthetic—they form the green forest canopy—but they also exchange nutrients with an underground network of fungi that form an intimate association with the plant’s roots. Fungi with this role are known as mycorrhizae, and they provide the tree with essential elements like nitrogen and phosphorus; in return, the tree passes some of its sugars on to the fungi. That win/win exchange is an example of a mutualistic symbiosis. Ghost plants intrude on that system. Their fine root hairs intertwine with the network of fungal strands (mycelia) and absorb some of the nutrients that originally derived from the tree. In other words, the ghost plants are indirectly parasitic on the tree, and more directly parasitic on the fungus. It’s a mild parasitism, though, as there may be little actual detriment to the fungus or the tree. It turns out that ghost plants are able to establish this relationship with a particular group of mycorrhizal fungi—the Russulas—which in turn associate with particular types of trees. Ghost plants are commonly found in the vicinity of beech trees.
So, plants grow, flower, and fruit based on an ancient symbiosis that transitioned free-living photosynthetic bacteria into plant cell organelles. A plant that evolves to lose that association must develop an alternative symbiosis—parasitism of one sort or another– to compensate. All of these circumstances illustrate a guiding principle of ecological systems. That is, their function depends on the interactions between species. It’s all about connections.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

What are these animals?

This is a pair of stream bluet damselflies, Enallagma exsulans, a common species found in every Ohio county. Damselflies, along with dragonflies, make up the insect order Odonata (so, to enthusiasts, they are called odonates, or sometimes just “odes”). Damselflies are typically smaller than dragonflies, with skinnier abdomens. Their prominent eyes, which sport cool colors and patterns in many species, are set on either side of their head. (In dragonflies, the eyes meet at the midline). And damselflies usually hold their wings vertically above their body, rather than out to the side as in dragonflies.

Why are they called stream bluets?

All adult odonates eat insects, which they catch on the wing, and so it’s easy to think of them as animals of the land and air. However, odonates lay their eggs in water, where the juveniles, called nymphs or naiads, are predators on pretty much anything that moves. In fact, the aquatic stage of life commonly lasts longer than the adult stage. Stream bluets prefer to lay their eggs in moving water rather than lakes or ponds, and so streamside habitat is a good place to find them. As for the name “bluet,” that’s simple: most of the “bluet” damselflies are, at least in part, blue. About ten species of bluets inhabit Greene and Montgomery Counties. Each species has a unique pattern of male coloration, though seeing those differences sometimes takes careful inspection. In fact, the genus name Enallagma derives from the Greek word for “confusing,” reflecting the many similar species of bluets.

Why are the two individuals different colors?

Odonates are visual animals, and their colors and patterns serve a variety of signaling functions. As part of that, many odonates exhibit sexual dimorphism, meaning that males and females look different. As in birds, the male is usually more colorful; the bright blue individual in this picture is the male. That male coloration contributes to species identification as males and females seek mates or as males compete with each other for access to females. Also similar to the situation in birds, blue coloration in damselflies does not result from blue pigments. Rather, the blue coloration is “structural”, meaning that it results from patterns of light reflection within the structure of the exoskeleton. However, insect exoskeletons are made of chitin, whereas bird feathers are keratin, and so the specific structures underlying color production are not identical.

Why are the animals forming a heart?

These animals are mating, meaning that the male is delivering sperm to the female. Male odonates produce sperm in the terminal segment of their abdomen (segment 10). However, from there they transfer the sperm in a packet to a more forward-positioned chamber, the sperm accessory organ, or receptacle, located near the thorax on abdominal segments 2 and 3. During mating, the male uses his cerci (specialized claspers at the tip of his abdomen) to grab onto the female near the front of her thorax. Each damselfly species has a specific shape of the male cerci and female thoracic groove, which helps to assure that only males and females of the same species join for mating. The female then places the tip of her abdomen by the male’s sperm receptacle and receives the packet of sperm. Mission accomplished! The combination of male and female positioning for that transfer results in what usually is called the “wheel position.” But it rarely actually forms a shape resembling a wheel, and sometimes, as in this photo, the animals curve their abdomens in a way that makes a perfect heart.

What happens next?

Damselflies can remain in the mating wheel formation for many minutes. Once sperm transfer is complete, the female goes on to lay her fertilized eggs. The male often remains attached to his mate’s thorax while she lays eggs, guarding his investment against intrusion by other males. Stream bluets deposit their eggs on streamside vegetation, either slightly above or below the water line. The adults probably die within the following few weeks. However, the nymphs overwinter under water and do not emerge and metamorphose into the next generation of adults until the following year.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

There’s no more relaxing way to spend a summer day than creekin’. Wander down a local creek and you’re sure to scare up a variety of critters: minnows and darters swim off to undisturbed waters, crayfish skitter under the nearest stone ledge, and the occasional water snake glides out of view. Other inhabitants require just a bit more effort to reveal. But turn over stones along the creek’s edge and it won’t be long before a skinny, shiny, yellowish little animal wriggles off to its next hiding place. You’ve found a southern two-lined salamander, Eurycea cirrigera!

Salamanders constitute an order of amphibians, the Urodela. In general, they have a readily recognizable body form: long and skinny, with moist skin and a squat four-legged posture. Eurycea salamanders exemplify, and even exaggerate, that shape. They are particularly skinny, and they have particularly dainty legs.

Two-lined salamanders are streamside residents. They lay their eggs in the water and hatch into aquatic larvae, similar to frogs developing from tadpoles. (Some plethodontid species are more terrestrial and skip the larval stage, instead hatching out directly as miniature adults.) While living under water, the larvae “breathe” (acquire oxygen) using two body surfaces. First, they have permeable skin that allows oxygen to enter their body from the surrounding water. And second, they have frilly external gills, which provide additional surface area for oxygen uptake.

The transition from aquatic larva to adult salamander includes several changes that facilitate a partially terrestrial existence, as the name “amphi-bian” (“double life”) implies. Some of those changes relate to locomotion on land; salamander larvae already have dainty legs, but they do lose their tail fin. Other changes facilitate terrestrial respiration. External gills do not function well in the air, and so the gills disappear. In most amphibians, an alternative set of breathing organs—the lungs—develop instead, providing a moist internal surface for acquiring oxygen. But two-lined salamanders and other members of their salamander family—the Plethodontidae—are an exception to that pattern. When plethodontids metamorphose to adulthood, their external gills do disappear, but they do not develop lungs. Indeed, the common name for plethodontids is the “lungless salamanders.”

How do two-lined salamanders get by without lungs? Plethodontids still need to acquire oxygen to support their metabolism, but in the absence of gills and lungs their only respiratory surface is the external skin. Despite that, two characteristics of plethodontids allow oxygen supply to meet demand.
First, two-lined salamanders have relatively low body temperatures (as residents of cool creeks) and quiet lifestyles. The resulting slow rates of metabolism generate low demand for oxygen. Second, their long, skinny shape means that plethodontids have a lot of body surface area (the site of oxygen uptake into the body) relative to their body mass (the volume of tissues that require oxygen). That high ratio of surface area to body volume facilitates an adequate match between oxygen uptake and demand.

Still, the skin is a less effective surface for acquiring oxygen than the gills or lungs, and so the absence of lungs does constrain the animal. Lungless salamanders can increase their rates of oxygen use just half as much as salamanders with lungs. As a result, they have limited capacity for exercise. Maximal rates of oxygen use occur at speeds just 10 – 50% of those achieved by salamanders with lungs, and lungless animals also fatigue much more quickly. Presumably, those relatively sluggish capacities are adequate for catching prey (a variety of aquatic invertebrates) and for their mostly quiet lifestyles. Two-lined salamanders still can put on a quick, short-term burst of activity if need be, using muscle metabolism that doesn’t require oxygen delivery (like a sprint vs. a jog). They can be surprisingly quick and wiggly!

Plethodontids have one additional survival strategy that helps them in the event of attack by a predator. Along with salamanders in a couple other families, plethodontid are able to regrow lost appendages, including both limbs and tails. Amazingly, the regenerated organs have full, normal skeleton and muscles. That ability derives from the activity of stem cells that can develop into a wide variety of cell types. Some lizards, which lack such fully functional stem cells, also can regrow tails, but not with the full suite of original structures.

With that capability in their toolkit, two-lined salamanders will sometimes self-release (“autotomize”) their tail if they are attacked. The base of the tail has specialized weak points in the skin, muscles, connective tissue, and skeleton that define the point of breakage. When the tail is lost, a cylinder of skin folds over the break point to stimulate clotting and enclose the wound. The disconnected tail segment wiggles in a way that attracts the attention of the predator, while the salamander itself sneaks off to live another day. In a few months, the salamander will have a tail as good as the original. But it still won’t have lungs!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Red, orange, yellow, green, blue….INDIGO. What is that color, the “I” in ROYGBIV? According to Wikipedia, ”indigo” might refer to a number of hues in the range from blue to violet. But if you look at the jazzy birds singing in and around Ohio’s summer meadows, the answer is clear: Indigo buntings are blue!

The story of how birds achieve their blue color is often told and well known. Birds don’t produce blue pigments. Rather, their blue color is structural. Feathers are made of keratin, like our hair and fingernails, and tiny air pockets (“nanostructures”) within the keratin scatter light so that only blue wavelengths are reflected out. Change the lighting—backlight the feather, or put the bird in shadows—and the blue disappears. But while “blueness” might be their most noticeable feature, two other aspects of bunting biology, related to migration and to song learning, also have been the focus of substantial research.

Each year, indigo buntings fly from Ohio to wintering grounds in the Caribbean and Central America, then return to Ohio around April. Like many songbirds, indigo buntings migrate at night. Presumably that confers advantages like protection from predators, calmer airstreams, and cooler temperatures. But nighttime migration also raises an obvious question: how do the birds find their way?

It turns out that indigo buntings were the subjects of seminal studies into the basis for avian migratory navigation. Ornithologists had postulated that night-flying birds might orient using star maps. Nearly 60 years ago, Stephen Emlen (who’s still affiliated with Cornell University) set out to test that idea by studying indigo buntings. Emlen housed birds in a planetarium, then observed their directional orientation as he manipulated the overhead star patterns.

Those studies revealed that indigo buntings do indeed use the night sky as a compass. Most importantly, they learn star patterns in the north-polar region of the sky, which changes the least over the course of a night. (The entire sky appears to rotate above the earth, so it’s important not to be disoriented by changing star positions.) Those star patterns then provide directional information—just as humans might use the Big Dipper to find Polaris. Navigation by the stars is not an inborn ability; buntings that are deprived of viewing the sky as youngsters do not develop directional migratory behavior.

But what happens on cloudy nights, when star patterns are obscured? Emlen tested an idea about that, too, and he confirmed that indigo buntings have a second superpower. That is, they can detect and orient by the earth’s magnetic field. Even in starless conditions, buntings still could orient using their magnetic sense. Scientists are still unraveling the mechanism of magnetic sensing. Current ideas involve chemicals called cryptochromes that are found in the eyes of migratory birds and that form “radical pairs” sensitive to weak magnetic fields.

Note that the stars provide buntings with a compass (how to head north or south), but migrants also need a map (where exactly are they, and how do they know when they reach their destination?). The identity of that map is not fully resolved. Young buntings often migrate separately from adults, and so “the voice of experience” does not guide them. One possibility is, again, the earth’s magnetic field; its local orientation (inclination and declination) can provide positional information. Other potential cues include topographic features like mountains and rivers, familiar smells, or global wind patterns. Whatever the answer, the system works. Indigo buntings are potentially long-lived (the record in the wild is a bird recaptured in Ohio more than 13 years after it was originally marked), and they return to the same breeding area year after year.

When male indigo buntings do return to Ohio, they quickly get back to the business of singing to establish territories and attract mates. Indigos are persistent singers; they can sing one song per minute for hours on end, and even more frequently than that at the start of the day. Interestingly, though, not all indigo buntings sing the same song. Instead, they have local “dialects.” Wander through a park and one might notice that indigo buntings tend to sound similar for a while—maybe a few hundred yards—but then one enters a new “bunting neighborhood” and the song shifts.

This pattern of song variation results from a couple of processes. The first is that young male indigo buntings (only the males sing) can vocalize disjointed song elements even if raised in isolation. But there are a lot of individual phrases, and to coalesce them into a mature song requires hearing other singing males. That learning continues for about 18 months, well into the second summer of life.

Upon return to Ohio, first year buntings tend to settle nearby to where they were hatched. Their neighbors, which might well (but might not) include their father, then serve as models for song development. However, some young buntings end up settling in locales somewhat removed from their natal nest, where they learn from buntings with songs constructed from a different combination of elements. The result is that neighbors are likely to share songs, but there is always a bit of mixing as birds resettle after migration.

Indigo buntings are songbirds, and the color blue in song often sets a tone of melancholy. “Mood Indigo,” Duke Ellington’s jazz standard, is emblematic. But it’s another, slightly earlier jazz classic that seems more appropriate here. With their vibrant color and their amazing secrets and powers, indigo buntings might well be described as Rhapsody in Blue.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Bats in the Beech Tree

With the arrival of April, lots of animal migrants are returning north to Ohio from their wintering grounds. In the tops of sycamore trees, yellow-throated warblers sing and flash their colors. Out in the wetlands, green darner dragonflies skim the water’s surface and deposit their eggs. And in the woods, hanging like fruits among the remnant leaves of understory beech trees, red bats wait to fly out after unsuspecting moths.

Eastern red bats, Lasiurus borealis, are one of more than a half-dozen species of “vesper bats”— small bats in the family Vespertillionidae — that inhabit Greene and Montgomery Counties. As their name suggests, red bats are almost uniformly a lovely chestnut color, other than small white patches on the shoulders. The genus name Lasiurus means “hairy tail”, which describes another characteristic feature, though one that’s not so easy to see.

With wings that span about 12 inches (30 cm) from tip to tip, red bats look rather large in flight. But really, they are mid-sized among Ohio’s vesper bats and weigh in at about 10 grams, just half of a house mouse. At that small size, winter poses a challenge for red bats. To function normally, they need to keep their bodies warm (bats maintain body temperatures similar to humans). Yet food (insects) is not available during cold weather, and the bats are susceptible to rapid cooling. Red bats meet that challenge using two strategies.

The primary strategy for surviving winter’s cold is to avoid it; red bats migrate south for winter. Two features of small bats allow that strategy to work. The most obvious is that they can fly. Red bats have been clocked at 40 miles per hour in level flight and so, unlike a similar sized rodent, they can realistically cover the distances between northern and southern US on a seasonal time scale. In addition, bats are long-lived relative to most small mammals. Some vesper bats have lived for 20 years or more, ten times as long as a like-sized mouse. (There seem not to be good records of lifespan for wild red bats.) Again, that means that seasonal movement between breeding and wintering sites is a realistic strategy. So, red bats mostly spend the winter in the southeastern US and northern Mexico, then fly north to the upper half of eastern US and southern Canada for the warmer months. They arrive in Ohio by March or April.

Even with that migration, red bats can encounter spells of cold weather. Their springtime local arrival occurs well before days become reliably warm. And so those cold nights are when red bats employ their second survival strategy. That is, they hibernate. Red bats are solitary animals and they roost in trees, so hibernation looks a bit different than the usual picture of dormant bats clustered in a cave. Instead, red bats curl up in a protected tree hollow, or sometimes bury into the leaf litter on the forest floor. There, they allow body temperature to drop to right near ambient temperature–as low as about 3oC, not far above freezing. That low body temperature reduces the rate of metabolism by more than 95% and allows them to get by using stored fat, without needing to eat.

When red bats do eat, their preferred food is moths. A study that used DNA sequencing to examine dietary leftovers in the feces of red bats identified more than 125 species of insects. Most of those were moths, including a number of species that are considered pests by humans, like gypsy moths, tent caterpillar moths, cutworm moths, and others. Notably missing from the diet were tiger moths and their relatives (moths in the group Arctiinae). Those moths have auditory systems and flight behaviors that facilitate bat detection and avoidance, and those systems seem to be effective against predation by red bats.

Red bats mostly feed at night, but they do sometimes fly in daylight. For the females, that “extra” feeding might support their reproductive efforts. Red bats have delayed fertilization: they actually mate in the fall, then the females store the sperm overwinter until the eggs are fertilized in spring. Females raise their young—typically twins—through the summer, so they need to feed voraciously for those months. Although red bats have been known to congregate into small groups while migrating, they typically are seen singly during their spring and summer residence.

Red bats roost in deciduous trees, where they hang from small branches by one or both feet. In summer, preferred roosting sites are under dense leaf cover, which provides protection from overhead predation (crows, blue jays, and owls are among their predators) but allows easy downward departure. Sycamores, oaks, elms, and box elders are commonly selected. But in April, before those species leaf out, red bats often roost among the dead, papery leaves that remain from last year on smaller beech trees. The color of the bats camouflages perfectly among those orange-brown leaves. Cities might have bats in the belfry—but out here in the parks, look out for bats in the beech trees instead!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Waiting for this moment: blackbirds announce spring

Spring is coming; the signs are all around! Robins have emerged from the forest and are plucking worms from lawns and fields. Back in the woods, the year’s first wildflowers, like harbinger-of-spring and spring beauties, are flowering among the leaf litter. But nothing declares spring as reliably and unmistakably as the territorial song of the male red-winged blackbird. Conk-la-reeee!

Historically, red-winged blackbirds (Agelaius phoeniceus) were birds of wetlands, at least for the breeding season, as they prefer to nest in cattail marshes. However, with the widespread loss of wetlands to agriculture and development during the past century, blackbirds expanded their nesting habits to include grasslands and other upland habitat. Modern agricultural practices have diminished Ohio’s population of red-wings, but still they nest in every Ohio county and remain among the state’s most numerous birds.

While sitting perched with wings closed, male red-winged blackbirds appear sleek and uniformly steely black. Females, in contrast, are streaky brown and white, easily mistaken for a large sparrow. The breeding season is when males show off their flashy yellow-bordered crimson wing patches (which, though called epaulets, actually are located at the wrist). To establish his territory and attract mates, a male sits on an exposed perch, throws back his head, flares his wings to expose his colors, and sings with beak opened wide. It’s hard to imagine a female blackbird, or a human observer for that matter, tiring of that spectacle!

Establishing a territory is just the beginning of the red-wing’s breeding season. The subsequent male/female relations that lead to a next generation of blackbirds have been the focus of substantial research. The great majority of bird species practice social monogamy, meaning that one male associates with one female for one or more breeding seasons. That makes sense, since nestlings are vulnerable and both males and females can feed them to promote speedy growth and maturation. (The opposite is true in mammals, in which only the female feeds the pre-weaning young and very few species are monogamous.) Red-winged blackbirds are an exception to that general avian rule. Instead, red-wings practice social polygyny, in which a single male on his territory associates with a number of females—maybe even a dozen or more. Each of those females builds a nest and raises young, with males helping mostly to defend the nests from predators.

The reasons for polygyny in red-wings probably relate to their habit of nesting in wetlands. Wetlands are a limited resource, and territories within a wetland vary in quality, perhaps especially in the availability of good nest locations. So, a female seeks a male with a high-quality territory, even if that male already has a mate. To make their selection, females may not actually evaluate the territory but instead evaluate the males themselves. The vigor of a male’s displays, including the vibrancy of his epaulets, may indicate the male’s health and, therefore, his ability to defend a good territory and father vigorous chicks.

Although polygyny was observed in red-winged blackbirds a long time ago, DNA testing in more recent decades has revealed additional complexities of the mating system. In particular, it turns out that a significant number of red-wing chicks—sometimes as many as 40%—result from “extra-pair copulations”—in other words, females mating with males other than their main social partner.

If females have successfully paired up with high-quality males, why would they also mate outside of that pairing? Research suggests several possible benefits of doing so. First, additional matings may increase the number of chicks that a female can raise. Extra-pair matings can improve the chances that all of a female’s eggs are fertilized, especially if the main male has numerous partners. In addition, the “outside” males may allow the female access to their territories, potentially increasing her foraging area and food supply. Beyond those benefits, multiple paternities produce more genetically diverse offspring, which may be better suited to meeting whatever challenges come in the seasons ahead.

Later in the year, after breeding is completed, blackbirds congregate in large flocks, sometimes with grackles and starlings and potentially numbering into the hundreds of thousands. In those collectives, blackbirds can become quite a scourge on neighborhoods and, especially, agricultural crops, as they descend on grain fields to satisfy their hunger. A lot of effort and ingenuity has been invested in developing methods to deter those flocks. But that’s a problem for another time of year.

As Wallace Stevens famously captured in his poem, there are many ways of looking at a blackbird. “I don’t know which I prefer, the beauty of inflections or the beauty of innuendoes, the blackbird whistling or just after.” Right now, territorial male blackbirds are brightening the wetlands with their flashes and trills. But what comes after—that’s springtime. And what’s not to love about that?

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

It’s midwinter and, as I write this, temperatures are predicted to remain below freezing for the January week ahead. Not a great time to go out looking for butterflies! Chances are, though, that the remaining weeks of winter will include a few warmer days, little previews of the springtime to come. When those days arrive, it won’t be surprising to see a flutter of bright orange out among the tree trunks. Butterflies!

Like most insects, butterflies depend on the environment—air temperature and sunshine—to achieve body temperatures warm enough to support bodily functions like flying, feeding, and reproduction. So, when temperatures cool in the fall, butterflies disappear from the landscape. A few species—monarchs most famously—accomplish that by migrating south. But most butterflies remain local and survive the cold months in a state of suspended development. Banded hairstreaks accomplish that as eggs; great spangled fritillaries and red-spotted purples overwinter as caterpillars (larvae); azures and swallowtails spend the winter in the chrysalis (pupal stage). Only a handful of species overwinter as adults. Among those are two local species in the “anglewing” group: the eastern comma (Polygonia comma) and the question mark (Polygonia interrogationis).

The name “anglewing”, like the genus name Polygonia, refers to the butterflies’ multi-angled wing shape. For both commas and question marks, the upper forewing surface is bright orange with dark spots, including a row of three spots in the comma and four in the question mark. The underside of the wings is mottled brown, which provides outstanding camouflage when the animals sit on a tree trunk with wings held upright. In the middle of the hindwing underside is the small decoration that gives each species its name: a silvery comma-shaped mark in the one species, a similar mark with an extra dot nearby—reminiscent of a written question mark—in the other.

The life cycles of commas and question marks include two generations per year. The butterflies that overwinter emerge to mate and lay eggs in spring. It takes several weeks for those eggs to hatch and complete the transition to adulthood. Those adults have hindwings with nearly uniformly dark upper surfaces. They live for just a few weeks, during which time they mate and lay their own eggs. Summer-form (dark-winged) commas and question marks are observed in Greene and Montgomery Counties from about May until September.

In contrast, eggs laid by those summer butterflies produce adults with hindwing upper surfaces that match the forewings (bright orange with dark spots). Those adults can be observed locally starting in about September or October. However, not long after appearing on the scene, the decreasing day length of autumn induces them to enter diapause—the state of suspended animation that is sustained through winter. In females, that process includes inhibited maturation of the reproductive organs, so that eggs are not produced until after diapause ends. For males, though, sperm are produced in fall and stored over winter. The adults hide out over winter in tree crevices or similar sites. After they emerge in springtime, they mate, lay eggs, and die by April or May, having lived for about 8 months.

Overwintering commas and question marks face two major challenges. First, they must survive on the energy they accumulate during fall. That is made possible by the combined effects of diapause and cold temperatures, both of which reduce the rates of energy use.

The second challenge is that butterflies’ bodies track environmental temperatures, and so during cold spells they risk freezing. Some insects (and other animals) actually can survive body water turning to ice. However, overwintering anglewing butterflies use a different strategy. That is, they avoid freezing, even when air temperatures drop below the normal freezing point of body fluids. To do so, they accumulate glycerol in their bodies, which lowers the freezing temperature much like antifreeze in a car radiator. (Glycerol is an organic alcohol that the insects probably synthesize from fat.) Glycerol also enhances the animals’ ability to “supercool,” meaning that their body fluids can remain liquid, without forming ice, even at temperatures below the freezing point. Some butterflies can chill below -20C (-4 F)—colder than a home freezer—while remaining in a liquid state.

That absence of actual freezing avoids potentially lethal damage from bodily ice (think of the damage ice can do to roadways). But the absence of freezing also means that the butterflies can arouse from dormancy relatively rapidly if temperatures warm. And that is exactly what happens on the occasional warm winter day. Commas and question marks can potentially be sighted in every month of the year in Ohio (though, for unknown reason, commas are sighted in winter significantly more often than question marks.) Of course, there are no flowers to feed on in January or February. But that’s ok for these two species; they prefer to sip liquids from tree sap—a tree tapped by sapsucker woodpeckers is perfect—or from rotting fruit, puddles, or other sources. The extra energy helps to carry the butterflies through the rest of winter and to fuel reproduction after springtime emergence.

So, right now it’s time to play in the snow and enjoy the cold. But at the same time, we can look forward to warmer weather that’s sure to come. If a few days of that warmth arrive in February, then look out for flashes of orange as you wander the woods. And don’t hesitate to shout out: it’s a butterfly! Exclamation point!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

As time goes by: Lessons on aging from the birds and the bees

While changing over the calendar from 2024 to 2025, it’s only natural that thoughts turn to the passage of time and the advancement of years. Aging and lifespan are sources of endless fascination, anxiety, and study. Why do we age? Might we find ways to extend lifespan, or to prolong wellness? Much of what we have learned about these weighty questions comes from studies of humans and of targeted research models (lab mice, fruit flies, and a few others). But the critters outside our windows provide intriguing opportunities for gaining additional insights.

Among mammals, larger species generally live longer. Humans with good access to modern health care have life expectancies in the range of 80+ years. Our pet dogs and cats might live a dozen years or so, whereas anyone choosing to adopt a mouse or hamster must be prepared for a lifespan just 20-25% as long. It turns out, though, that the natural world offers some rather different patterns of longevity. I will highlight two groups in particular: birds and insects.

Birds, like mammals, have lifespans that generally increase with species body size. Also like mammals, birds as a group are uniformly “warm blooded.” One might expect that the high rates of metabolism needed to sustain those warm bodies would exert similar patterns of wear and tear in birds as in mammals, translating into similar lifespans. And yet, birds substantially outlive mammals of similar size. Out on Midway Island in the Pacific, Wisdom the Laysan albatross, weighing in about like a mid-sized cat, made headlines recently by returning to breed at age 73. Closer to home, a 15-gram indigo bunting was captured in Ohio 13 years after it was initially marked; that’s five or six times as long as a similar-sized mouse would live. Even tiny ruby throated hummingbirds, which migrate annually between North and Central America, may return year after year to your feeder; they have lived longer than nine years in the wild. No shrew could match that record.

The long lifespans of birds are intriguing—but insects are where things really get interesting. Across the diversity of insects, adult lifespan (usually measured in the laboratory, but sometimes in the wild) ranges from hours to years. Interesting variations can occur even within a single species. In bumblebees, for example, the queens—females responsible for founding a colony and laying eggs—develop during summer and are fertilized by males during the subsequent few weeks. Those fertilized queens survive overwinter, then re-emerge the following spring to establish new colonies; they die a few months later, having lived for about a year. In contrast, male bumblebees (drones, which develop from unfertilized eggs) often are not produced until mid-summer. Their only job is to find and fertilize virgin queens, after which they die, having accomplished their mission in just one or two months of life. Honeybees provide an even more dramatic model. There, the female workers live just a few weeks in summer, whereas queens, which are genetically identical to workers but are fed a special “royal” diet and don’t leave the hive to forage, can live 20 times as long, up to five years.

Monarch butterflies provide another example of a species with variation in lifespan. Monarchs that develop in Ohio fly south to Mexico for the winter, then return to the southern US the following spring. They lay their eggs and die, having lived for 6-8 months. Those eggs develop into adults that fly a portion of the remaining journey back to Ohio, but after just a few weeks they lay their eggs and die. That happens again, and then again, so that the monarchs departing from Ohio in late summer are about four generations removed from the ones that left the year before. Of those four generations, one— the one that flies south to Mexico—lives several times as long as the others.

Two big questions arise from these patterns. The first is whether birds and insects actually exhibit signs of aging as they get older; do they suffer cognitive or physical decline? The short answer appears to be yes, at least in some cases. Birds do have a notable ability to regrow neurons in parts of their brains, which may forestall certain aspects of aging. However, older birds of at least some species have diminished visual acuity, immune function, and reproductive success. Likewise, there is evidence that some insects lose capacities as they age, including diminished vision, learning, and flight performance. For both birds and insects, we still have a lot to learn about the consequences of aging, especially for animals living in the wild.

The second question concerns the mechanisms responsible for aging. Why, in general, do animals age, and by what cellular or molecular mechanisms does aging occur? There isn’t space in this essay to address those important questions, including the roles of telomeres, anti-oxidants, and other pathways that promote or delay aging. But we can see hints that studies of birds and insects offer intriguing models for exploring those mechanisms. For example, birds achieve their long lives despite having blood sugar levels several times as high as in mammals. Could studies of birds offer insights into how to mitigate the damaging effects of high blood sugar seen in aging humans? Environmental factors also can influence lifespan. For example, a lot of insects, including overwintering bumblebee queens and monarch butterflies, enter a period of dormancy, when their metabolism is suppressed and they don’t feed. Could those animals offer clues to how we might induce “suspended animation” that prolongs life? And what accounts for the long lives of honeybee queens? One idea is that their special diet induces changes to gut bacteria that somehow promote longevity. Can humans tap into that phenomenon?

When we think about lessons we might learn from the birds and the bees, we might not immediately think about lifespan and aging. But many cellular mechanisms operate in common across a wide spectrum of animal life; the fundamental things apply, one might say. With the calendar turning to a new year, I offer a resolution to appreciate and enjoy the time that we have. For me, that includes taking pleasure and amazement in the beauty and diversity of our fellow creatures and all that we can learn from them. On that you can rely.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

From its name, one might reasonably expect that the Carolina wren — Thryothorus ludovicianus — is a bird of the south. That’s certainly true in part; Carolina wrens are common in the Carolinas and across the southeastern US. However, these feisty little birds have been well established in Ohio’s southern counties since at least the late 1800s, and today they are common throughout the state.

Southwest Ohio is home to five species of wrens. All of them are small, brown birds, characteristically perching with their tail in a cocky upright posture. With their camouflaging coloration and habit of searching for food among the undergrowth, Carolina wrens can be a challenge to spot. However, they also can be bold and obvious at times, as they sing loudly from exposed perches or confront intruders with pugnacious chatter.

Of Ohio’s wren species, Carolina wrens are the only year-round residents. Three of the other four species migrate south out of Ohio for winter and one species, the winter wren, migrates south into Ohio. Year-round residency provides opportunity for an extended breeding season. Carolina wrens build a domed nest, typically within an enclosed space like a set of roots, a tree hole, or (sometimes) a mailbox or hanging plant. That nest structure provides good protection from the elements, and Carolina wren nests have been observed in Ohio as early in the year as early April and as late as December. A single pair might raise two or three broods in a single season.

Male Carolina wrens pack a remarkably loud voice into a small body, and they sing loudly and persistently when they are on a nesting territory. The song commonly includes a repeated three-note phrase, with something like two dozen variations, often described as “tea kettle, tea kettle, tea kettle” (but also as “come to me, come to me, come to me,” or “liberty, liberty, liberty,” or many other variations). An individual male might belt out 3000 of those phrases per day. Carolina wrens start their singing early; a wren nest near one’s house provides a reliable morning alarm clock!

Carolina wrens do have a couple of interesting twists to their singing repertoire. First, while males sing most persistently during the breeding season, they actually sing year-round. Songs during the breeding seasons are slightly longer and more complex, but otherwise they are structurally similar across the year. This likely reflects the fact that males are territorial all year long, and singing is an important part of defending a good territory. A second feature is that although female Carolina wrens don’t sing, they produce a variety of chirring phrases that, sometimes, are coordinated with a male’s singing. That partnership represents a rudimentary version of a phenomenon called duetting. Many tropical wrens (and other birds) engage in rich, more complex vocal duets. Carolina wrens have evolved from tropical ancestors, but the female component of the behavior has largely been lost.

The diet of Carolina wrens is mostly insects and spiders. During cold weather, meeting their energy needs would require each bird to eat something like two-thirds of its body weight in insects per day. Wrens do continue to hunt for bugs during winter by scouring among loose bark and fallen leaves. However, with insects less available, they also expand their diet to include nuts and fruits. Carolina wrens readily come to bird feeders. Though they might sound like they’re calling for “cheeseburger, cheeseburger, cheeseburger,” what they really seem to treasure is hulled peanuts.

The combination of year-round residency and reliance on insects or low-lying foods means that Carolina wrens are particularly susceptible to impacts from snow, especially when it’s deep and persistent. In one large-scale study, each additional day of snow cover during winter–spring was associated with a 1.1% decline in the population of wrens. Ohio’s blizzards in the late 1970s extirpated the species from several counties. The population has rebounded, with fluctuations, in the decades since.

Although winter is a hazardous time, the birds that do survive are the ones that figure out how to find adequate food and shelter during cold weather. Gradually, evolution of those traits, along with warming at northern latitudes and increasing availability of winter bird feeders, has allowed Carolina wren populations to expand northward. They now breed commonly in every Ohio county. Northward range expansion seems to be occurring for a number of bird species that are year-round residents in temperate North America. In contrast, species that migrate south for the winter may encounter stresses of long-distance flight and degraded winter habitat; their populations are more likely to be in decline.

In the Star Wars universe, Kylo Ren was a dark side warrior. Carolina wrens might seem to have a few characteristics in common with Kylo — they are bold, charismatic, sometimes brash to the point of aggressive. But while Kylo Ren’s good side was suppressed, Carolina wrens seem to bubble over with joy. Just give them opportunities for shelter — a brush pile, some shrubbery — and a stocked birdfeeder, and you will enjoy the pleasure of their company. May the Thryothorus be with you!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

For any animal, the temperature of its body matters. Bodily functions depend on chemical processes that are temperature-sensitive and on enzymes whose functions vary with temperature. For many simple systems, chemical reactions proceed more quickly at higher temperatures. For biological systems, though, and particularly for proteins like enzymes, functionality typically peaks at some relatively narrow range of temperatures and falls off above and below. That translates directly to functionality of animal body systems.

