Wood Thrush: The Pavarotti of our Forests

When I got out of my car at the Center last Thursday morning, I was immediately greeted by one of the happiest sounds of the forest: the melodic church-organ voice of the wood thrush. A very close cousin of the uber-common robin, the wood thrush is one of the most important birds you should introduce yourself to as quickly as possible.

And a simple walk on our trails or along the Wissahickon should help you accomplish that.

A migrant, the wood thrush has only recently returned from its winter haunts in Central and South America. So its call is one of the keystones in my springtime arch– as is the first skunk cabbage, the first butterfly, the first warbler, the first turtle along our pond’s ledge. While last week’s call was not the first of the year– that came in April– it was a happy reminder that some parts of the world still work.  

The call is throaty and lush, a “haunting ee-oh-lay,” says on one website, with a bit of vibrato. It’s widely considered the preeminent songster of a Pennsylvania forest, our Adele, our Pavarotti. No less an observer than transcendentalist Henry David Thoreau agreed. “The thrush alone declares the immortal wealth and vigor that is in the forest,” he wrote. “Whenever a man hears it, he is young, and Nature is in her spring. It is a new world and a free country, and the gates of heaven are not shut against him.”

Doesn’t that alone make you want to go hear one? “Ethereal” is one descriptor you’ll encounter when reading about thrush song, as it uncannily can whistle two notes simultaneously, harmonizing with itself to produce the ringing that is so entrancing. It sings at both sunrise and sunset, making it one of the very first– and very last– birds you will hear that day.

It’s male that sings, often on an exposed perch in a tree, and the song carries surprisingly far in a dense forest. Like most birdsong, this accomplishes two tasks simultaneously. For one, it signals to other males to stay away, the male wielding his song to establish a territory of a few acres– so the male singing above me likely has his eyes set on a nest site not far from our Visitor Center.

But it also tells female thrushes he is in vibrant health and has a great nest site picked out. Within days of his territorial announcement, a female initiates their pairing, enticing him to chase her in silent circular flights only a few feet above the ground. 

The bird itself is strikingly handsome. About the same size as its robin cousin, it sports a reddish-brown coat on its back, but wears a bright-white vest speckled with large black dots– the contrasts are beautiful. Many websites describe it as being “potbellied,” which is cute, and this feature helps distinguish it from its close relatives veery and hermit thrush, none of whom have dots (or songs) quite as striking as the wood thrush.

Wood thrushes are omnivores, feeding mostly on leaf-litter invertebrates and fruits from shrubs. Their summer diet includes adult beetles and flies, caterpillars, spiders, millipedes, ants, and more, and snails and salamanders are occasional prey as well. These are also the foods parent thrushes stuff into the gaping maws of their nestlings.

By the late summer and early fall, however, the thrush shifts its diet to fruits– something robin do too. They especially crave fatty fruits that help them bulk up (and get even more potbellied) for their exhausting southern migration. So in this season, they are seeking out the fruits of woodland shrubs, vines, and wildflowers like spicebush, fox grape, blueberry, holly, elderberry, jack-in-the-pulpit, Virginia creeper, pokeweed, dogwood, black cherry, and black gum. Poison ivy, bless its heart, produces splendid fall fruits that are avian magnets.

Happily, our forest is loaded with these fruits, so wood thrushes are common here. 

A creature of the interior forest and an important indicator of forest health, the thrush has become a symbol of the vanishing American songbird; one study estimated that its population has declined 62% since 1966 in eastern North America. Forest fragmentation is often cited as a chief reason for its decline, as it requires more than small suburban woodlots, and fragmented forests offer fewer places to escape predators. The brown-headed cowbird, a social parasite that lays its eggs in other birds’ nests, will stay out of deep forest interiors, but can easily find thrushes in smaller forests– and lay its eggs in the nest, its larger nestling outcompeting smaller baby thrushes for parental attention.

It’s also a victim of being migratory. While North American forests are fragmenting, Central and South American forests– its winter home– are disappearing, so, like many birds, the wood thrush is being hit at both ends of its migration.

But the first time I hear one at the Center in the spring, I stop and savor the sound: the gates of heaven have just opened. 

By Mike Weilbacher, Executive Director

Bird Safe Philly: Helping Migrating Birds on their Journey North

A common yellowthroat, one of the many species of migrating birds passing over the city. This one collided with a plate glass window, but happily was only dazed, brought to the Wildlife Clinic, treated, and released– a conservation success story.

It’s migration season and millions of birds are right now pouring over the city of Philadelphia on their way to northern nesting grounds. A river of warblers, flycatchers, shorebirds, hummingbirds, thrushes, and more are heading to their ancestral mating grounds. 

