A Silent Fall: Vanishing Monarchs


A Monarch dries its wings after emerging from its chrysalis in our front garden. (Schuylkill Center, 2013)

By Mike Weilbacher, Executive Director

The new fall season brings a chain of wonderful events: trees turning color, birds migrating south, goldenrod fields bursting in bloom. But one of my favorite fall phenomena is sadly and strangely absent this year.

There are almost no Monarch butterflies afoot these days.  All summer, I’ve seen only three at the Schuylkill Center.  And my compatriots at other centers like Bowman’s Hill in New Hope and Peace Valley in Doylestown report the same horrific drop.

You know Monarchs, those large orange and black butterflies. Every fall, every Monarch east of the Rocky Mountains begins an extraordinary migration south, one of the strangest in the animal kingdom.  All Monarchs, whether hatching here in Roxborough or up in Nova Scotia, fly slowly to a couple of small, secluded mountain valleys not far from Mexico City.  Somehow encoded in the  pinhead-sized brains of these creatures is a road map to Mexican forests.  (West Coast Monarchs, by contrast, head downslope to multiple small locations along the Pacific coast.)

Arriving in Mexico around All Soul’s Day—folk tradition there says these are the returning souls of Aztec warriors—the butterflies cluster in large groups, clinging to each other, coating fir trees with their bodies.  Nicknamed the Methuselah generation because they live for many months, this group stays in their mountain cluster until the spring.  Then they fly north again, search for  the first growths of milkweed plants, (the host plant for their caterpillars), lay their eggs on the milkweed, and die of exhaustion.


Graphic by Journey North

When the next generation matures, it pushes north again—and Monarchs ultimately arrive back in Philadelphia in early summer.  Only to head back to Mexico two months later.

Last winter was the worst year on record for the size of the Monarch cluster—their group covered only three acres of forest, down 59% from the previous year, and down 94% from their 1994 high.  Think about it: most of North America’s Monarchs clinging to only three acres of trees.

So the drop this year was expected.  But it does have biologists wondering about the possibility of losing this utterly unique phenomenon.  And all eyes will be on Mexico this year to see how many butterflies return to their winter home.


A Monarch chrysalis hangs from a milkweed stem. (Schuylkill Center, 2013)

Why the drop?  Scientists expect many culprits, but highest on the list is the use of Roundup-ready crops through much of the Midwest.  Grown to be immune to this herbicide, the plants allow farmers to pour the chemical on fields for weed control, and take out all the milkweed that once supported populations of Monarchs.  Pennsylvania’s Monarchs can’t get through the Farm Belt, so few arrive to reproduce here; few in turn migrate back.

At the Schuylkill Center, we’ll watch the butterfly carefully, plant lots of milkweed to support the creature, and report back to you information as researchers discover it.  We can’t afford to lose this high-flying beauty from our fields.

Mike Weilbacher, Executive Director, the Schuylkill Center for Environmental Education

Learn more at:

“Bring Back the Monarchs,” Monarch Watch: http://monarchwatch.org/bring-back-the-monarchs/campaign/the-details

“Tracking the Causes of Sharp  Decline of the Monarch Butterfly,” Yale Environment 360: http://e360.yale.edu/feature/tracking_the_causes_of_sharp__decline_of_the_monarch_butterfly/2634/

US Forest Service, Celebrating Wildflowers: http://www.fs.fed.us/wildflowers/pollinators/monarchbutterfly/migration/


On Valentine’s Day, a Dive into the Weird World of Animal Sex

By Mike Weilbacher, Executive Director

It’s Valentine’s Day, and while we’re canceling our scheduled evening program, I thought I’d share the strange tales of amorous animals.  Nature is incredibly wonderful, but also incredibly weird. 