For dragonflies, critical functions like digestion, vision, flight, and prey capture all are most effective at some optimal range of body temperatures. Peak functionality commonly occurs at temperatures around 30 – 35^oC (85 – 95^oF), not much different from typical mammalian, including human, body temperature. Temperatures that warm are easiest for an insect to achieve during warm weather, and in Ohio, both the abundance and the diversity of dragonflies peaks in June and July.

Nevertheless, dragonflies appear on the landscape in Ohio as early as March, and the last dragonflies of the year are out and about until late November. Meadowhawk dragonflies from the genus Sympetrum —a group of smallish species, mostly with bright red bodies in males –occur at both ends of that seasonal spectrum. In early spring, variegated meadowhawks (Sympetrum corruptum) migrate into Ohio from more southern states. Autumn meadowhawks, Sympetrum vicinum, emerge later in the year and typically remain active well into November, later than any other species. In the months between those extremes, several other meadowhawk species, including band-winged (Sympetrum semicinctum), ruby (S. rubicundulum), and blue-faced (S. ambiguum), appear and then depart the landscape.

Given that broad seasonal occurrence, meadowhawks clearly must be able to function across a range of environmental temperatures. How do they do it?  One possibility is that different meadowhawks operate at different optimal body temperatures. For example, cool-season species might function with cooler bodies. That is somewhat true, but the differences are relatively minor. Moreover, all of the species prefer body temperatures warmer than usual air temperatures during their active seasons in Ohio.

A second possibility is that meadowhawks have ways to regulate the temperatures of their bodies. In particular, given their preferences for warm bodies, meadowhawks must be able, somehow, to warm themselves. How do they do so?

Animals fall into two major categories with respect to strategies for body warming. In some species—endotherms—the animal has a high enough rate of metabolism to generate body-warming heat. In contrast, species lacking that high rate of metabolism must rely on the environment to get warm. For those species—ectotherms—behaviors like basking in the sun are key. The vast majority of insects, like almost all animals other than birds and mammals, are ectotherms. The exceptions—the endothermic insects—are typically large, stout-bodied, and furry, like some species of bees, moths, and beetles, so that they can effectively retain the heat they generate. Sympetrum dragonflies, which are small, skinny, and hairless, seem like bad candidates for endothermy.

It turns out that the mechanism of body temperature regulation has been studied for just a couple of meadowhawk species, including one that occurs in Ohio, the autumn meadowhawk, and one from Europe, the common darter Sympetrum striolatum. As expected, autumn meadowhawks are ectotherms. They do function at slightly lower body temperatures than a lot of dragonflies, but it’s still critical for them to warm up by basking in the sun. Indeed, the genus name “Sympetrum” literally means “with rocks,” reflecting their habit of basking on rocks. Like most Sympetrum dragonflies, autumn meadowhawks are “perchers”; they fly just short distances to catch prey before resettling on a perch. So, the habit of basking fits their general lifestyle.

On the other hand, common darters offer a surprise. These dragonflies do bask as part of their warm-up strategy. But it turns out that they also are capable of endothermy. They accomplish that by “whirring” their wings, rapidly contracting their thoracic muscles in much the same way as mammals shiver. Once those thoracic muscles are warm, they can effectively power flight. Most likely, wing whirring is accompanied by some mechanism to restrict blood from flowing out of the thorax, so that heat is retained there rather than radiated away from the abdomen.

At this point, we can only speculate about how body temperature is regulated in Ohio’s other Sympetrum species. However, the comparison of autumn meadowhawks vs. common darters may be informative. As noted above, autumn meadowhawks are “perchers” and make just brief, short flights. In contrast, common darters sometimes migrate long distances, and endothermy may have evolved to support the vigorous flight required for those migrations. In Ohio, variegated meadowhawks engage in early spring migratory flights and as such may be candidates for endothermy. Our other meadowhawk species all are perchers, and it seems likely that they are ectotherms. Only further study will confirm that speculation. In the meantime, meadowhawks are little gems of local meadows and wetlands. Autumn meadowhawks are the species of meadowhawk seen most commonly in Ohio, and they are nearly the only kind of dragonfly still active in November. Keep an eye out for them!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

In 2020, the Board of Park Commissioners adopted a new master plan for Grant Park, the largest park in the District. The master plan reflects a large number of passionate voices from the community. The recommendation for safe, reliable access for students, visitors, maintenance and first responders came from community input. To address safety and accessibility within the park, the master plan calls for two new bridges to allow for reliable year-round access to the park’s trails.

The main trails at Grant Park are accessed via an existing 160-foot bridge near the park’s Normandy entrance. This bridge has reached the end of its lifespan. The plan calls for its replacement with a new vehicle load-rated, ADA-accessible bridge. The second bridge will cross Hole’s Creek upstream along the same trail network.

The Centerville-Washington Park District received $250,000 from the State Capital Budget’s One-Time Strategic Community Investment Fund to help fund this project. Construction on the new bridges will begin in mid-October. The main bridge at the Normandy entrance is expected to be completely removed in mid-November. But don’t worry, creek crossing stones will be placed upstream to allow park access until the new bridge is ready in the spring. Keep an eye out for directional signs at the park’s entrance to find the reroute!

Grant Park is a beautiful 222-acre nature park stretching along Hole’s Creek. It attracts more than 65,000 visitors each year. The park provides access to forests, meadows, prairies, wetlands and a meandering stream. A trail network connects the park’s natural and historic features, which include the Kennard Nature Nook, historic bank barn, nature play area, nature literature trail, fire circles and more.

Review the Grant Park Master Plan >

There’s something about spiders… Despite the numerous spider decorations that will appear on and around houses this October, spiders remain high on many people’s list of “least favorite animals.” Nevertheless, spiders have some amazing traits. They can travel hundreds of miles on the wind. They can sense minute vibrations with their legs. And they synthesize a substance that, like mithril in Lord of the Rings, is tough, flexible, and shiny: spider silk.

The silk we are most familiar with from its use in fabrics is silkworm silk, spun by caterpillars of the silkworm moth to construct their cocoons. All spiders also produce silk, which they use for webs, egg sacs, draglines, and other purposes. Different kinds of spiders–there are more than 600 species in Ohio–build webs with a variety of structures, from funnels and bowls to classic spoked orb webs. The silk from orb weavers, represented locally by the orchard orbweaver, garden spiders, arrowhead orbweaver, and others, is the variety that has been characterized most extensively.

It turns out that orb weavers synthesize several types of silk, each with particular properties and deriving from separate glands. The major accessory (MA) gland secretes the largest diameter silk (MA silk; about 5% the diameter of human hair), which is used to build the primary framework of the web and which has been studied the most. The web’s rings are built from thinner “flag silk” secreted from the flagelliform glands. Neither of those silks is sticky; the glue that helps to catch prey is an organic concoction secreted from yet a third gland, the aggregate silk gland, and coated onto certain of the silk capture threads.

Technically, spider silks are called spidroins, and they constitute a class of large protein molecules. Like all proteins, spidroins are constructed as chains of amino acids, like beads on a string. The specific amino acids and their sequences within a protein cause the molecules to fold into complex three-dimensional shapes that determine the protein’s properties. Spidroins are unusual in that they contain long sequences rich in two particular amino acids (out of the 20 common protein building blocks), glycine and alanine. Interactions between those amino acids generate three-dimensional protein shapes (which are microscopically present within the visible silk thread) that are responsible for the strength of silk fibers. In contrast, other regions of the proteins contain different combinations of amino acids whose interactions and resulting folding patterns confer elasticity.

Although we experience spider silk as long, thin threads, spidroins exist in liquid solution while they’re within the silk glands. That changes during the process of “spinning,” as the silks are extruded through the glands’ ductways. Some combination of factors, likely including both the mechanical stress of passing through those narrow pathways and the chemical environment within the ducts, induces the transformation from amorphous liquid to thread-like solid.

The fascination with spider silks derives at least in part from their amazing physical properties. Spider silk is notably tough; on a weight-for-weight basis, MA silk can absorb more than three times as much energy as Kevlar (one of the toughest synthetic materials) before rupturing. Synthetic materials do tend to have higher tensile strength (the amount of force required to pull until breakage) than natural materials; Kevlar has about four times the strength of MA silk. However, natural materials tend to be more extendible; MA silk can extend in length 10 times as much as Kevlar, and flag silk is 100 times as extendible. In addition, spider silk resists twisting; a spider that drops on its line rarely spins. The combination of all of these factors creates a tough, flexible, durable capture device that withstands environmental challenges like wind as well as the forces of incoming prey items.

One more property of spider silk is notable. That is, the small diameter fibers in a web interact with sunlight in complex and remarkable ways. A combination of refraction and diffraction, interacting with a web that includes several silk varieties and structures, produces interference patterns that create amazing color patterns. These are difficult to see with the naked eye. But photograph a shimmering cobweb, especially backlit against a dark background, and your image may well reveal banding patterns in a dazzling array of colors. This may be of no use to the spider (are they even aware of the light show surrounding them?), but it’s fantastic to observe.

Given their exceptional material properties, along with the fact that spidroins are highly biocompatible (they are biodegradable and induce little immune reactivity), it’s no surprise that there is strong interest in harnessing spider silk for commercial applications. Potential uses include wound dressing, drug delivery, textiles, filters, and more. Silkworm silk, which lacks spider silk’s versatility, is produced on a commercial scale. Why not spider silk? The simple answer is the challenge to cultivating spiders and harvesting their silk. Put a bunch of silkworm moths on some mulberry trees and their caterpillars spin cocoons that can be collected and unwound. On the other hand, growing spiders in large numbers is not so easy (they tend to cannibalize each other), and extracting or collecting their silk is tedious and challenging. Instead, industrialists have turned to biotechnology for a possible solution. Efforts are underway to induce a variety of organisms to produce spider silk through genetic manipulation (so-called recombinant silk), ranging from bacteria and fungi to plants and mice. Although there have been modest successes, production sufficient for commercial use has not yet been achieved.

As spiders have their “season of glory” this October, we may not all come to love these eight-legged creatures. But it’s worth recognizing that spiders have some serious superpowers, and spider webs house secrets that we’re just beginning to unravel. Got silk?

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Go to relax under a spreading oak tree this autumn and you may discover a somewhat unwelcome surprise. That oak may be buzzing with large, black and white hornets. What’s going on? The answer is a bit complicated. But rest easy: the wasps are seeking sugar water, not flesh!

What is that insect? The bald-faced (or white-faced) hornet (or wasp), Dolichovespula maculata, is a social wasp in the family Vespidae, along with yellow jackets, paper wasps, and other local species. They live in colonies of a few hundred individuals and build large hanging nests consisting of layers of cells for larvae surrounded by a papery shell. Bald-faced hornets have a sting that is only mildly toxic to their insect prey. Instead, the sting is used to defend against vertebrate intruders, which they do aggressively. According to Justin Schmidt, whose pain scale for insect stings derived from his own intimate experience, bald-faced hornet stings rate a “level 2” pain (level 4 is most intense), similar to that of a honeybee or yellow jacket. Schmidt describes the sting as “rich, hearty, slightly crunchy. Similar to getting your hand mashed in a revolving door.” The worst of it lasts for about 5 minutes.

What is the plant? The leaves and twig in this picture belong to a bur oak, Quercus marcocarpa. Bur oak is an important hardwood of Midwestern forests. Trees can live up to four hundred years and grow as large as 10 feet in trunk diameter. As a member of the “white oak” (as opposed to “red oak”) group, bur oaks have leaves with rounded lobes and acorns that are relatively low in tannins and mature in a single season.

If that’s an oak tree—are those round things acorns? Acorns—the fruits of an oak tree–consist of a nut set in a cap. Bur oaks have the largest acorns of any North American oak (up to 3.5 cm diameter), with a deep, bumpy, and heavily fringed cap attached at the end of a longish stem. The balls in this picture share none of those traits. Instead, they are relatively small (about 1 cm), have no cap, and appear directly along the twig. These are not, in fact, acorns. Rather, they are galls—abnormal plant growths induced by “irritation” of the plant. Most commonly, that irritation comes in the form of an insect laying its eggs, and the gall serves as an incubation chamber for insect development. However, galls also may be induced by insect feeding or by infection from bacteria or fungi, and they can occur on a variety of plant parts, including leaves, stems, and buds.

What induced these galls to grow? Oak bullet galls, as these are called, develop in response to a small wasp in the family Cynipidae (the gall wasps) laying its egg under the bark of a twig. Cynipids are a diverse group, with more than 100 species in Ohio. (The most famous oak gall researcher probably is Alfred Kinsey, author of the influential Kinsey reports on human male and female sexuality in the mid-20th century, who examined millions of galls and gall wasps before switching to his better-known studies.)

The wasp species that causes galls on bur oaks is Disholcaspis quercusmamma, the rough bulletgall wasp. Galls form in mid-summer, and each one houses a single wasp larva. In autumn, the larva metamorphoses into a self-fertile (asexual) female adult. She chews an escape tunnel out of the gall and then lays eggs in dormant oak leaf buds. In spring, male and female gall wasps hatch from those eggs. (Interestingly, each individual asexual female produces either only male or only female offspring). Those males and females mate, the females lay eggs in the twigs, and the next round of bullet galls begins. Theories about how the insect induces the tree to produce a gall include roles for mechanical signals, chemical activation, and viruses. The actual mechanism remains a mystery.

Why is the bald-faced hornet visiting the gall? Bald-faced hornets are omnivores. During much of the summer, they eat mostly bees, flies, and other insects. But they also consume sweet liquids like flower nectar and fruit juices. Some of that sugar water is returned to the nest to feed the larvae. Bullet galls take advantage of that sweet tooth. As the gall develops, it creates a specialized tissue called a nectary that secretes a sugary droplet of liquid. Wasps love that treat, and a large oak with thousands of galls can provide a rich banquet of sugar water.

Why should the gall attract wasps? Oak bullet galls are exposed and conspicuous, with a nutrient-rich nugget (the wasp larva) inside. So, the wasp larvae are vulnerable to predation by birds like chickadees and woodpeckers. The nectar is the price the gall pays to “hire” a guard—the bald-faced wasps—for the wasp larvae. Of course, it’s the tree, not the wasp, that pays the cost of the nectar. However, bullet galls seem to have just a minor impact on the host oak.

Conclusion: What starts out seeming like a relatively simple—if unwelcome—observation—some wasps hanging out in an oak tree—turns out to encompass a combination of complex biological processes. The gall wasp alternates between asexual (all-female) and sexual (male/female) generations. The placement of an insect egg under the bark of an oak twig induces a specific deformity. That growth—a plant gall—secretes sugar water that attracts larger, stinging wasps that protect the gall wasp larva inside. So many complications! And so many as yet unanswered questions! All of which might have led Alfred Kinsey to ponder: which is more complicated, the wasps and the trees, or the birds and the bees?!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Complete the sentence, “Thistles are _______.” Weeds? Prickly? Bothersome? Invasive? A lot of the obvious choices to fill in that blank carry a negative connotation. And there are good reasons for all of those choices! Yet thistles also have substantial positive attributes, and they are valuable—even invaluable, in some ways–members of our local ecological communities.

“Thistles” comprise a group of plants in the aster family (Asteraceae), especially those in the genera Carduus, Cirsium, and Onopordum, that are characterized by purplish fluffy flower heads and leaves with spiny margins. About a half-dozen species of thistles are found in Greene and Montgomery Counties. Of those, two (field thistle and swamp thistle) are native to this area. The others, including the rather common creeping, musk, and bull thistles, were introduced from Europe as long as several hundred years ago.

The most notable feature of thistles probably is their spines. A dense patch of thistles really does present an impenetrable barrier. No doubt, thistle spines evolved as a deterrent to herbivores, and deer certainly know to avoid munching on thistle leaves. Despite that, a number of beetles and other insects feed on thistle flowers, seeds, and even leaves, and painted lady butterflies even use thistles as a host plant for their caterpillars.

On the other hand, two features of thistles are highly attractive to wildlife. The first is their nectar. Many species of thistles, particularly those that are biennials like musk and swamp thistle, produce copious amounts of nectar. As a result, many butterflies, bees (including the distinctive thistle longhorn bee), flies, beetles, and other insects are attracted to thistle flowers. Even hummingbirds feed at thistles, especially the larger flowers like bull thistle. Locally, creeping thistle, Cirsium arvense, is one of the more abundant introduced thistle species, and it is considered invasive in Ohio. Creeping thistle is perennial, creating dense clonal colonies each year from its persistent roots. Even in its native Europe, creeping thistle is considered a weed—but it still is a strong nectar producer, and it attracts a lot of insects.

Thistles may be particularly important for monarch butterflies. Monarchs usually are associated with milkweeds, which serve as host plants for the species’ caterpillars. However, thistles may be nearly as critical, as they provide late summer nectar to fuel the butterflies’ southward migration after most other flowers have faded from the landscape.

The second feature of thistles that is valued by wildlife is the fluffy mass of seeds. As members of the Asteraceae family, each thistle flower head actually consists of hundreds of individual small flowers. And each of those flowers produces a seed that is attached to a feathery tuft of fluff that facilitates dispersion by the wind. The result is the characteristic white fluffy mass that develops as the flowers age. Both the seeds, which are used as food by various birds (sparrows, buntings, finches, and others) and rodents, and the fluff itself, which makes great nesting material for birds and mice, are valuable resources.

The only problem with thistle fluff as nesting material for birds is that thistles tend to flower relatively late in the season, after the nesting season of most birds. But one bird in particular has overcome that obstacle. Goldfinches don’t nest until late July or early August, the latest of our songbirds, and they time their nesting precisely to coincide with when thistles go to seed. What that means is that goldfinches are stimulated to nest at a time when day length is declining, well after the summer equinox. That’s the opposite of most temperate zone birds, whose reproductive hormones are triggered by increasing day length. Reproductive condition in goldfinches may be tied to environmental cues like light and temperature, but it also seems to be reinforced by the sight of thistle flowers and by consumption of thistle seeds.

Goldfinches take advantage of both elements of the late-stage thistle flower. First, goldfinches harvest thistle fluff to line their nest. It’s not hard to imagine that this creates a nice soft base on which to lay eggs. The packed fluff creates a strong, insulating cup, dense enough that it actually risks accumulating rainwater and flooding the chicks. Second, goldfinches harvest the seeds for food. These are eaten by the adults, similar to the niger (not thistle) seed sold commercially for winter goldfinch feeders. But goldfinches are unusual as one of the only birds that also feeds seeds to the nestlings. Even most finches that eat seeds as adults feed insects to the growing young. One side benefit of this habit is that it provides protection against parasitism by cowbirds, which lay their eggs in the nests of many species; cowbird chicks cannot survive on the goldfinch diet of seeds.

Thistles really do embody a combination of opposites. They are spiny but fluffy, weedy but beautiful, forbidding to some animals but critical to others. Not too many gardeners are likely to begin adding thistles to their flower beds. But out in our meadows and prairies, a patch of thistles can provide rich wildlife habitat. The thistle has been the national flower of Scotland for something like 750 years. Supposedly that’s because an invading soldier stepped on a thistle and cried out, alerting the Scots to his presence. But no doubt they also valued the flowers as elements of the landscape and boons to wildlife. As should we!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

The Centerville-Washington Park District began work on a Grant Park master plan project in March 2020 and the Park Board adopted the plan in January 2021. Based on collective input from the community and in collaboration with park staff, the master plan project team developed a number of recommendations. The recommendations reflect the community’s passion, the enthusiasm of the park staff and the vision of a park that will better serve the community in the coming years.

The first phase of the project was completed in 2023. This phase included enhancements to the McEwen entrance of the park, including an expanded parking lot, a paved multi-use path surrounding a 4-acre pollinator habitat, stormwater wetland creation, streambank restoration and a new picnic area.

This summer, staff began work on the Grant Park trail system. The trail improvements focus on developing a balanced system of trails that:

• Offers a variety of experiences,
• Provides inclusive opportunities to meet all skill levels,
• Improves signage and wayfinding,
• Reduces future maintenance and repair costs.

The project will include sustainable trail building and invasive species control. Work on the trail system is expected to take two to three years. The park will remain open during this time; however, you may encounter temporary and permanent trail closures during your hike.

Review a copy of the Grant Park master plan >

As pollinators of both crop species and wildflowers, bees are critical elements of Ohio’s economy and natural landscape. Our most familiar bees surely are honeybees, which were imported from Europe in the 1600s. However, Ohio also is home to more than 400 native species of bees. Among those, probably the most recognizable are the bumble bees. Bumble bees illustrate a number of points regarding Ohio’s bee diversity.

Although bumble bees might appear to be a single kind of bee, at least 9 species inhabit Greene and Montgomery Counties; several others have been seen (rarely) statewide in recent years. Common eastern bumble bees (Bombus impatiens) are the most common, followed by brown belted (Bombus griseocollis) and two-spotted bumble bees (Bombus bimaculatus). Each bumble bee species has diagnostic color patterns: common eastern bumble bees have a mostly black abdomen, while in golden northern bumble bees it’s almost completely yellow. However, there are variations even within a single species, and differences between others (e.g., black-and-gold vs. American bumble bees) can be rather subtle. So, distinguishing species sometimes takes close examination.

Bumble bees have distinct seasons of activity. Unlike honeybees, which accumulate food during summer and fall to sustain the colony through winter, only the mated queen bumble bee survives through the cold. All other bumble bees die off after their active season. In spring, bumble bee queens emerge, forage, and restart the colony. Two-spotted bumble bees are most active locally during March through August; for golden northern bumble bees, it’s April through September.

Bees pollinate something like 85% of wild plants. Some bees are generalist pollinators and visit a wide array of flowers, while others are specialists. Conversely, some flowers attract a wide variety of pollinating insects, while others depend on particular visitors. Bumble bees are generalists and can be found visiting flowers ranging from jewelweed to wild roses and from coneflowers to Virginia bluebells. Quite a few flowers, including mayapples, Dutchman’s breeches, pickerelweed, monkeyflower, and blue flag iris, rely primarily on bumble bees for pollination.

Bumble bees are cavity nesters; they live in colonies of several hundred bees (compared with many thousands in honeybees) in natural cavities, like rotting logs, that may be above ground or underground. Like honeybees, most bumble bee colonies have a distinct social system. A single female in each colony—the queen—establishes the nest and lays all of the eggs. Some of those eggs are fertilized and develop into female workers (a few of them grow to be new queens). Worker bees visit flowers to feed, and they return some nectar and pollen to the nest. Whereas honeybees accumulate enough honey to feed the hive for a full winter, bumble bees only make enough honey to carry them through a short spell of bad weather. Some time later in the active season, often not until summer, the queen also lays some unfertilized eggs. Those unfertilized eggs develop into male drones. Drones really have a single function: to find and fertilize virgin queens from other colonies that will go on to establish their own nests.

Bumble bees are the only truly social native bees in Ohio. Most other bees are solitary, though in the right conditions they may nests in aggregates that give the appearance of a colony. But even among bumble bees there are variations. The most extreme variation among our local bumble bees occurs in a species called the lemon cuckoo bumble bee, Bombus citrinus. Why “lemon cuckoo”? Well, the “lemon” part is easy: the thorax and about half of the abdomen is a pale, lemony yellow. As for the name “cuckoo”: that relates to the resemblance of the bee’s mating system to that of the famous European cuckoo bird. European cuckoos are nest parasites; they lay their eggs in the nests of other, usually smaller, species, and those other species then do all the work of raising the cuckoo chicks. Something similar occurs in lemon cuckoo bumble bees. In those bees, a mated lemon cuckoo queen sneaks into the nest of either a common eastern bumble bee colony or a half-black bumble bee (Bombus vagans) colony. There, she kills the resident queen, eggs, and larvae and lays her own eggs. She also acquires the chemical signals of the nest, which tricks the workers into taking care of her and her offspring. Pretty tricky!

Unfortunately, bumble bees also highlight another issue for Ohio’s bees—that is, the challenges to their numbers and diversity. In 2017 and 2018, a large state-wide survey found 10 species of bumble bees. One species (the rusty-patched bumble bee) previously widespread in Ohio was not found in that survey and appears to have disappeared from the state. Several other species now are rare. Challenges for populations of native bee species include land use practices (e.g., deep tilling that can disturb ground-nesting bees), diseases, and effects of pesticides, among others.

There are many ways to support the health of our native bees, including diversification of lawns and gardens to include more flowering plants, minimizing pesticide use, and fostering bee nesting sites (e.g., leaving soil undisturbed and providing log piles or rock walls). However, to rephrase a well-known saying, we are more likely to conserve what we know, and to know what we experience and attend to. Challenge yourself to identify and find a golden northern or a black-and gold bumble bee, or see how many bumble bee species you can identify around your own home. The better you know your bees, the more you will appreciate them!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Picture a white-tailed deer and chances are you will envision an animal bearing antlers. After all, a deer sighting may be charming, but if that deer is a buck with a large rack of antlers, the encounter becomes a “wow” moment. But visual impact isn’t the only exciting thing about antlers. Deer antlers are the fastest growing mammalian bones and may be the only mammalian tissues capable of full regeneration. Their annual replacement and growth provide a fascinating, and potentially valuable, model of tissue development.

Antlers are bony structures that arise from the pedicle of the skull’s frontal bone. In almost all members of the deer family (Cervidae), including our local white-tailed deer (Odocoelus virginianus), only males bear antlers. (Caribou, in which both males and females have antlers, are the exception.) The functions of those antlers are primarily for establishing reproductive success. First, the antlers are used directly in male-male contests for dominance. In autumn, males lock horns in battle for the right to secure primary access to females. Secondarily, the antlers serve as a signal to females. A larger rack signifies a male that has lived a long time and has successfully found high-nutrient foods (rack size increases with age and food quality). So, females seek out mates with large antlers, indicative of the likelihood that they will produce high-quality offspring.

While antlers do provide those important autumnal functions, they also have their down side. Antlers are heavy, costing energy to carry around. They potentially create challenges for unimpeded travel through woods and undergrowth, too. So, despite the costs of regrowing them, antlers are shed on an annual basis. Males typically lose their antlers sometime during winter. Growth of the new set begins immediately but may not be visible for a couple of months. Through spring and into summer, the antlers grow to full size.

Like other bones, antlers are built from minerals (especially calcium-phosphate) deposited around a matrix of protein (collagen). So, creating those structures requires both the building blocks—protein and minerals—and the blood supply for delivering those materials where they’re needed. Growing antlers arise from the pedicles and, under hormonal influence, blood vessels grow out from there. The energy required for a buck to grow a full set of antlers rivals that for a doe to produce a fawn. And indeed, the material demands of growing antlers may well outstrip the diet’s supply capacity. If so, then minerals are “borrowed” from other bones, especially non-weight-bearing bones like the ribs, which consequently suffer a seasonal weakening, or osteoporosis.

While growing, the antlers are somewhat soft and are covered in a specialized hairy coating called velvet. As fall arrives and antlers reach full size, testosterone levels surge; in response, the last stages of antler mineralization occur, blood flow ceases, the antlers harden, and the velvet dries and is scraped away. The antlers then are ready for combat. However, even while deer go head to head with their competitors, cells in the antler pedicles remain active. Osteoclasts reabsorb calcium at the junction with the antler, and by winter that connections weakens to the point that the antlers fall off to the forest floor. There, they are valued as food by rodents and provide nutrients back to the ecosystem.

As noted above, the size of a buck’s antlers is determined by three main factors. The first is age. Antlers in white-tailed deer tend to increase in size with age up to about six years. (In Ohio, with its active population of hunters, a minority of bucks may make it to their sixth birthday.) The second factor is genetics. Antler size does have an inheritable contribution, transmitted by both the does and the bucks. And the third factor is nutrition. While genetics help to determine the potential size of a rack, that potential can be achieved only if the buck’s diet includes adequate minerals and, especially, protein.

The rapid growth of deer antlers represents a tremendous mobilization of tissues. Antlers may increase in size by as much a 2 cm per day, and the nerves and blood vessels supplying them must match that pace. The factors that both enable and control rapid antler growth may provide insights into biomedical circumstances ranging from hair loss and replacement to repair of damaged organs and control of cancer proliferation. Unraveling those factors turns out to be a complex puzzle, with different players involved in different stages of the antler cycle. Regulation comes from both outside of the antlers, such as hormonal responses to environmental cues, and from internal elements, like patterns of gene activation and stem cell differentiation that are specific to particular antler tissues and stages of growth. One set of genes may activate rapid growth of cartilage and conversion to bone, while a separate set simultaneously prevents that growth from progressing in an unconstrained, cancer-like direction. One research article on this topic (Journal of Anatomy 207: 603 – 618) is entitled, “Deer antlers: a zoological curiosity or the key to understanding organ regeneration in mammals?” It turns out that the answer to that question almost certainly is: Both!

As spring advances toward summer, female deer are giving birth to their fawns. Bucks, on the other hand, are generally lying low this time of year. But those tissues on their heads—from the base of the pedicles to the tips of the tines—are busy at work, building another season’s rack of antlers—even bigger and better this year than last!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

We are lucky to live in the Miami Valley, a region that touts the largest paved trail network in the country! CWPD is proud to be part of this trail network with over 10 miles of multi-use paved trails for the community to enjoy for exploration, health, and wellness.

What exactly is a multi-use trail? Multi-use trails provide two-way travel for walking, bicycling, jogging, skating, strollers, dog walkers, etc. Also called shared-use paths, these pathways are usually built independently from the road network or alongside a roadway.

Speaking of sharing, here are tips for sharing the trails so each user can get the same enjoyment from the multi-use paths:

1. Stay on the right side of the path except to pass.
2. Wheels Yield to Heels! This is a popular motto amongst avid trail users. Bicycles and other path users with wheels should yield to those on feet. Safety Note: when crossing roadways, always yield to vehicle traffic.
3. Leave room for people to pass. All users need to leave enough room for others to get around them. Don’t spread out across the entire trail.
4. Slow your speed and announce yourself when passing to avoid startling someone. Shout, “On your left!” and consider using a bell. Do not pass people at high speeds. This is reckless.
5. Paved paths are wonderfully accessible for all abilities. While one person may use a wheelchair, another person may not have an obvious disability, i.e. a vision or hearing impairment, or a problem with balance. One more reason to pass slowly with care!
6. Motorized vehicles, with the exception of those used as a mobility device by persons with disabilities, are prohibited.
7. Dog walkers must keep dogs on a leash 6 feet or shorter. Keep your pets close on multi-use trails to avoid interfering with people passing on foot or on wheels.

Now that we know how to share the trails, let’s enjoy them! Here are the parks with multi-use trails and the distance of each.

• Activity Center Park 0.5-mile loop
• Bill Yeck/Forest Field Parks 0.5-mile paved loops and additional limestone trails
• Black Oak Park 0.2 miles (one way) up a steep hill. No bicycles permitted.
• Grant Park 0.25-mile loop
• Hithergreen Park 0.25-mile loop
• Holes Creek/Silvercreek Parks 1.3 miles (one way)
• Iron Horse Park 2 miles (one way) and 0.6-mile loop
• Oak Creek South Park 0.4-mile loop
• Oak Grove Park 1.5-mile loop (shorter loops also available)
• Robert F. Mays Park 0.75-mile loop
• Schoolhouse Park 0.75-mile loop
• Yankee Park 0.82-mile loop

We have numerous options if you want to join a program to celebrate National Bike Month or a wellness program on the multi-use trails.

CWPD partners with Bike Centerville, which offers Community Bike Rides throughout the year. The next Bike Centerville Community Rides are coming up on May 5 and May 19. The rides will be led by trained and experienced bike leaders and will help you learn routes to shopping, parks, and more! Rides are an easy-paced 10 to 15 miles that start and end at a park.

A Walk in the Park and Trail Trekking take place twice a week on paved paths at the eight community parks. Enjoy these self-guided walks with other walking enthusiasts seeking fresh air!

Lastly, the Sunshine and Feathers Adapted Fun Run is for everyone to enjoy! On May 11, participants can loop the paved path at the Kennard Nature Nook while stopping at various booths with interactive games, giveaways, and all things sunshine and feathers! The event falls on World Migratory Bird Day and will feature birding activities for all!

Register for these programs online >

Whether you are on feet or wheels, the multi-use trails are a wonderful community amenity to keep us moving, right in your community’s BIG backyard. To learn more about the Miami Valley’s network of trails visit www.miamivalleytrails.org. To learn more about Bike Centerville visit bikecenterville.com.

For Ohio’s bird enthusiasts, May is prime time, as the arrival of northbound migrants adds color and song to the landscape. No group of birds exemplifies migration season more than the wood warblers. That family of birds, the Parulidae, includes about ten dozen species. Nearly a third of those appear in Ohio in May, and individuals from about a dozen parulid species stay in Greene and Montgomery Counties to breed.

The parulids arriving in Ohio share a number of traits. All are small, about the size of a chickadee. They have pointy little beaks that facilitate their insect diet. And they are migratory, breeding in the US and/or Canada and wintering at latitudes ranging from the southern US to the tropics of Central and South America. Despite those commonalities, the species are readily identifiable by sight and sound. Biologists refer to a phenomenon like this—an evolutionary lineage that has diversified into a bunch of related species—as an adaptive radiation. And adaptive radiations raise two big questions: Why did they arise? And how are they maintained?

The origins of an adaptive radiation can be illustrated using a famous example: the finches studied by Charles Darwin. In that case, finches from mainland South America occasionally blew out to sea and landed on one of the numerous Galapagos Islands far off shore. Each of those islands provided unique biological and physical conditions. And so, over time, the combination of mutations and responses to environmental factors (weather, food availability, etc.) led to an accumulation of changes (in genetics, behavior, and form and function) over successive generations. This process happened repeatedly, and the result was an adaptive radiation—numerous, related finch species inhabiting the island group, differing from each other and from the original mainland species in a variety of characteristics.