And Bird Safe Philly, a new partnership, hopes to make their travels safer. Birds colliding with plate-glass windows in cities is, sadly, a longstanding issue that the group hopes to address– and mitigate. Two leaders of the Bird Safe Philly effort will be on hand at the Schuylkill Centers’s Earth Day Live event on Thursday, April 21 at 7:00 p.m., a free celebration of the Earth Day holiday.

Leigh Altadonna, president of Wyncote Audubon Society and one of the founders of Bird Safe Philly, joins Chris Strub, the director of the Wildlife Clinic at the Schuylkill Center, at the event. 

The partnership partly grew out of a horrific event on October 2, 2020, when, during the birds’ migration south, poor-visibility weather colluded with confusing big-city lights to cause the death of 1,500 migratory birds in a single night in Philadelphia, resulting in a lot of media attention in Philly and nationwide. Turns out bright lights can confuse birds, who migrate at night, especially when clouds don’t allow them to navigate via stars. 

“I reached out and convened a meeting of key bird people,” Leigh told me last week, “like Audubon Mid-Atlantic, Audubon’s Wyncote and Valley Forge chapters, the Delaware Valley Ornithological Club, probably the oldest bird club in Philly, and the Academy of Natural Sciences. We talked about the need to get on a light’s-out movement in the city.” Leigh was “anointed,” as he said, the coordinator of Bird Safe Philly, convening meetings and working groups, and a partnership was forged.

Lights Out Philly is one of the project’s big successes. Multiple brightly lit skyscrapers– the Cira Centre, the FMC Tower, Liberty Place, many owned by Brandywine Realty Trust– join other well-known buildings like the Convention Center and the Wells Fargo Center in agreeing to turn off their lights during migration season from midnight to 6 a.m. Maybe you’ve noticed this on late-night drives through the city. 

While PECO, a corporate sponsor of the program, hasn’t turned off its iconic crown lights, it has dimmed their intensity and shifted the wavelength. “They’ve agreed to change the light colors,” Leigh told me, “as blue and green are a little better than the other colors. Another big thing PECO did was volunteer to place info about us in their billing; they did a great insert– that was helpful too.”

He continued, “But well over 50% of these birds die from collisions with low-story buildings of four stories or less.” So it’s great that smaller buildings like the American Philosophical Society and Ursinus College have signed on. As a longtime administrator for the Abington School District, he said, “I’d love to see the Philadelphia School District adopt this program, and their buildings turn off their second, third and fourth floors light. They probably comply already in most cases.”

“What is really great,” he offered, “is we have volunteer monitors that go down early in the morning starting at five. They go around and look for bird casualties– ‘bag and tag’ them so to speak. These all go to the Academy of Natural Sciences, and become part of the research effort to get data on size and scope of the issue.”

Since not all of the birds are dead, happily some of them are only dazed, or perhaps suffering from concussions. “We have a cadre of volunteers who transport injured birds to the Wildlife Clinic.” That’s where Chris Strub comes in.

“Chris and his staff have been great,” Leigh offered. “These stunned birds, sitting on the ground, are easy prey for cats, rats, and more. Without intervention, they would likely die. But with the help from the clinic staff, the success rate in healing them has been close to 80%. That’s pretty significant– we really credit the clinic for helping with this.”

About 200 birds come to our clinic annually through the transport program. Chris Strub notes, “It’s really rewarding to actually make a difference in the window-strike story. We don’t have the capacity to go out and get the birds, but we do have the resources to treat them. Now that we are actually getting the birds, we can be part of the initiative, which eliminates a real source of frustration of not being able to go out and get them.

“I have immense respect for all the volunteers and organizers,” Chris continued, “who are walking the streets of Philadelphia in early mornings to find them while also witnessing the number of dead birds. This really inspires me, and brings home that bird conservation is a huge team effort– no one person can do it. It takes partnerships like this to ensure that a lot more of the birds survive and get a chance to further their species.”

Earth Day Live features both Chris and Leigh. In addition, historian Adam Rose, author of “The Genius of Earth Day,” recounts the importance of Earth Day in galvanizing environmental action, and the Center’s land stewardship coordinator Sam Bucciarelli highlights edible native plants you can grow in your garden. The free event is set for Thursday, April 21 at 7:00 p.m. via Zoom; register here.

By: Mike Weilbacher, Executive Director

New Mystery Illness Killing our Birds

A robin that has passed away from the new mystery bird illness sweeping across the country. Photo courtesy of Tamarack Wildlife Center.

