Tag Archives: Tent Caterpillar

Stony Creek Ravine Nature Park: Meadows A-Flutter and a Steep Forest with… Tulip Trees!

The west branch of Stony Creek winds through the ravine

Stony Creek Ravine Nature Park is a small park with big contrasts – between the sunlit, gently rolling meadow and the forest with large trees grasping the steep slope that plunges down to the creek stippled with sunlight below. It’s a fairly short walk, just in and out, for now. Eventually, we hope this elbow of a park will be joined to 208 spectacular acres to the east, now being acquired by our Parks & Recreation Commission. So I’d suggest you see it soon, so you can say you “knew it when!”

An Undulating Path through a Meadow of Fluttering Wings

The trail begins in a grove of trees at the end of Knob Creek Drive with its single parking space. A few years ago, Stewardship Manager Dr. Ben VanderWeide removed walls of invasive shrubs that crowded the edges of the trail into the park, obscuring the meadow. Now when I step into the park, the landscape is open to fields filled with tall flowers and sunlight. The meadow is an exuberant, dense tangle of native and non-native wildflowers –  and a lot of thistle! But the butterflies and bees make do with what they find and they are everywhere! So I periodically ventured out as far as possible into the shoulder-high plants to get a little closer!

Cam among the incredibly tall flowers and thistles of the meadow at Stony Creek Ravine.

Ben had reported seeing lots of Giant Swallowtails (Papilio cresphontes) on thistles at the park. Having seen them there in previous years, I was excited to look for them. But after a very hot week, they had evidently moved on to greener pastures. I only saw one at an unreachable distance across the meadow on my first visit. But since I saw many of them later at Charles Ilsley Park, here’s a photo of one to refresh your memory. Pretty impressive size, eh? They are actually the largest butterfly in North America!

Giant Swallowtail butterflies seem to be coming to our area in increasing numbers.

My birding friend, Bob Bonin, also saw something at Stony Creek in August that I only saw from a distance. I had a quick glimpse of a Snowberry Clearwing Moth (Hemaris diffinis) but couldn’t wade fast enough into the greenery to catch a shot of it. Bob generously shared his beautiful shot of one feeding on the last drops of nectar from a native  Bee Balm (Monarda fistulosa).  Clearwings lose some of the wing scales due to their hummingbird-style, hovering flight, leaving areas of their wings almost transparent. The yellow and black fuzziness of the  Snowberry Clearwing (Snowberry is one of its host plants) means that it’s often mistaken for a bumblebee – perhaps providing some protection from predators.

The Snowberry Clearwing Moth can be mistaken for a bumblebee. Photo at Stony Creek Ravine Nature Park by Bob Bonin, used with permission

Native bee-balm also prompted a stopover by the Silver-spotted Skipper (Epargyreus clarus) which, according to Wikipedia, prefers to hang from the underside of leaves at night or on hot and humid days. Bee-balm, true to its name, attracts many native insects, including the ubiquitous native Bumblebees (genus Bombus).  (Click on photos to enlarge; hover cursor for captions.)

 

For the first time ever, I noticed European Honeybees (Apis mellifera) literally running around the tops of non-native Queen Anne’s Lace. I’d never before noticed this “busy bee” activity! They rush across each lacy blossom, perhaps quickly gathering nectar or pollen. Bee Culture, a beekeeping magazine, says that Queen Anne’s Lace produces the greatest amount of nectar in hot weather, so perhaps that’s what attracted them. Let me know in the comments if you have more info than I could find on this phenomenon. Here’s my amateur video of the bee race at Stony Creek Ravine.

It’s always heartening to see Monarch Butterflies (Danaus plexippus) in our parks, especially a female one sipping on Common Milkweed (Asclepias syriaca), its favorite host plant on which to lay eggs!

A female Monarch on Common Milkweed! Every year our parks do their part to protect this beloved species.