Take the clownfish, for example, so famously depicted in Finding Nemo, that sweet name abducted by last week’s horrific storm.  All clownfish are born male—not a girl in the bunch.  They live in and around anemones, stinging relatives of corals and jellyfish; plantlike but actually animals, anemones are unable to move anywhere.  So clownfish don’t go very far either.  (And sadly, rarely go on any adventures of any kind.)  Clownfish, immune from anemone stings, groom their host to remove dead and dying “branches,” and in exchange dine on dead fish left behind from the anemone’s handiwork. 

A large female clownfish rules the anemone, a colony of males of a variety of ages and sizes hanging out with her, competing to mate, the largest using winning.  But when the female dies, the next-in-size clownfish, the largest male, simply changes sex, and becomes the colony’s official female, establishing a whole new pecking order.  (So in the movie, when Nemo’s mom disappears, the dad simply becomes the mom.)  And it turns out this sequential hermaphrodism is not too rare in the wide, wide world—lots of species do it. 

Fireflies are cool.  A flashing field of fireflies is a huge stag party, acres of males flying the friendly skies.  The females—bigger, abdomens overloaded with eggs—cannot fly, but sit watching the signals, as males flash their codes to potential mates, each firefly species using species-specific signals to seduce mates.  When the female sees the right kind of male fly by, she gives him the correctly coded answer—and mating ensues.

Except one species knows the correct answer to a second species of firefly—she’s cracked his code.  When she’s hungry and sees one of these hapless guys flashing by, she gives him the answer he’s looking for.  He lands—and she devours him, using his protein to create her eggs. 

Which reminds me of the honeybee.  A hive is almost completely female, thousands of female workers grooming and caring for one supersized queen, the egg-layer of the group, the workers moving through life tackling a sequence of jobs, beginning as, say, a funeral bee carrying dead bees out of the hive, and ending as a field worker collecting nectar and pollen. 

There are male bees, drones, creatures unable to perform any useful jobs, existing for one purpose: their sperm.  Drones of many hives hang out in designated areas—like teenage boys in front of the Wawa—waiting for a potential queen to fly by. 

When a queenless hive raises a new ruler, she takes a maiden voyage into that drone cloud, and ostensibly the fastest, strongest drone succeeds.  Tragically, he dies upon ejaculation, most of his innards flying out with the sperm packet to form a plug that prevents the queen from ever mating again.  Yup, it’s one and done for both.

And when autumn comes, drones become a liability, unable to work or feed, not needed during the long, cold winter.  Drones tap the antennae of workers for food, but the workers walk away, refusing the request.  In late autumn, funeral bees spend a fair amount of time dumping the bodies of starved, dead drones outside the hive’s doors.

Speaking of all females, you’ve likely seen photos of anglerfish, a chunky deep sea fish named for the projection on its head that it dangles in front of prey, using a little worm-like lump on this appendage to lure unsuspecting fish into its jaws. Scientists were once intrigued that all anglerfish were female—and that all seemed to have a small parasitic creature stuck to its body.

Turns out the parasite is a male.  Its mate.  Anglerfish inhabit the deep ocean bottom, where it’s bleak and black and speed-dating doesn’t occur.  Males hatch as very small versions of the female, but without a stomach.  Once born, they immediately seek out mates; when they find her, male bites into female and releases an enzyme that digests their skin.  He fuses onto the side of her body, wasting away to become this odd lump literally glued to her side.  And when the female is ready to spawn, he is there, releasing the sperm she needs to fertilize her eggs.

Let’s stay in the ocean one more time. Male octopuses and squid have a breakaway arm that holds his sperm packet.  In mating, the male uses this arm to reach into the female’s body cavity, placing the package carefully inside, whereupon it breaks off.  Like the anglerfish, early naturalists thought female octopi all had parasitic worms in them, and actually gave the male arms formal scientific names.