The circumstances that produced isolated populations of ancestral parulid warblers were different—not islands separated by stretches of ocean, but temperate, insect-rich habitat isolated by incursions of colder, inhospitable conditions. Scientists are still collecting evidence—from DNA sequencing to comparisons of flight calls—to test ideas on the exact timing and conditions that induced the adaptive radiation. Was it during the Pleistocene Ice Ages or just before? Were the ancestral warblers tropical and non-migratory or temperate and migratory? But under any of those scenarios, the critical circumstances were a changing and fragmented landscape induced by fluctuations in climate that repeatedly separated and isolated warbler populations in North America. We now see the result: lots of warbler species!

As an adaptive radiation evolves, the question then is whether it can persist. How do the related species coexist in a common environment, and what prevents them from interbreeding and “washing out” any accumulated differences? Ecologists believe that for species to stably coexist within a shared community, they need to somehow use the environment differently from each other-, a phenomenon called resource partitioning. Indeed, the term “adaptive” radiation implies that the various species have adapted new traits that might separate them from each other. Galapagos Island finch species, for example, have diverged in size and, notably, in beak morphology such that diets of particular species now range from small seeds to large, and from seeds to fruits to insects.

As noted above, parulid warblers all are small, insect-eating birds; there is little diversification of body structure or diet along the lines of Darwin’s finches. So how do they partition the environment? In his pioneering research in the 1950s, Robert MacArthur, one of the founders of the modern science of ecology, observed that a group of five warbler species inhabiting Maine evergreens separated from each other using behavior: what parts of the tree they prefer (e.g., high up vs. low down, interior vs. exterior), foraging habits (e.g., whether or not they fly out after insects), and timing of peak activity. MacArthur generalized those observations into theories of species coexistence and resource partitioning.

Parulid warblers maintain species diversity in another obvious way, too. That is, members of a species recognize each other using unique combinations of visual and auditory signals. Some of the species names reflect those visual patterns: black-throated green warbler; blue-winged warbler; black and white warbler. And the songs are equally distinct. As described by David Sibley: “zeeeeeeeeeeee-tsup” for the northern parula, Setophaga americana, which breeds locally; “tsi tsi tsi tsi tsi ti ti ti ti ti seeeeee” for the beautiful Blackburnian warbler, Setophaga fusca, which migrates through Ohio.

Three locally breeding species, all small, colorful, insectivores in the genus Setophaga, illustrate these patterns of differentiation. The yellow warbler, Setophaga petechia, is bright yellow, with red streaking on the breast in males. Yellow warblers prefer shrubby wetlands, and the males can be heard singing, “sweet sweet ti ti ti to soo,” from the branches of water-side willows. Prairie warblers, Setophaga discolor, also are mostly yellow, though not so bright as yellow warblers. They also like shrubby habitat but prefer second-growth meadows and woods rather than wetlands. “Zooo zoo zo zozozozoZEEET!” Yellow-throated warblers, Setophaga dominica, have bodies handsomely striped in black and white, with brilliant yellow throats. They are closely associated with sycamore trees, and watching them sing from the high treetops, “teedl teedl teedl teedl teedl teedl teedl tew tew twee,” is a great way to earn a case of “warbler neck.”

Warblers are small enough that it’s easy to overlook them. But the arrival of these colorful, musical, active birds is highly anticipated each year, and the combination of colors, songs, and habits provides a key to finding them. May, especially early in the month before trees fully leaf out, is prime time for warblering. To quote the magnolia warbler, Setophaga magnolia: “sweeter sweeter SWEETEST!!”

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Spring beauties, Claytonia virginica, are among the earliest blooming of our so-called “spring ephemerals,” the woodland wildflowers that bloom in succession between March and May. Spring beauties survive the winter as a mini-potato-like tuberous root that provides the plant with another name, the “fairy spud.” As soils warm in the spring, the tuber sprouts a pair of leaves with buds that open into attractive saucer-shaped flowers with five petals and bright pink anthers at the tip of each stamen.

Spring beauty flowers bloom for just a few days; the stamens stand upright and release pollen for just the first of those. Fruits of pollinated flowers mature in about ten days and then eject their seeds, each of which bears a fatty, tasty attachment (an eliasome) that attracts ants. The ants carry off the seeds to their nest, where they consume the eliasome and leave the seed, effectively planting the next generation.

Insects are instrumental in achieving pollination, too. At the early date when spring beauties start to bloom, the diversity of insect pollinators is somewhat limited. Still, a number of insects emerge with the warming soils. For spring beauties, the most important among those is a smallish bee from the miner bee family, Andrenidae.

Miner bees are a diverse group of solitary nesting bees; each female digs her own burrow where she lays her eggs. In sites with favorable soil—often sandy spots that are good for digging—many miner bees may nest in close proximity, giving the appearance of a hive. These nesting congregations may well occur in lawns and gardens, where they should be valued; the bees are totally harmless to humans and are important pollinators.

The particular miner bee that pollinates spring beauties is Andrena erigeneae, the spring beauty miner, one of about 100 Andrenid bee species in Ohio. (Miner bees have fuzzy bands between their eyes, but identifying them to species can be challenging.) Not surprisingly from their name, spring beauty miners are specialist pollinators of spring beauties. The bees feed from nectar in the flower center, directed there by pink veins in the petals and by UV-reflecting stamen filaments. In the process, pollen collects on their hairy bodies, providing a fashionable pink tint. This pollen collection is so effective that it can deplete the flowers of pollen. As long as the bees subsequently visit and pollinate other spring beauties, though, they have done their job.

The female miner bee takes adherent pollen back to her underground nest, where she crafts it into a little ball on which she lays a single egg. That egg hatches into a larva during summer, feeds on the pollen, then metamorphoses into a pupa. In late autumn, adults emerge from the pupae, but they remain underground until the following spring. Presumably, their emergence depends on temperature cues that align with those triggering spring beauties to bloom.

Spring beauties are abundant in local woods, and a quick scan reveals that not all spring beauties look the same. On some plants, the petals are nearly pure white, contrasting with the bright pink stamen tips. For others, the petals and stamens form a matched set, glowing pink against the brown leaf litter. Why that variation?

What appears to be the case is that pink flowers are more effectively pollinated than white, especially by spring beauty miners. Distinctively pink flowers may help the bees avoid mistakenly visiting other white spring ephemerals that are blooming nearby, thereby facilitating efficient pollination. However, pinker flowers also suffer some detriment. In particular, the leaves of plants with pinker flowers suffer more damage from herbivorous slugs. White petals, it turns out, are richer in chemicals called flavonols; those chemicals are present in leaves, too, and they deter slug herbivory. As a further complication, that damage from herbivores apparently induces the plants to gear up against other damage, and as a result, the white-flowered plants (with less slug damage, and so less elevated defenses) are more susceptible to fungal attack. The relative intensities of these various factors—pollinator preference and the threats from herbivores (slugs) and pathogens (fungi)–probably vary from year to year. And so, the flower color that more successfully sets seeds also varies from year to year. Like many aspects of ecology and physiology, the color of spring beauty flowers represents a trade-off, and the population ends up including a mix of flowers ranging from white to pink.

Spring beauties vary in another way, too, one that is not so visible. Plant cells, like those of animals, normally have two copies of each chromosome, the so-called “diploid” condition. However, many plants undergo processes during cell division, gamete (ovule and pollen) formation, and fertilization that end up producing cells with extra sets of chromosomes, so-called “polyploidy.” Plants seem to tolerate polyploidy better than animals. Although there can be negative consequences of polyploidy, including reduced fertility, there may be benefits, too. For example, the additional copies of each gene mean that the original copy can continue to perform its original function, while the extra copies can diverge to provide new capabilities. As a result, polyploid plants may be better able to tolerate more variable or harsher conditions than “regular” diploid relatives. Spring beauties seem to be even more susceptible to, or tolerant of, polyploidy than most plants, and a population of spring beauties may include plants with 2, 4, 8, even 12 copies of each chromosome. This presents a variety of interesting possibilities for ecological adaptation and the evolution of traits and species—though those sorts of outcomes have not yet been well defined for Claytonia virginica.

Spring beauties and spring beauty miner bees help to ring in springtime and, in the process, they exemplify a variety of issues in ecology and evolution. Each species has its own interests and secrets, but at the same time each is dependent on the other. Spring beauties and the bees; it’s a tale as old as time.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

It’s February, often Dayton’s coldest month. Groundhogs, aka woodchucks, which amuse us with their antics during the warmer seasons, have long since hidden away in their underground hibernation retreats. At the same time, the broad green leaves of skunk cabbages, which mark the wet woods and marshes of summer, have died off, leaving their copious root systems to survive until the next growing season.

So, what do these two seemingly unrelated organisms, one a mammal and one a plant, have in common? The whole-organism answer is that neither of them waits for warm weather to “wake up.” Rather, both groundhogs and skunk cabbages initiate activity while the mercury sits low in the thermometer. It also turns out that groundhogs and skunk cabbages share a deeper commonality. That is, they both warm themselves against the cold using a protein shared from deep evolutionary history.

Groundhogs are among the largest true hibernators, meaning those mammals whose body temperature drops substantially for an extended period. (Bears do spend the winter in lethargic slumber, but their body temperature drops by just a few degrees.) Groundhog body temperature drops from 36oC (97oF) to about 10oC (50oF) during hibernation. At the same time, bodily functions slow profoundly. Heart rate, for example, drops from ~80 to ~5 bt/min, and breathing slows to just a couple of breaths per minute. The marked decrease in cellular metabolism at low body temperature means that the animal can survive for several months on nothing but the energy reserves (mostly fat) that it accumulated during the previous fall.

Despite all that, groundhogs, like other mammalian hibernators, don’t remain at uninterrupted low body temperature throughout their nearly five months of hibernation. Rather, every 6 days or so they arouse for about 1.5 days. (Needless to say, most groundhogs don’t time an arousal to fall on February 2 each year–Punxsutawney Phil notwithstanding.) During those arousals, body temperature temporarily rewarms to normal before cooling back to hibernation levels. Arousals can account for more than 90% of all energy use during hibernation, and their exact function remains unclear. They might allow the animal to urinate and thereby rid its body of accumulating wastes, or they may allow sensing and synchronization with environmental cues.

The rise in body temperature during arousal from hibernation is rapid, and it is achieved not by shivering but through the activity of a specialized tissue called brown fat. Brown fat is characteristic of hibernators, in which it is localized most prominently between the shoulders. It’s present in infants of some non-hibernators, too, including humans, but tends to disappear by adulthood. Brown fat has one specific function: to generate heat. The process is called “non-shivering thermogenesis,” and the key is a molecule called uncoupling protein, or UCP1. In mammals, UCP1 is active only in cells of brown fat. Within those cells, UCP1 sits in the inner membrane of the mitochondria (mitochondria have a double membrane, inner and outer). Those organelles are known as the powerhouses of the cell because they synthesize ATP, which stores cellular energy. The process that drives ATP formation in the mitochondria involves an enzyme (ATP synthase) that is powered by the movement of hydrogen ions (protons) across the mitochondrial inner membrane. It’s analogous to water generating electricity by flowing through a dam’s turbine.

That’s where UCP1 comes in. UCP1 “uncouples” the movement of hydrogen ions from the action of ATP synthase. Instead of powering ATP synthase, the energy from the hydrogen ion movement is dissipated as heat. (To pursue the analogy, it’s as though the turbines were bypassed and the water was allowed to just flow downstream, without producing electricity.) The result is that brown fat doesn’t produce a lot of ATP, but it does produce a lot of heat.

It turns out that skunk cabbages use exactly the same trick. Skunk cabbage is famously among the earliest plants to emerge from winter, often appearing as early as late February. And it accomplishes that by using the amazing trick of melting its way up through the snow. In particular, the spadix of the plant (the central spike that eventually will support the plant’s tiny flowers) heats up as it grows. And that heat is generated in just the same way as occurs in brown fat, a function of UCP1 acting in the mitochondria of spadix cells. As a result, the spadix can keep its internal temperature at ~20oC (68oF), even in air temperatures below freezing.

How did two organisms as unrelated as a swamp-dwelling plant and a woodland mammal both end up having the same protein? It now appears that uncoupling proteins probably arose quite early in evolution. Even some single-celled organisms like amoebae possess genes that code for UCP-related molecules. That’s really not too surprising. One of the key lines of evidence supporting the deep relatedness of all living things, from bacteria to fungi, plants, and mammals, is that they share so much molecular machinery, including DNA, ATP, and many other examples. Useful molecules that arise in evolution persist, sometimes retaining their original function, sometimes modified or co-opted for other uses. Amoebas appeared in evolutionary history something like a billion years ago, and so there has been lots of time for those molecules to diversify. UCP1 from plants (skunk cabbage) and from mammals (groundhogs) have diverged somewhat over time, the result of mutations coupled with the demands of living in particular environments. But they are on the same branch of the UCP family tree and they retain the same basic structure and function. On the other hand, UCP1 is just one of several related proteins in the UCP family. Mammals, for example, have several versions (UCP2, UCP3, and others) that are active in various tissues and that may have a variety of functions, like as anti-oxidants.

As Punxsutawney Phil emerges to check for his shadow one state to our east, our local groundhogs and skunk cabbages also will be mobilizing to meet the cold. UCP1 will be doing its thing and, from the depths of underground, and of time, the first signs of spring warming will arise.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Through the cold months of winter, the animals that remain active in our woods, meadows, and neighborhoods are those with high rates of metabolism that sustain warm body temperatures—the endothermic (“warm-blooded”) birds and mammals. While some small mammals, like mice and shrews, are busy under the snow, those that are out and about this time of year are in the larger size range, from squirrels to raccoons, foxes, and deer. In contrast, winter-active birds—mostly from the group of perching birds called passerines–are, by and large, small. Carolina chickadees weigh in at about 12 grams, barely more than two teaspoons of water. Dark-eyed juncos (18 g), white-breasted nuthatches (20 g), and tufted titmice (20 – 25 g) are not much larger. Even the “big” species like cardinals (45 g), robins (75 g), and blue jays (100 g) are just 10 – 25% the size of a gray squirrel. How do these small birds manage to stay warm, even on days when most of us choose to remain comfortably indoors?

The underlying problem is that endotherms stay warm using their metabolism, burning fuels like sugar and fat to liberate energy. That energy ultimately is lost as heat, and in endotherms the metabolism proceeds at a high enough rate to warm the body. Heat loss is driven by the temperature difference between the body and the environment, and so heat escapes more readily during the cold of winter. Offsetting that heat loss therefore requires higher than usual rates of metabolism. Worse for birds, they are mostly active during daytime, and so the food that fuels heat production must be acquired in the relatively few hours of daylight.

Meeting those challenges entails two main strategies. The first is to reduce heat loss to the environment, thereby reducing the need for metabolic heat production. The second is to find and process enough nutrients to support a high metabolic rate.

Small birds can minimize heat loss by a number of means. One is structural: they can add insulation to their feathers. Chickadees, juncos, goldfinches, and others molt and replace their feathers after their summer reproductive season, which presents the opportunity to add insulation before cold sets in. Surprisingly, though, the feather coats of winter-acclimated small northern birds provide insulation not much better than those of summer birds. Instead, birds use a variety of behavioral tricks to reduce heat loss. Small birds fluff up their feathers to improve insulation and they seek out sheltered roost sites where wind is minimized. They also may roost communally on really cold nights, huddling with “neighbors” to reduce their exposed surface area.

Beyond that, birds may employ one other mechanism to reduce heat loss. Although, with one weird exception, birds don’t hibernate (a sustained reduction in body temperature and metabolism), they do use a less profound version of that strategy called torpor. In that condition, birds reduce their body temperature by a few degrees. That hypothermia usually occurs at night while the birds are roosting, often triggered by cold or by low energy reserves. Hypothermia reduces both heat loss to the environment (because the body-to-air temperature difference is diminished) and metabolic rate, which slows down at the lower body temperature. Chickadees may reduce body temperature by as much as 5-10oC during cold nights, and as a result may reduce energy expenditure by as much as a third. The trade-off of is that torpor induces lethargy and so might increase vulnerability. But it’s worthwhile; the energy saving from torpor means that less food needs to be gathered during the day and that fat stores last longer.

Even with those energy-saving measures, small birds in winter need high metabolic rates to generate adequate body heat. The first step toward achieving that is to acquire enough food. Birds shift their diet in winter to take advantage of what’s available. Even birds like chickadees, which mostly eat insects in summer, switch substantially to seeds and fruits in winter. Some small birds, like chickadees and titmice, also implement caching behavior in winter, collecting surplus food on good days and storing the extra for days when foraging is difficult.

Internal mechanisms also adjust to winter conditions. The breast muscles (pectorals), which power flight, are the largest organ contributing to heat production, and their size enlarges for winter. Body mass also increases through fat deposition, which contributes to insulation while providing critical reserves for non-feeding hours or days. Within the heat-generating tissues, winter passerines shift their metabolism substantially toward reliance on burning fats, rather than sugar. To do so, they boost levels of molecules (enzymes, lipid transporters, and lipid binding proteins) involved in the pathways for fat metabolism. The result is that metabolic capacity, including both the rate of metabolism at rest and the ability to increase metabolism—either the peak rate, or the stamina to sustain that high rate, or both—is enhanced. Winter-acclimated chickadees, for example, can achieve rates of heat production 50% greater than summer birds.

Not all species or populations use all of these mechanisms, but the combination of strategies can be highly effective. Put a tablespoon of water outdoors in mid-winter and it will freeze solid in short order. In contrast, a winter-acclimated American goldfinch with similar mass (12 – 15 grams) can elevate its metabolism more than five times its resting rate for up to eight hours straight, enough to stay warm at environmental temperatures of -70oC (nearly 100oF below zero!) for that entire eight hours. Summer-acclimated goldfinches exposed to those same conditions become hypothermic in minutes.

The Swiss biologist Max Kleiber studied many aspects of animal metabolism, and he titled his integrative book on that subject “The Fire of Life.” Nothing exemplifies that term better than passerines in winter. Even in summer, small birds run their engines at a high level. But in winter, they really turn up the fire.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

As fall turns to winter, and green leaves and insects have substantially disappeared until next spring, fruits and nuts become increasingly important in the diets of animals that remain active in the cold. Among those, the hard nuts produced by a variety of trees—walnuts, hickories, and oaks, for example—are known as “mast.” Acorns are on the small side of mast crops, but they can be extremely numerous, and they play key roles in northern deciduous ecosystems.

Acorns, of course, are the nuts produced by oak trees. Acorns are rich in fat, carbohydrates, and protein (about 8, 12, and 2 grams, respectively, per 28 gram (1 oz) serving), and so they provide a nourishing meal for both wildlife and people. (Acorn-based recipes for human consumption usually start by processing them to reduce bitterness.) However, not all acorns are alike. Just like the oak trees themselves, acorns come in two major varieties.

Oaks in the “white oak” group (trees with rounded leaf lobes, like white oak and bur oak) produce acorns that mature in a single year. They contain relatively low concentrations of tannins, plant chemicals that confer a bitter taste and inhibit digestion. As such, they are preferred by wildlife. However, “white” acorns also germinate relatively quickly, and so they are most available in the weeks soon after they fall in autumn.

In contrast, acorns from “red” oaks (species with pointed leaf lobes, like red oak) require two years to mature. They tend to be slightly richer in nutrients than acorns from white oaks, but their higher tannin concentrations make them more bitter and less digestible. Nevertheless, “red” acorns germinate less readily than “white,” and so they persist longer and become increasingly important to wildlife as winter progresses.

A single oak tree can produce ten thousand or more acorns. However, not every tree produces in every year. In Ohio, something like 30 – 50% of oaks, on average, produce acorns each year. For reasons that are not well understood, some years—so-called “mast years”– are highly prolific for oaks across a geographic region, while others are much less so. 2023 has been a good year for acorns in our region; a walk through an oaky section of woods can feel like crossing a room full of spilled marbles.

Given the huge number of acorns produced by a single oak, the vast majority of acorns clearly do not end up as oak trees. Instead, they fuel the ecosystem in a variety of other ways. As noted above, one of those important roles is to provide food for winter wildlife, especially the warm-blooded (endothermic) animals—mammals and birds—that remain active through winter. Locally, acorns are favorite foods for white-tailed deer, mice, chipmunks and squirrels, raccoons, turkeys, woodpeckers, blue jays, and others. Acorns are particularly favored by deer. In a strong acorn mast year, deer are well fed, they stay in the area of acorn production, and more of them bear twin fawns. In contrast, in a year with low acorn abundance, deer wander in search of other options. Populations of mice, chipmunks, and squirrels also fluctuate with acorn abundance.

A number of animals collect and store acorns for later consumption and are important agents for dispersing the nuts away from their parent tree. Woodpeckers that hide and later retrieve stored nuts, like red-bellied woodpeckers, actually have larger brain areas devoted to memory (the hippocampus) than species that don’t. Squirrels and blue jays bury their stored acorns, thereby hiding them from potential competitors. Buried acorns that survive the winter are effectively planted and ready to germinate.

At the same time that birds and mammals are harvesting fallen acorns, another critter is enjoying that meal from the inside. Earlier in the year, acorn weevils—a long-nosed little beetle—lay their eggs inside immature acorns. The larva (grub) begins its development while the acorn grows on the tree. Then, in late fall or winter, after the acorns have fallen, the grub chews its way out and completes development in the soil. Squirrels and blue jays can distinguish acorns that host weevil grubs from those that don’t and avoid harvesting the buggy ones, presumably because the growing grub would consume the acorn meat during the weeks of underground storage.

Fallen acorns are part of another important set of interactions, too. White-footed mice eat acorns. They also serve as hosts for both the bacterium, Borrelia burgdorferi, that causes Lyme disease and for the black-legged tick, Ixodes scapularis, that transmits the bacteria to humans. (For some reason, white-footed mice have weak immune responses to infection and are not very fastidious at grooming, so they provide a welcome home to both the bacteria and the ticks.) In a strong acorn mast year, mice are well fed in the autumn and they produce a lot of offspring the following year. Immature black-legged ticks, meanwhile, wander the forest floor looking for a mammal to feed from; those that bite a mouse, quite likely picking up Borrelia in the process, are more likely to grow and mature into adults. That maturation takes a while, though, and so adult ticks that can bite humans appear in the year after the juvenile ticks feed on the mice. The result of all this is that the risk of Lyme disease for humans, transmitted by black-legged ticks, is strongly related to the population of white-footed mice one year previously and to acorn abundance the year before that. Lyme disease remains uncommon in Greene and Montgomery Counties (just one or two cases per year), but it is increasing significantly in Ohio, up from 67 cases in 2012 to over 750 ten years later. 2023 is a strong acorn year; watch out for Lyme disease in 2025.

The old English proverb notes that “mighty oaks from tiny acorns grow.” But while acorns do grow into oak trees, they also feed myriad wildlife, influence behavior and reproductive output of animals ranging from mice to deer, and underlie the risk for a serious disease of humans. As such, acorns are central players in Ohio’s forest dynamics, with connections in many directions. “No acorn is an island,” one might say.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

It’s November, and across the country, turkeys are arriving in grocery stores and home freezers. The great majority of those, of course, are domestic turkeys, raised on farms and bred for meat production. But wild turkeys are on the rise, too, and they’re quite a different beast.

Wild turkeys are the largest North American upland game birds. In fact, male turkeys, which can weigh 10 kg (22 pounds) or more, are among the heaviest of all North American birds, rivaled only by some swans. Toms, as the males are known, are easy to recognize. Their large size, head ornamentation (red wattle hanging down from a bare, gnarly blue and red head), and glossy bronze feathers are distinctive. A strutting tom, with feathers fluffed, tail spread, and in full gobble, is a sight to behold. Females (hens), in contrast, are about half the size of males, don’t gobble, and lack a lot of the ornamentation. Still, their feathers have a beautiful iridescence, and a large female prowling the woods or fields can’t help but bring to mind a small dinosaur.

Although wild turkeys can be seen in open habitat, they are primarily creatures of forests and forest edges, which provide both food and secure hiding spots. Their preferred diet includes acorns and other nuts and seeds, though they are quite omnivorous and also will consume berries, fruits, and animals like insects or frogs.

Turkeys are members of the galliform order of birds, along with chickens, quails, pheasants, and others. Like many galliform birds, turkeys have high “wing loading,” meaning that they are heavy-bodied relative to the size of their wings. The corollary, of course, is that turkeys are built for walking, not flying. The leg muscles of galliform birds include a lot of red muscle fibers (“dark meat”), which supports the sustained, aerobic work of walking. In contrast, breast muscles (pectorals), which power flight, are mostly white muscle, structured to support intense, short-lived bursts of activity. As such, turkeys don’t migrate, and they typically fly for just short durations as they erupt from the ground after being disturbed. Nevertheless, those short bursts can take them aloft, and a mother hen with her chicks may well roost for the night high up in the branches of a large tree.

Mating activity—when males gather to strut their stuff to attract females–peaks for Ohio’s turkeys in mid-April. Males and females then part ways; males are not involved in parental duties. Hens lay up to a dozen or more eggs, which hatch in May or June after 28 days of incubation. The precocial chicks hatch with eyes open and ready to search for food, and they take their first flight in about two weeks. Those several weeks—nesting for the females, pre-flight for the juveniles—are times of high risk for mortality. As the chicks mature, the families wander in search of food. In the Centerville-Washington Township parks, sightings of females with young have become more common in recent summers, and family groups sometimes appear in the yards, or on the rooftops, of homes along woods edges. Turkeys remain in the area during the colder fall and winter months. However, they may shift locations as they search for good feeding grounds and shelter from wind and cold.

In the early 19th century, Ohio likely was home to more than a million turkeys, among the most of any state. Amazingly, though, that number declined to zero by about 1900, the result of habitat loss (deforestation) and unregulated hunting. In the 1950s, as Ohio’s forests were recovering, efforts were initiated to re-introduce turkeys to the state. Releases of captive-bred birds proved unsuccessful, but several hundred wild turkeys transplanted from eastern states to Ohio’s southeastern forests between 1956 and 1971 fared better. With turkey hunting having been banned, that population thrived and expanded to more than 7,500 birds by 1983, mostly still in the southeast quadrant of the state. Today, something like 175,000 turkeys inhabit all 88 of Ohio’s counties. Montgomery and Greene Counties, like much of west-central Ohio, remain on the low end of the population distribution.

Turkey hunting was reinstated in Ohio in the 1970s. On average, springtime hunters claimed more than 13,000 wild turkeys per year from 2020 – 2022, including 21 in Montgomery and 19 in Greene County. Numbers were higher in Spring, 2023, perhaps reflecting strong production of chicks in recent years. The fall hunting season is smaller, claiming about 1,000 birds in 2022, none in Greene or Montgomery County. Something like 90% of those hunted turkeys were male. That is partly compensated by differential mortality of males and females from other sources, but the Ohio wild turkey population is slightly more heavily female than would be the case without hunting.

The turkey is one of only two North American native birds to be domesticated, along with the Muscovy duck. At the same time, Ohio’s wild turkeys, like its white-tailed deer and bald eagles, now serve as examples of a highly successful conservation story. What a treat to come upon a turkey family on a park trail, or in the backyard. Let us be thankful for the resurgence of this splendid bird!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

October is a great month for mushrooms. The cooler temperatures and moist soils promote mushroom emergence, and more than 125 species have been observed in Greene and Montgomery Counties. Some of those mushroom varieties can be hard to identify. But one that is quite common and recognizable is the shaggy mane, Coprinus comatus, also known as the lawyer’s wig.

Shaggy manes are saprobes—they grow on dead or decaying organic matter, thereby helping to recycle those materials back to the ecosystem. (For a good glossary of fungal terminology, check out http://www.mushroomexpert.com/glossary.html.) Shaggy manes can be found in lawns, by roadsides, or among leaf litter in the woods. Often they appear in clusters, sometimes in lines or as “fairy rings.”

Shaggy manes are the most common local representative of the group of mushrooms known as “inky caps.” Young, freshly emerged shaggy manes form tight, white cones up to 3 or more inches tall atop white stalks. As the cone matures, scales form on the surface, contributing the shaggy, “wig-like” appearance. But, as described below, the appearance changes even more as the mushroom ages.

Mushrooms serve as the reproductive organs of fungi. Shaggy manes, like other mushrooms, primarily exist as strands of fungal cells—mycelia—that may stretch for long distances on or under the soil surface. When it’s time to reproduce—that is, to generate spores that can disperse to grow new fungi—the fungus constructs an above-ground structure that we call a mushroom. In mushrooms with distinct caps, the spores are produced on the underside of the cap.

For shaggy manes, the problem is that the cap is such a closed, tight structure—like an umbrella that has been furled up tight—that there is no convenient way for the spores to escape. And so, the mushroom employs a trick: as the tight, whitish cone ages, it opens and browns and appears to “melt” from the edges, dripping off as a dark black liquid. Technically, that melting is called deliquescence, and it results from enzymes within the cap that digest the cap itself. The spores are released as the cap opens or they drop off with the inky droplets. Other mushrooms also disintegrate after spore release—by that point, they are no longer needed—but not usually in such dramatically liquid form.

As young, white caps, shaggy mane mushrooms are an appreciated edible mushroom. (Note: do not consume wild mushrooms without first consulting an expert.) They are cultivated for human consumption in China and other Asian countries, though not so much in the U.S., and they sometimes are called chicken leg mushrooms. But people who harvest them for eating need to process them quickly. In China, the young cultivated mushrooms are quickly dried to preserve them. Otherwise, the liquefaction process begins within hours of harvest and turns the firm, edible cap into a slimy mess.

There’s another potential problem with eating shaggy manes. That is, a similar-looking mushroom, the common inky-cap (Corpinopsis atramentaria, which until recently was included with shaggy manes in the genus Coprinus), contains a chemical called coprine. Coprine interferes with humans’ metabolism of acetaldehyde, a chemical produced from ingested ethanol. Acetaldehyde is responsible for hangover symptoms and is toxic as it accumulates. So, common inky caps should not be consumed within about three days before or after drinking alcohol. This is not a problem with shaggy manes, which lack coprine, but good identification is important.

That being said, the black liquid from the “melted” mushroom—of either species—really does function as ink. It is easy to produce (just put some shaggy mane mushrooms in a jar for a while and let them liquefy; then strain the liquid through fine mesh), and it lasts for months. Indeed, numerous artists attest to the high quality of the ink. The only problem is that it smells a bit of decomposed mushrooms; but that’s just a minor inconvenience!

Autumn is always a fine time for wandering the woods and fields. This year, keep an eye out for clusters of tight, white, cone-shaped mushrooms. With proper skill, you could consider eating them. But even easier, amaze your friends by melting some mushrooms and filling a few vials of ink. What a great holiday gift! And if you have a lot of ink—well, Dr. Seuss has the answer, I think (if I remember Green Eggs and Ham correctly).

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Your Centerville-Washington Park District is serious about providing the park and recreation opportunities you want! CWPD perpetually seeks resident and stakeholder input to build strategic plans, master plans, programming plans, capital improvements plans and budgets. This allows us to align resources with community priorities.

Our most recent Community Needs Assessment was conducted in 2022 — and in 2019 before that! Resident feedback generates great ideas and opinions, and we would like to share the many improvements that are a direct result of your input. So, every two weeks from July to November, we will post a short message about what’s been added, fixed, improved or expanded to meet your requests!

Community Events up 100%

Large-scale community events always receive a high priority ranking on Park District surveys. Staff have taken that to heart, and over the past two years, we have increased special event offerings by 100%! We went from offering 18 community events in 2021 to 36 in both 2022 and 2023, which equates to serving thousands of residents with expanded opportunities to enjoy their parks with family and friends!

Fall is our busiest special event season and we have lots of great events heading your way! We hope to see you at one, or more, of them!

• Pumpkin Patch Dash Fun Run
• Halloween Hop & Howl
• Truck or Treat
• Hound Hike
• Girl Scout Tree Promise
• The Great Turkey Trek

To explore more, visit our upcoming events calendar.

The Park District is fortunate to have forged many wonderful partnerships and sponsorships with local clubs, organizations and businesses, which greatly enrich these FREE events for the benefit of the community.

We are proud to deliver so many opportunities for you to spend quality outdoor time with family and friends of all ages. If you have an idea for a community event, don’t keep it to yourself, let us know about it! Maybe we can make it happen!

Previous installments of You Spoke, We Listened:

• Making the Outdoors Inclusive
• Parks Build Healthy Communities
• We’re Walking, We’re Walking…
• Introducing: In Your BIG Backyard
• Conserving Habitats and Ecosystems
• Throwing Shade … The Good Kind

Your Centerville-Washington Park District is serious about providing the park and recreation opportunities you want! CWPD perpetually seeks resident and stakeholder input to build strategic plans, master plans, programming plans, capital improvements plans and budgets. This allows us to align resources with community priorities.

Our most recent Community Needs Assessment was conducted in 2022 — and in 2019 before that! Resident feedback generates great ideas and opinions, and we would like to share the many improvements that are a direct result of your input. So, every two weeks from July to November, we will post a short message about what’s been added, fixed, improved or expanded to meet your requests!

Making the Outdoors Inclusive

Improving park access and inclusivity is a key priority. Since 2020, we have installed two all-inclusive playgrounds at your large community parks, one at Schoolhouse Park and one at Yankee Park. The public was able to choose the playground design, and the end result goes beyond minimum accessibility to welcome children and adults of all abilities to play and interact together!

Staff have also strategically added over 2.5 miles of paved paths to create connections to countless park amenities, such as ballfields, playgrounds, tennis courts, natural habitats, as well as neighborhoods. To enhance the visitor experience, we have also installed over a dozen inclusive play features at neighborhood park playgrounds. In 2022, the community benefited from a generous $20,000 donation from the Centerville Noon Optimist Club. The funds enabled the Park District to purchase 23 accessible swings. With this purchase, we are proud to say all 41 Centerville-Washington Park District playgrounds have an accessible swing!