The Eastern Tiger Swallowtail (Papilio glaucus) is a generalist who can live in lots of habitats, from forests to meadows to urban areas. Its caterpillar can eat and grow on many of the trees in our parks, including Wild Black Cherry, Willows, Cottonwoods and Tulip Trees (see below!), but also on non-native plants like Lilacs. This adaptability means it’s thriving, and that made me glad as it paused so delicately to sip from the only tender part of a Plumeless Thistle (Carduus acanthoides).

An Eastern Tiger Swallowtail sips nectar from a non-native plumeless thistle.

Great Spangled Fritillary (Speyeria cybele) looked a bit ragged and uncomfortable one humid afternoon. I wonder if it had landed on too many prickly, bristly plants like the Plumeless Thistle! Most of the “spangles” are on the underside of the hindwings, so I’ve included an older photo to show them, since this butterfly clearly had no attention of feeding with its wings up.

A Great Spangled Fritillary on a very uncomfortable  plant!
Most of the silver spangles on a Great Spangled Fritillary are on the underside of the hindwings.

Red-spotted Purple (Limenitis arthemis) paused on non-native Queen Anne’s Lace (Daucus carota). It prefers rotted fruit or even dung and carrion, but occasionally it sips nectar from small white flowers like these, according to the citizen science website, butterfliesandmoths.org.  These butterflies sometimes produce two broods. The first caterpillars hatch and once half-grown, form a “hibernaculum,” an over-wintering refuge which for caterpillars usually involves a folded leaf and some spun silk to secure it. They then emerge in the spring and finish maturing.  According to Wikipedia, some of  the first larvae “are able to mature during the summer, so they emerge as the second brood [in] early fall,” but may have a tough time surviving winter cold. The prime condition of the butterfly below makes me wonder if it was from an early second hatch.

A Red-spotted Purple rests on a non-native Queen Anne’s Lace.

Some small butterflies also made the most of the late summer meadow. The  common and colorful Pearl Crescent (Phyciodes tharos) landed repeatedly on the path in front of me, as they often do. These very small butterflies can mate many times between April and November so we’re almost bound to see one on any summer walk  in our parks. And we’re also likely to see the non-native Cabbage Butterfly (Pieris rapae). I just love the sculptural look of the ventral (underside) of the wings on the one below. I think she’s a female since I can just make out the double wing spots on the dorsal (upper side); males have only one spot.

Right now, you’ll probably see a creature along the trail that looks like a butterfly with its black wings edged in beige, but is really the Carolina Locust (Dissosteira carolina). Despite seeing them every summer, I’ve never gotten a shot of their sudden flights from under my feet. So I can only show you what they look like once they land. But I’ve borrowed with permission a photo from an iNaturalist.org photographer, Joshua G. Smith, who held one in his hand to get a photo of the wing.

The Woods, the Deer Effect and a Bubbling Creek Below

A panorama of the woods where it begins to slope toward Stony Creek

The woods at Stony Creek Ravine Nature Park is full of big oaks and some beautiful native Tulip Trees (Lirodendron tulipfera)! These are not the shorter, heavy flowering cultivated trees that I grew up seeing in people’s yards. These mighty trees grow beautifully straight and tall often with few limbs once they reach 80-100 feet. In virgin habitat, they can grow to 160 feet and their girth can be as wide as 10 feet! According to Ben, there’s a huge one on the new piece of property that is planned to eventually connect with the existing 60 acre park. I hope someday I’ll be able to see it and show it to you here!

Tulip trees were once valued as timber because they grow straight and tall with few limbs until they are 80-100 feet tall.

Wild tulip trees (vs. nursery cultivated ones) only bloom at the top of the tree, so their glamorous flowers are rarely seen, but are rich with nectar. Their bark is ridged in an orderly pattern. The leaves have a unique, squared-off shape. And the graceful, seed-filled cones stay on the tree all winter only falling to the forest floor in the spring. I have never seen the flowers up close or the cones, so my thanks go to iNaturalist.org photographers kwilie and Sandy Wolkenberg for sharing the bloom and cone photos below. We’re lucky to see Tulip trees here because we are at the far north edge of their range. Can you tell I’ve found a new favorite native tree?