Listen to Chris Strub, Director of Wildlife rehabilitation on WHYY’s Radio Times discussing this disease (starts at 32:00)

For bird enthusiasts, this spring had an ominous touch of COVID deja vu. Young birds were falling ill with alarming symptoms and dying– and no one knew the cause. Most commonly impacting starlings, blue jays, and grackles, the illness typically shows up with weeping, crusted-shut eyes and neurological symptoms. And like COVID, some birds are asymptomatic, or show a completely different suite of symptoms. It has also affected robins, cardinals, and others. It seems to strike mostly young birds, often fledglings who have recently left the nest, and the disease progression is rapid, leading to death in just days.

Starting out around DC, the illness spread quickly across the Mid-Atlantic, north into New Jersey and Pennsylvania, south into Florida, and as far west as Ohio. Wildlife rehabilitation clinics sounded the alarm, hoping to get out in front of the disease and mitigate its effects, even without fully understanding why or how it was happening.

One thing we do know, even without a year and a half of COVID-19 keeping us on our toes, was that social distancing was key. However the disease was spread, keeping birds from congregating in close quarters would surely slow it down. But how do you tell a blue jay to stay clear of its neighbors? You don’t need to speak blue jay– you just need to acknowledge the role humans play in encouraging wildlife to congregate in large numbers. In nature, most animals don’t like to be too close to their neighbors, especially during the breeding season when territorial feelings are high.  

Wildlife clinics have dealt with outbreaks like this before, usually of known diseases like finch conjunctivitis, and the answer is always the same: take down those bird feeders!

While it may seem unkind to withhold food at a time of crisis, spring and summer are actually the best time to remove your feeders. Birds have plenty of natural, native food sources, and those with nestlings (even seed-eating birds) rely more heavily on wild insects than anything that can be placed in a feeder. In terms of disease prevention, bird feeders are contagion hotspots, as their hard non-porous surfaces allow pathogens to live longer and infect more birds. Competition around feeders also brings birds into much closer contact than they would naturally tolerate, creating yet another disease vector.  

Whatever was causing the illness, if it was contagious at all, it would spread much more rapidly around bird feeders, and so they had to go. Environmental centers like the Schuylkill Center led the charge in removing feeders, and encouraged members of the community to follow suit. We also suspended our birdseed sales just to be safe.  Even scatter-feeding birds can promote disease spread, as it still encourages close contact.  

Luckily, by stewarding native plants and diverse natural ecosystems, environmental centers like ours provide lots of foraging opportunities, ensuring the birds won’t go hungry.  

Where does that leave us as wildlife rehabilitators as we look towards the beginning of fall migration? Even though the disease seems to be waning in some areas, we still don’t know what caused it, nor what impact it might have in the fall. No definitive diagnosis has emerged, but researchers across the region are working on it, including the University of Pennsylvania’s Wildlife Futures Program.  

Our Wildlife Clinic is prepared to handle whatever happens as the summer wears on. We hope that the mysterious illness will leave as suddenly as it appeared, but we may also see new outbreaks as birds begin to naturally congregate for fall migration. Migration is also very taxing on a bird’s body, leaving them more open to pathogens. On the plus side, as birds mature, so do their immune systems, giving them a better chance of fighting off illness.

In the meantime, it’s best to keep those feeders down, and keep an eye on our feathered neighbors. As with mask-wearing and social distancing, encouraging birds to keep their distance from one another can only help. Suspected cases can be reported to the UPenn Wildlife Futures Program, and birds who are sick but still living can be brought to your nearest wildlife rehabilitation center for care.

If you encounter a sick wild animal, whether or not it appears to have symptoms of a specific illness, it’s important to contact your local wildlife rehabilitator right away. We can provide guidance and information, and do everything we can to help animals brought in to us for care.  We also play an important role in disease outbreaks like this, keeping tabs on disease spread on a local level and collaborating with researchers working on diagnoses.

By Chris Strub, Director of Wildlife Rehabilitation

A Tale of Two Birds

While planting trees over the last two weeks at the Schuylkill Center, a familiar sound echoed through our Roxborough woods, something like an ethereal organ being played in the forest. I smiled: the wood thrush is back.

The wood thrush—a cousin of the robin and about the same size, but with a cinnamon coat and dramatic black spots on a bright white chest—is widely considered the best singer of all songbirds. No less an observer than Henry David Thoreau agreed. “The thrush alone declares the immortal wealth and vigor that is in the forest,” he wrote. “Whenever a man hears it, he is young, and Nature is in her spring. It is a new world and a free country, and the gates of heaven are not shut against him.”

Doesn’t that alone make you want to go hear one? The “ethereal” piece is because, almost uniquely, the bird uncannily can whistle two notes simultaneously, harmonizing with itself to produce the ringing that is so entrancing. Even better, it often sings at both sunrise and sunset, making it one of the first as well as one of the last birds you might hear during the day.