Inclusive programming is also important to the Park District. Over the past few years, we have added countless options to prioritize access to parks and recreation opportunities. Adapted programming has been added to the line-up, including the award-winning Adapted Action Day, Adapted Archery and the Rainbows and Raindrops Adapted Fun Run. The staff has also created an early arrival option for popular special events to make them a sensory-friendly experience, such as the Fairy & Gnome Home Festival and Truck or Treat.

Roughly 30% of programs are offered at no cost or low cost to residents, and for those programs requiring higher fees, we have implemented a process for requesting financial assistance to further remove barriers to participation.

While not every part of every park can be fully accessible, it is our desire to make every type of experience available to all. Suggestions and ideas are most welcome. If you have a thought to help make any part of the district more accessible, please let us know. We would like to invite you to attend an inclusion focus group. Help us continue to promote inclusion and accessibility for all at your Centerville-Washington Park District parks and programs!

Tuesday, September 19
6:30 – 7:30 p.m.
Activity Center Park, Community Room
221 N. Main St., Centerville

If the date and time don’t work for you, but you have feedback to share, please RSVP and we will email you questions to answer as your schedule allows!

As a thank you, all participants will receive a $15 household credit for future park programs. (One credit per household.)

RSVP for the focus group >

Previous installments of You Spoke, We Listened:

• Parks Build Healthy Communities
• We’re Walking, We’re Walking…
• Introducing: In Your BIG Backyard
• Conserving Habitats and Ecosystems
• Throwing Shade … The Good Kind

Ruby-throated hummingbirds are jewels of local summer landscapes. Hummingbirds arrive in Ohio from their southern wintering sites around the beginning of May and spend the summer feeding and raising young. By September, daylight, temperature, and nectar sources all are declining. It’s time to prepare for the return journey south! According to eBird, the online public database of bird sightings, early September is when reports of hummingbirds in Greene County are most common. By the end of the month, the birds are nearly gone.

Like all birds, hummingbirds are endothermic, meaning that they use their high rate of metabolism to generate heat that warms their body. It turns out that the smaller the animal, the relatively higher its rate of metabolism. And so ruby-throats, with an adult body mass of just a few grams (a penny or two), have exceptionally high relative metabolic rates. What that means is that a hummingbird’s energy reserves don’t last long. A hummingbird going about its daily business—mostly sitting around, interrupted by occasional bouts of flight–burns about 7 Calories per day. That might not seem like a lot (a human burns about 2000 Cal/d), but it’s equivalent to metabolizing nearly a gram of fat, about 25% of the bird’s body mass, each day.

With reserves that deplete so quickly, migration season poses a particular challenge. Ruby-throats mostly spend the winter in southern Mexico and Central America, about 2500 km (1500 miles) from Ohio as the crow (hummingbird?) flies. How do they manage the energy demands of that journey?

Not surprisingly, one strategy is to store energy before leaving. Despite eating a carbohydrate-rich diet (nectar is mostly sugar water), hummingbirds store most of their energy reserves as fat. Naturally, a hummingbird’s small size limits how much fat it can carry; 2 or 3 grams—about half a teaspoon’s worth—is about it! Each gram of fat provides about 9 Calories of energy, so a ruby-throat can carry something like 25 Calories of fuel reserves.

Interestingly, though, only some hummingbirds, mostly adults, fatten up before they begin their journey south. To do so, they add bouts of feeding during midday rather than resting at those hours, and they lengthen the duration of individual feeding bouts. In contrast, many juveniles forego increased feeding before they depart and instead feed en route. Hummingbird southward migration tends to track the peak blooming of orange jewelweed, a favorite source of sugar-rich nectar. The result is that hummingbirds reach the Gulf Coast in varying states of energy balance; some have well-stocked fat reserves upon arrival, and others are quite lean.

The big decision the birds then need to make is what path to follow from the southern US to their final wintering grounds. The most direct route to Central America is across the Gulf of Mexico, a journey of about 850 km (500+ miles). But that path does not provide opportunities to feed. Alternatively, a bird could follow the coast around the Gulf, a much longer flight but with food along the way. An intriguing question emerges from that decision: Is it really feasible for a hummingbird to fly non-stop across the Gulf of Mexico?

To answer that question, one needs three main pieces of information. First, how much energy can a hummingbird carry? (We have already answered that: about 25 Calories worth of fat.) Second, how much energy does it take for a hummingbird to fly? And third, how fast does a hummingbird fly while migrating?

A number of approaches have been used to estimate the energy cost of hummingbird flight. Those techniques include aerodynamic analyses; measuring rates of respiration (oxygen use or carbon dioxide production) of hummingbirds hovering inside of closed chambers; and tracking of chemical tracers in free-living birds (the so-called doubly labeled water method). One innovative study modified an outdoor hummingbird feeder to capture air as the bird hovered to feed, much like a human wearing a mask while testing on an exercise bike. Although the energy cost of migratory flight might differ somewhat from values measured in those other circumstances, the research indicates that hummingbirds use about 1 Calorie per hour while flying—and so each Calorie of stored fat can fuel about an hour of flight; 25 stored Calories can support 25 hours of flight.

How far will that get them? Hummingbird flight speed no doubt depends to some extent on environmental conditions like wind and temperature. However, 40 km/hr (25 miles/hr) seems to be a reasonable estimate. At that speed, 25 Calories of stored fat, lasting 25 hours of flight time, will carry the birds for about 1000 km (625 miles). That’s more than enough range for these tiny birds to cross the Gulf of Mexico non-stop without feeding. Wow!

Surprisingly, given the appeal of ruby-throated hummingbirds, there remain a lot of unanswered questions about their lives. Some of the hummingbirds that reach the southern US each autumn remain there through the winter, but most depart for destinations further south. What route do they follow: across the Gulf, or along the coast of Texas and Mexico? And how does an individual bird decide which path to take? While we are pretty sure that a hummingbird could cross the Gulf of Mexico non-stop, at least with decent weather, how many actually do that? We still don’t know.

Regardless of the answers to those questions, the life of a ruby-throated hummingbird is remarkable. The birds avidly feeding at jewelweed and backyard feeders in Greene County, Ohio in September will make a 3,000-mile journey to Central America and back, powered by about 21 million (!) wing beats during 120 hours of flight. And they do that year after year; the oldest recorded wild ruby-throat lived for more than 6 years. Hummingbirds pack a lot of awesome into those tiny bodies!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Your Centerville-Washington Park District is serious about providing the park and recreation opportunities you want! CWPD perpetually seeks resident and stakeholder input to build strategic plans, master plans, programming plans, capital improvements plans and budgets. This allows us to align resources with community priorities.

Our most recent Community Needs Assessment was conducted in 2022 — and in 2019 before that! Resident feedback generates great ideas and opinions, and we would like to share the many improvements that are a direct result of your input. So, every two weeks from July to November, we will post a short message about what’s been added, fixed, improved or expanded to meet your requests!

Parks Build Healthy Communities

At the Park District, we know parks help build healthy communities by providing opportunities to improve the physical and mental health of citizens. It turns out residents know the same! In fact, adult fitness and wellness programming had the highest priority investment ranking in our most recent community survey.

We have increased fitness and wellness program partnerships by 91% since 2020, and we also added 62 new fitness and wellness offerings over the past 18 months! The programs are diverse and include fitness special events, new pickleball leagues, ACtivity Squad summer day camps, community bike rides, archery and much more. The majority of these programs take place outdoors, allowing for a significant impact on both the physical and mental health of participants.

Strategic partnerships are vital to reaching more residents with FREE fitness and wellness programming. Over the past year, 20% of the fitness and wellness offerings were free to residents. Forging intentional partnerships has resulted in increased reach in the community. Working with our partners, such as Dayton Children’s Hospital and Bike Centerville, we have increased fitness and wellness enrollment by 107% from 2021 to 2022—from 1,151 participants to 2,394!

Check our upcoming events calendar to find a fitness and wellness offering that works for you!

Thank you for your input. It is only with resident input and feedback that the Park District can put resources where it is most important to you. Keep your suggestions coming!

Previous installments of You Spoke, We Listened:

• We’re Walking, We’re Walking…
• Introducing: In Your BIG Backyard
• Conserving Habitats and Ecosystems
• Throwing Shade … The Good Kind

Your Centerville-Washington Park District is serious about providing the park and recreation opportunities you want! CWPD perpetually seeks resident and stakeholder input to build strategic plans, master plans, programming plans, capital improvements plans and budgets. This allows us to align resources with community priorities.

Our most recent Community Needs Assessment was conducted in 2022 — and in 2019 before that! Resident feedback generates great ideas and opinions, and we would like to share the many improvements that are a direct result of your input. So, every two weeks from July to November, we will post a short message about what’s been added, fixed, improved or expanded to meet your requests!

We’re Walking, We’re Walking…

Once again, survey data showed that residents would like CWPD to continue focusing on trails and paths. Over the past 5 years staff have added or improved about 9 miles of trails and paths. Your park district promotes community health and wellness by providing 39 miles of trails and pathways in 18 different parks.

Trails provide health and fitness by providing an enjoyable and safe place for bicycling, walking, and jogging, removed from the hazards of motor vehicles. (source, American Trails)

Over the past several years, many trail improvements have taken place at Bill Yeck Park in conjunction with the park’s master plan, which was driven by public input. The installation of a reliable wayfinding system was the most requested improvement for the park, and was installed this past spring. The feedback has been positive!

Also this year, paved paths have been added to both Grant Park and Iron Horse Park. The completion of the 0.6-mile path around Iron Horse Park means that all eight community parks now boast a paved perimeter path, providing ample opportunity for you to be active and enjoy the outdoors with family, friends and your furry friends!

Next on our list is initiating the improvements to the Grant Park trail system per the community-driven park master plan. The updated trail system will even feature the District’s very first water trail!

Whether you are hiking, walking, biking, rolling, strolling or toddling, you do not have to travel far to find the perfect path! For more information on trails and pathways visit our Find a Park page. Have more thoughts or suggestions on where to put trails and paths? Let us know. We are listening!

Previous installments of You Spoke, We Listened:

• Introducing: In Your BIG Backyard
• Conserving Habitats and Ecosystems
• Throwing Shade … The Good Kind

Of the million or so insect species that have been described so far, between 100 and 150 thousand are in the order Diptera—the flies. As the name Diptera indicates (“di” means “two,” and “ptera” means “wings”), flies share the characteristic of having just two wings for flight, unlike most insects, which have four. But while they do have that trait in common, there’s also a lot of diversity among the flies. The dipteran order is divided into more than 150 families, including well-known groups like the house flies (family Muscidae), fruit flies (Drosophilidae), hover flies (Syrphidae), and mosquitoes (Culicidae).

Bristle flies, family Tachinidae, might be less familiar than some of those other groups. However, they are one of the most diverse dipteran families, with about 10,000 species described so far, including more than 500 in Ohio. Tachinids play important roles in natural systems, and some species have even been imported as biological agents of pest control.

The name “bristle fly” implies that members of this group are spiky or hairy. That certainly is true for many species, impressively so for some. However, tachinids are quite variable in appearance. Among the species that are common locally are feather-legged flies (with bright orange abdomens, black wings that are held out to the sides, and feathery hind legs), Juriniopsis flies (covered front to back in spiky black bristles), and Gymnosoma flies (with bulging red eyes and smooth, round, patterned abdomens).

What all tachinid flies do share is a particular life cycle: they are parasitoids. What that means is that the juvenile form of the fly—the larva, or maggot—develops inside the body of a host, which ultimately dies as a result. Caterpillars of moths and butterflies are the most common hosts, but some tachinids parasitize other insects like beetles, wasps, or grasshoppers. The larva feeds on its host from the inside and ultimately kills it—not unlike the xenomorphs in Alien!

Female tachinids use a variety of strategies for getting their offspring into a host. Most often, tachinid eggs begin to develop while they are still inside the female fly, so they are ready to hatch shortly after laying. In some species, the fly uses the direct approach, injecting her eggs into a host. In other species, the eggs are attached onto the surface of the host; when the larvae emerge, they burrow inside. Yet another strategy is for the female fly to lay her eggs in sites where hosts are likely to encounter them, such as on leaves where the host feeds or by the host’s burrow in the soil. The fly larvae then either seek out the host or grab onto it when it happens by.

As the larva consumes its host, it matures and then metamorphoses into a pupa. That is often the life stage that overwinters, in which case the adults emerge the following year as temperatures warm. Adult tachinids mostly feed on nectar and pollen. Locally, they can be found visiting many species of wildflowers and, like bees and butterflies, are important pollinators.

Those two elements of their lifestyle—adults as pollinators, larvae as caterpillar killers—make tachinids welcome elements of human agriculture and gardening. It is thought that tachinids and other parasitoids (like some wasps) limit populations of caterpillars in the wild. Humans have tried to exploit that capability, using tachinids for non-chemical control of pests in forest and agricultural settings. More than 100 years ago, tachinids from Europe were brought to the U. S. to control gypsy moth caterpillars, which had been introduced previously from Europe and were defoliating northeastern forests. That effort, and repeated efforts since then to use tachinids to control stink bugs, various caterpillars, and other pests, have met with mixed success.

Unfortunately, as so often happens when people try to tinker with natural systems, tachinid introductions have had unintended side effects. In particular, most tachinids attack more than one host species, and so flies introduced for biocontrol of particular pests have ended up reducing populations of desirable native species as well. Moreover, it remains a challenge to generate large numbers of tachinids in laboratory settings for commercial purposes. Tachinids remain a part of the arsenal for crop management, but they do not seem to be a “magic bullet” for chemical-free pest control.

That being said, tachinid flies are interesting, cool-looking animals and are good for the garden. In a recent study of tachinid diversity in nearby Greene County, about 200 species were identified at a single site over the course of a couple of years. Both the number of individual flies and the diversity of species were greatest in early autumn. Tachinids like to feed on Queen Anne’s lace, goldenrod, and many other late-season wildflowers; now is the time to head out to look for them!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Your Centerville-Washington Park District is serious about providing the park and recreation opportunities you want! CWPD perpetually seeks resident and stakeholder input to build strategic plans, master plans, programming plans, capital improvements plans and budgets. This allows us to align resources with community priorities.

Our most recent Community Needs Assessment was conducted in 2022 — and in 2019 before that! Resident feedback generates great ideas and opinions, and we would like to share the many improvements that are a direct result of your input. So, every two weeks from July to November, we will post a short message about what’s been added, fixed, improved or expanded to meet your requests!

Introducing: In Your BIG Backyard

One of the Park District’s strategic plan priorities is to effectively engage stakeholders. Time and time again, our surveys show that our biggest engagement opportunity comes from in-person interactions and from the seasonal Park District News & Events publication. However, the most recent survey also revealed that one of our residents’ most preferred ways to learn what is happening in their parks is through an e-newsletter. Interesting to note, especially since we did not offer an e-newsletter!

Shortly after receiving that information last summer, we quickly changed that and issued the first edition of In Your BIG Backyard! This monthly e-newsletter has a “Top 5” format to let subscribers know about five noteworthy ways to enjoy the parks each month. It is delivered on the last Friday of the month. Since its inception, the newsletter has grown to more than 500 subscribers — and it continues to grow! The Park Moments section of the e-newsletter is a staff favorite because it highlights your experiences in the parks, and we love to see the park experiences you all share!

We recently sent out the 13th installment of In Your BIG Backyard. You can subscribe to the monthly e-newsletter by scrolling to the bottom of the home page and providing your name and email address in the designated fields.

Check out last Friday’s issue of In Your BIG Backyard >

Thank you for your input. It is only with resident input and feedback that the Park District can put resources where it is most important to you. Keep your suggestions coming!

Previous installments of You Spoke, We Listened:

• Conserving Habitats and Ecosystems
• Throwing Shade … The Good Kind

Your Centerville-Washington Park District is serious about providing the park and recreation opportunities you want! CWPD perpetually seeks resident and stakeholder input to build strategic plans, master plans, programming plans, capital improvements plans and budgets. This allows us to align resources with community priorities.

Our most recent Community Needs Assessment was conducted in 2022 — and in 2019 before that! Resident feedback generates great ideas and opinions, and we would like to share the many improvements that are a direct result of your input. So, every two weeks from July to November, we will post a short message about what’s been added, fixed, improved or expanded to meet your requests!

Conserving Habitats and Ecosystems

We have the unique privilege of conserving habitats and ecosystems right here in the suburbs of Dayton. We are happy to report that 88% of our residents support conservation activities by the Park District! A good thing, because environmental responsibility is one of our five core values!

CWPD staff created a Land Stewardship Team who work to accomplish best practices in land management — including invasive species control, enhancing pollinator habitats, promoting healthy forests and carrying out streambank and wetland restoration.

Invasive species can be prolific and take over, causing a loss of diversity in the natural landscape. Controlling invasive species like honeysuckle, multi-flora rose, garlic mustard or pear trees, for example, is responsible land stewardship — it allows people of all ages the chance to experience what makes our community and region unique as far as the biological diversity that can exist in healthy natural habitats.

Through a combination of staff, volunteers, partnerships with universities and contracted experts, there are countless conservation projects happening in your parks every season. This summer we are completing streambank restoration projects along Hole’s Creek at Grant Park. The Teen Conservation Crew is participating in a camera trap survey to monitor for amphibians at Bill Yeck Park. Residents are taking on the role of citizen scientists by participating in monthly butterfly surveys and nestbox monitoring. And, in an effort to provide access to nature while also reducing erosion and habitat impact, staff have worked with trail-building experts to create sustainable trails at Bill Yeck Park.

Thank you for your input. It is only with resident input and feedback that the Park District can put resources where it is most important to you. Keep your suggestions coming!

Previous installments of You Spoke, We Listened:

• Throwing Shade … The Good Kind

Your Centerville-Washington Park District is serious about providing the park and recreation opportunities you want! CWPD perpetually seeks resident and stakeholder input to build strategic plans, master plans, programming plans, capital improvements plans and budgets. This allows us to align resources with community priorities.

Our most recent Community Needs Assessment was conducted in 2022 — and in 2019 before that! Resident feedback generates great ideas and opinions, and we would like to share the many improvements that are a direct result of your input. So, every two weeks from July to November, we will post a short message about what’s been added, fixed, improved or expanded to meet your requests!

Throwing Shade…the Good Kind!

Shade trees and shade structures have become a reoccurring request on Park District input surveys. In fact, they are in the top ten investment priorities requested by residents. Therefore, we have been intentional about adding hundreds of shade trees and several shade structures to your parks. Over the past 5 years, staff have planted 796 trees around the Park District! Not only does this enhance the visitor experience with more opportunities to relax in the cool shade, but it also provides habitat for wildlife, improves water quality, and aids in the reforestation efforts related to the loss of thousands of ash trees from the emerald ash borer.

Over the past two years, we have enjoyed partnering with the City of Centerville to plant dozens of beautiful Red horse chestnuts in parks located within the City. The blooms are a welcome sight in spring, along with the shade they provide during the hotter months.

Over this same time period, shade structures were installed at Yankee, Forest Field, Hithergreen and Bill Yeck Parks. Next year’s budget will include allocations for additional shade trees and shade structures.

Thank you for your input. It is only with resident input and feedback that the Park District can put resources where it is most important to you. Keep your suggestions coming!

Mid-summer is prime time for our meadows and prairies. Butterflies are prominent among the insects visiting the yellow, pink, and purple flowers, drinking their nectar and distributing their pollen. But look carefully and you may spot the occasional moth among the butterflies. If that moth darts from flower to flower, more like a large bee or a hummingbird than a butterfly, you’ve probably found a clearwing!

What is this animal?

The snowberry clearwing moth, Hemaris diffinis, is one of two species of clearwing moths in Ohio; the other, Hemaris thysbe, is the hummingbird clearwing. Clearwings are day-flying moths in the family Sphingidae, the sphinx moths. Most sphinx moths are nocturnal, and so usually they are encountered when they come in to lights at night. Perhaps the most familiar representative of the family is the tomato hornworm, a sphinx moth caterpillar that feeds voraciously on tomato leaves.

Why is it furry?

The “fur” on snowberry clearwings—actually modified scales made of chitin, not hair made of keratin—serves two functions. The first relates to body temperature regulation. Unlike most insects, sphinx moths are endothermic, meaning that they maintain a warm body temperature using heat generated internally from muscle contractions. Sphinx moths actually achieve body temperatures much like our own, and they can’t fly until they warm up. (You can see them shiver when they are preparing for flight.) The insulating fur on their bodies helps these moths to retain heat rather than lose it to the environment.

The second function of the furry body is to create a disguise. Snowberry clearwings also are known as bumblebee moths, and they are thought to gain protection from predators by mimicking bumblebees. Their coloration and furriness, along with behavior, are keys to that mimicry.

Aren’t moths nocturnal?

Indeed, the great majority of moths, including sphinx moths, are nocturnal. But exceptions occur among many groups of moths. In sphinx moths, genetic comparisons between day- and night-active species suggest that those groups evolutionarily diverged nearly 30 million years ago. Day-flying may have been an evolutionary response to the diversification of nocturnal predators (bats), which occurred around that same time.

Why is it visiting that flower?

The mouthparts of moths and butterflies are specialized for feeding on liquids. For most species, that liquid is flower nectar, though some species feed on sap, rotting fruits, and other juices, and many occasionally drink water. Hemaris diffinis moths feed from a variety of flowers, but locally they seem to favor bee balm (also called wild bergamot; the flower in the photo) when it’s available.

Nectar is pretty much just sugar water, though the concentration and specific identity of nectar sugars—e.g., glucose vs. sucrose–vary from plant to plant. Nectar contains just traces of other nutrients like amino acids (the building blocks of proteins) and minerals. How do these moths get by on such a nutrient-poor diet? In fact, adult moths don’t live very long and they aren’t growing. The females do lay eggs, but the nutrients to support that activity are accumulated by the caterpillar and retained through metamorphosis to the adult. Many adult moths even have reduced mouthparts and don’t eat at all. But for those that do—like clearwings–the diet just needs to provide energy for flight so they can find a mate. Sugar water (nectar) is perfectly adequate!

How does the moth stay in place to drink nectar?

Like hummingbirds, clearwing moths hover in front of flowers while they feed. To do that, they beat their wings even a little faster than hummingbirds, about 75 flaps per second! Their shallow figure-eight pattern of wing movement generates the lift that supports hovering. Unlike hummingbirds, clearwings further stabilize their feeding position by lightly touching their front two feet on the flower. It’s hard to see in real-time, but very clear in photos.

What’s up with that tongue?

Moths feed on liquids, and so the tongue (more properly, the proboscis) functions much like a straw. The proboscis is constructed from two long, crescent-shaped halves that adhere together, forming a tube with a hollow center. When not in use, the proboscis is flattened and coiled up tight, like an empty fire hose. To extend the tongue for feeding, muscles in the head squeeze insect body fluid (hemolymph) through a valve into hollow chambers of the proboscis wall; the fluid pressure straightens out the coil. After feeding, another muscle opens the valve, and tiny muscles inside the proboscis, along with natural elasticity, restore the coiled configuration.

Drinking relies on a combination of mechanisms. Initial fluid uptake apparently occurs by capillary action, drawing liquid through the open tip of the tongue and narrow slits in its sides. Then, muscles in the head activate a pump, expanding a chamber to create suction pressure that moves the liquid up the proboscis and into the digestive system.

The effectiveness of the moth proboscis depends on its length and diameter, along with the viscosity (sugar concentration) of the nectar—sort of like trying to drink a milkshake through a straw. Over the millennia, those properties of moths and flowers have evolved together. Clearwing moths have tongues nearly as long as their body, which they use to reach nectar deep within the bergamot flowers. The longest known moth tongue actually belongs to another sphinx moth, one that feeds from orchids in Madagascar and has a tongue that’s 25 – 30 cm (10+ inches) long! In each case: the moth gets its nectar and, in the process, the flowers are pollinated.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

The common hoptree, Ptelea trifoliata, is the northernmost New World representative of the citrus, or rue, family of plants. It’s a relatively small tree, less than 20’ (6 m) tall and less than 10” (25 cm) trunk diameter, found in the woods understory or edges, so it is not highly conspicuous. But hoptree is of growing use in the landscaping trade, and both the tree itself and the insects it hosts are worth a second look.

Hoptrees are recognizable from two key features. The first is the leaves, which, as the species name “trifoliata” indicates, are arranged in threes. That arrangement is reminiscent of poison ivy, but the form of the plant—a small tree for hoptree, a tangled mass or vine for poison ivy—readily differentiates them.

The second distinctive feature of a hoptree is its fruit. Hoptrees flower in early summer, and the flowers give rise to hanging clusters of papery, nearly circular fruits that each encase a single seed (technically, the fruits are samaras, as in elms, ashes, and maples). Those fruits provide the hoptree with its most common alternate name, the wafer ash. Hoptree wafers persist on the tree until they blow off in early winter.

Given the famously aromatic nature of cultivated citrus flowers and fruits, it should not be surprising that hoptrees, as members of the citrus family, are rich in chemicals. Hoptree bark has a long history of medicinal uses among Native Americans, both on its own and to potentiate the effectiveness of other medicines. The leaves have a bitter flavor that is thought to deter herbivory by deer and that provides yet a third name for the tree: stinking ash. The flowers emit aromas that are appealing to most people. Male and female flowers have slightly different complements of chemicals, so that, according to one study, the former are described as “light, fresh, and pleasant,” while the latter are “damp-earthy, spicy, and sweet.” And finally, the wafers also have a distinct chemical composition that confers a bitter flavor. Historically, those wafers have substituted for hops in beer brewing (hence the name hoptree), and some modern craft brewers are reintroducing that practice as a local specialty.

It’s probably those chemicals that serve to attract two distinctive insect visitors to the hoptree. While the tree itself might be confused for poison ivy, the specialist insects both are more interesting mimics. In biological mimicry, an animal has evolved a resemblance to some other element of its environment and gains some benefit from that resemblance. Often the model for mimicry is another animal; the viceroy butterfly, for example, resembles the more toxic monarch and thereby gains protection from predators. The hoptree insects offer a different version of mimicry.

One of those mimics is the giant swallowtail, Ohio’s largest butterfly. These butterflies only lay their eggs on hoptree and other plants of the rue family (there are only two native to Ohio, hoptree and prickly ash). Want to attract giant swallowtails to your yard? Plant a hoptree! The adult butterfly itself generally resembles other swallowtails–the yellow under-surface is similar to a tiger swallowtail, the black upper surface more like several dark swallowtail species. But it’s the caterpillar that’s the real mimic. Giant swallowtail caterpillars bear a striking resemblance to bird droppings! The smaller caterpillars especially sit exposed on hoptree leaf surfaces and look for all the world like a bird recently passed by. What predator would stop to feed on that!?

A second insect that specializes on hoptrees is the two-spotted treehopper (yes, treehoppers on hoptrees!). Treehoppers are small insects, maybe a quarter-inch (half-centimeter) in length, related to cicadas and leafhoppers. The species that lives on hoptrees completes its entire life cycle on the tree: females lay eggs under the bark, which overwinter and then emerge as juveniles in spring, which mature into adults; both the juveniles and the adults feed on sap (phloem, like aphids), and so they never need to leave the tree. Two-spotted treehoppers can occur in large numbers and often end up forming lines of insects along a branch. They really don’t have any protection from predators, other than their appearance: the thoracic shell in this species extends forward and forms a point, so that the insect on a small branch closely resembles a thorn. Indeed, the insects are sometimes called thornbugs. A row of treehoppers can present an intimidating sight, like a super-thorny rose cane.

So, keep an eye out for hoptrees. And when you do find one, look carefully among the leaves and branches. You never know what might be hiding in there!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Nothing says May like mayapples! Mayapples (technically, Podophyllum peltatum) have no relation to apples, and they first poke up through the leaf litter around the end of March. It takes a few weeks, though, for the large, umbrella-like leaves to unfurl and grow, and for buds to set and mature. So, it’s the mayapple flowers that ring in the month of May.

Mayapples usually appear in clusters, or colonies, containing up to hundreds of plants. But really, those plants in a colony are all part of the same individual; they all connect to a common underground stem, or rhizome, and they are genetically identical. That doesn’t mean that all of the emerging shoots look the same, though. In fact, mayapple plants grow in two forms. Most emerge as a single leaf on a stalk and are vegetative. They do not produce flowers or fruit, but their photosynthesis generates nutrients that are stored in the rhizome to support the next year’s growth. A minority of shoots, sometimes fewer than 5%, instead have a stalk that splits to support two leaves. On those shoots, a flower emerges at the junction of the split.

Mayapple flowers are quite beautiful. They are about 4 cm (1.5 inches) in diameter, with pure white petals and stamens that bear bright yellow anthers. Despite that showy form, mayapple flowers are easy to miss, as they hang under the converging umbrellas of the colony’s leaves. The flowers open right about at the start of May, then begin to fade after a week or so of blooming.

Mayapple flowers cannot fertilize themselves (they are “self–incompatible”). So, they need assistance in transferring pollen from one flower to another (or, really, from one colony to another). The mayapples’ main pollinators are bumblebee queens; bumblebee workers typically don’t appear in Ohio until about mid-May, too late to pollinate mayapples. Oddly, though, mayapple flowers do not produce nectar as a lure for the bees. Instead, they rely on bees that are in the neighborhood visiting other flowers and that happen to stop by the mayapple blossoms almost by accident. Mayapples thus rely on flowering in the vicinity of nectar-rich “magnet” species that encourage visits from bees; a deficiency of pollinators sometimes limits mayapple fruit production.

The green, oblong fruit of the mayapple is about 1 cm long and hangs on the plant through July. The fruit is consumed by a number of animals, even before it’s fully ripe. Most seeds die if they are digested by deer, but raccoons and box turtles pass the seeds through and help to disperse them away from the parent population.

Although the ripe mayapple fruit is edible, the unripe fruit and the rest of the plant are quite toxic. The main active chemical is eponymously called podophyllotoxin, PPT. PPT inhibits cellular division (mitosis), and it has been evaluated for human medicinal uses related to that action. PPT, or derivatives of it, has proven effective for several forms of cancer. It also is used in topical application against viruses like herpes. PPT is listed by the World Health Organization as an essential medication.

It turns out that PPT is quite a complex chemical, and it has proven difficult to synthesize in the laboratory. So, most podophyllotoxin has continued to be procured by extracting mayapple rhizomes or leaves. The industry has mostly done this using an Asian relative of our local species, but overharvesting has substantially reduced its availability. There now are efforts both to cultivate North American mayapples commercially and to develop new methods for synthesizing PPT, perhaps by genetically programming bacteria.

Although the plants are full of toxic podophyllotoxin, that does not inhibit the mayapple rust fungus, Allodus podophylli, from colonizing the leaves. As the growing season progresses, it becomes more and more common to see mayapple leaves patterned with light-colored spots on their upper surfaces. Turn those leaves over and you’ll see the tiny orange spore cups produced by the fungus. The plant seems to tolerate the fungus well, and the spotty leaves are quite attractive.

With or without the fungus, mayapple leaves begin to wither by July and fall away by August. The rhizomes persist underground, mostly replenished by the year’s vegetative growth, but somewhat depleted at the nodes that bore flowering stems. The old joke says that April showers bring May flowers, and Mayflowers bring … Pilgrims. Mayapples, on the other hand, bring beautiful flowers, food for box turtles, therapeutic medicine, and the promise of a repeat show the next year. That’s pretty nice!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

With the return of songbird nesting season, it’s time for cowbirds to get busy! But not everybody will be happy about that. Cowbirds are a native species, but their reputation is as invaders who displace other more “desirable” birds. The journal Birding even published an article (Vol. 26, pp. 254–257) entitled “An open solicitation for cowbird recipes.” Why are they so disliked?

Cowbirds are in the family Icteridae, related to blackbirds and orioles. Our local species, the brown-headed cowbird, Molothrus ater, occurs across the U.S. and is the only cowbird in Ohio. Brown-headed cowbirds are rather drab; the male sports a brown head and glossy black body, while females are brown all over. The name “cowbird” derives from their historical habit of following large mammals—first bison, then horses and cattle—to find their seed and insect foods, but they now occur widely in open habitat, and their numbers have increased as humans have cleared and fragmented forests.

The cowbird trait that disenchants bird lovers, but that raises many fascinating questions, is their mode of reproduction. That is, cowbirds are among a small number of birds, and the only ones in North America, that lay eggs in the nests of other species rather than build their own nests. Those host parents then do all the work of raising the cowbird nestlings. Other so-called “brood parasites” include some cuckoos, African honeyguides, and a few other species.

Several aspects of cowbird nest parasitism contribute to their success. Among all nest parasitic birds, cowbirds are the least selective; they have been recorded laying eggs in nests of more than 200 species. They also are prolific egg layers. Most songbirds lay a clutch of four or five eggs, and they may repeat that two or, perhaps, three times per season. In contrast, cowbirds lay nearly an egg a day throughout their breeding season, totaling 30 or more eggs per year. Those eggs hatch slightly ahead of the host eggs and the chicks often are larger than those of the host. (Many cowbird host species are small, like sparrows, warblers, and wrens.) The host parents are highly stimulated to feed the large gaping cowbird mouths, and smaller host chicks may suffer food deprivation as a result.

For nest parasitism to work, the cowbird needs to find a host nest and lay its egg at just the right time. How does it do that? The answer is rather simple but impressive: cowbirds have great powers of observation. When breeding season arrives, females start surveying the landscape, often from elevated perches. They are experts at spotting nests and interpreting host behavior. They wait until the host is just beginning to lay eggs, then usually lay their own eggs in early morning, when dim light makes them less conspicuous. The female often removes a host egg in the process. Those exceptional “puzzle-solving” skills are supported by the hippocampus, a brain structure critical to memory formation, which is larger in female cowbirds than in males.