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The forest floor beneath the impressive trees, though, is almost barren. The shade of course is very dense. But a huge problem is that, despite a limited hunting season in this park two days each week in from October to January, the deer are plentiful. As a result, few woodland plants reach maturity on the forest floor. Deer have no front teeth, so the stems left on the plants they graze are ripped and flattened as seen below. Rabbits, for instance, with their incisors, make a neat, angular cut. But hope springs eternal! Though most tulip tree seeds don’t survive, I found a small sapling that somehow had escaped the notice of the deer -so far.

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As you hike down to the creek, more grasses appear. The creek’s moisture encourages some flowers, especially in the spring when the trees haven’t leafed out and more sunlight reaches the forest floor. In summer, the moist river bank is a  hangout for damselflies. One warm, gray afternoon,  I saw a female Ebony Jewel Wing (Calopteryx maculata) looking at me head-on from a fallen branch.

A female Ebony Jewelwing damselfly looked at me intently!

Her mate is a bit more glamorous, but I also like the elegant understatement of the female.

The west branch of Stony Creek burbles along, tumbling over rocks, slipping under fallen trees, catching glints of sunlight on its surface. And beneath the surface, small fish school in the shallows.

Small fish schooling in the clear water of Stony Creek as it runs through the ravine.

Deep in the woods on the far side of the creek, the shriek of a young Red-tailed Hawk begging to be fed grated upon my ears. Young hawks can repeat this harsh cry for 4 to 6 weeks! I know what adult hawks are dealing with, because in some years, a young hawk subjects my husband and I to their cries from the field next to our house! But hawks believe in tough love and eventually it gets hungry enough, I guess, to do its own hunting. Here’s my recording at Stony Creek Ravine Nature Park.

The youngster was nowhere in sight, but here’s a photo of one taken along Predmore Road near Lost Lake Park in 2017.

Red-tailed Hawk juvenile near Lost Lake in 2017

On a later visit, I was startled by a flash of huge wings, as a young hawk (I think!) flashed across the path in front of me and stumbled into a tree much too small for its size and weight. It wobbled back and forth on a thin branch for a few seconds. But before I raised my camera, it lumbered up into the air and soared off into the woods on the far side of the meadow. As far as I could tell this “desperate escape” was caused by the harassing pursuit of a single Blue Jay (Cyanocitta cristata) – hardly the behavior of an adult hawk!  Like a lot of adolescents, this young bird just needs a bit more time to grow up.

Back Up in the Meadow – Baby Birds and a Fun Baby Insect

It’s a steep climb out of the ravine, up through the woods to the path and the sunlit meadow. Back on the trail,  I noticed out in the meadow a few fledglings learning to make their own way in the world. A juvenile Eastern Bluebird (Sialia sialis) still sported the fledgling’s dappled chest, a field mark common to other members of the thrush family. It had landed high on the bare branch of a snag to survey the field, looking quite confident that it could survive on its own.

A Bluebird fledgling out on its own and surveying its world.

A little Song Sparrow (Melospiza melodia) popped up out of the greenery, looking like a plush toy! Donald W. Stokes’ Guide to Bird Behavior (Vol. 1) points out that a good field mark for juveniles is that their tails are about half the size of an adult Song Sparrow. Next spring, this little sparrow will look for a nesting site within its “song neighborhood,” i.e. close to the the place where adult birds sing the songs that it heard and memorized as a nestling. According to this Cornell Ornithology Bird Academy website, juvenile male sparrows need to practice for several months before they can sing their repertoire perfectly – sort of like babies babbling before talking.

A Song Sparrow fledgling learns its song repertoire from neighboring adults while still in the nest.

Far out in the meadow, I saw a hard-working male American Goldfinch (Spinus tristis) traveling about with a juvenile. Male Goldfinches do most of the fledgling feeding because the females are busy with a second clutch of eggs. Goldfinches wait to breed until mid-summer when thistles provide them with fluffy pappus (downy plant material) to make an almost water-tight nest lining. Then they feed their young with partially digested thistle seed. I could hear an insistent fledgling calling to be fed and could see the adult male flying to meet it. Each time, the two of them disappeared into the greenery for a meal. I moved further into the dense undergrowth, trying to see the adult feeding the youngster. Finally, the fledgling, alone again, came out onto a bare tree stem and diligently chewed at its tip. My best guess is that this behavior is a way to practice stripping hulls from the seeds that make up almost all of a goldfinch’s diet. But I’m not sure, though I’ve seen two young goldfinches do this in the last week!