A creature of the interior forest and an important indicator of forest health, the thrush has become a symbol of the vanishing American songbird; one study estimated that its population has declined 62% since 1966 in eastern North America. Forest fragmentation is often cited as a chief reason for its decline, as it requires more than small suburban woodlots, and fragmented forests offer fewer places to escape predators. The brown-headed cowbird, a social parasite that lays its eggs in other birds’ nests, will stay out of deep interiors, but can easily find thrushes in smaller forests—and lay its eggs in the nest, its nestling outcompeting baby thrushes for parental attention.

It’s also a victim of being migratory. While North American forests are fragmenting, Central and South American forests—its winter home—are disappearing too, so, like many birds, the wood thrush is being hit at both ends of its migration.

But the first time I hear one every April at the Schuylkill Center, I stop and savor the sound: the gates of heaven have just opened. Please come and hear, maybe even see, it yourself.

And there’s a second bird I’d love for you to hear, this one the most common bird you’ve never heard of. If you have ever walked through a summertime forest anywhere in the Philadelphia region, you have heard this bird—and heard it, and heard it, and heard it.

Red-eyed vireo

Because the red-eyed vireo may just be the most abundant forest bird across Pennsylvania. Warbler-small and usually gleaning insects high up in the treetops, the bird sings incessantly, holding an ongoing monologue of usually three-noted sounds, some rising, some falling, as if it were asking and answering its own questions: “How are you? I am fine. Doing well. Pretty good. Are you sure?”

And it does have a red eye, but while I have heard thousands of vireos sing, I can count on only one hand the number of times I have actually seen the red eye—and the first time made me scream with delight. If you can see the red eye, you’ll also catch the two black stripes sandwiching a white one, slicing right through the red eye.

The name vireo is Latin for “I am green,” which its body feathers are—sort of. Its species name olivaceus only drives home that point in case you missed it the first time.

It builds one of the smallest non-hummingbird nests, a petite cup that dangles from the crotch of a high tree branch, held together with a number of fibers—and spider silk. These nests are even harder to find than the vireo’s eye.

The red-eye may be the most prominent member of a clan of songbirds, others of which drive even expert birders batty. There’s currently a solitary vireo hanging out behind the Schuylkill Center’s preschool classrooms that one of our teachers—an ace bidder herself—has been hearing. So consider the red-eye your gateway into the vireo kingdom. If you’ve heard one, challenge yourself to see the eye; if you’ve never heard of this bird, here’s a wonderful assignment for you.

Go for a walk this week, and listen for both the organ pipes of the thrush and the chatty monologist, the red-eyed vireo. The gates of heaven will open for you too.

Mike Weilbacher, Executive Director

 

Gardening with Native Plants: Great for You AND the Planet

Like all forests around us, the Schuylkill Center is in full bloom right now. You really have to see it to believe it. 

Virginia bluebells, pink buds opening into bright blue flowers. Shooting stars, white flowers blazing across the forest floor. Trillium, a gorgeous but an oh-so-ephemeral plant, the species over here blooming in white, but the one over there in red. Solomon’s seal, named for the Biblical king, its delicate bell-like flowers dangling from zig-zags of leaves. Jack-in-the-pulpit, poking through the forest floor, Jack dutifully staying inside his lectern. And that’s just a start.

Solomon’s seal

And the good news? You can plant these in your yard. In fact, planting these in your yard is one of the most powerful acts you can do to improve the health of our planet. (And many of them require shade, even better for many of us without good sun in our yards.) 

The better news?  They are perennial; planting them now often means they come up better next year, spreading a bit. And unlike impatiens, they require little watering.

But why is this a powerful act? The tulips, daffodils and crocuses that grace most of our gardens are without question beautiful flowers. But since they are not native to Pennsylvania or even America, few other living things live on them. Sure, deer might eat them (as deer seem to like everything), but caterpillars don’t touch most of them, and neither do many or any other insects. While that makes us and landscapers happy—the plants are not getting consumed by hungry insects—it makes a mother robin looking for caterpillars to feed her fast-growing, hungry babies very sad.  

That’s the problem: a yard filled with tulips, daffodils, and crocuses sadly has no wildlife value for birds looking to feed bugs to their babies. And surprisingly, almost all birds feed bugs to their babies—even the babies of seed-eating birds grow up being fed bugs first. So that means a world filled with daffodils is by necessity one devoid of robins, wrens, thrushes, and more.

That’s the beauty of places like the Schuylkill Center and the Wissahickon—we’re islands of native plants in an ocean of inedible lawns and plantings. Truthfully, a lawn is an ecological desert.

Spring violets

One native Pennsylvania oak, as we noted last week, supports literally thousands of species of insects, including hundreds of caterpillars of different moths and butterflies. Same with the wild black cherry tree, with leaves that caterpillars devour, flowers that offer nectar for butterflies, and fruit that birds crave. One tree holds up an entire world.