Why don’t hosts reject the cowbird egg? In most cases, that egg does not match the appearance of the host eggs. Despite that, most North American host species tolerate cowbird eggs. (In a few exceptions, such as robins, catbirds, and warbling vireos, the host does resist by puncturing, ejecting, or burying the invader egg.) There certainly are costs to accepting the cowbird; fledging success of host chicks can be reduced by 50% or more in parasitized nests. But there may be costs of rejecting the cowbird egg, too; for example, cowbirds may return to destroy the host eggs in nests where their own egg has been rejected. If the host can re-nest later in the season, there’s a lower risk of cowbird parasitism, which wanes through the summer. Continuing evolution may lead to more selectivity by cowbirds and greater rejection by hosts, as occurs in European cuckoos.

Like other birds, cowbirds have distinct, recognizable vocalizations. (It’s a stretch to call the male’s milky whistling a “song”!) But the chicks grow up mostly hearing their hosts, not their blood relatives. How do they learn to “speak cowbird”? Studies of brain structures important for singing suggest that the window for song learning stays open longer for cowbirds than for many other species. So, cowbird chicks can learn their correct vocalizations even after leaving the nest. Cowbird chicks also may sneak away (and return) occasionally as they become able to fly, so that they start spending time with other cowbirds even before they leave the care of their host parents.

Cowbird chicks also face another challenge. That is, they are exposed to the pests—lice and bacteria, for example—of whatever host nest they parasitize. As such, they must be able to fend off infestation of more diverse pathogens than a typical songbird. To assist with that, cowbirds have more robust immune systems than other songbirds. In particular, their innate immunity—the systems that provide non-specific, fast-acting defenses against diverse pathogens—is unusually strong, even compared with related species like red-winged blackbirds (which are not nest parasites) or bronzed cowbirds (which are more selective nest parasites).

So, it is true that cowbirds invade other species’ nests, and that they have abandoned their duties as parents. Moreover, cowbird parasitism can, sometimes, endanger the survival of birds with small populations. For example, trapping and removal of cowbirds has been critical to sustaining Kirtland’s warblers nesting in the jackpines of Michigan. More often, though, evidence that cowbirds cause declines of host populations is scant. Cowbirds may not be the most beautiful or melodious of songbirds, and they may have habits that give us pause. But they do have some remarkable special talents, and really, they are worthy at least of tolerance, if not of grudging respect.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Ohio is home to something like 100 species of dragonflies, and to a large extent, they are creatures of summer. Both the abundance and the diversity of dragonflies peak in June and July. But a few species stretch those seasonal boundaries, appearing on the landscape earlier in spring or sustaining activity well into autumn. The earliest of those is the green darner, Anax junius. In 2022, the first sighting of dragonflies in Ohio (as reported to iNaturalist.org, the online database of critter sightings) was a mating pair of green darners observed on 5 March in Montgomery County. For the rest of March and all through April, green darners were pretty much the only dragonflies reported in the state. How do they do it?

Green darners are large dragonflies, up to 8 cm (3 inches) in length and with a 10 cm (4 inch) wingspan. In both males and females, the thorax is green; however, the abdomen is bright blue in adult males, whereas it’s purple/brown in females and young males. Green darners cruise the landscape in search of insect prey. Indeed, more than most species, they seem to fly non-stop most of the time; they can be a real challenge for photographers!

Like other dragonflies, green darners are tied to water for breeding. Dragonfly pairs mate and then, with the male holding on, the female lands on the water surface to deposit eggs in wet vegetation (as pictured above). The juveniles (nymphs) that emerge from those eggs go through several rounds of molting as they grow to become voracious wetland predators; tadpoles beware! Eventually—either later that same season or after an over-winter hibernation—late-stage nymphs climb onto stems of waterside plants, complete metamorphosis, and emerge as adults.

As in all insects, the effectiveness of those bodily functions—flight, hunting, mating, maturation—depends on the dragonfly’s body temperature. Surprisingly, though, despite their early arrival in Ohio, green darners’ range of operating body temperatures is not lower than that of other local dragonflies. So how is it that they—and only they—manage to appear on the scene and stay active during the cool weeks of spring? The answer lies with two features that derive from their strong flight abilities.

The first special feature of green darners, directly responsible for their early appearance in Ohio, is their tendency to migrate. Whereas migration is well known in some insects (monarch butterflies and locusts especially), it is much less well characterized in dragonflies. Among Ohio’s numerous species, only a handful are thought to perform regular, seasonal migrations. Green darners are surely the most well-known of these, as they sometimes move in conspicuous swarms of thousands of individuals, especially during southward migration in autumn.

Modern technology has provided novel insights into green darner migration. Researchers have attached miniature radio transmitter devices to individual dragonflies, then followed the signal from those transmitters using a network of ground-based sensors (www.motus.org, used mostly to track bird migration). Green darners migrate only during the daytime, and they travel up to 120 km (more than 70 miles) in a single day. Not bad for an insect weighing half as much as a penny! Ohio’s migrating darners probably head to the southern US, where they breed and die; their offspring then return north.

In Ohio, the darners that appear and lay eggs in early spring have migrated from the south; at that time of year, Dayton’s wetlands are too cold for nymphs to metamorphose and emerge. Most likely, nymphs that arise from those springtime bouts of egg-laying mature into adults during the summer months that follow, and then may migrate south as the season advances further. However, green darners also continue to breed throughout summer. Those that hatch from later breeders probably over-winter as nymphs (they enter suspended animation, called diapause, as the waters cool) and emerge the following year when waters re-warm.

The second special feature that enables green darners to be active on cool spring days also derives from their strong powers of flight. The considerable muscular work required for these large insects to fly generates a lot of heat. In spring, green darners use that heat to elevate the temperature of their thorax, where the flight muscles are located. They also regulate a warm head temperature, which probably enhances visual acuity. On warmer summer days, darners actually generate too much heat, and they cool off by directing the flow of blood (called hemolymph in insects) to their abdomen, where heat can radiate away. They also change flight behavior, using more gliding and less flapping to reduce heat production. That overall phenomenon, where internally-produced heat is used to regulate body temperature, is known as endothermy. Endothermy is uncommon in insects and has been documented just a few times in dragonflies.

So, green darners use migration to arrive in Ohio early and, once here, they use endothermy to support activity on cool spring days. Still, many questions remain about these phenomena. Why do so few dragonfly species migrate? Why do some individual green darners migrate and others not, and what triggers the migratory flight? March 5, 2022—that early date when green darners appeared in Dayton–was a warm day (22oC, 71oF), good for dragonfly activity; but where did they come from? How common is endothermy in dragonflies?

March is a transitional time of year, and new signs marking the progression of spring seem to appear on a daily basis. Toads and robins sing, mourning cloak butterflies emerge from hiding, and trout lilies color the forest floor. The appearance of green darners seems like a good addition to that list. Keep an eye out for them!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

For most of us, the word “marsupial” brings to mind kangaroos and koalas—animals we might describe as cute, or even charismatic. But those adjectives probably are applied less often to our one local marsupial, the Virginia opossum, Dildelphis virginiana. With their black-eyed pointy face, rat-like hairless tail, and toothy grin (their 50 teeth are the most of any North American mammal), opossums don’t so readily endear themselves to humans. And yet, opossums are a fascinating and beneficial (they eat ticks!) member of our natural community.

Marsupials are a subgroup of mammals, characterized by having young that are born at an early stage of development and then move to the mother’s pouch (“marsupium”) for continued nourishment. This contrasts with the great majority of mammals—the placentals—which develop more fully in the uterus, supported by nutrition from the placenta.

Today, marsupials are predominantly animals of the southern world. The best known are Australian, but South America is home to about 100 mostly small, opossum-like species. Surprisingly, though, the fossil record indicates that marsupials first evolved in the north. They entered South America from North America about 65 million years ago, after which the continents drifted apart. North American marsupials subsequently went extinct. It wasn’t until about 3 million years ago that the Panama land bridge formed and allowed some marsupials to extend their ranges northward through Central America. Only the Virginia opossum has made it beyond southern Mexico.

Despite that successful range expansion, Virginia opossums retain a number of marsupial characteristics that suit them poorly for cold winters. Like other mammals, opossums are endotherms, meaning that they generate internal heat from metabolism to establish a warm body temperature. However, those features are “turned down” slightly in marsupials. Opossums have rates of metabolism about 30% lower than similar-sized placental mammals like cats or skunks. Associated with that, body temperature of marsupials is slightly lower than in placentals, about 34oC (93oF) for opossums rather than 37oC (98.6oF).

The low metabolic rate means that opossums have a harder time staying warm in winter. Unfortunately (for them), they also lack several of the strategies that might offset that challenge. Many small placental mammals deal with winter’s cold temperatures and low food availability by hibernating. That state of suspended animation, with its greatly reduced metabolism and body temperature, requires much less energy expenditure. Hibernators can survive for weeks or months by burning stored fat, sometimes supplemented by food that was stashed away ahead of time.

Opossums do none of those things. Although some small marsupials hibernate, Virginia opossums do not. Nor do opossums store substantial body fat or food. Whereas a woodchuck, which does hibernate, might add three-quarters of its body mass as fat during autumn, opossums add very little. Similarly, while you might see squirrels (which do not hibernate) avidly collecting nuts as the weather cools, opossums do not store food. Moreover, opossum fur is not very dense or insulating, and that does not improve from summer to winter. And they are awkward! With short legs and a waddling sort of gait, the energy cost for opossums to walk is unusually high.

All of this adds up to an animal that is challenged to balance its energy needs during cold weather. As a result, opossums basically are home-bound on days that are too snowy or that stay below freezing; they find a sheltered spot and curl up to reduce heat loss. But, with their limited fat reserves, opossums still require something like 35 days of feeding during winter to make it through.

Even if they do survive, opossums may suffer from the cold. When temperatures drop, they prioritize warming their vital organs. Blood flow to the extremities is restricted, and it’s not uncommon for the hairless ears and tail to suffer frostbite. Many northern opossums run a little ragged at the edges!

This susceptibility to cold suggests that winter conditions limit Virginia opossums’ northward expansion. And yet, that range continues to expand. Opossums have been in Ohio for at least a few hundred years—they show up in trapping records—but they became established in southern Canada only in recent decades. At least three factors contribute to that expansion.

The first factor is that cold temperatures act as an agent of natural selection. Those individuals better able to tolerate cold are more likely to survive winter and to pass along their traits to the next generation. As a result, more northerly opossums now have larger body size, and shorter tails and ears, than their southern relatives. Those patterns are consistent with trends seen in mammals generally, known as Allen’s rule (shorter appendages in cold-adapted mammals) and Bergmann’s rule (larger body size).

The second factor promoting northward expansion of opossums is climate change. As northern winters warm, the number of days suitable for foraging increases. So, opossums progressively further north are able to maintain adequate energy balance through winter.

Finally, opossums benefit from patterns of land use by humans.

Opossums are true omnivores—they eat insects, fruits, carrion, trash, cat food, whatever—and human habitation provides both food and shelter. Conversion of forests to agricultural land probably promoted historical range expansion, and urban/suburban environments today may host denser populations of opossums than natural habitat.

Opossums may not possess classic good looks and charisma, but they are amusing and tenacious critters. If you happen to find one in your garage this winter, know that it’s just looking for a bit of warmth—and maybe some food. It’s cold out there!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Sycamore trees are easy to spot on the landscape. Sycamores thrive in well-drained riparian (streamside) soils, and from the air they are conspicuous as large white sentinels marking the paths of creeks and rivers. On the ground, even in summer but especially in the leafless woods of winter, the sycamore’s pale bark stands out among the surrounding trees.

The local native tree that we call “sycamore” is Platanus occidentalis, the American sycamore. Confusingly, though, in England our sycamore is called a planetree, and “sycamore” refers to a species of maple, Acer pseudoplatanus. Maples and sycamores resemble each other in having leaves with several pointed lobes, but in fact, they are not closely related. The several tree species in the genus Platanus actually are related most closely (technically, in the plant order Proteales) to a variety of rather exotic plants that look nothing like sycamore trees, including the local American lotus and proteas (often used as decorative cut flowers) native mostly to Australia and South Africa.

As noted above, the most obvious distinguishing feature of sycamores is their bark. As the trees grow, the upper trunks and branches shed plates of dark outer bark, exposing the lighter-colored layers beneath. Successive bouts of exfoliation leave a mottled pattern that resembles camouflage gear. The benefits to the tree of shedding bark remain unclear. One possibility is that it removes pests from the tree surface. However, a recent study found that sycamores did not host fewer climbing vines than other nearby non-shedding trees. It’s also possible that the exposed inner bark has the potential for photosynthesis that supports tree growth. Indeed, sycamores are among the fastest growing of our trees and achieve the largest diameter, and possibly the greatest total bulk, of any temperate hardwood.

The bark of sycamores contains bioactive chemicals that might deter both pests and the growth of competitors under the canopy. Native Americans and early European settlers used sycamore bark as a cold remedy and for treating a variety of gastrointestinal and respiratory maladies. More recently, extracts of sycamore bark containing betulinic acid have been shown to have anti-anxiety properties, potentially helpful for both people and their pets.

Despite those chemicals, sycamores are susceptible to infection by anthracnose fungus, especially during cool, wet days of spring. Substantial amounts of new spring growth may be killed off as a result. The regrowth that follows contributes to the trees’ characteristic gnarly configuration.

In winter, one additional feature of sycamores is prominent. That is, they are adorned with inch-diameter balls of seeds hanging from stems at the ends of each small branch. Each seed ball has three components. The seeds themselves are interspersed with “fluff” that aids in dispersal once seeds are released. All of that is attached to a hard, pea-sized central core, sometimes referred to as a “pioneer button,” in reference to one of its historical uses. After the seed balls drop and the seeds fall away, the ground under a sycamore can be littered with those buttons.

Seed balls mostly are held on the tree through winter and released in spring. Each ball contains 1000 or more seeds. With thousands of fruits on a mature tree, a single sycamore can produce on the order of five or ten million seeds in a single season. Imagine if all of those seeds survived to produce trees—the landscape would be covered in nothing but sycamores! Alas, the vast majority of seeds are eaten, float away to unsuitable habitat, die off as saplings, or otherwise disappear from the pathway to adulthood. Such is the basis for natural selection, as Charles Darwin recognized: many potential offspring are produced, but only some, with traits that allow them to survive, grow, and reproduce, contribute to the next generation.

Their broad crowns and waterside habitat make sycamores attractive to a variety of wildlife. The large branches provide suitable support for the bulky stick nests of hawks and eagles, and the cavities that often form in older trees serve as nesting sites for wood ducks and as refuges for squirrels, raccoons, and other critters. Parula and yellow-throated warblers, which favor riparian habitat, have an especially strong affinity for sycamores.

Sycamores don’t produce the most colorful autumn foliage, but their pale, mottled, gnarly trunks create beautiful patterns that highlight the changing seasons. Look for them as you wander the woods. And if you’re ever lost on one of those walks—search out the sycamores, they will lead you to water!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Southwest Ohio is home to seven species of woodpeckers. Six of those species—downy and hairy, red-bellied and red-headed, pileated and flicker—are year-round residents, and most of them are common in woods and neighborhoods and at feeders. But the seventh species, with a name that sounds like a joke (or maybe an insult!), is a seasonal visitor to this part of Ohio and is probably the least known of the group. Meet the yellow-bellied sapsucker.

During the summer breeding season, yellow-bellied sapsuckers are birds of the northern forests, occurring across the width of Canada and in the northern reaches of the midwestern and northeastern US. The sapsuckers that we see in southwest Ohio mostly are in transit, migrating between those northern breeding grounds and their non-breeding habitat further south. However, some sapsuckers spend the winter in Ohio. Because females of this species migrate further south than males, the birds that one encounters during winter in Ohio most commonly are males.

Yellow-bellied sapsuckers are immediately recognizable as woodpeckers. They climb up trunks and along branches, using stiff, pointy tail feathers for support. Like other woodpeckers, they have a roller-coaster pattern of flight, alternating flapping with tucked-wing glides. And like most of our woodpeckers, they are mostly black and white, with red highlights. For sapsuckers, that includes a white stripe visible on the black wings both in flight and at rest, a boldly striped face, and a red cap. Males also have a red throat and, often, a yellow(ish) belly.

While sapsuckers are typical woodpeckers in many ways, they also have a number of distinctive features. For example, their long-distance migration is unusual, and they hammer out their nest holes in live trees (often softened by fungi) rather than in dead wood. The most distinctive sapsucker feature, though, is their diet. For much of winter, while sapsuckers reside in Ohio, the birds feed on a combination of insects and fruits, like other woodpeckers, and they will come to bird feeders for suet. However, as days lengthen in later winter and sap begins to flow in trees, sapsuckers live up to their names and develop a sweet tooth.

Sapsuckers drink two forms of tree sap. (They don’t actually “suck” the sap. Rather, they lap it up with a finely fringed tongue. Yellow-bellied saplappers?) Xylem sap flows through the more interior fluid-filled tubes in trees, the xylem vessels. Ordinarily, xylem sap is drawn up the tree to deliver soil-derived nutrients to emerging new growth. But in a few species—most famously maples, but also a few others like butternut, beech, and birches—temperatures that alternate between sub-freezing and above-freezing drive a copious flow of xylem sap in late winter and early spring, before new leaves emerge. Under those conditions, xylem sap will leak out from sites of injury. Sapsuckers have figured that out, and they take advantage by hammering deep round holes into the xylem. Xylem sap at that time of year is relatively sugary compared with “normal” xylem sap—though the sugar content still is just 2 or 3 percent. (More than 95% of the water in maple xylem sap must be boiled off to create the rich maple syrup we enjoy.) So, sapsuckers drinking xylem sap need to lap up a lot of it to get enough energy (how much sap could a sapsucker lap…?), and they urinate away a lot of excess water in the process.

During the warmer months, when trees once again have leaves, sapsuckers turn to the other form of sap. Leaves use photosynthesis to generate sugar, and that sugar is circulated through the phloem to support growth and energy storage throughout the tree. Phloem vessels are located closer to the tree surface than xylem vessels, and so sapsuckers excavate rows of shallow, rectangular holes to tap that sugar-rich sap. However, phloem tubes are living structures (unlike xylem vessels), and they seal up after they have been injured. Somehow, sapsuckers keep the phloem sap flowing. It has been speculated that their saliva contains a compound that sustains the flow—something like an anti-coagulant.

The sap that exudes from the sapsucker holes, whether from xylem or from phloem, attracts numerous other critters as well, including squirrels, mice, and many kinds of birds and insects, among others. The sap-trapped insects in turn supplement the diets of both sapsuckers and of the other animals—sort of like eating breakfast sausages dipped in syrup! Ruby throated hummingbirds may even time their northward migration to coincide with sapsucker tree-tapping, since flowers are in short supply at that time of year.

Because their activities, including excavation of nest holes and tapping of tree sap, provide valuable resources to a wide range of other species, yellow-bellied sapsuckers are sometimes considered to be “keystone species,” a term denoting species of particular importance to the function of an ecosystem. Here in southwest Ohio, they are not as abundant as some of the other woodpeckers, but they are a fascinating member of the community. This winter, warm up on a hearty breakfast of pancakes with syrup, then head out to the woods to find the real experts at tapping trees for sap!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Honeybees and Bumblebees Prepare for Winter

Honeybees (introduced from Europe to North America in the early 17th century) and bumblebees (several species native to southwest Ohio, including common eastern bumblebees, golden northern bumblebees, two-spotted bumblebees, and others) have a lot in common. Both types of bees are important pollinators of wild and agricultural plants. Both honeybees and bumblebees are social insects, meaning that they live in colonies where individuals have specialized roles. (Queens are females that lay eggs; workers are females that collect food for the hive and support and protect the colony; and drones are males that mate with queens.) Both types of bees have the ability, and the need, to warm themselves (more on that later). And both types of bees pretty much disappear from the local landscape during the colder months of the year. Despite those similarities, though, honeybees and bumblebees differ in some important ways, including their strategies for enduring winter.

Honeybees live in large colonies, consisting of a single queen, tens of thousands of workers, and hundreds of drones. Through spring and summer, the queen lays eggs that produce the next generation of honeybees. Workers nourish that reproductive effort by collecting pollen and nectar, which is fed to the developing young and stored in the nest as honey.

It turns out that many of these activities—including flying by the adults and growth of the young—only function well if the bees are warm. Honeybee adults are among the relatively few kinds of insects that are able to actively warm themselves. They do so by rapidly contracting their thoracic muscles without flapping their wings—in other words, by shivering. While out foraging, worker bees also generate heat from the exercise of flying. Actively foraging bees have body temperatures similar to our own, around 35oC (95oF). Back in the hive, the workers’ shivering is used to keep the developing brood similarly warm.

As fall arrives and temperatures cool, flowers and nectar become less available, and honeybee workers largely curtail their flights and stay home in the hive. Throughout the next few cold months, workers instead devote their energy to keeping their queen and brood warm. Drones are relatively unhelpful in this task, and workers kick them out to die. (Drones develop from unfertilized eggs; their population will be replenished next season.) The workers form a cluster around the queen and, fueled by stored honey, shiver through the winter to create a warm all-female hive. All that shivering takes a lot of energy, but if honey stores are sufficient then the queen and many of the workers can survive the winter, ready to begin another reproductive cycle when warmer weather returns.

Bumblebees, in contrast, live in smaller colonies, often below ground, consisting of a single queen and a few hundred workers. Bumblebee drones live independently of the colony. Like honeybees, bumblebees are able to warm themselves by shivering the muscles in their thorax. For bumblebees preparing to forage, that heat is retained in the thorax, where it activates flight. When they return to the nest to care for the brood, bumblebee workers instead circulate heat from the thorax to the abdomen, where it is used to warm the developing larvae.

The seasonal cycle of bumblebees differs from that of honeybees. Throughout summer, queen bumblebees produce offspring. Most eggs are fertilized and develop into female workers. Later in the reproductive season, some of those fertilized eggs are induced by a special diet to become new queens, and some unfertilized eggs develop as males (drones). Those drones leave the nest as they mature; their late-summer job is to fertilize newly emerging queens from other nests.

As the weather cools in autumn, almost all of those bumblebees die, including the drones, the workers, and the original queens. Only the fertilized new queens survive. Those queens, bearing the eggs that will found new colonies next spring, find an underground refuge to spend the winter. There, they hibernate, going cold but avoiding freezing, until warmer weather returns. Their low rate of metabolism in those conditions means that they can survive for several months without feeding. Come spring, each lone queen will begin to lay eggs. She will need to forage for food to nourish herself and her new offspring until enough workers mature to reestablish the colony and take over support of the brood.

The result of all this is that both honeybees and bumblebees are most abundant and visible in later summer, and both kinds of bees become scarce during the colder months. But during those “off months,” honeybees are hiding out by the thousands in their hives, shivering to keep themselves and their queen warm and cozy. Meanwhile, bumblebee queens are hidden away by themselves, cold and inactive.

The family trees (i.e., evolutionary lineages) of bumblebees and honeybees are thought to have separated about 100 million years ago. During the many years since that split, the two kinds of bees have retained a lot of shared characteristics. But a lot also has changed. There is no “right way” to be a bee, only a variety of ways that work. The details of that diversity provide no end of fascination.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

October is a transitional month. With the recent passing of the autumnal equinox, the sun now sits above the horizon for less than half the day. And as autumn marches on, temperatures drop. Together, these changes impose challenges for local birds. First, the shortening daylight provides less time to find food. And second, the amount of energy—and therefore food—required to stay warm increases as temperatures cool. These challenges are particularly acute for birds that eat invertebrates (insects, spiders, or worms, for example) because those food items become scarcer in the cooler weather. What’s a bird to do?

The everyday American robin provides lots of answers to that question. Robins are one of the most abundant birds in North America, and one of the most familiar. Their commonness might make them seem a little boring. But no! Robins have all kinds of tricks “up their wings” to deal with the challenges of the changing seasons.

One obvious option for a bird facing seasonal hardships is to leave town for more favorable surroundings. Migrating south addresses all three of the relevant issues, providing more daylight, warmer temperatures, and more insects. And indeed, many birds do migrate south in October, into and out of Ohio. The robin’s scientific name, Turdus migratorius, suggests that it is, in fact, one of those migratory species. (The genus name, Turdus, comes from the Latin word for thrush, the family of birds to which robins belong.) However, the migration story for robins is not simple. Robins occupy most of the US and Canada during summer. Some of those birds migrate south in the fall, so that northern Canada empties of robins, and the southern US fills with them. But other populations of robins remain pretty much sedentary year-round. Nobody knows how a particular robin, or population of robins, decides whether or not to migrate. In southwest Ohio, it’s likely that many of our winter robins are the same birds that were here in summer, but they may be joined by others that have moved south for the colder months.

Robins that stay in Ohio for fall and winter must find a way to satisfy their hunger as worms and insects disappear. Their solution is to shift their diet. Robins are famous for eating worms, but during the warmer months their diet also includes a variety of insects (especially beetles and caterpillars) and some fruit. As the weather cools, that diet shifts to being nearly 100% fruit. Wild cherries, dogwoods, hawthorn, and others are among their favorites. Invasive honeysuckle can be an important diet item, too, and the proliferation of honeysuckle and its fruit may have induced more robins to overwinter in Ohio in recent decades.

Eating all of that fruit presents some digestive challenges. Whereas insects are rich in fat and protein, fruits have more water and fiber and most of their calories come as carbohydrates. To get enough of those calories, along with other essential nutrients, robins increase their rate of food processing. The rapid passage of fruit through their gut does result in some wastage, but it allows them to get at least most of the nutrients they need. Robins still may need to eat an occasional insect to meet their protein requirements. Interestingly, robins do not have the enzyme sucrase, which is needed to digest sucrose (table sugar). Fortunately, the fruits they eat mostly contain sugar as glucose and/or fructose, which robins can readily absorb and use.

All of that food fuels a high metabolism that allows robins to stay warm, with a body temperature slightly higher than ours. Reducing heat loss as the weather cools is thus an important priority for energy balance. A fresh set of feathers is one important way to achieve that. Robins replace their flight feathers in mid-summer, followed by new body feathers in later summer and early fall. That nice new down coat insulates well against the cold. Robins also reduce heat loss through behavior. They shift from being vocal, territorial individuals during spring and summer, singing from the treetops, to congregating quietly in flocks during colder months. Those flocks tend to hang out in the woods rather than in open fields, and they roost collectively in trees that provide shelter from wind. Those behaviors all help to reduce heat loss and thus conserve energy.

We tend to think of robins as harbingers of spring and as a part of the summer landscape. But take a walk in the woods of southwest Ohio during fall or winter and you’re likely to find yourself surrounded by a flock of robins. They might look like the birds you see in summer—that familiar brown back, dark head, and rusty breast–but their habitat preferences, their social behavior, their feathers, their diet, and their digestive physiology all have changed to accommodate the demands of winter. That “boring” everyday bird is actually quite the quick-change artist!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Tiger swallowtails are among the most recognizable of our local butterflies, maybe second only to monarchs. There are two reasons for this. First, with their large size and prominent pattern, their appearance is pretty unmistakable. And second, tiger swallowtails are widespread and abundant. Both of those features—abundance and appearance—come with some interesting biology.

Tiger swallowtails (technically, Eastern tiger swallowtails, Papilio glaucus) are the most numerous of the six swallowtail species in southwest Ohio (the others are the black, spicebush, pipevine, giant, and zebra swallowtails). In the summer, of 2022, for example, iNaturalist.com, the public database for reporting sightings of living things, received more reports of tiger swallowtails in Ohio than of the other five species combined. Why are tigers so much more abundant than the other swallowtails?

Tiger swallowtails have an advantage in being able to use a wide variety of plant species as hosts for their caterpillars. For most of our swallowtails, females only lay eggs on a very specific set of plants, and the caterpillars develop only there. For example, spicebush swallowtails specifically seek out spicebush and a few related species like sassafras; pipevine swallowtails seek out pipevine or its close relatives; and zebra swallowtails only lay eggs on (no, not zebras…) pawpaws. In contrast, tiger swallowtails are compatible with a wide range of common host plants, including tulip trees, white ash, cottonwood, willows, wild cherry, magnolias, and others. The basis for this broad array of hosts rests in a mutation to a protein (the enzyme CYP6 P450) that helps to detoxify plant chemicals, giving tiger swallowtails a broader detoxifying ability. Just a minor change in that one protein has helped to open great ecological opportunities.

Tiger swallowtails are big, black and yellow striped butterflies (“Tyger, tyger, burning bright,” in the words of William Blake). But not all tiger swallowtails look the same. Whereas males are pretty much black and yellow all over, females incorporate a beautiful iridescent blue pattern in the rear upper (dorsal) surface of their hind wings. That brilliant blue color does not come from any blue pigment; rather, it is structural, created by tiny scales that refract light and reflect out blue wavelengths.

Tiger swallowtail color also varies in another more dramatic way that does depend on pigment. That is, some female tiger swallowtails, rather than “burning bright,” are all black instead of black and yellow. The percent of black females varies across the eastern US, from nearly absent in some regions to nearly 100% in others. (They are relatively common in southwest Ohio.) What’s that all about? Why are only females, and only some females, black?

The basis for female-only black coloration lies in the genetic control of the dark pigment melanin. Butterflies, like humans, have two sex chromosomes. However, whereas in humans it’s males that have two different chromosomes (XY, vs. XX in females), in butterflies it’s females (called ZW in butterfly females, vs. ZZ in males). The production of melanin that colors dark-form female tiger swallowtails is controlled by a gene on the W chromosome; if that gene is active, then dark melanin is produced instead of yellow pigment. Since only females have a W chromosome, only females can be all-black.

So why aren’t all female tiger swallowtails black? The fact that the trait is common in some populations suggests that it provides some advantage. On the other hand, not all individuals have that trait, and so there may be costs to dark coloration as well. That trade-off between costs and benefits is likely to bear on two important aspects of the butterfly’s biology: its ability to survive, and its ability to reproduce. How might black wings do that?

Black pigment could affect survival in a number of ways. For example, it could affect the wing’s resistance to wear and tear (probably why so many butterflies have black wing edges), or it could influence the rate of warming in the sun (tiger swallowtails need to be warm to fly). However, the most widely accepted explanation is that black tiger swallowtails look like another swallowtail species, the pipevine swallowtail, that is toxic and distasteful to predators. Indeed, the percent of black female tiger swallowtails is highest in regions where pipevine swallowtails are more numerous. This phenomenon, where a harmless species gains protection by mimicking a more harmful one, is called Batesian mimicry. Viceroy butterflies, which mimic toxic monarchs, provide another example.

If black coloration provides all those potential benefits, why doesn’t the trait spread throughout the population, so that all female tiger swallowtails are black? The usual simple answer is that male tiger swallowtails, for some reason, prefer to mate with yellow females. “Sexual selection,” where traits persist because they promote success at reproduction, occurs in many animals; the peacock’s tail is a famous example. However, data still are not conclusive as to the strength of those male butterfly preferences.

The factors influencing yellow vs. black coloration of female tiger swallowtails may now be shifting. After many decades of stable populations, the numbers of dark females have declined in the past 20 years in several regions, including southern Ohio. One possible reason, among several, is that warmer temperatures may induce genetically black female caterpillars to develop into butterflies with intermediate coloration; those intermediates may be less successful at surviving, reproducing, and passing on their genes.

Who knew that the lives of tiger swallowtails were so complex? Host diversity, Batesian mimicry, sexual selection, gene mutations; it’s as though tiger swallowtails encompass an entire biology textbook! And indeed they do. There’s nothing prettier than a fresh tiger swallowtail, wings open on a flowering Joe-Pye weed. But dive a little deeper, and these beauties are full of secrets and surprises!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

When you think about flies, you probably don’t think about descriptions like, “tremendous size and leg strength,” “potent saliva laced with neurotoxins,” “think fighter jet,” or “iron maiden death grasp.” Yet all of these phrases appear in postings about a pair of insect species—the giant robber flies—that frequent our local meadows in late summer. Clearly, these are no ordinary flies!

Technically, flies are members of the insect order Diptera. As that name implies (“di – ptera” literally means “two wings”), flies are characterized by having just a single pair of wings, rather than two pairs as in most insects. (In flies, the hind wings are modified into sensory organs called halteres.) The million or so species of flies are diverse, including such well known representatives as house flies, fruit flies, and mosquitoes. Robber flies, with their large wide-set eyes, bristly moustache, chunky midsection, and spiky legs, are distinctive.

Robber flies come in a range of sizes. At any size, though, they are fierce predators of other insects. Two local species–the cannibal flies Promachus rufipes, with black and yellow legs, and Promachus hinei, with red legs–are among the largest robber flies. At 35 mm (1.5 inches) in body length, they are truly impressive.

Robber flies are sometimes called assassin flies, consistent with their “sit and wait” strategy for hunting prey. That is, they find a perch and sit quietly, scanning their environment. When an unsuspecting insect flies past, any effort at stealth is abandoned. The cannibal fly takes off with an unmistakable loud buzz—like “a six-legged Sikorski Skycrane helicopter,” according to Jim McCormac in his Ohio Biodiversity blog. Learning to recognize that sound is a key to finding cannibal flies on the prowl.

The name “cannibal fly” implies that these insects feed on others of their own kind. Although that occasionally happens, cannibal flies eat pretty much any insect that flies, including bees, beetles, and butterflies. There’s even a report of a cannibal fly subduing a hummingbird! Wasps and bees are the preferred prey, though, and one name for Promachus rufipes is the “bee panther.” Both rufipes and hinei have striped abdomens that may resemble bees enough to fool those potential prey items into ignoring the danger lurking nearby.

Robber flies have notably large eyes that extend beyond the diameter of the head, creating a distinctive depression in between. Each compound eye contains thousands of individual lenses, which are larger in the front and center of the eye (the “acute zone”). This feature contributes to the flies’ high visual acuity. The Air Force has even funded research on robber fly visual systems, hoping to learn the secrets of how they track and home in on their prey.

Cannibal flies deploy a combination of weapons. First, they sometimes fly into their prey item at full speed, stunning them into initial submission. The robber fly then grasps its prey using strong, sharply barbed legs from which there is no escape. The prey item is carried back to a perch, where the robber fly inserts its sharp proboscis—a combination syringe and straw–and injects toxins (to paralyze the prey) and enzymes (to digest its meal into a liquid soup). Robber fly toxins have not been studied much, but they contain a complex mix of proteins and peptides with neurotoxic activity similar to that of some snake venoms.