But the argonaut, a small cousin in this clan, takes this strategy on strange step further.  His mating arm is kept tucked in a pocket below his eye.  When he spies a suitable mate, he approaches her tenderly, and if she is receptive, the mating arm suddenly explodes out of his body, killing him instantly, the detachable arm taking on a life of its own, swimming to the female, clinging to her, and worming its way into her insides.  Some female argonauts have actually been found with multiple arms in her cavity, her collection of conquests.  But a free-swimming penis-like structure is, let’s face it, the stuff of science fiction.

Last example: red-sided garter snakes.  A female awakens from a long winter’s nap, and begins giving off a pheromone that males find irresistible.  Quickly, a mating ball of hundreds of writhing snakes forms, the female surrounded by scores of hopeful males—put THAT in the next Indiana Jones movie. 

And so it goes through the animal kingdom. If you’d like to continue researching this, er, “fertile” field, check out the following: banana slugs (the most highly endowed animal of all), flatworms and their penis jousting, the male frigate bird’s display, and perhaps the horniest animal of all time, our cousin the chimp-like bonobo. 

Happy Valentine’s Day.

Mike Weilbacher directs the Schuylkill Center for Environmental Education in Philadelphia, tweets at @SCEEMike, and can be reached at mike@schuylkillcenter.org.

Making Room for Rain – Stacy Levy

The Schuylkill Center for Environmental Education is working to investigate the intersection of nature and the city. The role of rain in the landscape is being actively explored in programs and planning around its buildings. As a nature center, SCEE is at the forefront of solving site issues through art based intervention. On May 31, 2013 a conference on New Environmental Art will be held at SCEE to look at ways that art and science can collaborate to solve ecological problems in urban nature, and enlighten citizens to find new solutions in their own lives.

Rain is usually given a long narrow space to inhabit: gutters, downspouts, underground pipes. People can walk practically anywhere in a building and on the surrounding landscape. What if this paradigm got turned on its head? Give people a more narrow path of movement around a site while rain gets plenty of space to spread out and linger? How would our built environments change? And how would it change our relationship to rain?As an eco-artist, I want art to be an advocate of rain. Art is good at giving meaning to the leftover or abandoned aspects of the world—and rain is one of those abandoned elements. Though a yardstick worth of rain falls every yearin this region, we hardly register rain’s presence. In urban settings, architecture and engineering have generally kept rain invisible to us. The relationship between rain and the built environment needs to be changed, and art is well positioned to alter that relationship.At SCEE, I am working with ecologists, engineers and educators to create an artwork that gives the rain room to spread out while keeping people in a defined space. But people do not lose out in this design— both rain and visitors get a dynamic space to co-exist.Rain Gardens create spaces that can get wet and stay wet while the water infiltrates into the soil.

Instead of becoming a muddy soup, the rain garden holds the rain within the permeable soil and the roots of a diverse community of native plants . These plants also make good habitat for other species like insects and food for birds and other small mammals.

This new artwork deals with two types of visitors to the site: rain and humans. A grated metal catwalk prevents the plants from being trampled while also keeping people’s feet dry. ‘Staying dry’ and ‘soaking in’ are two incongruent activities—one of the reasons that rain has no place to go in the built world is the hierarchy of the dry human foot!

We want to demonstrate ways to change rain’s journey in the built environment. We also want to give visitors a chance to test out the very materials of the city: the surfaces we spend our lives walking on like asphalt, concrete and grass. How do these materials work with or work against rain?

How this art works: Some of the rainwater will be diverted and stored in an above ground cistern. Then during dry days, our visitors can pump this contained water into 5 different troughs. Each trough contains a different familiar surface materials from the landscape: concrete, asphalt, gravel lawn and meadow. People can direct the rainwater onto these different surfaces to see how the water responds— by soaking in or running off.

At SCEE rainwater will be given both the time and the place to act the way rain should act. And people will be given a place to interact with the falling rain while staying out of its way as it soaks into the soil. The idea of rain needing a refuge is a new idea to most of us. We hope people learn about rain, and the surfaces it meets in our world. This piece gives people a new angle on rain and its relationship to our built environment.