Gardening with native plants, a modest movement that we wholeheartedly support, is thus a powerful act of environmental improvement, as it supports the many species of small creatures that inhabit this part of the planet, protecting our biological diversity.

The Schuylkill Center also makes this action easy for you: right now, online, we are offering our annual Native Plant Sale, your one-stop shopping for many of  the flowers I noted above (and so many more!). We’re also selling shrubs. ferns, grasses, vines and trees as well, plus soil and other gardening supplies. If you become a Schuylkill Center member, we’ll even give you a discount on the flowers you buy, all by itself reason enough to join.

In the shrub department alone, for example, several of the shrubs offer berries that are completely irresistible to songbirds. Serviceberry (also called shadbush because it blooms about when shad run up rivers), chokeberry, elderberry, and blueberry are just a few of the shrubs in our sale that sport wonderful berries that feed a diversity of native wildlife; blueberries especially attract a  large number of insects pollinators to them. 

In the tree section, redbuds and magnolias offer beautiful springtime flowers—redbuds are the medium sized trees blushing lilac right now. Oaks, birches, pawpaws, cedars, and horse chestnuts are a sampling of some of the other high-value native trees.

Redbud tree

We’ve even got sedges and grasses that offer visual interest in your garden. 

To hold your hand in this, on this week’s Thursday Night Live, our weekly deep dive into all things natural, we’re offering the Native Plants Hotline, a chance for anyone to call in with their garden questions about gardening with natives. Register for that on our website as well; the free event starts Thursday, April 29 at 7 p.m. and features both gardening and tree experts. Do call.

Spring is busting out all over—and you can bring that action into your yard. To be sure, you don’t have to replant your entire yard. Not at all. Just buy a few plants at the sale, add them to your yard, and every year tuck a few more here and there. It’s so easy. Come see. And the plants are easily as beautiful as daffodils—some, even more so. (Check out Virginia bluebells and white trillium.)

And the best part, our birds and butterflies will thank you.  

—Mike Weilbacher, Executive Director

Migration Nature Kit: At-Home Version

This week’s nature kits focus on migration. Twice a year creatures such as certain birds and butterflies make thousand-mile journeys between North and South America. After today’s activity you will understand some of the unique challenges and needs of migrating animals, and you will learn how you can help them safely make their journeys. 

Every Saturday, Nature Kits are given out on a first-come, first-served basis from 10:00 am–12:00 pm. Nature Kits focus on a different theme each week and are meant to be done along our trails and given back once completed. If you can’t make it out to the Center to pick up a kit, make sure to check our blog each week for ways to get in some nature exploration at home.

Activity #1: Migration Hopscotch:
  • Draw a hopscotch board with 10 numbered squares on the pavement with chalk.
  • Then gather 8-10 items that will be placed on the squares later.
    • The items can be anything that you find—sticks, pinecones, toys, rocks, utensils, etc.
  • After drawing your board, stand in front of the #1 square; you are a bird starting your migration from north to south.
    • Each square represents a stopover-site between North America (Canada) and South America.
    • Migrate southward on the course by hopping from square to square until you arrive past square #10.
    • Before you turn to head back north, have your grownup place 2 items on 2 different squares—these are sites that no longer have resources for you to use.
    • Hop back north without stepping on the squares that have these props.
    • Continue placing more props on empty squares before every new round until it is impossible to migrate due to lack of squares (resources).
  • When the game is done, think about the importance of resources such as food, water, and land to a bird’s successful migration.
    • What happens if those resources are taken away? How can we save resources for migrating birds? 

 

Activity #2: Nesting Tree Memory Game

Did you know that some birds, such as swallows, return to one tree year after year to nest? Scientists are still unsure how they are able to find the same tree after migrating thousands of miles away from their warm overwinter spots in the south. Do you think you would be able to remember your nesting tree?

    • In your yard or a park, choose one tree that will be your final destination nesting tree.
    • Then create a trail to get to your final tree, finding 4 trees along the way to “rest” at before arriving at your destination.
      • Touch each tree before moving onto the next one, as your grownup records the order of the trees that you stopped at.
    • After you arrive at your nesting tree, leave the area for at least 10 minutes, then return and try to perfectly repeat the order of the trees you touched on your trail to your nesting tree.
    • Were you able to remember your route precisely? 
Activity #3: Migration Resources Scavenger Hunt

Nearly all migrating creatures need to make stops along the way to their destination to replenish on water, food, and rest.

  • Choose a migrating bird you would like to become.
  • Think about what resources this bird would need during its journey – what food do you eat, and where would you find it?
    • Where do you like to rest – in water, in a tree, in a meadow?
    • What about drinking water?
  • Plan out places in your yard or a park that you would need to visit to survive your flight.
    • In the table below, record the resources you find by checking off boxes with a pencil. 