At less than 2 inches in length, cannibal flies are top predators in their insect communities. They have evolved to have keen vision, a piercing grip, and novel toxins. Imagine how fearsome they would be if they were 10 times bigger! Why haven’t they evolved larger size? The answer probably lies in limitations of the insect respiratory system, which delivers oxygen by way of internal branching tubes (tracheae) connected to the outside air by openings in the insect body wall (spiracles). That system seems to dictate the maximum sizes that insects can achieve. At one time, 300 million years ago, Earth’s atmosphere had 50% more oxygen, and dragonflies reached wingspans of up to 30 inches (75 cm). Today, there are some insects bigger than cannibal flies, but not too much bigger. As we wander the late summer meadows, we can listen for the roar of cannibal flies and marvel at their predatory prowess. At the same time, we can be grateful that they aren’t the size of crows!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

In most plants, offspring grow from seeds. Flowers are a plant’s mechanism for producing those seeds. To do so, flowers must fertilize the female reproductive cells (ovules), located within the pistil, with male reproductive cells, contained in pollen produced by the stamens.

Many flowers produce both pollen and ovules, and so in principle, they can fertilize themselves. However, cross-pollination, where pollen is transferred from one plant to another, produces hardier, more genetically diverse offspring, and plants have evolved a variety of ways to accomplish that. One of the most important of those mechanisms, used by about 90% of flowering plants, is pollen transfer by insects or other animals.

Pollination represents a form of symbiosis called mutualism, in which both partners gain some benefit. Typically, that exchange of benefits entails “food for pollination services.” Plants produce nectar (a sugar-rich liquid) as a “bribe” to encourage insects to visit. While acquiring that nectar, insects pick up pollen (usually unintentionally, as it sticks to their body), some of which then transfers to the pistil of another flower when the insect moves on. It’s a win/win exchange.

Still, there are lots of variations on that theme. Local flora provide some great examples.

In some cases, the win/win relationship persists, but with extra twists. Cardinal flowers, Lobelia cardinalis, for example, send up a stalk of flowers that produce both male and female structures. However, those structures mature in sequence as the flowers age. Flowers lower on the stalk are older and have elongated female structures; flowers higher up are newer and produce pollen. Hummingbirds are attracted to the red flowers and tend to visit the stalks in a “bottom-up” pattern, seeking nectar from the older (female) flowers first. What that means is that after they visit the upper male flowers, picking up pollen as they feed, they move on to the lower flowers of another plant. In the process, they accomplish cross-pollination. How clever!

Evolution doesn’t always produce “happy” outcomes, though. Sometimes cheaters win! Traits that allow survival and reproduction will persist, even if that comes at the expense of one of the players.

Pollination of foxglove beardtongue (Penstemon digitalis), which blooms in local meadows through early summer, provides an example. Beardtongue has a deep white flower that attracts a lot of bees. Bumblebees are common pollinators, and it’s fun to watch them practically disappear inside the flower; they emerge with a belly full of nectar and a dusting of pollen on their fuzzy bodies. Carpenter bees also love to visit beardtongue. However, watch closely and you will see that carpenter bees never enter the flower. Instead, they straddle the blossom with their head at the base, near where it attaches to the stem. Then, they cut a slit in the base of the flower and drink the nectar directly, without ever encountering the pollen. Carpenter bees are nectar thieves! They take advantage of the flower’s reward system, but they steal the bribe without repaying the gift.

Pollination of Jack-in-the-pulpit, Arisaema triphyllum, offers an even starker variation—but one in which the plant is the winner. Jack-in-the-pulpit flowers occur on a stalk (the spadix) that is surrounded by a hood. Smaller plants produce male flowers, whereas larger plants produce female flowers. Jack-in-the-pulpits emit a scent that tricks fungus gnats into visiting. When the gnats visit the male plants, they explore deep inside, thinking they will find fungus (their preferred food). Instead, they encounter pollen, which sticks to their surface. When they try to escape, it’s too slippery to climb up, and the only available exit is a small hole at the base of the spadix. Later, they may try again to find food and instead enter a female Jack-in-the-pulpit. Again, they enter deep inside, in the process transferring pollen to the female flowers. The females, though, offer no escape. Instead, the gnats are trapped, and they die inside the flower. Talk about shooting the messenger!

Pollination systems represent great examples of ecological symbiosis (interaction between different species) and provide wonderful opportunities for watching evolution in action. Pollination of plants by insects is also incredibly important to humans. Insects are responsible for fertilizing about a third of all the world’s food crops. Whichever is your interest, you are well advised to pay attention to the birds and the bees.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

You may be familiar with the phrase “a snake in the grass,” an unflattering term for a sneaky person. In the CWPD parks, though, you are just as likely to encounter a snake in the bush, or a snake in the water. If you’re lucky, those encounters will be queen snakes, common residents around our local streams.

Queen snakes, Regina septemvittata, are medium sized, non-venomous snakes, typically 1.5 – 2 feet (50 – 60 cm) in length as adults. They are olive-brown above, with a cream-colored stripe extending down the body. The belly has four dark stripes on a creamy background, markings that help distinguish this species from similar-looking garter snakes. Young queen snakes also have additional stripes that tend to disappear with age; the species name “septemvittata” means “seven stripes,” referring to the juvenile appearance.

Queen snakes sometimes are known as olive water snakes, and they are most closely related to a more western species, Graham’s crayfish snake. Those two descriptors—water and crayfish—are critical to the life of queen snakes. Crayfish constitute about 95% of a queen snake’s diet, and so they live in waters—most commonly in rocky streams—where that prey is available. Even within that specialized diet, queen snakes are picky: they consume only freshly-molted crayfish with soft shells. (Crayfish shed once or twice per year to allow growth, each time becoming temporarily soft until they re-calcify their shell.) Queen snakes have flexible jaws, but they mostly avoid prey larger than about 60% of their gape area. If small crayfish are in short supply, the snakes may eat just the claws of larger specimens — not so different from humans eating lobster!

Like almost all reptiles, queen snakes are ectotherms (“cold-blooded”), meaning that their body temperature is determined by the environment, rather than by heat produced from their own metabolism (as in birds and mammals). Still, though, these snakes still seek to maintain a relatively narrow range of body temperatures. Queen snakes can tolerate body temperatures as high as our own (about 37^oC, or 98^oF). In the wild, though, they prefer a somewhat cooler temperature, about 27^oC (82^oF). Queen snakes achieve that preferred body temperature through behavior. In springtime, creek waters are likely to be well below the snakes’ preferred body temperature, whereas summer air temperatures may be warmer than they like. So, as days and seasons progress, the snakes shuttle between land and water, basking in sunlit creek-side vegetation to warm up, then dropping into the creek to feed.

A queen snake’s body temperature is important for many of its bodily and ecological functions. One of those is locomotion, which is critical both for catching food and for escaping danger. Queen snakes are faster in the water than on land, but in both environments their speed increases three- or four-fold as they warm from 10 to 30^oC. The ability to digest food also depends on body temperature. In garter snakes, for example, digestion is twice as fast at 30^oC as at 20^oC; the same is probably true for queen snakes.

The active season for queen snakes lasts only as long as they are able to achieve body temperatures near their preferred level. In the cooler months they hide out in a secluded spot, sometimes in groups of one or two dozen, where they cool to the temperature of their environment and wait for spring.

Queen snakes have a set of characteristics—small body size, relatively limited movement, specific habitat and dietary needs—that may reduce their risk from some forms of expanding human activities, like hazards from car traffic. On the other hand, that specialization also makes them vulnerable to habitat degradation. Our robust local queen snake population reflects that our creeks are clean and healthy. Long live the queen!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

April and May are prime time for woodland wildflowers in Southwest Ohio. Among the dozens of species that bloom through the spring months—spring beauties, bloodroot, Virginia bluebells, trout lilies, May apples, and many others—some of the easiest to recognize are the trilliums. The name “trillium” incorporates the Latin word for three (“tri”), which refers to their most obvious identifying feature: that is, their single blossom has parts (petals, sepals) organized in threes, and likewise, the leaves (technically, bracts) also come three to a plant.

Four species of trilliums occur locally. Snow trilliums (Trillium nivale), as the name implies, bloom in earliest spring. But April/May is showtime for the remaining three—sessile trillium (Trillium sessile), drooping trillium (Trillium flexipes), and great white trillium (Trillium grandiflorum, the state wildflower of Ohio).

Those three trillium species are most easily distinguished based on two characteristics. The first is the presentation of the flower. In drooping and great white trilliums, the flowers sit at the end of a stalk (in botanical terms, they are “pedicillate”). In drooping trilliums that stalk hangs down under the leaves so that the flower, though quite large and beautiful, is hidden and easily overlooked. In contrast, great white trilliums project above the leaves, and populations of this species can present quite a show on a sunlit hillside. In the third species, sessile trillium, the blossom lacks a stalk and sits upright directly on the leaves.

The second identifying feature is the flower’s color. Great white trillium blossoms are—surprise!—white. Drooping trilliums are white too, though a somewhat creamier shade, often with minor reddish highlights in the center. Sessile trilliums are deep maroon, sometimes seeming to camouflage against the dappled underlying leaves.

Trillium flower color is not always constant, though. In some species, individual plants have unusual blossoms. Sessile trilliums populations may include a few yellow flowers among the red, and drooping trilliums occasionally have deep red petals. The situation is slightly different for great white trilliums. There, flowers may change color with age. Those large, shocking pink trilliums? They are older blossoms of the “white” Trillium grandiflorum.

What is the basis for these color variations? Flower pigments are produced by a series of chemical reactions within cells of the petals. Red and pink colors in trilliums come from a group of chemicals called anthocyanins—the same chemicals that lend color to red grapes and beets. In sessile and drooping trilliums, genetic mutations can affect the plant’s ability to produce these chemicals. It isn’t clear whether the resulting unusual colors reduce the attractiveness of flowers to pollinating insects. In contrast, some great white trillium flowers turn on the anthocyanin pathway (and turn pink) only when the flower is aging, well after pollination is completed. In that case, the flower probably is benefiting from the anti-oxidant actions of anthocyanins, which helps the plant to manage the stress of aging. The color change is just a side-effect that happens to be very pretty.

Trillium plants grow slowly, requiring five or more years to proceed from seed to flowering. White and drooping trilliums are pollinated by bumblebees and related insects, whereas flies and beetles visit sessile trillium flowers. After pollination, seeds takes two months or more to mature, so that they are ready for release in mid-summer. Trillium plants receive help in spreading their seeds from ants, which are attracted by an oil-rich structure called an eliasome that is attached to the seed. The ants carry the seeds to their nest, then consume the eliasome but leave the seed intact. Deer also can disperse trillium seeds. Deer like to eat trilliums, but the seeds can survive passage through their gut and go on to germinate. On the other hand, deer browsing also can significantly suppress growth and flowering of trilliums. The heights of trillium plants can even serve as an indicator of the intensity of deer browsing in a patch of woods: more deer equals shorter trilliums.

Trilliums and the other woodland wildflowers of this season collectively are called “spring ephemerals,” reflecting that they come and go pretty quickly. But a big patch of trilliums is well worth the effort of a walk in the woods. Get out and see them while they last!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Spring is such a beautiful season. Color returns to the landscape, and birdsong fills the air. Even a late dose of winter sometimes just adds to the enchantment. In April 2021, at the peak of redbud flowering, a nighttime storm dropped several inches of snow on the south side of Dayton. The resulting landscape created scenes that looked like set-ups for a Valentine’s Day card! But beyond that initial impression, the images brought many questions to mind, including:

What kind of birds are these?

The Northern Cardinal, genus and species Cardinalis cardinalis, is the state bird of Ohio. The male cardinal, with its bright red feathers, black mask, and prominent crest, is one of the most recognizable local birds. Females sport just splashes of red, but their crest and orange beak are still easy to spot. Cardinals used to be considered as large finches, related to sparrows, finches, and other birds with sturdy beaks suited for cracking seeds. However, DNA evidence has revealed that cardinals are most closely related to a group that includes some of those seed-eaters (like our local indigo bunting and rose-breasted grosbeak) but also a bunch of tanagers (like the local scarlet tanager). Together, that group of birds is classified as the family Cardinalidae; sparrows and finches are in separate families.

Why are the two birds different colors?

Northern cardinals are sexually dimorphic, meaning that males and females have different appearances. This is true for many birds (e.g., mallard ducks and red-winged blackbirds) but not for others (e.g., robins and blue jays). For males, the bright coloration serves as a signal. Male cardinals often display from prominent perches, advertising their presence both to other males, who might be competitors, and to females, who might be mates. The brightness of the red coloration may even inform about the health of the bird. Females, on the other hand, are responsible for building the nest and incubating the eggs. At those times especially, but probably all year round, the duller coloration provides camouflage and safety among the vegetation. (Both male and female cardinals sing, so females do sometimes make themselves conspicuous.)

How does the male (but not the female) become red?

The cardinal’s red coloration comes from chemicals called carotenoids, similar to what gives carrots and tomatoes their bright colors. Cardinals need to acquire those pigment chemicals from their diet. Some foods, like dogwood fruits (a cardinal favorite), provide red-colored carotenoids directly. However, carotenoids in other foods, like sunflower seeds, are yellow or otherwise less colorful. Cardinals possess the mechanism (enzymes) to chemically transform dietary carotenoids into a red product.

Feathers can gain red pigment only when they are growing. Mature, fully formed feathers are non-living and cannot be brightened. In cardinals, feather growth occurs in late summer or early fall, during the annual molt that follows the breeding season. Thus, carotenoids acquired or produced at other times of year must be stored until it is time to grow new feathers. Both males and females molt, but only males produce the brilliant red plumage. Presumably, the acquisition, production, and/or storage of red pigment, or its distribution to developing feathers, differs between males and females.

How do cardinals stay warm in the snow?

An adult cardinal weighs about 45 grams—equivalent to about 3 tablespoons of water. Most of the bird is fluff! How does a small bird like that stay warm on a cold, snowy day? Two key features contribute. First, cardinals, like other warm-blooded (“endothermic”) animals, including ourselves, produce a lot of body heat from their own metabolism. As they sense cooler outside temperatures, their rate of metabolism—burning body fuels, like fats and sugars—increases so that they generate more heat. (Of course, that also means that they need to eat more food.) Second, bird feathers provide excellent insulation; think about the warmth provided by a down coat. Cardinals can further minimize heat loss by fluffing up their feathers and by roosting in dense vegetation when they are inactive.

What is this pair of birds doing?

The male cardinal in the picture is feeding seeds to the female. That behavior, called “allofeeding”, continues while the female constructs the nest and incubates the eggs, and during those times it may provide valuable nutrition for the busy female. But more generally, allofeeding is part of the complex set of behaviors (visual displays, songs, etc.) that helps to establish and maintain the bond between male and female. Cardinals may live for 5 to 10 years in the wild, and the same male/female pair may remain bonded over several years. Allofeeding supports the stability of that bond.

Conclusion:

Cardinals add a splash of beauty and color to any landscape. But look beyond the initial visual impression, and they also stimulate interesting questions about the intricate mechanisms of nature. As the great physicist Richard Feynmann said about his thoughts on viewing a flower, adding a scientific perspective to one’s aesthetic appreciation, “only adds to the excitement, the mystery and the awe.”

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

The chatter is unmistakable. All winter long, the woods have been full of American red squirrels, Tamiasciurus hudsonicus. According to Wikipedia, red squirrels are one of three species known as “pine squirrels,” and they are “widely distributed across North America wherever conifers are common.” So, what are they doing in the mostly deciduous woods of Centerville parks?

Red squirrels are easy to recognize. They are noticeably smaller than the common gray squirrels, just a little bit larger than chipmunks. The fur on their back and tail is a beautiful orange-chestnut color that contrasts with a white belly. And they have white “spectacles” that highlight big black eyes.

Red squirrels have recognizable behavior too. They are fast and acrobatic, so it can be a challenge to follow one as it scampers through the trees. And they are famously feisty, even aggressive. Red squirrels announce their presence with loud chatter, and they avidly chase gray squirrels out of their territory. No sharing for them!

Red squirrels do not hibernate. Instead, they build leaf-lined nests where they can stay warm during cold winter nights. And to meet their energy and nutritional needs through the winter, they store food. Unlike gray squirrels, which bury seeds and nuts in scattered locations, red squirrels are hoarders. They collect food during the autumn and stash it in a collective location called a midden, which may contain hundreds or even thousands of pine cones or nuts. (In a well-publicized 2021 incident, a North Dakota man discovered that a red squirrel had stashed 42 gallons of black walnuts inside his vehicle.)

As noted above, red squirrels are strongly associated with coniferous forests. In those habitats, they specialize in eating conifer seeds, especially favoring spruce. However, even in evergreen forests, red squirrels add other elements to their diet, including sprigs of trees like willows, various fruits and berries, and fungi.
Red squirrels also have another clever dietary trick. That is, they tap sugar maples for their sap. However, maple sap is highly dilute; a squirrel would need to consume many gallons of fresh sap to satisfy its daily energy requirements. So, red squirrels chew scrapes in trunks to let the sap run onto the tree surface, then return a day or so later, after the water has evaporated to concentrate the sugar. Basically, they make maple syrup!

Still, why are there so many red squirrels in our deciduous forests? At least two factors seem to be at work. The first is that red squirrels apparently are better than gray squirrels at dispersing into fragmented forest habitat. (Red squirrels disperse away from their mother’s territory in their first year, as they reach adulthood.) That has allowed red squirrels to expand their range in the mid-west, where forests often are fragmented into small woodlots among agricultural lands. The second factor relates to diet. Interestingly, even though red squirrels are strongly associated with pine forests, they actually prefer black walnuts to pine seeds when given the choice. Conifers still provide red squirrels with protection from predators like hawks and owls, and so red squirrels survive well in Midwestern woodlots, where conifers often are planted alongside native deciduous trees. Conifers also may provide food in years when walnuts are in short supply. But given the choice, red squirrels in mixed forests select hard nuts as their preferred food. Indeed, red squirrels in Indiana, where black walnuts dominate the diet, have evolved to have larger skulls, better able to open those hard nuts, than squirrels in Michigan, where pine cones are the main food.

The net result of all this is that red squirrels are continuing to expand their range in North America, out of the northern pine forests and into the midwest. While still considered to be “pine squirrels,” we now have robust populations of these engaging creatures in our largely deciduous parklands. Listen for the chatter, then prepare to be entertained!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

As humans, we are accustomed to having a relatively constant, warm body temperature. Whether it’s the middle of summer or the cold of winter, we steam right along at about 37oC (98.6oF), almost always warmer than the surrounding air. That body warmth is the result of our high rate of metabolism; we burn fuels (sugar and fat) fast enough to produce heat that keeps us warm, just as a car engine heats up as it powers the vehicle.

In contrast, frogs, like almost all animals other than birds and mammals, are ectotherms, meaning that they burn their body’s fuels too slowly to warm the animal. Instead, a frog’s body temperature depends on its environment. In summer, a frog takes on the temperature of the air while it’s on land (with some possible warming from the sun or cooling from evaporation) and of the water when it enters a stream or pond. At those summer temperatures, their body systems can function normally for locomotion, feeding, reproduction, and growth.

In the cooler seasons, though, there is little option to bask in warming sunlight, and frogs match their cold environment. A low body temperature results in a reduced rate of metabolism (as body chemistry slows down), and normal body functions become less active. Frogs can’t escape winter by migrating—their locomotor speeds are too slow for them to reach warmer weather—so they must tolerate the cold if they are to survive until spring. How do they do it?

The more aquatic “typical frog” species, like bullfrogs, green frogs, and leopard frogs, seek out water that’s deep enough to remain unfrozen, and they spend the winter hiding underwater. Because their rates of metabolism are reduced in the cold, so too are their requirements for oxygen, which is used to burn fuels. Cold frogs can acquire sufficient oxygen across their skin, directly from the water, without having to breathe air. Activity is minimal under those conditions—no feeding, not much movement, slow rates of breathing and heartbeat—and so the animals basically just go dormant until warmer days.

More terrestrial species, like toads and treefrogs, spend the winter on land. Toads are good diggers, and they burrow down to sites where the temperature remains fairly stable and above freezing. There, they just hunker down, inactive, for the winter. Treefrogs, on the other hand, are not good diggers, and so they shelter under tree bark or leaf litter. In those circumstances, they are more likely to encounter temperatures that drop below freezing. With their body temperature tracking the environment, how do they survive those sub-freezing conditions?

The answer is that a few species of frogs are able to survive being frozen, with up to 60% of their body water turning to ice. Several local species of treefrogs are in that freeze-tolerant group, including gray treefrogs, spring peepers, and chorus frogs.

Whole-body freezing creates a number of challenges. First, ice formation interferes with the body acquiring oxygen. A frozen frog stops breathing, has no heartbeat, and the frozen bloodstream does not circulate. Nevertheless, at those cold temperatures, metabolism is slow enough that the animals can tolerate the interruption to oxygen delivery.

A second challenge is that ice can be highly damaging to body structures (just think of its ability to split rocks or to carve out potholes). The key to survival seems to be controlling the location of ice formation in the body. Ice is tolerable only in the body fluids outside of the cells. If ice were to form inside cells, the crystals would tear them apart. Freeze-tolerant frogs are able to restrict freezing to those non-cellular fluids, and they also accumulate chemicals (usually glucose, sometimes glycerol) that protect the cells from freeze damage. (Biomedical freezing of tissues like embryos is done at ultra-cold temperatures—much colder than natural winters—that prevent destructive ice crystals from forming. But biomedical freezing does make use of freeze-protective chemicals, just like in the frogs.)

Despite these protective mechanisms, it is likely that frogs suffer some damage during bouts of freezing. Red blood cells, for example, are suspended in blood plasma that freezes solid; some of those blood cells probably are ruptured in the process. This might be particularly problematic if animals repeatedly freeze and thaw during periods of variable temperature, as commonly occur during Dayton winters. The ability to recover from tissue damage may determine how well frogs survive winter and resume normal function.

Interestingly, summer-active treefrogs are not able to survive freezing. Rather, freeze tolerance develops each year with the arrival of cold weather. So, what is it that changes to make the animals freeze-tolerant? We really still don’t know, but it probably involves changes in several body systems, including those involved in fuel metabolism, oxygen management, production and distribution of freeze-protective chemicals, and others. Unraveling the mechanisms of amphibian freeze tolerance may well provide clues to more successful biomedical cryo-preservation of complex tissues like kidneys or hearts. At the very least, it will help to explain one of the more spectacular feats of animal biology.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

The Centerville-Washington Park District maintains 20 soccer game fields, 18 baseball/softball diamonds, 2 football game fields, 2 lacrosse game fields, 5 acres of lacrosse practice area, 5.5 acres of football practice area and 20 acres of soccer practice fields! We hope you have enjoyed your experience on the fields and in the parks. We are always looking to improve our services and appreciate all feedback about your athletic fields.

In 2021, we launched a survey aimed to learn more about your experiences with the Centerville-Washington Park District athletic fields. We received more than 550 responses! Thank you for taking the time to share your thoughts! The full results, including comments, will be shared with each of the Recognized Organizations. We look forward to welcoming you back to the parks in 2022!

View the summary of results >

This winter, the edges of the wood are rich with fruits. Wild grapes, eastern red cedar, crabapple, dogwood, honeysuckle, bittersweet, and others all seem to have thrived. For birds that seek fruits for winter sustenance–robins, cardinals, white-throated sparrows, and others–that’s great news! But no bird relies on fruits more than the cedar waxwing.

Cedar waxwings are elegant little birds. Their sleek gray-brown body is adorned with a sharp crest, a dashing black mask, and a lemon-yellow belly. The tail ends in a bright yellow band, commonly described as looking like it was dipped in paint. And some adult birds feature the trait that provides their name: a few of the secondary (inner) wing feathers are tipped with bright red beads of wax that are readily visible on the closed wings. Those wax tips are laid down during molt, when new feathers grow in, and they are thought to function as social signals; more beads indicate a healthier, better-fed bird.

Fruit makes up nearly 85% of a waxwing’s annual diet, and for more than half the year, October through April, they eat fruit almost exclusively. The diet expands to include flowers and insects during warmer months. Fruits of eastern red cedar are a favorite diet item (hence “cedar” waxwings), especially in winter. Various species of crabapples and cherries are mainstays of the menu as well.

Fruit can be a challenging basis for a diet. Fruits do contain some valuable nutrients, like water and sugar. However, they are low in protein and they contain a lot of fiber, which fills the gut without providing nutritional value. How do waxwings adapt to these circumstances?

One basic strategy is that waxwings eat a lot. For example, they can consume more than 50 red cedar cones per hour. Waxwings have relatively short intestinal tracts and, as you might expect with their pulpy diet, fruits pass through the gut quickly. Cedar fruits are eliminated in about 12 minutes, and dogwood fruits in just half that time. (It’s also the case that a red cedar fruit that has passed through a waxwing is about three times as likely to germinate as one that falls directly to the ground.)

Despite that quick rate of passage and short gut, waxwings succeed in extracting a lot of the nutrients from their food. Waxwings selectively feed on fruits that are rich in sugar (in contrast to robins, which prefer fruits with higher fat content). In the winter diet, those sugars mostly are simple sugars (glucose and fructose, similar to honey), rather than more complex sucrose (table sugar). The advantage of simple sugars is that they can be easily and directly absorbed from the gut into the bloodstream. As a result, the birds are able to acquire something like 90% of the glucose and fructose that they consume.

Another challenge of being a strict fruit eater is that fruit abundance varies from place to place and year to year. Cedar waxwings do generally migrate southward during the winter, but they also wander the landscape in search of food. As a result, rather than being called migratory, they usually are described as “nomadic” (meaning that they follow their food supply in whatever direction that takes them) or “irruptive” (meaning that they sometimes appear in large numbers, and sometimes not at all).

Despite their lovely appearance, it’s easy to overlook cedar waxwings. They often hang out in the upper branches of forest edges, or they hide in shrubbery as they seek out fruits. But they almost always occur in flocks, rather than as individual birds, and their high-pitched calls give away their locations. So, keep your ears alert and then look for a small flock of birds perched in a treetop, or foraging among the fruits of a red cedar. If you’re lucky enough to see the birds up close, you’re in for a treat.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

It’s been a good year for Osage oranges (Maclura pomifera). Now, in mid-to late-autumn, the grapefruit-sized “monkey brains” (as Osage orange fruits are commonly called) litter the ground, turning from chartreuse to brown as they soften and decay. What are these weird trees?

Osage orange trees are not native to Ohio. Rather, they originated in the south-central US, around Texas and Oklahoma. European settlers who crossed the Mississippi into that territory discovered that the Native Americans living there—the Osage Nation—highly valued the wood of a particular tree for constructing hunting bows. Those Frenchmen coined the name “bois d’arc” (wood of the bow) for the tree, and the simplified version of that term, bodark, remains in use, alongside Osage orange, hedge apple, mock orange, yellowwood and others.

Settlers subsequently discovered additional values for this tree. The wood is strong and flexible—ideal not only for bows but also for wagon wheels and axles. Osage orange wood also is durable and resists rot; it makes excellent fence posts and tool handles. And in the wilderness, Osage orange wood could be split and the interior wood splintered to build a fire, even in wet conditions. The dense wood (30% denser than oak) burns hotter than any other native tree. Beyond that, the hard, yellow wood is appealing for carving into pens, musical instruments, and other items, and it yields an attractive yellow dye.

More relevant to how Osage orange came to Ohio, the trees themselves proved useful. With their tangled growth form and sharp thorns, a close-grown row of Osage orange trees forms a nearly impenetrable barrier. As such, hedges of Osage orange were perfect for creating natural fences to define property boundaries and enclose livestock. Trees were planted across the Midwest for that purpose. The practice diminished after the introduction of barbed wire in the late 1800s, but windbreak hedges of Osage orange remain common in the Plains states. The trees we see in Ohio today likely derive mostly from those planted many decades ago for their utilitarian purposes.

Although the Osage orange name recognizes the fruit’s superficial resemblance to an unripe (large!) orange, the tree is not a citrus. Rather, it is in the Moraceae family, along with mulberries, figs and jackfruit. Like those other fruits, Osage orange fruits technically are “syncarps” or collective fruits, meaning they form from a cluster of fruiting flowers. Each of the individual fruits in that collective consists of an elongated green pulpy flesh, with a single seed buried in the fruit interior. The pulp produces a white latex that oozes out if the fruit is damaged.

Osage orange and related Maclura species have been used in folk medicine around the world, including by Native Americans. Chemicals isolated from Osage orange leaves, seeds and latex have potential value in treating conditions ranging from cancer and Alzheimer’s disease to gastric ulcers and viral or fungal infections. Extracts have been incorporated into health care and beauty products, too, and the fruits have been touted (with weak evidence) as insect repellants.

According to Wikipedia, Osage orange fruits have “a cucumber-like flavor.” However, they are generally considered inedible, for humans and even for wildlife. Squirrels do eat some of the seeds from rotting fruits, but hedge apples generally just lie in place where they fall.

Ordinarily, trees produce fruits as bribes to attract fruit-eating animals, which subsequently deposit undigested seeds in new habitat. In other words, fruits are a plant’s way of sending their offspring out into the world. So, why would a tree invest so much energy in producing large fruits with such limited attraction to consumers, and such limited dispersal ability?

Biologists believe that the answer lies in history. Fruits evolve alongside other members of their ecological communities. Osage oranges may not attract consumers today—but it wasn’t always that way. During the time of the most recent ice ages—known as the Pleistocene epoch—North America was home to a diverse array of large herbivores. Camels and llamas, giant (3 ton!) ground sloths, shrub oxen, woodland muskox, and mammoths and mastodons all roamed the countryside. These animals would have been fully capable of eating Osage orange fruits. Then, about 10-15,000 years ago, the continent’s large mammals mostly went extinct. That demise probably reflected the combined effects of human hunting—humans had recently arrived to North America from Asia—and climate change as the last ice age ended. Whatever the cause, mammoths and ground sloths disappeared; but the trees survived. And so Osage orange now is thought of as an ecological anachronism: a plant that remains alive and well, but whose ecological counterparts—the animals that ate its fruits and dispersed its offspring—are missing.

Osage oranges may yet enter the market as ornamental trees. There are separate male and female trees, and so male trees, which don’t produce fruit, are more desirable as plantings. Selective breeding also has made inroads at reducing or eliminating thorns, but with somewhat limited success. For now, Osage orange remains an interesting member of our forest communities, producing a notable THUD when it drops a fruit and serving as a reminder of our wild past. Next time you look at a fruit-laden Osage orange tree, just picture a mammoth strolling by for a snack!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

The parks of Southwest Ohio are home to two of the country’s smallest “warm-blooded” critters. Ruby-throated hummingbirds, Archilochus colubris, are conspicuous throughout the warmer months; least shrews, Cryptotis parva, also are common residents, though ¬much less visible. Adults of each of these species weigh in at a paltry 3-4 grams, barely more than a penny (2.5 g). That small size imposes some significant challenges. However, the two species solve those challenges in quite different ways.

When we call animals “warm-blooded,” what we really mean is that their metabolism produces enough heat to support a relatively constant high body temperature. Technically, that is referred to as endothermy. Humans are endotherms, too, and our normal body temperature is 37oC (98.6oF), significantly warmer—at least most of the time in Ohio—than the surrounding air temperature. It turns out that, despite their small size, least shrews and ruby-throated hummingbirds maintain body temperatures similar to humans—about 37oC for shrews, slightly higher for hummingbirds. Doing so requires a high rate of heat production. A small animal—or any small object—has a lot of surface area relative to its volume (or mass). Since it is the animal’s mass (muscle, liver, and other active tissues) that produces metabolic heat, the tissues need to work extra hard to offset all of the heat lost to the environment across the body’s surfaces. Indeed, the tissues of shrews and hummingbirds burn fuel at rates about 50 times as high as those in the much larger human. (To support that, they have heart rates up to 1,000 beats per minute!)

To fuel that high metabolism, shrews and hummingbirds need to feed at high rates. Both species may consume twice their body mass per day in food. However, their calories come from very different sources. Shrews are in the order Insectivora, and their protein-rich diet consists largely of insects and other invertebrates that they find in their tunnels under the leaf litter and dirt. Hummingbirds, in contrast, specialize in consuming flower nectar, which is largely just sugar water. Flower species vary in the concentration of sugar, but 40 – 60% sugar (several times as sugary as Coca-Cola) is typical. On the other hand, nectar has very low concentrations of amino acids, and hummingbirds need to catch an occasional insect to meet their needs for dietary protein.

Staying warm becomes increasingly challenging for these small endothermic animals as cool weather arrives and they lose heat even more quickly to the environment. Some small local endotherms—chipmunks, ground squirrels, some bats—solve that problem by giving up on high body temperature. Instead, they hibernate, allowing body temperature to drop for extended periods and, in the process, substantially reducing the rate of metabolism and the need for fuel. However, neither shrews nor hummingbirds hibernate.

For shrews, the strategy for winter is simply to keep on keeping on. Shrews remain active in their (possibly snow-covered) tunnels all through the winter. Their metabolism may need to increase in the cooler temperatures, but their habitat is well enough insulated that they don’t suffer the full cold of winter, and they are able to find adequate food to meet their metabolic needs. Although we rarely see shrews in winter, they are all around us, actively scurrying under the snow and fallen leaves through the season.

Hummingbirds, in contrast, give up on Ohio for the winter. (Ruby-throated hummingbirds have been sighted occasionally in Ohio through at least the first 3 weeks of October this year.) Whereas the short legs of shrews could never get them far from home, hummingbirds can fly with enough speed—about 40 km/hr, or 25 mph—that they can reach warmer southern wintering grounds within a few days. And while they may feed along the way—migration coincides with jewelweed blooming as they move south—even their small amount of stored body fat is enough to support a non-stop flight across the Caribbean. Once there, nectar feeding can continue. Amazingly enough, hummingbirds can sustain this extreme lifestyle—high feeding rates on a specialized food source, rapid heart rate, long-distance migration—for a long time; the oldest known wild ruby-throated hummingbird is nearly 7 years old. Shrews, in contrast, live for about a year.