A juvenile Goldfinch gnaws the end of a stem, perhaps practice for removing hulls from seeds in the future.

Out in the field, the adult male Goldfinch hopped about on a thistle, filling his beak with seed to share with the youngster. I believe the thistle he chose  is again Plumeless Thistle.  At least it appears to feed the birds and butterflies!

A Goldfinch male filling his beak with native seed from a Plumeless Thistle to share with his nearby fledgling.

The birds will be able to enjoy a treat before too long, because a big, energetic patch of  American Pokeweed (Phytolacca americana) with its Dr. Seuss-style color scheme has appeared along the trail! The green berries in the photo below will gradually turn white and then deep purplish-black. When ripe, they are much beloved by birds, particularly the Gray Catbird, Brown Thrasher, Northern Cardinal and the Northern Mockingbird, according to Wikipedia. However, they are highly toxic to most mammals, including us humans! So admire them,  but no snacking, not even one!

On the way back to the car, I spotted one of the largest and  most graceful nests of Eastern Tent Caterpillars (Malacosoma americanum) I’ve ever seen. These gregarious caterpillars head out each morning to forage together and return to their tents at night. The tents are added to each day before they leave, so they have multiple layers. As a result, the caterpillars can go to different parts of the tent for heating or cooling.  Though their feeding can defoliate trees, they cause little permanent damage and the trees generally re-leaf once they’re gone.

This tent is almost empty probably because in the morning, the Tent Caterpillars leave en masse to find food together.

My forays deeper into the meadow left me with socks covered in burs and sticky seeds. So on my way back to the car, I stopped at the beautiful bench commemorating the Kezlarian’s generosity toward this park. Along with the burs, I plucked a small caterpillar from one sock and set it on the bench. To my delight, it quickly began scooting around on the granite at a rapid pace. I laughed out loud! It was an inchworm! I looked them up when I got home and discovered they are caterpillars of the large and diverse moth family, Geometridae. Here’s the 30 second video I took of it that still tickles me. (It should have some cartoon music in the background, but again, I’m a complete beginner at videography!)

By the way, after filming, I let it climb on a dry leaf, carried it to a nice green one and wished it well.

The Persistence of Nature as a Challenge to Care

Water flows around a bend in Stony Creek Ravine Nature Park.

Places like Stony Creek Ravine Nature Park strengthen my hope when life feels challenging. The intense July heat – reportedly the hottest July in history worldwide! – finished the bloom of many flowers that might have lasted longer in a normal year. But honey bees rush about on less nectar-rich blooms, trying to gather their much-needed supply of pollen to feed the young  or  the nectar for making honey to feed the over-wintering colony. Some butterflies make their way across great distances  in unpredictable weather, seeking out available nectar to feed themselves and suitable host plants for their eggs. Young birds exercise their new skills, learning within weeks how to forage on their own in a landscape shaped by the changing climate. The glimmering creek down in the shadows of the forest rises and falls with the rainfall, but, for now,  flows on.

This same persistence, I think, also challenges us to do what we can to cool our planet and return to the patterns that nature has bequeathed to us through eons of experimentation. We owe it to the wildflowers, bees, butterflies – all of the natural world that supports us – to shape our lives not just to our human needs, but the needs of all the living beings that share this little blue planet with us. The township stewardship program is working on that, I’m working on that – and I bet you are, too. Let’s press on!

THIS WEEK AT BEAR CREEK: A Chickadee’s “Bed,” plus Insects Alive in Our Wintry World

insect tunnels on tree branch
The filigree of bark beetles on a fallen tree
Cam in red winter coat BC
Blog post and photos by Cam Mannino

During this cold week, when nature seemed pretty hunkered down – and I sure was! – I decided to explore how our local bugs get through the winter.  I’d always thought of insects as killed off by the cold – and many are – but others are biding their time and getting through the winter in surprising ways – like the bark beetle larvae which left their filigree in the fallen tree above.