The piece will be under construction over the early spring. Please come by and see it!

Want to know more about Rain Gardens?

The Philadelphia Water Department

The Rain Garden Network

The Groundwater Foundation

The Department of Environmental Conservation

Rain Garden Alliance

Want to see more of Stacy Levy’s work?


Restoring childhood play… and Philly’s first nature preschool

Gail Farmer, Director of Education

I was born in 1975, part of Generation X, probably the last generation whose parents felt comfortable sending their kids out into the neighborhood after school.  “Go outside and be back by dinner,” was a common directive from my mother.   My street ran along the bottom of an undeveloped hill, and “The Hill” was where my sisters and I went when my mom sent us outdoors.  My childhood was also filled with Girl Scouts, dance classes and community soccer, but my best memories and my most formative experiences come from the times my mother wanted nothing more than to get me and my sisters out of her hair for a few hours.

preschool hikeUnlike more structured activities, The Hill was totally open to our interpretation and needs:  it was a place where we could try to make sense of the complex world in which we lived by reconstructing it on a much smaller scale.  The Hill had scary places (“the swamp”) and refuges (“rainbow rock”).  On The Hill we were sometimes brave explorers discovering new lands and other times victims in need of rescue.   The Hill was whatever we needed it to be.

A growing body of research in early childhood development is revealing the critical connection between this type of exposure to nature and the developing brain.  Children who spend immersive time in nature (not just outdoors on the basketball court or playground, but in nature), tend to be less anxious and better able to focus, and to have fewer health issues and more emotional resilience, than children who don’t.  (Learn more at http://www.childrenandnature.org/documents/C118/.) The challenge in our increasingly urban environment is: how do we provide very young children with the kind of immersive exposure to nature they really need?

The Schuylkill Center is keenly aware of this challenge, and already offers opportunities for nature play in many of its programs.  Now we are adding another path for children in the critical early years of development: we are opening a “nature preschool.”

The Schuylkill Center Nature Preschool will provide Philadelphia children with regular opportunities for direct contact with nature, on a daily basis and across the seasons—in a risk-managed environment.  Our classroom will open directly into our nature preserve, so students can jump into forests, streams, ponds and meadows.  They will grow and plant trees, rear tadpoles, catch butterflies, and generally just be outdoors in all seasons.

Although our preschool is the first of its kind in Pennsylvania, there are more than a dozen nature preschools across the country, and we are modeling our program on the best practices of those schools.

For more on Nature Preschools, visit: http://www.greenheartsinc.org/Nature_Preschools.htmlGreen Hearts founding director, Ken Finch, will be at the Schulkill Center January 10, 2013 to present the 2nd annual Dick James Lecture: Go Outside & Play! Restoring the Nature of Childhood.  If you’re in the area, come check it out!

Wellness Walks Even In The Winter

The temperature might be dropping, and the trees might be losing their leaves, but that doesn’t mean keeping up your exercise routine isn’t just as important.

Winter wellness walks have obvious benefits, but we found some more with a little research. In fact, it has been proven that winter walks may have surprising health benefits.

Benefit #1: Reduces Stress

Walking in the winter offers you a refreshing change of pace, says Alan Mikesky, PhD on Prevention.com, director of the human performance and biomechanics laboratory at Indiana University-Purdue University in Indianapolis. The invigorating cold air can clear your mind and reduce stress, which can be helpful for weight loss.

Benefit #2: Keeps bones strong.

As Lynn Millar, PhD, a physical therapist and professor at Andrews University in Barrien Springs, Mich explains on Arthritis Today, any kind of sun exposure triggers vitamin D production in the skin, and bones need the “sunshine vitamin” to make the body absorb bone-strengthening calcium properly. Not getting outside during winter months slows down production and decreases the body’s store of vitamin D. “Vitamin D is important for keeping bones strong…because they have an increased risk of brittle bones,” says Millar. Going for a winter walk and getting 15 minutes of sun on your face and hands two to three times per week should suffice for getting enough sun for vitamin D production.