In Aesop’s ancient fables, we often read of animals with opposing characteristics—the tortoise and the hare, or the ant and the grasshopper—that are thrust together by circumstances. Of course, those fables conclude with pithy moral lessons: “slow but steady wins the race”, or “work today to eat tomorrow”. “The hummingbird and the shrew” sounds like another fable in the collection. In this case, though, there is no winner or loser. Both of these small endothermic animals live precarious lives, pushing the limits of physiology. But both have evolved successful—though very different—solutions to that challenge. Evolution doesn’t produce one optimal solution, but rather preserves any trait that enhances survival and reproduction. Perhaps the moral to this story comes from a more modern fable, Jurassic Park: “Life, uh, finds a way!”

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

In early August, the Intergovernmental Panel on Climate Change, a working group of the United Nations, released their latest report. The message was stark: human-induced climate change is ongoing at an unprecedented scale and, if not curtailed quickly, will have dire consequences. The implications of that assessment are far-reaching. But what might this mean for local parks?

First, a quick (very quick!) capsule summary of climate change. A fundamental element of ongoing climate change is a rise in global average temperature. On a planetary scale, the impacts of that warming are evident in phenomena like melting of polar and glacial ice and rising sea level. However, warming is not uniform across the globe, and that variable warming generates shifts in patterns of wind, precipitation, and ocean currents. As a result, the local experience of climate change may well include warming, but an additional effect is increased climate variability, including more frequent extreme events like droughts, hot spells, and storms.

The biggest driver of climate change is the greenhouse effect. Like the glass in a greenhouse, Earth’s atmosphere allows sunlight to pass through and heat the planet, but then blocks much of that heat from escaping back to space. Certain components of the atmosphere—known as greenhouse gases—are particularly effective at retaining heat. Carbon dioxide (CO2) is one of those greenhouse gases. Since the industrial revolution, human activity like burning fossil fuels has released huge amounts of CO2 into the atmosphere. At the same time, clearing of forests has reduced the capacity for plants to soak up that gas (which is what happens in photosynthesis). As a result, atmospheric CO2 levels have increased substantially, by 25% just since 1980, resulting in a warmer planet.

The most obvious consequences of that warming for local parks and natural areas would be direct impacts of previously inexperienced weather events, like spells of hot, dry, or wet weather. In Australia, die-offs of birds and mammals from heat stress have occurred already. Tolerance for variable climate, and the ability to escape unfavorable conditions, varies among species. The Audubon Society identifies 19 Ohio bird species (wood thrushes, scarlet tanagers, and others) that are “highly vulnerable” to climate change. Even a “moderately vulnerable” species like the tree swallow, a lovely summer resident of local parks, may disappear from some or all of Ohio as temperatures warm.

Changing climate can influence organisms’ life cycles in other ways, too. Many plants emerge and flower in association with warming temperatures. Studies of Ohio flowers reveal that with warmer spring temperatures, the date at which many flowers first bloom or reach peak blooming is earlier now than it used to be. For many insects, winter is spent in a dormant state (diapause), often in juvenile form (e.g., as caterpillars or grubs), supported by stored body fat. With warmer winters, the insects’ metabolism is increased so that they use their fat reserves more quickly. They may then be less able to fuel spring emergence and transition to the next life stage.

While changes to climate may create less habitable environment for some species, it also may create conditions that favor previously absent species. For example, the sachem skipper, a small butterfly, has limited tolerance for cold but has expanded its range northward as winters have warmed. Likewise, sandhill cranes, which historically migrated south in winter, now commonly remain in the northern Midwest, including Ohio, throughout the year.

Predicted changes in climate – warmer, wetter springs followed by hotter, drier summers – are likely to create change for forests, too. Growing seasons will be longer and may well favor success of many local tree species (sycamore, silver maple, and others), but other species (basswood, beech) may be less tolerant. Moreover, conditions also may improve for disease-causing organisms, and the smaller number of days with frozen soil may increase risk for erosion and treefall.

One concern of land managers is that climate change will particularly favor invasive species, which already pose substantial challenges to our parks. These opportunistic invaders often are more tolerant of unique and variable conditions than specialized native species. Kudzu and Chinese privet are moving north!

As climate change leads to new combinations of species, ecological relationships between species also might be altered. If spring migration of birds is triggered by changes in daylength (which is predictable), but insect emergence depends on local temperatures (which are changing), then climate change can create mismatches between the birds’ northern arrival and their food supply. Other mismatches might occur between the timing of plant flowering and the availability of pollinating insects, or between animals and the plants they rely on for support. For example, the monarch butterflies that grace Ohio meadows in summer feed on milkweeds in Texas on their autumn southward migration to Mexico, and they lay eggs on milkweeds in Texas on their way back north in spring. Changes to milkweed availability in Texas at either season can, ultimately, affect the abundance of monarchs in Ohio. In 2021, for example, Texas was hit by a winter storm that froze much of the milkweed crop; the monarch population in Ohio has suffered as a result.

Only time will tell how these processes play out in the years ahead. Both the magnitude of impending climate change and the ecological consequences of that change are complex and difficult to predict with certainty. However, climate change poses a diverse set of risks for Ohio and the Midwest. Actions by individuals, businesses, and governments can help to minimize the progression of climate change and preserve the biological systems and diversity that we have inherited. In the meantime, our parks can help to remind us of the riches of that diversity, and of the value in acting to protect our natural heritage.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

In Greek mythology, Icarus attempted to escape from Crete by flying to the mainland, using wings that his father crafted by waxing feathers to Icarus’ arms. However, Icarus flew too close to the sun, the wax melted, and the feathers detached; Icarus fell into the sea. Two millennia later, Dayton’s own Wright Brothers also looked to birds for inspiration, developing ideas about wing warping from observations of birds in flight. The simple take-home message from both of those episodes is the same: to achieve flight, wings need to combine appropriate characteristics of size and shape.

This time of year, birds and butterflies are putting those notions to the test. As autumn approaches, many birds, and a few insects, are preparing for southward migration. Surely that would best be accomplished with healthy, intact wings. However, these animals have wings made of relatively fragile materials—feathers of keratin for birds, chitinous membranes for butterflies—that have been subject to wear and tear through the active months of summer. By September, those wings may be beat up and tattered. How do they support the long airborne trip south?

Birds address this issue by replacing worn feathers. Although feathers themselves are non-living and not repairable, birds can shed old feathers and regrow new ones—much like hairs in a mammal. The pattern of feather replacement (molt)—both timing and extent—is quite variable among species. However, in species that migrate, one bout of molting typically occurs after the summer reproductive season and before migration. In many species, that molt accomplishes two functions. First, it provides a new set of feathers to support the southward flight. And second, it shifts the bird from its colorful reproductive plumage to less conspicuous colors for the non-breeding months of the year.

One group of birds that illustrates these patterns is the North American wood warblers. The northward spring migration of these colorful birds—black-throated blue, yellow-rumped, chestnut-sided, and many other species—is one of the great annual birding events in Ohio. On their return southward migration in fall, however, warbler identification presents a much greater challenge, as they shed their summer colors for drab, non-breeding plumage.

Surprisingly, the details of that late summer molt have been described just recently. It turns out that many warblers go through a rapid, intensive feather molt. For a period of two or three weeks in late summer, these birds shed and replace up to two-thirds of the feathers that power and guide flight, including simultaneous loss (and then replacement) of all 12 tail feathers and of 6 – 10 flight feathers on each wing. (You might find the shed feathers on the trails.) During that period, the birds’ ability to fly—and hence to feed and to escape predators—is seriously compromised, and so they skulk inconspicuously in the bushes. Once a fresh, new set of feathers grows in, the birds are ready for the long flight south.

Like birds, butterflies also have wings with no capacity for repair. Unlike birds, though, butterflies cannot shed and replace their wings. For most species, that might not matter so much; they are short-lived and die after the reproductive season, with no long migratory flights. Still, it is not uncommon to see butterflies with tattered wings in late summer; how does that affect their flight?

A few studies have explored that question by testing butterflies with naturally or experimentally damaged wings. In most cases, wing damage induces more rapid wingbeats, which compensates to allow relatively normal flight. Beyond that, though, even butterflies with 20% wing reduction apparently can get by reasonably well, with near-normal flight activity and survivorship.

If that’s the case, then why do butterflies have wings that are seemingly bigger than they need to be? The answer might still relate to flight characteristics; for example, the energy required to fly, or maneuverability in flight, might be influenced by wing area and shape. Butterfly wings also serve other functions, including as visual signals and as heat-absorbing surfaces. Those functions might have favored the evolution of relatively large wings.

Does wing reduction impede butterfly migration? It has been suggested that food shortages for monarch caterpillars could inhibit wing growth and potentially impair migratory flight. However, in pictures of those fantastic congregations of monarchs on their Mexican wintering grounds, wings look to be intact. Perhaps individuals with tattered wings fall by the wayside en route, or maybe migratory species have more resilient wings that resist wear and tear. Those are topics for further investigation.

The human urge to fly is deep-seated, and since ancient times humans have looked to nature for inspiration to realize that dream. As we continue to push the frontiers of flight—from miniaturized drones on Earth to helicopters on Mars—we will, no doubt, seek to float like a butterfly and to soar like an eagle.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

As the name implies, milkweeds – a group of plants in the genus Asclepias – are weedy plants. They are characteristic of disturbed habitats like forest edges and open meadows, and though they are perennials, they also produce copious wind-borne seeds and so can readily disperse and multiply. However, milkweeds also possess complex, attractive flowers in a variety of colors, they produce nectar that attracts a diverse insect community, and they are essential in the life cycle of the beloved monarch butterfly. Thus, despite their potential for “weediness,” milkweeds have become valued and widely planted garden plants.

Milkweeds derive their name from the white latex that exudes from most species’ leaves and stems if they are damaged. (Butterflyweed, Asclepias tuberosa, is an exception that lacks latex.) Latex is a complex emulsion containing compounds that coagulate upon exposure to air. The concentration of gum in milkweed latex is too low (about 2 – 3%, compared with 30 – 40% in latex from Brazilian rubber trees) to be commercially viable as a source of rubber. Still, the latex does have the potential to clog up feeding structures of herbivorous insects, and it functions at least in part as a defensive mechanism against those consumers.

In milkweeds, the latex and leaf and stem tissues (but not nectar), also contain toxins synthesized by the plant. Those toxins are primarily cardenolides, a steroid-based group of compounds within the cardiac glycoside family. Milkweed cardenolides exert their toxicity by inhibiting the function of a protein in animals—the “sodium pump”—that is critical to the function of nerve and muscle cells. (Sodium ions enter those cells as part of their activation mechanism, and the sodium pump helps the cells reset for another round of function.) Like digitoxin, in the same chemical family, milkweed cardenolides can interfere with diverse physiological functions.

The combination of latex and toxins is formidable; who would want to eat that?! And yet, several insects, including monarch butterflies, milkweed tussock moths, swamp milkweed leaf beetles, milkweed bugs and beetles, and milkweed aphids, specialize on milkweed as food during at least part of their life cycle. How do they manage?

The trick to preventing latex from “gumming up the works” is basically to avoid it. Latex circulates through the plant via channels that run through the veins. Some insects, like red milkweed beetles and monarch caterpillars, interrupt that flow by chewing through a leaf vein, then eat “downstream” from the leak. A second strategy, used by tussock moth caterpillars, is to eat just the leaf tissue between the veins, leaving behind a veiny skeleton and avoiding most of the latex.

Avoiding the toxins is less simple since they are found throughout the leaves and stems. In some species, the gut simply prevents the ingested toxin from entering the insect’s body. In a few species, like the milkweed aphid (introduced from Asia), ingested cardenolides are metabolically modified and then excreted. However, milkweed specialists of several varieties have evolved a different solution. That is, the structure of their sodium pump protein—the toxin’s target—is modified through a set of genetic mutations that changes the protein’s amino acid sequence. The cardenolide is less able to bind onto its target, and so the insect suffers minimized effects. The mutation may not be effective against all varieties of cardenolide, though, and even monarchs may need to convert some of those compounds to less toxic forms.

Given that tolerance, many milkweed specialists have taken things one step further. That is, rather than excreting all of the toxin that they ingest, they accumulate it in their bodies. In monarchs, the caterpillars sequester much of the ingested toxin into their integument, and as much as 70% of those toxins then is retained through metamorphosis. The adult thereby remains toxic even as it feeds on toxin-free nectar. In fact, research suggests that the ability to sequester toxins in the body may have been the evolutionary driving force behind the alterations in sodium pump structure.

Insects gain an obvious advantage from accumulating toxins. About 50 years ago, Lincoln Brower conducted a famous set of experiments demonstrating that blue jays learned to avoid toxic monarch butterflies. And indeed, insects that are specialists on toxic milkweed tend to be brightly colored (so-called aposematic coloration) as a warning to predators, who learn to leave them alone. Interestingly, milkweed tussock moths, whose caterpillars accumulate toxins just like monarchs, are nocturnal and eaten mostly by bats; bright colors wouldn’t help in this case, and so instead the boring gray moths emit a clicking sound that bats learn to avoid.

Milkweeds have traits shaped by the complex coevolution of plants and insects. Milkweeds need to attract insect pollinators, and they do so by producing showy flowers with nutritious nectar. On the other hand, they want to discourage herbivorous insects, and to do that they invest in latex and toxins. As insects have evolved alongside those milkweeds, a number have acquired traits that allow them to find and consume the nectar, but also to avoid, overcome, and even commandeer the defenses. Plant some milkweed in your garden, and not only will you support healthy populations of monarch butterflies, but you will gain a front-row seat to the evolutionary arms race. Got milkweed?

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

The Centerville-Washington Park District maintains 20 soccer game fields, 18 baseball/softball diamonds, 2 football game fields, 2 lacrosse game fields, 5 acres of lacrosse practice area, 5.5 acres of football practice area and 20 acres of soccer practice fields! We hope you have enjoyed your experience on the fields and in the parks. We are always looking to improve our services and we appreciate your feedback about your athletic fields. If you have used the fields in the past year, please take a few moments to let us know what you think. Thanks!

Take the survey >

The Yankee Park playground is getting an upgrade! The Centerville-Washington Park District is interested in learning which of the proposed playground designs the community prefers. Goals previously identified for this project are: an ADA safety surface, an ADA specific element, swings, a separate structure for ages 2 – 5 and shade features. Please view all three options. Each option is displayed with two renderings and a video. We would appreciate it if you could also share the options with your children!

Thank you for taking the time to help shape your community’s BIG backyard! We appreciate your feedback!

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The survey was open July 13 through the morning of Wednesday, July 21. We will post the new design soon! To see future Centerville-Washington Park District surveys, make sure you are following us on Facebook or Twitter!

It’s the middle of summer; mosquitoes are buzzing, the nighttime chorus of crickets and katydids is picking up volume, and we’re just coming down from an emergence of periodical cicadas. It might seem like an odd time to be asking: Are there enough insects out there?

No doubt about it, some insects can be pests. We do what we can to keep mosquitoes from our patios and ants from our kitchen. However, insects play crucial roles in ecosystems. About three-quarters of flowering plants, and a third of all food crops, depend on animal pollinators—mostly insects—to reproduce. Moreover, because of their numbers and diversity, insects serve as food for all manner of animals and are critical links in food webs. Because of these pivotal roles, insect abundance is key to the stability and productivity of natural systems and agriculture. It should be no surprise that a 2017 study from Germany, indicating that insect abundance had declined by about 75% over 27 years, set off alarms. A recent collection of papers followed up on that finding, with the lead article calling the decline in insect populations “death by a thousand cuts.”

Perhaps the most widely discussed example of insect declines in Ohio and the US has been concern in recent decades regarding threats to honeybee colonies, including the phenomenon of colony collapse. Honeybees are not native to the U.S., and their populations are controlled substantially by human management of hives, like those in Bill Yeck Park. Nevertheless, the proposed causes for honeybee die-offs—including pesticides, parasites, changing land use practices, and disease—do raise red flags for other species, too. Broadly speaking, climate change, habitat loss and degradation, and agriculture (including pesticides and herbicides) are likely to be important stressors for many insect populations.

Alongside honeybees, native bees of many species are effective and important pollinators. In Ohio, that includes 20 species of bumblebees that have been reported historically in the state. However, a large state-wide survey in 2017-18 identified just 10 bumblebee species in nearly 25,000 observations. That survey provides a baseline for assessing bumblebee populations in the years ahead.

A group of insects that has near-universal public appeal and that is well suited to public monitoring is the butterflies. Who wouldn’t lament the loss of these insects, practically the symbol of ethereal beauty? And yet, we should not discount that possibility. The most recent survey of monarch butterflies in California reported a decline of 99.9% from the numbers 30 years ago, reduced from 4.5 million to just 30,000. In western Europe, butterfly numbers have declined by 50% in the past 45 years, and nearly one in ten resident species in the UK have gone extinct.

One of the best long-term surveys of butterfly numbers comes from Ohio. A 2019 report summarized the results from 24,405 butterfly surveys provided by trained volunteers from 1996 to 2016, as part of the Ohio Lepidopterists Long-term Monitoring of Butterflies program. Overall, for the 81 species analyzed, abundance declined at a rate of about 2% per year, with a cumulative 33% reduction over the duration of the study. Three times as many species declined in population as increased. You can join the Park District on butterfly surveys July 10 and/or August 7 to take part in this long-term project!

That trend seemed manifest in the Centerville parks and across Ohio in 2020. Numerous observers reported a paucity of butterflies; the big, obvious species, like swallowtails, red-spotted purples, and fritillaries, just seemed to be missing. The phenomenon was not universal across locations and dates, and the findings were not rigorously quantified. But still, it was a disconcerting season for butterfly lovers, who were left wondering whether the 2021 season would see a repeat or a rebound.

Defining and understanding these trends, in Ohio and elsewhere, will depend on the accumulation of data. Observations from the general public are likely to contribute importantly to that effort. iNaturalist, the repository for public records of species observations, is growing at a rate that likely will make it the largest single source of data on species-level occurrence of visually identifiable insects. Surveys with more standardized methodologies, like the North American Butterfly Association’s 4th of July counts, also will be critical.

So, as you wander the parks this summer, keep an eye out for butterflies—not to mention bumblebees, wasps, dragonflies, and other insects. Consider entering those observations on iNaturalist, where others can make use of them. At the same time, even if we don’t all come to love mosquitoes and dandelions, planting a few more flowers, and spraying a little less bug and weed killer, will help to boost insect populations and the ecological functions they support. The future of those summer pleasures—butterflies on the wing, and peaches in our picnic baskets—might depend on it.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Birds’ nests serve a number of functions. One of those, of course, is to provide a secure place to lay and incubate eggs and, for many species, to raise young. In addition, the design and structure of nests may help to attract mates, discourage parasites, and regulate environmental conditions like temperature and humidity. Given those diverse functions, it is not surprising that nests are highly variable, ranging from simple scrapes in the ground to elaborate cups, platforms and baskets. In North America, about 15% of species are cavity nesters, laying their eggs in enclosed spaces.

North American cavity nesters represent several orders of birds. Locally, that includes woodpeckers, ducks (e.g., wood ducks), many owls, a falcon (the kestrel), and a number of passerines (perching birds), such as bluebirds, tree swallows, wrens, chickadees and titmice, nuthatches and prothonotary warblers. Only a few of those species, mostly woodpeckers, are “primary” cavity nesters, meaning that they construct their own nest cavity. The others either take over cavities abandoned by primary nesters or, more commonly, find cavities formed naturally by processes like tree rot and breakage.

Cavity nesting birds share a number of traits. Many have white eggs, presumably because there is no need for camouflage within the concealed nest site. In addition, cavity-nesting birds tend to have slightly higher clutch sizes (number of eggs laid per nesting cycle) than non-cavity nesters. Ecologists have debated potential explanations for this finding. One possibility is that cavity nests are easier to conceal and protect than open nests and so they suffer less predation. As a result, parents have a lower “risk-to reward” ratio from nesting and are able to invest in more offspring. Another possibility is that suitable cavities are a limited resource—there are only so many good nest holes in any particular habitat—and so a cavity-nesting bird that finds a good nesting site needs to take the fullest advantage of the opportunity.

Research suggests that in old-growth forests, with lots of large, aging trees, cavity availability does not, in fact, limit nesting. However, in managed landscapes nest-hole availability is critical. One of the most prominent examples of that relationship is the Eastern bluebird. With their beautiful colors and sweet sounds, bluebirds appeal naturally to humans. As the song lyrics say, “Life is sweet, tender and complete, when you find the bluebird of happiness.” And yet, over the past 100+ years, the push to clear forests for agriculture, and the forestry practice of removing old and dying trees and limbs, substantially diminished the birds’ natural nest sites. Bluebird populations declined by as much as two-thirds between 1950 and the 1970s. Numerous factors probably contributed, including not only loss of habitat and nest sites but also increased threats from cowbirds, raccoons, starlings, house sparrows, cats, pesticides and cars. Efforts to encourage construction of bluebird nest boxes, including by the North American Bluebird Society formed in 1978, led to a resurgence of bluebird populations, which now have recovered from those mid-20th-century declines.

The wood duck—beloved for its beautiful coloration, and also as a game species across the country—has a similar story. Wood ducks need relatively large tree holes for nesting, and these became rarer as woods were cleared. With the emergence of professional wildlife management in the mid-20th century, and the implementation of programs to install wood duck nest boxes, populations have surged and stabilized.

Purple martins—a species of swallow—provide one more example. Martins nest in small colonies, and both the availability of adequate natural nesting sites and competition from other species like house sparrows probably contributed to martins becoming more and more affiliated with humans. Today, purple martins nest almost entirely in artificial multi-compartment nest houses erected by people for that purpose.

One of the keys to establishing successful nest box programs was defining exactly what sorts of boxes would attract the desired species while discouraging competitors. Early versions of bluebird nest boxes often suffered from starling occupancy, as that introduced species aggressively out-competed bluebirds. We now know that entrance holes 1.5 inches in diameter effectively admit bluebirds while excluding the larger starlings.

Of course, smaller birds still can enter bluebird boxes. Locally, tree swallows—attractive aerialists with iridescent blue plumage, which also suffered population decline in the mid-20th century—commonly occupy nest boxes placed in park meadows. Small but pugnacious house wrens also commandeer quite a few bluebird boxes, especially those near forest edges.

For wood ducks, which are larger and prefer nests in the woods near water, Ducks Unlimited recommends a 4 1/2″ x 3 1/2″ oval nest box entry hole. Managers of those nest boxes also should provide nest box lining materials, like wood chips, since wood ducks will not provide their own nest materials. Other species that might take over these sites include screech owls, great crested flycatchers, and kestrels.

People often wonder what they can do as individuals to support conservation efforts. The success of nest box construction programs is one of the great examples of citizen action contributing to a large-scale conservation objective. Today, Irving Berlin’s lyrics once again describe Ohio’s suburban landscape: “Bluebirds singing a song, Nothing but bluebirds all day long.” Build, and enjoy!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

In some ways, frogs and toads (amphibians in the order Anura, meaning “no tail”) are visual creatures. Their eyes are finely attuned to movement, and they feed on insects that make the mistake of crossing their visual paths. But when it comes to reproduction, most anurans are all about sound. The croaks, trills, and grunts of frogs and toads at their breeding sites provide musical accompaniment for spring and summer.

Amphibians require a wet or moist environment for their eggs and larvae. Local frogs and toads mostly reproduce in still water, like ponds and wetlands, where they often congregate in large numbers during their breeding seasons. Here in the Dayton area, Western chorus frogs (Pseudacris triseriata) and spring peepers (Pseudacris crucifer) began calling in early March. A few weeks later, American toads (Anaxyrus americanus) join the chorus, and by May or June an active frog pond might include gray treefrogs (Dryophytes versicolor and chrysoscelis), green frogs (Lithobates clamitans), cricket frogs (Acris crepitans), bullfrogs (Lithobates catesbiana), and others.

Even a small pond might attract many hundreds of breeding frogs, and the collective chorus can be loud enough—100 dB or more at 1 m distance—to hear from more than a kilometer away. The calls of early arrivers even help guide other individuals to the pond. This mating system, where males converge and display to females in groups, benefits both sexes: males have numerous potential opportunities to mate (an individual male can mate with more than one female), and females can compare lots of males and select their preferred partner.

The idea that females select their mates from among a chorus of males suggests that males are variable in a way that females can detect. And indeed, even within a species, male vocalizations can vary in many characteristics, including location within the chorus, timing of call initiation, call duration, and call frequency and loudness. In some species, calls vary with temperature, but males also can adjust the timing and loudness of their calls in response to other callers. For example, frogs are adept at initiating their calls during quieter intervals between calls of neighbors.

Females must be able to detect those differences against a lot of background noise from their own species, other amphibians, and the broader environment. This challenge to auditory perception—how to isolate the sound of a single individual in a noisy crowd—is known in human studies as the “cocktail party problem.” Humans are quite good at this, and can carry on a conversation at a cocktail party, or listen selectively to a single instrument within a complex piece of music. As in humans, frog hearing is based mostly on the activity of specialized sensory cells—“hair cells” (unrelated to hair follicles)—each of which responds to a narrow range of frequencies. In frogs, these cells are housed in two inner ear organs, one (the amphibian papilla) with hair cells sensitive to low frequencies (~100 – 1000 Hz) and the other (the basilar papilla) that can detect higher frequencies typical of calls from males (1000 – 1500 Hz in bullfrogs, 2000 – 4000 Hz in some treefrogs). In contrast, human hair cells are housed in a single structure, the cochlea, but collectively can detect a wider range of frequencies (~100 – 20,000 Hz). Frogs may out-perform humans on some tasks, such as discriminating loudness differences between sounds. And frogs have some special mechanisms, too, like discerning directional origin of calls in part based on whole-body vibration—a form of seismic sensing. Although we know that frogs ultimately do “solve” the cocktail party problem—they find mates within the loud chorus—much remains to be learned about how the mechanisms of hearing relate to the behavioral responses.

So, male calls vary, and females can detect those variations. Do females have preferences? At least in some cases they do. For example, gray treefrog females may prefer calls with particular combinations of call duration and pulse rate, and American toad females mate preferentially with males calling at lower frequency. Those preferences make the most evolutionary sense if they reliably select males whose offspring are more likely to survive, reproduce, and pass on her genes. For American toads, the preferred lower-frequency call typically means a larger male, which may well signify good health. However, it is unclear whether large male size is associated with robust tadpole characteristics (like time to, or size at, metamorphosis), and little is known about how female choice relates to “quality” of her offspring or the extent to which those male traits are inherited.

Given that females have preferences, why don’t male frogs develop calls that are more and more eccentric, so that they more readily stand out from the crowd? Anuran vocalization is energetically expensive, and there may be limits to how long and loud a male can afford to call. Males also need to call within the detection limits of females, whose auditory systems are quite finely tuned. In addition, frog calls may attract more than just potential mates. Predators—larger frogs or herons, for example—may target conspicuous callers, and even parasitic flies that feed on frog blood find their meals by homing in on male calls.

So, male calling represents a tradeoff. On the one hand, competition for females drives the evolution of male characteristics that best attract mates; this is known as sexual selection. On the other hand, if those traits create risks to survivorship, such as by costing energy or attracting predators, then they will be disfavored by natural selection. The traits that we see today—all those grunts, trills, and croaks—represent the balance between those two forms of selection. The analogy of frog choruses to cocktail parties goes beyond just consideration of auditory processing!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University. Image: American toads in amplexus (mating position), with the smaller male grabbing the female. Strands of eggs are visible in the water.

Image: courtesy of Katja Schulz, Creative Commons

I have lived in Dayton, OH, since 1986. This May and June, for just the third time in those 35 years, I look forward to the spectacle of Magicicada Brood X, the 17-year periodical cicada. Across several eastern US states, billions of these 4 cm (1.5 inch) insects will emerge from the soil where they have been developing since they hatched from their eggs as nymphs, fell to the ground, and burrowed down back in 2004. The adult males among that throng of insects will vibrate their tymbals (drum-like membranes on their abdominal undersides) and create a collective buzz that will be hard to miss, as it can reach up to 100 dB in loudness, similar to a jackhammer or an outboard motor.

Periodical cicadas are fascinating, and much has been written about the phenomenon of their synchronized massive emergence: that there are several species and “broods” (synchronized populations) that emerge in different parts of the eastern U.S.; that they emerge on 13 or 17-year cycles; that with those long intervals from hatching to adult, they are the longest-lived insects; and that they can be cooked and baked into many nutritious, tasty dishes (!). But cicadas are fascinating in many other ways, too.

Cicadas are relatively large insects, and you might guess that they require a fairly energy-rich diet to acquire adequate calories. That is not their strategy, though. Both nymph (feeding on plant rootlets) and adult (feeding on above-ground twigs) cicadas are specialized for drinking from the fluids of plants. Interestingly, though, cicadas do not feed, like aphids, on phloem sap, which is full of nutrients descending from the photosynthetic leaves. Rather, they feed on xylem sap, which is quite nutrient-poor as it rises from the soil. Although some have speculated that the poor-quality diet accounts for the long maturation time of periodical cicadas, even annual cicadas, which can grow to equally large size in a single year, feed on xylem.

The ability to feed on xylem is associated with certain anatomical features. The labium (beak) of a cicada contains a stylet, which combines features of a needle (to pierce through to the phloem) and a straw. However, cicadas need to work to extract that fluid. Xylem sap is under negative pressure, as it is pulled up the plant by suction, driven by evapo-transpiration of water from the leaves. Cicadas therefore must exert their own suction pressure, which they achieve using large pumping muscles. The bulge of those muscles beneath the facial exoskeleton creates the nose-like appearance on a cicada’s head.

The xylem sap by itself provides an incomplete mix of organic molecules needed to build the insect’s tissues. Cicadas overcome that limitation by housing bacteria capable of synthesizing the required building blocks. In cicadas, those bacteria are largely endosymbiotic — meaning that they reside inside the cicada’s cells, rather than in the gut, as in termites and us. These “reduced” bacteria have genomes that are transitional between those of free-living bacteria and symbiont-derived cellular organelles like mitochondria. In long-lived periodical cicadas, the endosymbiotic bacteria are even more specialized, having evolved into a number of separate species, each with just a subset of the genes needed to survive. These bacteria are transmitted from adult to offspring inside the cicada’s eggs; a full set of bacteria must be incorporated to be successful.

Given the huge number of cicadas and their large size, a population of cicadas embodies a lot of energy and nutrients. These conspicuous insects make ready targets for many predators, including birds, mammals, and amphibians, and this pulse of food can influence bird populations for up to several years. But a cicada outbreak readily saturates the needs of predators. (That assured survival of some individuals is a benefit of synchronized emergence.) Thus, when the insects die off in mid-summer, after an adult lifespan of just a few weeks, a large flush of energy and nutrients enters the local ecosystem. That giant dose of “fertilizer” can increase the productivity of understory vegetation, of microbial communities in forest soils, and of nearby aquatic communities. Although these animals appear on the landscape for just a few weeks every 17 years, they have a large impact across the ecosystem.

The detailed structure of the insects themselves also is of interest. Engineers who look to nature for inspiration have discovered that the surfaces of cicada wings are constructed using periodic arrays of very small (“nanoscale”) non-close packing pillars. These structures create highly water-repellant surfaces that make the wings self-cleaning. In addition, the physical properties of those pillars are bactericidal, particularly against certain classes (gram-negative) of bacteria. Not all cicadas have the same wing structure. In the periodical cicada, Magicicada cassinii, the wings are not as water repellant as in annual cicada species, but the chemical composition of the wing surface is bactericidal. Research groups are actively exploring ways to mimic these properties in human-made materials, with many potential applications.

So, cicadas are studied as models for understanding the regulation of growth and lifespan, ecological dynamics, bacterial evolution, and nanoengineering. And yet, fundamental questions about cicadas remain unanswered. Why does it take them so long to develop from nymph to adult? What is it that synchronizes the 13 or 17-year life cycles across wide geographic areas? What is the significance, if any, of cycle lengths being prime numbers? Magicicada may not be magical, as the name seems to suggest. But they do present mysteries that are worth contemplating while snacking on some delicious Emergence Cookies (cicadas required; nuts optional) under the loud buzz of summer.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

Spring! It’s the season when robins and red-winged blackbirds regale us with song and, in Ohio, when Hinckley welcomes back its turkey vultures. Who doesn’t look forward to the lengthening daylight and warming weather? But why wait for the robins and blackbirds, when earlier events can provide a head start to welcoming the new season?

Fully a month ahead of the returning vultures—even a couple of weeks before the aptly named harbinger-of-spring flowers poke through the leaf litter—the first wildflowers emerge in Ohio. Those early bloomers might not make great candidates for a kitchen bouquet—no showy petals or bright colors—but as skunk cabbages melt their way to the surface, they are sure signs of impending spring. Skunk cabbages, Symplocarpus foetidus, are in the Arum family (Araceae), in which small flowers are located on a fleshy stalk called a spadix. In a number of arum species, most of which are tropical, the spadix is thermogenic. In other words, just as in birds and mammals that maintain warm body temperatures, the mitochondria in cells of the spadix liberate cellular energy to generate heat. A skunk cabbage spadix can be more than 30oC (>50oF) warmer than the surrounding air temperature, and skunk cabbages even adjust their heat production to regulate spadix temperature as the environment warms and cools. But why spend all that energy to heat up? Arums often emit stinky odors that attract flies as pollinators. (In skunk cabbages, the leaves, too, emit a skunky odor when crushed.) Most likely, thermogenesis in arums evolved as a mechanism to volatilize and disperse their “aroma,” thereby notifying flies far and wide that they are open for business. But in skunk cabbages, which live in cold northern habitat, the heat provides an additional benefit, allowing the plant to melt its way through the snow as early as mid-February. Only the earliest insects are available to pollinate at that season. But spending energy to bloom ahead of everyone else allows the plant to monopolize those pollinator services.