A Chickadee’s Home for the Night?

But I did venture out at dusk to see if I could spot birds settling in for the night.  And a couple of Black-Capped Chickadees (Poecile atricapillus) obliged by disappearing into a snag.  One let its tail protrude from the hole long enough for me to locate it once it suddenly disappeared!

A closer look at the chickadee's tail coming out of its night-time hole
A chickadee’s tail protrudes from its night-time hole

When I tried lightening this hole on the computer, the little bird appeared to have turned its head straight upward to fit into the hole!  If that’s what really happened, I hope it found a more comfortable place to spend the night once I left. Perhaps just getting out of the cold, though,  is more important than a stiff neck.

Chickadee in hole for the night.jpg
The closest shot I managed to get of the chickadee in its hole for the night.

Now, Concerning the Winter Survival Strategies of Insects…

Bernd Heinrich, in his book, Winter World: The Ingenuity of Animal Survival,  claims“…there is no life-form on earth as diverse, varied, tough, and inventive as the insects. ”   Heinrich’s adjectives – diverse, tough, and inventive – certainly apply to the varied and creative strategies that our Bear Creek insects employ during the winter months!   So now,  while walking along the snowy trails, I can imagine all these small creatures swimming under the ice, tunneling beneath the bark, dozing in tree holes or eating inside plant galls, waiting like we all are, for the burgeoning of spring.

Wasps, Hornets, Bees and Ants:  Long Live the Queen!

This category of insect winter survival has two sub-strategies.  Almost all wasps, hornets and many bees, including our native Bumblebees (genus Bombus),  live only one season.  After mating in the fall, the only member of the hive that survives is the fertile queen.  She leaves  the hive and inserts herself into a crevice in a log or under bark – some moist place in which she won’t dry out as easily in the winter.  If she survives, she rouses in the spring and goes off to find a new nest location, lays eggs and the hive begins again (click on photos to enlarge or hover over them for captions).

European Honey Bees (Apis mellifera)and Ants (family Formiciadae) have a different strategy – staying in the hive with the queen, and protecting her during the winter. Honey Bees eat honey during the winter and they keep their hive and the queen warm by fanning their wings. They were imported from Europe because this survival strategy meant that Honey Bees dependably provided honey and crop fertilization from the same hive year after year.

Ants lower their metabolism in the winter and pile onto their queen in order to keep her warm. I believe I saw evidence of Carpenter Ants (genus Camponotus) in this tree on the western trail through our Oak/Hickory forest last summer and fall.

Carpenter ants
Possible evidence of Carpenter Ants who chew wood to create galleries between areas of their nest and then deposit it outside.

Carpenter Ants don’t eat wood like termites; they chew it to make the galleries that connect parts of their nest, and then deposit it outside. Assuming that these were Carpenter Ants, they will have moved deeper into the nest and are now hibernating together with their queen.

When spring warms a bee hive or an ant nest, bees and ants are ready to go, having survived the winter as adult insects.

Green Darners: Migration

A very small number of  insects migrate much as birds do. Those of you who read the blog this summer will remember that some of the Green Darners (Anax junius) head south in the winter.

Green Darner3
Some Green Darners, large dragonflies, migrate south in the winter and their offspring return in the spring.

According to National Geographic, these large dragonflies build up fat reserves and as cold weather sets in, some of them ride south on a north wind. Like avian migrants, they make stopovers to rest and feed along the way and, strangely, follow  the same flight paths as birds (don’t they worry about being eaten?). But unlike birds, it’s a one-way ticket for these Green Darners. They breed in the south and die and it’s their offspring that arrive the following spring.  Some Green Darners and many other dragonflies, though, use the following strategy.