Benefit #3: Improves Mood

Sunlight and just being outdoors can do wonders for lifting your mood, says Millar. Just a simple walk in the woods with friends can not only be enjoyable, but also can have positive side effects on your mood and even decrease pain. A University of Washington in Seattle study of 112 women aged 19 to 78 shows that women who took a brisk, outdoor walk for 20 minutes daily had better mood, higher self-esteem and an improved sense of well-being at the end of the eight-week study. Winter walking could provide an effective, easy-to-stick-with therapy for mild-to-moderate depression, say the researchers, especially for those who experience side effects from prescription treatment options.

Benefit #4: Burns Calories

This one might seem a little obvious, and it is true that outdoor walking through the park or around the neighborhood on a cold day won’t burn any more calories than walking on a warm summer day, but walking in the snow will. “You expend more energy because it’s harder to move your feet in the snow, and you lift your legs a little higher,” Dr. Millar explains.

It might be cold outside, but clearly #WellnessWalks are a great idea.

Your Voice for the Event of Your Choice

The Schuylkill Center is expanding its programming for adults, and we need the help of our members and friends!

We want to get the word out–the Center is an amazing, relaxing, and informative place for adults too.

What better way to do that, than through the voices of those who know us best?

So, what are we asking? Send in a quick video testimonial clip telling us why you love the Schuylkill Center.+  In return, we’ll give you admission to an event of your choice,* and send you a freshly printed Schuylkill Center bumper sticker.  Your voice, for the event of your choice!

Don’t have the time to record a video? We can still use your help! Upload a picture of you at the Schuylkill Center to Facebook or Twitter and tag us. We would love to send you a sticker as well!

Thanks in advance for all your help,

The Schuylkill Center Team


+Videos can be sent via Facebook, Twitter or Email.

*Admission to events under $50, as space allows, for the first 10 videos received

Wild Turkeys: Of Wingmen and Bands of Brothers

By Mike Weilbacher


A strutting tom and his band of brothers courting a hen.

On Thanksgiving Day, we’ll gather around tables overflowing with food and stuff ourselves silly.  And while every family has its own unique take on the traditional meal, in most homes a big turkey anchors the feast, the centerpiece of the table.

While a lot of us might remember that Ben Franklin favored the turkey as the national symbol, what else do we know about turkeys?  Not much, right?  So here are some turkey facts to gobble up alongside your meal.

In the wild, turkeys are now busily forming winter single-sex flocks, a tom and his brothers joining a fraternal order of other males.  During this first winter, the toms spar viciously and violently to establish their pecking order—striking each other with wings, spurred feet and head until exhausted.  He who fights longest is the winner, and to him goes the spoils of war: the right to mate in spring.

For when the winter flocks break up, brother turkeys stay together.  Finding clearings in forests, they strut their stuff like hyperactive mummers, gobbling loudly, desperately seeking hens.  They puff their feathers, fan their tails, drag their wings; on their heads and necks, projections called wattles, snoods and carbuncles variously swell, stand erect and turn bright colors—the better to attract females.  THAT’s the turkey our kids draw and we decorate with, by the way, the mature male in full sexual strut.

When the hens arrive, only the strongest brother—top gun—mates.  Weaker brothers never mate—never!—but strut every spring in a brotherhood of turkeys that stays together for life, weaker brothers acting as literal wingmen in support of the dominant, he in turn mating with multiple females to spread strong genes throughout the pool.

Despite all that strutting, the wild turkey came thisclose to becoming another passenger pigeon.  While turkeys now nest in every Pennsylvania county save Delaware and Philadelphia, turkeys were on the edge of extinction only 40 years ago.  Through overhunting and deforestation, 30,000 turkeys strutted in 18 states by 1900; the animal had disappeared completely from all of Canada and New England.  While Pennsylvania was the northernmost East Coast state to retain wild turkeys, they had vanished from this corner of the state.