Speaking of early insects: It is entirely possible that be a beautiful large butterfly might be found flitting above those emerging skunk cabbages, with flashes of blue and creamy edges adorning its mottled brown wings. Those butterflies are mourning cloaks (pictured above), Nymphalis antiopa. Where do they come from in February and March? Most Ohio butterflies die off in late summer and fall, leaving behind their eggs (as in some hairstreak butterflies), caterpillars (as in tailed blues and fritillaries), or chrysalises (e.g., swallowtails) to overwinter; development to adulthood comes with the return of sustained warm weather. A few others—monarchs and buckeyes, for example—fly south for the winter and return in spring. But a few species, including mourning cloaks, overwinter as adults in a dormant state called diapause, hiding in bark crevices and similar shelters. Whichever stage of the life cycle overwinters—egg, larva, pupa, or adult– must be able to tolerate the cold. And indeed, during the weeks preceding winter dormancy, mourning cloaks become tolerant of whole-body freezing, which in insects typically involves the accumulation of cryoprotective compounds like glycerol. If a spell of warm weather arrives in late winter, the butterflies may thaw and become active. Of course, there are no flowers blooming yet—except maybe the odd skunk cabbage—so mourning cloaks feed on tree sap, rotting fruits, and similar fluids. When the temperature drops again, they return into dormancy. By the time warm weather really arrives and it’s time to mate and then give way to the next generation, mourning cloaks may have lived 10 months or more, among the longest lifespans of North American butterflies.

Finding food in the winter is a challenge for any animal, and along with the cold temperatures, it would seem like a tough time to raise a family. Despite that, there are animals that make it work. Among those are the earliest breeders of the local birds. Great horned owls, Bubo virginianus, may lay their eggs as early as January or February and rear their young in advance of the coming spring. These largest North American owls have among the most diverse diets of any hawk or owl. Prey items may include large insects and spiders, crayfish, frogs and snakes, all sorts of mammals ranging in size from mice to skunks and woodchucks (adult owls weigh about 1.5 kg but can carry up to 3 or more times their weight), and other birds, even including other owls. How do these nocturnal raptors find enough food to feed themselves and their chicks during the last weeks of winter? One benefit of early nesting is that there are a lot of hours of darkness. And so part of their strategy is to prey on other animals that are active through the winter nights, such as flying squirrels, rabbits above the snow and voles tunneling underneath (detected with the owls’ keen hearing), and perhaps the occasional other owl. In addition, if necessary, great horned owls will extend their foraging activity into daylight, when squirrels and crows, among other potential prey items, are active. Their large size does help great horned owls stay warm, but the ability to raise a family in mid-winter mostly depends on fine hunting skills and a flexible menu.

For each of these spring early risers, the key to success lies in being able to take advantage of “marginal” conditions—periods of cold, or intermittent warm spells, or limited daylight—that other organisms cannot. It is interesting to consider that the traits providing that edge do not entail major evolutionary innovations. Great horned owls are carnivores like other owls, but with more expansive diets; mourning cloaks have traits (glycerol accumulation, cold-dormancy) present in many other butterflies, but extended into the adult phase of the life cycle; and skunk cabbages co-opt a trait (thermogenesis) that is present in related species, albeit used for other purposes. Natural selection—the “survival of the fittest” that drives Darwinian evolution—typically works upon a framework of variations within existing traits. Major innovations are rare, but sometimes even a small variation can provide a significant advantage that opens up new opportunities. The cold of winter imposes substantial challenges for living organisms. The ability to meet those challenges apparently requires combinations of traits that appear in just a small subset of plants and animals. But in the cold weeks of February, those exceptions to the rule provide welcome hints of things to come.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University.

In late summer, at their colorful flowering peak, goldenrod (Solidago) flowers provide an important source of nectar for the late-season activities of butterflies, bees and wasps, flies, and other insects. But even in winter, when the plants have long since dried and browned, a few insects continue to call goldenrod home. One of these, the goldenrod gall fly, Eurosta solidaginis, is at the center (literally) of a lot of interesting science and nicely illustrates the notion succinctly stated by pioneering conservationist and writer Rachel Carson: “In nature, nothing exists alone.”

Goldenrod gall fly adults are short-lived. During their two-week lifespan in the spring, their only mission is to mate and lay eggs. (They really do little else. They are weak fliers, so they don’t move far, and they have no mouthparts, so they don’t feed.) Those eggs are laid on the goldenrod stem, where they hatch into larvae that burrow into the stem interior, usually just one per stem. A secretion from the larva induces the stem to accelerate local growth, and the result is a swelling that grows to about 2 cm diameter, green in summer, then turning brown in autumn. The exterior of the gall is hard and woody, but the interior is softer and nutritiou¬¬s. The larva feeds on that inner tissue during summer, creating a chamber where it matures and grows to about 0.5 cm length. At the end of summer, when it has reached its last larval stage (the third instar), the larva chews an exit tunnel from the gall center to just under the surface. It then retreats into the central chamber and enters a dormant phase—diapause. In spring, the larva resumes development, first to a pupa and then an adult. The adult pushes its way through the cap on the exit tunnel (it can’t chew its way out since it lacks mouthparts, so it creates pressure by inflating a structure between the eyes) and emerges onto the plant surface.

Goldenrod galls are easy to spot in a field of winter stems. And if you cut a winter gall in half, you will readily discover the plump little larva inside. In the process, you will notice that the gall is hard and woody, and you would probably guess that it provides a secure hideaway for the larva. Despite that, gall fly larvae are subject to a number of challenges.

One of those challenges comes from parasitoid wasps. Two species of wasps (Eurytoma gigantea and E. obtusiventris) target goldenrod gall flies. The female wasp extends its long ovipositor into the relatively soft green gall and lays an egg. That egg then hatches into a wasp larva that infiltrates and feeds on the developing fly, killing it in the process. The following spring, instead of a fly emerging from the gall—out comes a wasp.

Another threat to gall fly larvae comes from avian predators in winter. Downy woodpeckers in particular avidly seek out gall fly larvae. The woodpecker finds a gall, chisels a hole into the center, often targeting the insect’s exit tunnel, and eats the nutritious prey. In different meadows, anywhere from very few to nearly half of all gall fly larvae are eaten by woodpeckers. Predation is particularly intense for large galls on tall stems—whereas wasps, as it happens, prefer to attack smaller galls.

The third threat to gall fly development comes not from the biological world but from the physical. Galls often are positioned well above the snow line and, as such, are exposed to the full brunt of sub-freezing winter temperatures. However, while gall fly larvae will die if frozen during summer, they become freeze-tolerant during autumn. By winter, they survive freezing of more than 60% of their body water at temperatures down to -25oC or lower. That tolerance may be related to the accumulation of unusual lipids, acetylated tryacylglycerols, that have particularly low melting points and so remain liquid at low temperatures. Freeze tolerance also is supported by synthesis and accumulation in the insect’s tissues of the compounds glycerol and sorbitol, which protect cellular structures from freeze-induced damage. In addition, at least some cells in gall flies can survive ice formation inside the cell (as opposed to just freezing of fluids surrounding cells); even in other freeze-tolerant organisms, that circumstance commonly is damaging.

The traits exhibited by goldenrod gall flies have evolved as outcomes of the flies’ interactions with their living and physical environment. In the face of those interactions, any particular trait may provide both benefits and costs. For example, the ability to induce gall formation provides the gall fly with a protective environment and a built-in food source. On the other hand, that same trait, development within a gall, provides an easy target for parasitoids and predators and prevents the gall fly from escaping winter’s cold. Each of the other “players” in this “game”—the plant, the wasp, the bird—likewise has traits, some shaped by interactions with the fly, that allow it to survive and reproduce, but at certain costs. As environmental conditions vary—the numbers of birds and wasps, or the temperature and precipitation, for example—the traits that are beneficial and are passed on to the offspring also may shift. The result is that organisms and their traits also change over time. Evolution, like ecology, is all about connections. “In nature, nothing exists alone.”

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University

The Centerville-Washington Park District began work on the Grant Park master plan project in March 2020. Due to the COVID-19 pandemic, proposed community engagement sessions were modified to include an online survey and a virtual community meeting. The online survey was posted in late spring and remained open through the end of August. The virtual community meeting was held in early July.

Based on collective input from the community and in collaboration with park staff, the master plan project team developed a number of recommendations. The recommendations reflect the passion of the community, the enthusiasm of the park staff and the vision of a park that will better serve the community today and in the coming years.

The Board of Park Commissioners adopted the master plan at the January 11, 2021 board meeting.

The master plan recommendations fall into four categories.

Provide a Quality Trail Network.

Develop a balanced system of trails that offers a variety of experiences, provides inclusive opportunities to meet all skill levels, improves signage and wayfinding, and reduces future maintenance and repair costs.

Enhance the Two Primary Park Entrances.

Reimagine and enrich the Normandy Ridge Rd. and the Kennard Nature Nook entrances to create clearly identifiable and memorable arrival experiences that orient and draw visitors into the park and provide a sense of wonder and excitement for both new and existing park visitors.

Develop Quality Program Areas.

These areas will improve upon existing programs and support program expansion focusing on nature-based recreation, education, and wellness.

Advance Ecological Resiliency.

In cooperation with other agencies and organizations, continue efforts to manage and stabilize streambank erosion, improve water quality, control invasive species, and improve habitats for flora, fauna and wildlife.

Master plan recommendations set the stage for future Grant Park improvements to enhance the visitor experience and provide a prioritized guide for short- and long-term capital improvement budgeting. As priorities change, the improvement projects may shift, but overall, the master plan provides a vision that will assist us in our decision-making process.

We will focus efforts on the master plan in a four-phased approach over the next five years. In 2021, the Centerville-Washington Park District will concentrate efforts on improving trails, decommissioning rogue trails and tackling streambank erosion issues.

Review the full Grant Park Master Plan (PDF) >

We want to hear your thoughts about the Grant Park master plan! Please send your comments to mail@cwpd.org.

Grant Park is a beautiful and scenic 189-acre natural area that stretches along Holes Creek from Normandy Elementary School to McEwen Road. Developed on a former country estate, Normandy Farms, the park contains remnants of buildings and structures developed by Richard H. Grant, Sr. Today, the park is surrounded by residential neighborhoods, I-675, two schools and a retirement community. The park provides access to protected forests, meadows, prairies, wetlands and a meandering stream. A popular and extensive trail network connects the park’s natural and historic features with amenities such as an indoor program space, natural play area, storybook trail, campfire circles, sled hills and picnic areas.

Squirrels are among the most recognizable local wildlife; they’re noisy, they’re active, and they always seem to be around. But there’s more than one way to be a squirrel! Squirrels are members of the rodent family Sciuridae, and our local parks are home to several species within that group, including the bushy-tailed tree squirrels (gray, red, and fox species), mischievous eastern chipmunks, nocturnal northern flying squirrels, and stocky woodchucks of Groundhog Day fame. During summer, the day-active members of this group are conspicuous. But now, with winter upon us, chipmunks and, especially, woodchucks have gone missing. They’re still here, though; they’re just hiding for a few months, dormant in their underground nests.

The challenge for any mammal in winter is to maintain energy balance. Mammals are endothermic, meaning they generate enough heat from their own metabolism to maintain a warm body temperature. Like us, an active squirrel at any time of year has a body temperature of about 37 degrees Celsius (95 – 100 oF). As the outside temperature cools, the animal loses more heat to the environment, and so it must generate more heat to stay warm. In general, staying warm is more of a challenge for a smaller animal, which has a larger surface area (loses more heat) relative to its body mass. And so, as the colder seasons advance, small mammals must have strategies to match their energy expenditure to available resources.

One strategy to accomplish that balance is to sustain a warm body temperature throughout winter, at the cost of high energy expenditure. Tree squirrels and flying squirrels employ this strategy. In part, they use behaviors to reduce heat loss, including building insulated shelters and, particularly for flying squirrels, huddling in groups. But even with those behaviors, winter-active squirrels require adequate food resources to fuel their metabolism. These squirrels don’t store much extra fat, maybe 10% or less of body mass. Instead, they survive by caching food in advance of winter. Whereas red squirrels create a single large collection of seeds, gray squirrels may bury as many as 10,000 nuts and seeds in up to 1,000 different sites. Then, they have an incredible ability to find those stashed resources during winter. (Those left unretrieved help to reseed the forest.)

In contrast, both the smallest of our squirrels (chipmunks) and the largest (woodchucks) use a different winter strategy. That is, they (partially) give up on staying warm during cold weather and instead hibernate, dropping body temperature toward environmental temperature. Energy expenditure declines by a factor of 2 – 3 for each 10oC drop in body temperature, so a hibernating mammal conserves its fuel stores by burning energy at 5% or less of the rate when it’s warm-bodied. Some hibernating mammals support their winter metabolism from stored fat; woodchucks may double their body mass with fat before winter, then cease eating for the next several months. In contrast, chipmunks gain a little fat but mostly store food in their burrows during autumn, then arouse to eat at intervals during hibernation. They may even emerge aboveground if food is abundant.

Hibernation entails major resets to the body’s regulatory systems. As a woodchuck reduces its body temperature from “normal” (37oC) to hypothermic (7oC or so at a burrow temperature of 5oC), heart rate drops from 100 to 1 or 2 beats per minute. Breathing rate may be reduced to 10% and blood pressure to one-third of normal values. In hibernators that stop feeding, the intestinal tract undergoes substantial reduction in size and function. However, despite long spells of inactivity, hibernators seem not to suffer loss of bone or muscle strength.

Hibernation is not a simple on/off phenomenon. During a hibernation season lasting several months, the animal alternates between bouts of hibernation (each lasting 15 – 20 hours in chipmunks, ~150 hrs in woodchucks) and arousals back to normal body temperature (for ~15 hrs in chipmunks, 35 hrs in woodchucks). Overall, depending on species and conditions, 10 – 50%, of the hibernation season is spent at normal body temperature. Those arousal bouts may provide the opportunity to eliminate metabolic wastes, to eat (in some species), and to check on environmental conditions.

The diversity of winter strategies within a group of related species is fascinating, and it offers a framework for research. Studies of sciurid rodents might help us understand the underlying mechanisms behind regulation of metabolism and fattening, support of bone and muscle strength, the ability to induce prolonged sleep, the workings of memory, and other topics of biomedical interest. And while we contemplate those heady topics—squirrels are always a good source of entertainment, too!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University

With the season of diminished daylight upon us, the shift from summer wildlife to winter wildlife is pretty much complete. Insects have substantially disappeared from the meadows. You’re not likely to see a snake in your path through the woods. And hummingbirds have long since stopped appearing at feeders. Where have all those critters gone?

There is no single answer to that question. Many of the insects have died, leaving their eggs and larvae to survive the winter. Reptiles and amphibians largely have sought out sub-surface refuges protected from the coldest temperatures. Robins and bluebirds have retreated from the meadows into more sheltered forests. But for some animals, the answer is that they have moved out or in, migrating between their summer breeding grounds and their winter habitat. In southwest Ohio, many summer resident birds (hummingbirds, warblers, orioles, swallows, and others) and a few insects (monarch butterflies and green darner dragonflies, for example) leave for the southern US or beyond. Other species, including some common visitors to winter birdfeeders like dark-eyed juncos, pine siskins, and white-throated sparrows, arrive to Ohio from their breeding grounds further north.

The details of animal migration still hold much mystery. As recently as the 1700s, the best thinkers in Europe proposed that swallows (birds that, like here, are common in summer but absent in winter) spend the winter on the moon, or hiding in riverbeds. Now, we know that among Dayton’s summer-resident migratory animals, wood thrushes winter in the Yucatan region of Mexico, purple martins (a variety of swallow) in the Amazon basin of South America, and buckeye butterflies in the southeastern US.

A migrating animal has two fundamental needs. First, it must acquire sufficient fuel to sustain a long trip.  Some migrants fatten up before leaving and fuel their travels with stored energy. Amazingly, a bird as small as a ruby-throated hummingbird, with a lean body mass like a penny, can store enough fat—a few grams, equivalent to about a teaspoonful–to fuel a flight of 1000 miles (1600 km) or more. These tiny birds potentially can fly non-stop across the Gulf of Mexico to their wintering grounds in southern Mexico, where they resume their nectar diet. Monarch butterflies also winter in Mexico, but in contrast to the hummingbirds, they must feed en route. Monarchs actually gain fat during migration, which helps to sustain them during the winter when they feed little if at all.

The second fundamental need for a migrant is a map and compass; the animal needs to find its way back and forth between summer and winter ranges. Much remains to be learned about how animals accomplish those feats.  Studies of indigo buntings (common summer breeding birds in Dayton) in planetariums revealed that young birds learn the nighttime star patterns and can orient relative to the North Star. But they can find their way on cloudy nights, too. We now know that possible aids to avian navigation include geographic landmarks, the position of the sun, atmospheric phenomena, olfactory cues, the pattern of stars in the night sky, and the earth’s magnetic field.

One might think that a migrating animal would benefit, too, from following its experienced neighbors and relatives, so that migration routes could be learned from generation to generation. That might help long-lived animals that return each year to the same sites. But consider the monarch butterfly. Individual monarchs make the trip from Ohio to Mexico. On the northward return, though, those individuals breed in the southern US and then die; their offspring continue north. Indeed, the monarchs leaving Ohio for Mexico typically are about four generations removed from the individuals that departed the previous year. Next spring, the hummingbird at your feeder might be the same individual as last summer (wild hummingbirds can live for several years); but not so for the monarchs. That means that the entire southbound flock of monarch butterflies is “migrationally naïve.” And yet somehow their brain, the size of a pinhead, orchestrates the flight from here to there. (According to recent research, the monarch brain actually integrates a light-sensitive clock from the antennae with information from the eyes about the sun’s position.)

To me, the notion that a butterfly can chart a course from Ohio to Mexico is barely more plausible than that swallows fly to the moon. But we now know that it’s true. Ain’t nature amazing!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University

Honeysuckle was introduced in the United States in the mid to late 1800s as an ornamental plant. It has since become one of the most aggressive invasive, non-native plants in the state of Ohio. Honeysuckle shades out desirable native woodland plants, a problem for native wildlife that depend on native plants for food and shelter. As one of the first plants to green up in the spring, you are more likely to notice honeysuckle along roadsides and in local woodlands at that time. However, fall is the best time of year to make efforts to eliminate honeysuckle.

Centerville-Washington Park District (CWPD) is working to reduce honeysuckle in fourteen of your parks this fall, including Beechwood Springs, Bill Yeck, Big Bend, Black Oak, Donnybrook, Forest Walk, Grant, Greene Line, Nutt Woods, Oak Creek South, Pleasant Hill, Rooks Ravine, Rosewood and Yankee Parks. Removal techniques include digging out plants and using targeted foliar spraying. After dense honeysuckle removal, extended sightlines are reestablished in park woodlands and wildflowers begin to emerge in their place. Both are benefits for park visitors, making for a more pleasant hiking experience.

CWPD volunteers have contributed to the fight against honeysuckle. Local scout groups, park neighbors and volunteer groups from Yaskawa Motoman and Centerville City Schools have worked tirelessly to clear honeysuckle from Grant Park.

“The Centerville-Washington Park District appreciates the efforts of our volunteers to restore natural areas,” said CWPD Community Engagement Coordinator Ginger Clark. “We welcome additional assistance in the fight against this threat to the local ecosystem.”

You can help reduce the impact of invasive honeysuckle by volunteering to clear honeysuckle in your local parks. To get involved with efforts in Centerville, contact Ginger Clark at gclark@cwpd.org. In addition, removing honeysuckle from your own yard will keep this invasive plant from spreading to other areas.

(Image: Dense honeysuckle, cleared honeysuckle and new growth after removal)

We have been lucky again this autumn, living as we do in the temperate forest biome of Ohio, to witness one of nature’s spectacles, as summer’s green leaves turn to red, orange, and yellow. Now, as the weather cools, those colors are mostly shifting to brown and the branches are quickly losing their leaves. What’s going on here?

Scientists address those sorts of questions with two kinds of answers. One approach looks at proximate causes: what are the mechanisms that cause leaves to change color and fall off the tree? The other looks at ultimate causes: why do these phenomena occur, how do they fit into the life strategy of the tree?

The proximate mechanisms behind autumnal leaf transitions involve two main sets of processes. One of these is responsible for color change. Leaves are green because they contain chlorophyll, a pigment molecule that absorbs mostly blue and red light (so that we see the reflected green) and uses that light energy to begin the process of photosynthesis, yielding sugar that fuels plant cells. As sunshine lessens in autumn and temperatures fall, photosynthesis slows and there is less need for chlorophyll. So, the leaf begins to digest the molecules of chlorophyll and to recycle the components for other uses. As the abundant chlorophyll degrades, other pigments in the leaves become visible. Carotenoids, which absorb blue/green light for photosynthesis and also protect leaves against damage from excessive light, provide yellow and orange colors in autumn leaves in trees like beeches and tulip trees. Anthocyanins, which protect leaves against a variety of stresses, appear red as in some oaks and maples.

The second set of mechanisms in autumn trees results in leaf fall (abscission). That process is regulated by hormones, probably auxin and ethylene, whose abundance change seasonally. Under hormonal influence, the leaf digests the cell walls in the abscission zone at the base of each leaf petiole. As those cell walls deteriorate, the bond of leaf to tree weakens, and eventually the leaf falls off.

Those proximate causes define mechanisms. But what are the ultimate causes of autumn leaf transitions: not HOW, but WHY do trees give up on chlorophyll and shed their leaves each autumn? The bottom line is that leaves impose costs. Even during summer, when photosynthesis feeds the tree, making and sustaining leaves and chlorophyll is expensive. Moreover, leaves are sites of substantial water loss, and during winter they may accumulate snow that creates risk of limb breakage. Thus, during darker, colder months, when tree growth is slowed, leaves present more of a burden than a benefit, and they are released.

And yet, one of the beautiful sights on a clear winter day’s walk in the woods is the brown leaves of beech trees coated in snow and glowing backlit by the low-lying sun. The implication, of course, is that beech trees retain leaves during winter. And indeed, beeches, along with oaks and some other species, are “marcescent”: they retain at least some of their leaves, usually on immature parts of the tree, into the cold seasons. Why?

Perhaps the unpalatable, dry winter leaves protect next year’s buds from being eaten by browsers like deer, or from the drying winds of winter. Or maybe the ability of winter leaves to trap snow actually benefits the tree by retaining water that supports growth upon springtime thaw.

All living organisms incorporate tradeoffs. Any trait that allows an organism to survive and reproduce will be passed on to the offspring, even if that trait proves sub-optimal in some circumstances. So it is with leaves. Leaves are the sites of vital photosynthesis, but also of desiccating water loss. Leaves may protect a tree from winter browsing, but they also cost energy to build and maintain. As the diversity of North American trees evolved—Ohio forests contain more than 100 species—different species succeeded with different strategies. The result is that we now see the green leafy forests of summer, the multi-colored foliage of autumn, and the shimmering dead leaves of winter. As Simon and Garfunkel put it in their song A Hazy Shade of Winter, “Seasons change with the scenery, weaving time in a tapestry.”

Enjoy!

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University

Going nuts! A good year for walnuts — and squirrels.

These days, every squirrel seems to have a nut in its mouth. And if you walk in the woods, it’s hard not to notice the crunch of acorns underfoot, or the periodic crash of walnuts dropping like bombs from the treetops. These events signal the ripening of the local mast crops. Many of Ohio’s tree species produce fruits and nuts. Fleshy fruits like crabapples, pawpaws, and black cherries are known as “soft mast” crops; many of these ripen during summer or early autumn, and they substantially decay through the course of those seasons. In contrast, hard-shelled nuts like acorns, beech nuts, walnuts, and hickory nuts — so-called “hard mast” – tend to ripen later, and their protective shells allow them to persist through the winter. Hard mast fruits may be tough on the outside, but the inner flesh is rich in nutrients and calories. As such, hard mast provides critical food for woodland animals through the cold, when other foods like insects and fresh plants are unavailable.

Although black walnuts and red oak acorns litter the ground this year, that’s not the case every year. “Mast years,” with abundant crops of nuts, occur every few years, with different cycles for different tree species. Interestingly, mast years are not a feature of individual trees. Rather, they tend to be synchronized across forests or geographic areas. Scientists still are not certain about the explanation for these patterns: what is it that triggers a mast year, and what generates the geographic synchrony? The most obvious explanation is climate; particular conditions of temperature or precipitation may induce particular species to produce fruit. Researchers also postulate that trees may “communicate” with each other to synchronize, through chemical signals transmitted across their roots or leaves.

This strategy of variable productivity probably helps the trees to secure their reproduction. Many mast fruits are infested with pests, rot on the forest floor, or are eaten by animals. Producing huge crops in selected years may assure that at least some nuts survive to germinate and produce new trees.

In years when mast crops are abundant, the animals that eat those crops likewise thrive. Deer, squirrels, chipmunks, mice, turkeys, and other animals are better able to survive and proliferate in years with rich winter food supplies. In turn, organisms that rely on those consumers — hawks that eat squirrels, or ticks that live on mice, for example — also thrive in parallel. The cycle of nuts substantially drives the dynamics of the ecosystem.

So, if you’re walking in the woods, beware of falling walnuts! And in the year ahead: be on the lookout for a lot of squirrels.

Article and photo contributed by Dr. David L. Goldstein, Emeritus Professor, Department of Biological Sciences, Wright State University

Pleasant Hill Park has a new Little Free Library! Patrick Hansford designed the Little Free Library to resemble the iconic sunscreen at Woodbourne Library. It was a gift from the Friends of Washington-Centerville Public Library to honor the contributions made by Kim Senft-Paras during her time as Director of Washington-Centerville Public Library, 2009 – 2019.

“What better way to celebrate Kim’s contributions to the Library than with a Little Free Library that resembles the Woodbourne Library, which she was so instrumental in renovating and expanding,” says Marilouise Beeman, President of Friends of WCPL.

This is the sixth Little Free Library in your parks. Others are located at Forest Field, Iron Horse, Robert F. Mays, Schoolhouse and Yankee Parks. Stop by to find a book and leave a book to share!

You can find other Little Free Libraries in our area and all over the world by visiting the Little Free Library website.

After two years, a popular hiking trail has reopened in Centerville-Washington Park District’s (CWPD) Grant Park. We closed the yellow trail, a one-mile natural path, in 2018 after stream bank erosion made conditions unsafe for park visitors. Grant Park has two main entrances, one on Normandy Ridge Road and the other on McEwen Road. The McEwen Road entrance is home to the Kennard Nature Nook, the Mark Kreusch Nature Playce and the McEwen Barn. The yellow trail is the only route connecting the Kennard Nature Nook area to the rest of the 189-acre nature park. Without a trail reconstruction, the park would have evolved into two smaller nature parks. After considering several alternatives, we began reconstruction of the trail in fall 2019. The project entailed re-grading the hillside, constructing a gabion rock wall to control erosion, and repositioning the trail. A $215K park improvement, the project was a major undertaking for CWPD.

CWPD Planning and Project Manager Nick Meyer said, “During the closure, it was clear how well-loved this particular trail is within our local community. It was a big project and it was important that we get it right. We are proud of the results and are excited to open a safer trail for our visitors.”

The trail reopened to visitors just before the Fourth of July weekend. There is still clean-up work to do and it will take time for the vegetation to grow around the construction site. Nine hundred new trees were planted and the prairie behind the Kennard Nature Nook on McEwen Road was re-seeded with native wildflowers and grasses.

This is just the beginning of Grant Park improvements. We are creating a master plan that will determine future improvements to the park. We welcome public input in the planning process.

Take the survey to tell us your comments about Grant Park >

Grant Park features a nature playground, nature literature trail, fire circles, creek and several miles of natural hiking trails.

Map of Grant Park (PDF) >

Discover a fun way to get together with your neighbors and their dogs this summer! In an effort to create more active and social outdoor spaces, we will rotate pop-up dog parks to various neighborhood parks every three weeks throughout the summer months. Temporary fencing will delineate the dog parks. Dogs are still required to be on a leash when they are outside of the designated fenced areas. Rules will be posted to help everyone respectfully utilize the space.

The first park visited by the Pop-Up Pup Park this summer was Quail Run Park. The Pop-Up Pup Park is tentatively scheduled to visit Little Mound, Concept and Stringtown Parks before the summer ends!

Pop-Up Pup Park Rules

• This is an unsupervised dog park. The use of this facility is strictly at your own risk (ORC 2744). The Centerville-Washington Park District does not assume any responsibility for loss or injuries.
• Dogs MUST be leashed outside the enclosed area.
• Children 8 – 14 must be with an adult.
• Current vaccinations and licenses are required.
• Maximum of two dogs per adult visitor.
• Dogs displaying aggressive behavior are to be removed immediately.
• You are liable for injuries and damage caused by your dog.
• Please clean up after your dog.

Prohibited from the Pop-Up Pup Park

• Children 7 and under
• Puppies under 4 months
• Dogs in heat
• Toys, treats, food
• Smoking
• Glass containers
• Other animals

The Pop-Up Pup Parks are generously sponsored by the Centerville Rotary Club.

Pelbrook Park, a 5.5-acre neighborhood park near the eastern edge of the City of Centerville, has been officially renamed Cloverbrook Park. Park neighbors requested the name change during two public input meetings about future improvements to the park. The change was approved by the Board of Park Commissioners in August 2019 and a new park sign was installed in June 2020.

“During a public input meeting, we were surprised to learn that many neighbors of Pelbrook Park did not recognize Pelbrook as the park name. Neighbors have been calling the park ‘Cloverbrook Park’ for years because the park is on Cloverbook Park Drive. The neighbors were overwhelmingly in favor of changing the name and we were happy to make it official,” said Carrie Dittman, marketing and communications supervisor for the Centerville-Washington Park District.

Cloverbrook Park will be receiving a paved walking path this summer, an improvement also requested at the public input meetings.

Grant Park is a 189-acre natural area. Trails in the park lead along creeks and through meadow, forest, prairie and wetland habitats. The trails are of varying difficulty; some follow ridgelines or bottomlands, while others climb fairly steep hills.

We are preparing a new master plan for the park! At this first stage in the planning process, your feedback is important and greatly appreciated.

We are conducting a short survey of trail users. Thank you for taking a few moments to share your thoughts!

Take the survey >

The Centerville-Washington Park District initiated a Bill Yeck Park trail master plan as a priority from the CWPD 2016-2019 Strategic Plan. The goal of the project was to analyze the environmental, ecological and experiential aspects of the park’s trail system and develop recommendations for how the park should evolve in future years. A consultant team of landscape architects, ecological scientists and trail builders conducted various site visits throughout 2018 and facilitated a public engagement strategy to develop an understanding of the park and its users. An online survey and multiple public forums were held in 2018.

At the conclusion of the planning effort, a Bill Yeck Park trail master plan was written to summarize the site observations and public feedback and propose recommendations for the future of the park’s trail system.

The biggest plan priority is trail improvement. The first course of action is to increase the quality of trail surface, eliminating tripping hazards and allowing for park use throughout the year. Additional improvements will include trail accessibility, creek crossings, wayfinding and signage.

Work on new trails began in the summer of 2019 and will continue for several years.

Read the Bill Yeck Park Trail Master Plan Executive Summary (PDF) >

Download a new trail map (updated 9-27-2019) >

In the fall of 2018, the Centerville-Washington Park District embarked on an effort to get neighbor input and opinion about two local, neighborhood parks — Pelbrook Park and Willowbrook Park. The process began with guided discussions with park neighbors. The main question was, “What would entice neighbors to visit the park more often?” Two different consultants led the group conversations and followed up with a compilation of the comments and the data about each of the immediate neighborhoods.

Both consultants presented a report to the Park District showing the desired elements, ranked in order of importance. The report was accompanied by a concept layout of the park, based on residents’ comments.

In May of 2019, neighbors were invited to come to the park to have a look at the concept layout and to take a look at the priorities from the fall event. They were asked to look at pictures representing possible improvements, and the concept drawing.

While there were specific differences and preferences regarding the future of the two parks, there were many similarities. Patterns from the two groups’ input may give good overall direction for the future of all neighborhood parks. The similarities are as follows:

• Un-interrupted, lawn space for open play is valued for a variety of self-directed play (Frisbee, touch football, tag, etc.)
• Both groups see the neighborhood parks as places for children to play, and for parents/grandparents to visit with children
• People like shade trees in the parks, especially around the playgrounds
• Where the playground is set well back from the street/sidewalk, a paved path from the sidewalk to the playground is highly desired (for strollers, toddlers, older people, bicycles, wagons, etc.)

We will begin work soon on improvements to each park, and follow a similar process in the future for neighborhood park improvements!

For more specific information, you can review a summary for each park.

Pelbrook Park summary (PDF) >

Willowbrook Park summary (PDF) >

In late April, the Park District officially took ownership of the Hithergreen site! The property is now owned by the Park District to convert into a public, neighborhood park.

Park conversion approximate timeline

• May –  demolition specifications completed
• Early June – opening competitive bids for demolition of the building and parking lots
• Mid-June – demolition start date should be finalized. Current plans allow for demolition and basic site restoration of 150-day completion specification (approximately mid-June to mid-November)
• Mid-summer – park planning consultant engaged
• Late-summer – neighborhood engagement process to develop a concept plan based on neighbors’ vision.
• October – re-seeding of damaged, re-graded portions of the site
• December – Park Board will approve a budget for park development for work that will be done in 2020

When a contractor for demolition is hired, and work is permitted by the County and Township, a more specific timeline will be created.

CWPD will utilize the engagement process used and refined by Willowbrook Park and Pelbrook Park neighbors in 2018-19.

The new, 51st park for the community comes from a cooperative venture between Washington Township and the Centerville-Washington Park District. The two agencies created a plan and applied for an Ohio Public Works “Clean Ohio” grant to fund the majority of the project. The total grant amount was for $558,000, which represents 75% of the project cost.