Migration Resources Scavenger Hunt

Resource 

(up to 3 sites)

Check box when you find this resource Check box when you find this resource Check box when you find this resource
Food (must find at least 1)

What does your bird eat? Examples: insects, worms, berries, plants

Drinking Water (must find at least 2)
Shelter or a place to rest (must find at least 1)

 

—Rebecca Deegan, Environmental Educator

Naughty by Nature: A Valentine’s Day Special Event

Birds do it, bees do it, and sentimental fleas? Don’t even ask. 

In celebration of the coming Valentine’s Day holiday, the Schuylkill Center cordially invites you to a special edition of our new Thursday Night Live series. “Naughty by Nature” features the amazing stories of sex and courtship in the animal kingdom, as these stories are extraordinary and just not shared often enough. I’ll be offering this PG-13 lecture on Thursday, February 11 at 7:00 p.m. The event is free, but you’ll need to register and get the Zoom link. 

Animals possess a wide range of adaptations to court their mates. So lion manes, buck antlers, firefly flashes, cricket chirps, cardinal songs, and peacock feathers—among many others—are all adaptations to seduce females. Let’s start with those buck antlers.

The antlers give a female strong visual cues as to the health and vitality of the male—the size of the rack matters, and as bucks mature the antlers tend to get larger and larger. But the story doesn’t stop there. Many times on autumn walks around the Schuylkill Center’s trails, I’ve come across a buck’s rut, a scrape in the ground made by the male. He not only scratches the ground clear of grass, but urinates down his hind legs, the urine mixing with hormones secreted by glands in his knee joints, and a witch’s brew of liquids puddles in the mud. The does find the smell, well, irresistible. He has staked out his turf, laid down his calling card—and likely will find does there the next evening. This system works exceptionally well, as just about every doe is pregnant by the time winter settles in. 

Let’s swim over to the clownfish, the brightly colored star of “Finding Nemo.” Well, surprise, the movie got it all wrong. In much of the animal kingdom, gender is relatively straightforward; an organism is oftentimes born or hatched as male or female. Bucks are bucks; does remain does. Not so among clownfish.

Clownsfih have this marvelous adaptation of being immune to the stings of the sea anemones that live alongside them in coral reefs. The clownfish uses the anemone as  protection, making it harder for those hungry moray eels to get them. A small cluster of clownfish live in and around one anemone, a little community of clowns cloaked by anemone tentacles.

But two of the clownfish are larger, one male and one female, and these are the two that mate; the others are not only celibate, they are all male. Let’s say that moray eel gets lucky, or old age catches up to the female, and she either perishes or is someone’s dinner. What then?

Easy. Turns out clownfish, like a surprising number of fish, are sequential hermaphrodites, possessing the sexual organs of both sexes but suppressing one until needed. In the sudden absence of a female, the large male shifts his sex over and becomes the new female; the remaining smaller males then jockey for position, with usually the next-larger male winning the right to be the new dominant male, bulking up rapidly in size to take his position atop the sexual food chain. Situation solved. 

Or let’s see how bees do it, as the song notes. Most of the honeybees you have seen in your life are female workers. There are male bees, the drones, but these bees do not work: they gather no nectar, make no honey, clean no queen, raise no brood. They have only one, albeit important, reason for being, a singular task to accomplish: they are living sperm containers waiting for a virgin queen to fly. They are flying insurance policies.

And somehow the drones of neighboring hives all know where to congregate—they all get an unwritten memo and map in a secret code that scientists have yet to crack. And there they wait… 

So when a new queen emerges from her special queen cell in the hive, her first task is to scour the hive looking for other queen cells, as hives with an aging queen likely raise multiple new queens to make sure one works out. The first queen that hatches then kills the others immediately; sororicide, the killing of sisters, is her very first act.

Her next act is to tank up on sperm. To do that, she flies to those same drone congregation areas; she’s got the map as well. And the fastest, maybe the luckiest, male who catches her first mates in mid-flight. Unfortunately for him, copulation results in death; he immediately falls to the ground as the climax to her nuptial flight, and she has the sperm she needs for a lifetime of egg laying.

Those drones are also incapable of feeding themselves; they beg for food in the hive by tapping on the antennae of female workers who obligingly regurgitate food for them. Until the fall. As the hive slides towards winter’s lean season, no nuptial flights will be occurring and the hive needs its honey to survive the winter. Now, drones are expendable. So when the males tap females for food, the workers deny the request, and the drones starve. They die in the hive, and are carried out by female undertaker workers to be unceremoniously dumped outside the entrance. Ah, love.