But three things happened that altered its future.  Too many hunters let wildlife agencies know that they demanded the bird’s return; wildlife managers learned how to use relict populations in captive breeding programs, re-introducing newly hatched chicks to their former haunts; and in recent decades, forests slowly returned.  Creatures of the edge, they crave forests for cover and fields for the seeds and insects they eat.  And as their habitat returned, so did they.  The National Wild Turkey Federation now estimates some seven million turkeys range across America; Audubon named it one of the “10 Creatures We Saved” in its centennial celebration. 

Finally, it is a singular oddity that a North American fowl anchoring a uniquely American holiday is named for a Middle Eastern country.  First domesticated by the Aztecs and brought to Spain in the 16th century, the bird found its way to England through Turkey—hence the name. 

In fact, everyone around the world seems to name it for an exotic faraway place.  The Greeks call it a “French rooster,” while its French nametranslates as “from India.”  Bulgarians give it an Arabic word for Egypt, but Arabs dub it the “Roman rooster.”  Brazilians inexplicably call it “peru,” a neighboring country with no turkeys.  In Pakistan, it is “elephant chicken,” a delightfully evocative name, and the Japanese call it the “seven-faced bird,” a reference to the turkey’s strange face that changes colors and shapes with its mood.

Strangely, only the Russians get it right: their word for turkey means “Native American.”

After your feast, check out the band of brothers watching football, strutting their stuff and fighting for dominance.  Some things never change.  

Naturalist Mike Weilbacher directs the Schuylkill Center , where turkeys can occasionally be seen. His email is mike@schuylkillcenter.org.

Philadelphia’s Top Trails

On one of Schuylkill Center’s Trails

As Thanksgiving is fast approaching, you might be in need of an activity for your visiting family members.

Even as the weather starts to grow colder, the greater Philadelphia area offers many beautiful and relaxing nature trails. Try one of the following trails with your family, your partner, or even just for yourself this holiday season.

Looking for a more active day?

Wissahickon’s Green Ribbon Trail (20 miles): This multi-purpose path stretches along the Wissahickon Creek from Whitemarsh Township to a point near Lansdale Borough.

Schuylkill River Trail (27 miles): Following the beautiful Schuylkill River, this trail ranges from the Valley Forge National Historic Park to the Philadelphia Art Museum, while passing the Center in between.

The Manayunk Towpath (28 miles): Parallel to the Canal and the Schuylkill River, this varied-surface path is a favorite for joggers and off-road cyclists.

Want something a bit more peaceful?

Schuylkill Center’s Ravine Loop (1.0 miles): Crisscrossing a spring-fed stream, several rustic bridges, and Smith’s run, this peaceful walking trail includes a few challenging slopes and even a view into the Center’s oldest section of forest in Roxborough.

Cobbs Creak Recreation Path (4 miles): Particularly cyclist-friendly, this path runs from Market Street to 70th Street, hugging the westernmost boundary of West Philadelphia.

Butterfly Land

As the mercury hovers around 100, people might wilt and retreat indoors—but the butterflies are having a ball. Summer is high season for butterflies, and the hotter it is, the happier they seem.  In fact, driving down SCEE’s long driveway between the nature center and Hagy’s Mill Road, literally dozens of butterflies jump up from the dusty driveway to avoid the car, and dozens more flit across the driveway flying past.

We are Butterfly Land.  Come see.  Right now.

Just outside our front door, common milkweed is in full glorious bloom, perfect globular bursts that resemble pink fireworks.  Smelling unbelievably beautiful—Chanel No. 5 has nothing on milkweed—the flower attracts scores of butterflies: the ubiquitous cabbage whites, the big and boldly striped tiger swallowtail, the Flyers-colored monarch, and small brown skippers of innumerable species. A red admiral popped into view yesterday on the milkweed, sporting its gaudy bright red diagonal stripe. Fresh out of the chrysalis, it was a sight for a summer’s morning.