So calling all bucks and does, or even stags: join me for a lively evening discussing the delightful and surprising sexual antics of the animal kingdom, just in time for Valentine’s Day. 

 

–By Mike Weilbacher, Executive Director

At-Home Nature Exploration: Animals in Winter

COVID-19 has forced the Schuylkill Center to pivot and reimagine many of our programs. At the beginning of September, we began to reinvent our popular Schuylkill Saturday program so that families could explore our trails through self-guided activities available in Nature Kits. Every Saturday, Nature Kits have been given out on a first-come, first-served basis from 10:00 am–12:00 pm. Nature kits focus on a different theme each week and are meant to be done along our trails. Since the start of our nature kit program, we have seen more than 800 people come out and have handed out over 450 kits.

Starting this week, we are going to be featuring at-home versions of our popular Nature Kit activities so if you can’t make it out to the Center to pick up a kit, make sure to check our blog each week for ways to still get in some weekly nature exploration right where you are.

 

Animals in Winter

In the winter, temperatures drop and it gets really cold. In order to survive, animals will do one of three things: hibernate, adapt, or migrate. Animals such as bears and chipmunks will hibernate. This means that they curl up in a warm place, such as a cave or tunnel, and stay there until winter ends. Other animals, such as fox and deer, will adapt. To adapt means to use a special feature, such as a thick fur coat or stored food, in order to survive the cold temperatures. Lastly, to migrate means to travel to a warmer spot. Animals such as birds and even some marine mammals will migrate. Follow the directions for the activities below to learn more about hibernation, adaptation, and migration.

 

ACTIVITY #1: Squirrels and Adaptation

Squirrels are examples of animals that adapt in the winter. To stay warm in the winter, they will spend more time in their nests and less time out foraging—similar to us staying inside when it gets cold. Before winter starts, they will also bury food such as acorns. It can be hard to find food in the winter so squirrels will return to these stashes of food for something to eat throughout the winter.

  • Draw a number of acorns on a piece of paper (Tip: Put a paperclip on them if it’s a windy day!)
    • Hide them in either your backyard or a nearby park.
    • Wait 5-10 minutes—and then see if you can find them all again.
      • If you have real acorns around, you could do this same activity with real acorns—just make sure to mark them in some way (ex. wrapping a piece of yarn around them) so that you can tell them apart from other acorns. 
  • Take a moment to look around your backyard or a nearby park to see if you see any squirrels out and about.
    • Are they digging up acorns that they buried before the winter?
    • Try looking up in the trees for squirrel nests. Squirrel nests look like large bundles of leaves balanced between tree branches. They are often easier to see in the winter when there are no leaves on the trees.
ACTIVITY #2: Birds and Migration

Birds are an example of an animal that migrates. Birds migrate to warmer areas to find food and lay their eggs. Birds, however, often face challenges as they migrate. They rely on areas such as wetlands for food, rest, and shelter—similar to how we stop at rest stops and hotels when we travel. These areas though are oftentimes developed to make way for houses or shopping centers. Grab a piece of chalk and make a hopscotch board on a nearby sidewalk.

  • Take a moment to look around for birds in your backyard or a nearby park.
    • Although many birds migrate, some do stick around in the winter and will often change their diet depending on what foods are around.
      • For example, birds that eat insects in the spring and summer may switch to eating more seeds, nuts, and berries in the winter when insects aren’t as readily available.
    • What type of food do you see that is still around for these birds?

 

ACTIVITY #3: Bears and Hibernation

Bears, chipmunks, skunks, groundhogs, and snakes are all examples of animals that either enter true hibernation or something similar to it. Animals that hibernate usually find warm areas such as tunnels, burrows, or caves.

  • Make a warm den outside for a stuffed animal that you have at home.
    • Try to find a small crevice and use natural materials such as sticks and leaves to make it nice and warm.
    • Besides warmth, try to think of some other features that would make for a good den (ex. shelter from rain or snow, hidden from potential predators, etc.).
  • Take a moment to look around in your backyard or a nearby park. Can you locate some areas that would make for good places for animals to seek shelter or cover?

 

If you do any of these activities, be sure to snap a picture and share it with us on social media (tag us @schuylkillcenter)—we’d love to see what you discover in your own backyard!

Window Strike Season

A towel, some gloves, and a cardboard box are all you need to help rescue window-strike victims like this black-throated blue warbler.

It’s fall migration season- do you have your bird rescue kit ready? 

During the summer, if you come across a bird on the ground that can’t fly, it’s often safe to assume that bird is a baby. But during spring and fall migration, birds that are found on the ground that do not fly away are frequently adult migratory birds that have struck a window or become disoriented and are in need of human help. 

Many migratory birds do most of their travelling at night, when they use the light from the moon and stars, reflections from bodies of water, and even particular sounds to help them navigate their way to their winter grounds down south. Bright lights of urban areas, especially those that extend high into the sky such as skylights and skyscrapers, are particularly dangerous. The most common places to find these birds will be early in the morning on the sidewalk below tall city buildings, but you may find them sitting below the windows of your home and business as well. 

Remember- the head and spinal trauma that can result from colliding with a window at high speed is a medical emergency! Common signs of collision include: looking “puffed up”, squinting eyes, squatting down instead of standing upright, and neurologic signs like trembling or a head tilt. 

Rapid action is so important to the bird’s survival.

Here’s what to do if you find a bird on the ground that you suspect may have hit a window. First, have a “rescue kit” ready so you can act quickly if you see a bird in distress. Keep the following items handy in your car or bag: a paper bag or a small cardboard box with a lid, a tea towel, old t-shirt, or small blanket, and a pair of gloves. They are small things to have, but they can help to save a bird’s life! 

  Be sure to approach the bird slowly and from a safe angle. Even if a bird is stunned, they may still have limited ability to fly so we don’t want them to fly into traffic or back into a window or building again! As soon as you are close enough, drop a small towel or cloth down over top of the bird, completely covering the head and wings. This will help to reduce stress and keep the bird calm. While wearing gloves, pick up the bird in the towel and place them in the paper bag or cardboard box. Fold the top of the bag down and secure it with a paperclip, or close the lid of the box. This is very important- the bird is likely in shock, and needs to be kept as quiet and stress-free as possible during transport. 

As with any injured animal, do not try to give them food or water. A bird with head trauma could drown or choke if they can’t properly hold up their head, and eating improper food items can cause serious medical issues. Keep the bird in a quiet, dark place and transport them to your closest wildlife rehabilitation centre as soon as possible. 

Migratory bird populations are declining all over the world due to climate change, habitat destruction, and human-caused conflicts like window strikes. Keep your eyes open and your rescue kit ready, and be a hero to the birds!

By Rebecca Michelin, CWR | Wildlife Rehabilitation Consultant

Fall Bird Migration

By Jasmine Lee, Communications Intern

Fall migration, the large-scale movement of birds from their summer breeding homes to their winter grounds is part of an annual cycle that is undertaken by more than half of all the birds in North America. Unfortunately, it is estimated that in the U.S. alone, one billion birds die each year as a result of collisions with glass windows, walls, and other structures, with numbers typically spiking during migration months. At the Schuylkill Center and the Wildlife Clinic, warblers of all kinds, flycatchers, woodcocks, and even hummingbirds are passing through as they make their way down south for the winter. 

As a student at the University of Pennsylvania obtaining my Masters in Environmental Studies, I have a special interest in birdwatching and ornithology, in addition to my career interests in conservation science. Back in March, I moved from West Philly back to my parents suburban New Jersey home due to the pandemic, and I was excited to spend some time closer to nature, as opposed to the bustling city streets. Using a recycled glass beer bottle, I fashioned a homemade bird feeder to attract some feathered friends for the spring.

Homemade bird feeder: birdseed comes out from the bottle and into the tray.

Attaching it to the trees in our yard posed a problem, as the squirrels had easy access to the birdseed tray and would often scare off any potential bird visitors. I decided to use an old patio umbrella frame to secure the bird feeder so it was away from any branches where the squirrels could jump onto it.

Feeder attached to umbrella frame. Bag of finch food hanging off to the side. 

Within hours of setting up the frame and feeder, we saw a cardinal munching from the food tray. I stayed at our kitchen table all morning so I could watch the feeder through the window.

Northern Cardinal

Brown-headed cowbird on feeder, American goldfinch on finch food bag

We did continue to fight the squirrels on occasion, when they tried to climb the umbrella pole. Eventually, we removed the bottle because it encouraged them to to climb up and gorge themselves.  Now, my dad puts out a handful of seeds for the birds each day, but not enough to tempt the squirrels.

Now that it is October, the feeder is less busy, although we do still see the occasional fall migrant passing through. We are looking forward to springtime next year, when the migratory songbirds return. 

As part of our #YearOfActionChallenge, the Schuylkill Center encourages you to take some actions to help protect our travelling feathery friends. 

  1. Urge your senators to co-sponsor the Bird-Safe Buildings Act requiring public buildings to incorporate bird-friendly building designs and materials.
  2. Apply decals, window guards, uv-coverings or other collision preventing materials to windows to make glass more visible to birds and reduce the chances of flying into them.

3. Turn off the lights! Many birds migrate at night, and can become disorientated by bright artificial lights, increasing the chances they will collide with a window. Whenever possible turn off excess exterior lights and reduce interior lights at night, especially those on higher floors or in building atriums. Visit Lights Out- Audubon to learn more.