We’ve got a butterfly count coming up soon, and a butterfly evening too—we’ll sip wine while the butterflies sip nectar; nibble on cheese while the butterflies, well, sip nectar.

So while our center is 365 acres of fields and forests, all you have to do is drive down our driveway and head to our front door, and you’ll have already seen scores of butterflies.  Walk out to our butterfly meadow, and you’ll be in heaven.

Come see Butterfly Land for yourself.

Sex and the Single Firefly

The male firefly, flashing in search of a female

By Mike Weilbacher, Exec Director

Saw my first firefly just last week, right after Memorial Day.  For me, a naturalist who marks the passage of time by nature’s calendar, nothing says summer like an evening of fireflies.

And one of my favorite stories is the secrets of a firefly’s flash.

When you see a cloud of fireflies rising from your lawn like liquid lightning, you are witnessing a stag party, a collection of horny males desperately seeking Susans– every firefly flashing around you is male, the flash used to seduce a female into responding.  Firefly females are generally flightless, their abdomens too weighted down with the machinery of egg production.  

Males seek them out by strafing the grasses, cruising tree branches, looking for female perching spots—flashing females in both senses of the word.  

And each firefly species has its own unique flash pattern– its own Morse code– which one species uses distinguishes itself from another.  So the firefly flashing in a J-pattern is a separate species from one flashing two dashes, though both appear identical to the untrained eye.  In some cases, even the best microscopes can’t tell discern one species from another, but they know who is who.  And who is where.  Some species flash high, others flash low: fireflies sort out species by both pattern and space.  

For every male’s flash, there is a correct answer, perhaps a two-second pause and then a quick, surreptitious dash.  The males flash questions into the night air, hoping (if insects truly hope) for an answer to appear from below. 

Then the story gets knotty.  There is a species of firefly the female of which also has decoded the correct response to another species.  When she’s interested in mating, she answers the male with the appropriate answer, and sex ensues. But when she’s hungry, she searches for the flash of the other, and gives that one’s appropriate response.  That male lands thinking he’s about to mate, and the female happily devours him, getting the protein she needs to create a batch of eggs. 

One helluva way to leave this world. 

That’s the why of firefly flashing.  Like a butterfly’s bright colors, a house wren’s bubbly song, a cricket’s scratchy chirrup, and a deer’s horny antlers, a firefly’s light is a neon sign, advertising its species, its sex, and its availability. 

The how is different:  a firefly’s abdomen is loaded with a pair of chemicals, luciferin and luciferase, held in separate sacks.  When exposed to each other, a powerful chemical reaction occurs that releases large amounts of energy as light, a light that magically generates infinitesimally small amounts of heat (unlike, say, a light bulb).  This bioluminescence is astonishingly common under the sea, where everything from single-celled dinoflagellates (a kind of plankton) to large bony fish glow in the ocean.  On land, however, bright life is exceedingly uncommon. 

In the tropics, where the forests are dense, fireflies can’t see or find each other in the growth.  There, flashing fireflies migrate to river corridors, and cover trees by the thousands– all flashing synchronously, the entire forest along a riverbank beckoning to firefly females to come closer.The flash of a firefly is a short-lived phenomenon– only a few weeks centered on the summer solstice, their bright lights marking the beginning of summer.  

One firefly-filled night soon, open a bottle of wine, lure your spouse onto the deck or the porch, witness the wonder of thousands of insects glowing all around you, whisper in his or her ear the full story of the firefly’s flash– and see what else develops that night.

Special Event: Join me for Firefly Nights, the first in our new Nature Uncorked series of events.  We’ll enjoy a wine and cheese reception in our firefly meadow while learning the natural history of these, and other, evening critters.  Nature Uncorked is $10/event (member price), $25 for the series of three.  Pre-registration required!  Register on our web site, schuylkillcenter.org.