Damselflies and Most Dragonflies:  Naiads under the Ice

Naiads appear in Greek mythology and children’s books (like C.S. Lewis’ The Chronicles of Narnia) as glamorous winged water nymphs overseeing streams, rivers, and fountains. The naiads under the ice at Bear Creek, however, are simply the homely immature life stage of the beautiful dragonflies and damselflies we see in the summer. In warm weather,  the females lay their eggs on vegetation  in the pond or marsh. Drab, wingless naiads with hooked jaws  hatch from the eggs.  Even in winter, these hungry carnivores are swimming about consuming mosquito larvae and other invertebrates.  After molting up to 15 times (some dragonflies take 3 years to finish molting!), they crawl up out of the water onto a plant, bend backwards out of their exoskeleton in one last molt and emerge in the warm sunshine as brightly colored and patterned dragonflies or damselflies like these:

A Quick Overview Before We Go On:  The rest of the insects I’m exploring here have a four stage development: 1) Fertile females produce eggs; 2) Larvae , which in butterflies and moths are also called caterpillars, emerge from the eggs and eat like crazy; 3) Pupae form. In butterflies, their bodies harden into their pupal form which  is called a chrysalis. Moths and many other insects spin cocoons and go through the pupal stage inside them; 4) Adults emerge from chrysalises or cocoons and mate to start the cycle again.  It turns out that different insects spend the winter alive and well –  but in different stages of development.

Overwintering as Adult Insects:  Mourning Cloak Butterflies

The adult Mourning Cloaks (Nymphalis antiopa) that we see in early spring emerge from bark crevices or trees holes where they hibernated during the winter (those woodpecker holes in snags do a lot of good, don’t they?).

mourning cloak (1)
Mourning Cloaks hibernate in tree holes so they can emerge in early spring to mate.

These early spring butterflies hatched the previous summer. They ate a little and then went into summer torpor, which is called “estivating.” In the fall, the adult butterflies became active again, ate to put on weight,  and settled into a hole to wait out the winter. In the spring, they emerge very early, sometimes when snow is still on the ground, and mate. And their eggs, larvae and pupae  begin the cycle again.

Overwintering as adults gives some butterflies an advantage since in early spring, there is less competition for food (tree sap, decaying matter) and fewer predators, since many birds haven’t yet returned from migration.

Overwintering as Pupae:  Spring Azure Butterflies

According to the University of Wisconsin Madison Field Station website, the tiny lavender/blue Spring Azure butterfly (Celastrina ladon) overwinters in the pupal stage that in butterflies is called a chrysalis. When the female emerges in early spring, she mates within hours of hatching, lays her eggs the next day and dies on the third – an extremely short adult life!

The Spring Azure overwinters, hatches, mates, lays egss and dies in three days!
The Spring Azure overwinters as a pupa.When the adult female butterfly emerges, it mates, lays eggs and dies in three days!

Larvae hatch from the eggs and eat for about a month. Each then forms a pupa (called a chrysalis in butterflies) and the Spring Azure stays in that form from early summer until the following spring! A long wait as a pupa for a very short time as adult mating butterfly!

Overwintering as Larvae (commonly called caterpillars): Bark Beetles and Woolly Bears

This overwintering strategy, like the Queen strategy of bees and ants,  takes at least a couple of forms – staying under bark or freezing solid!

Bark Beetles:  Busy Tunneling Under the Bark

Bark Beetles (family Curculionidae) are tiny insects (about 1/10 of an inch) that can survive the winter as larvae, pupae or adults. They are a major food source for woodpeckers, especially in the winter (so that’s why woodpeckers continuously peck at tree bark!). According to Donald Stokes’ book, Nature in Winter, adult insects bore through the bark to a softer inner layer. The males enlarge a “nuptial chamber” where mating takes place. The females then tunnel out into a branch or the trunk, under the bark, to lay their eggs. The larvae who hatch from the eggs make increasingly larger tunnels as they eat and grow during the winter.

Eventually, they form pupae under the bark from which adults emerge in the spring.  The adults  bore back through the bark and fly off to another tree. According to Wikipedia, some of these tiny insects become pests and kill trees, especially when climate change and other factors promote their survival.  Most, however, tunnel within weak and dying trees or aid in recycling the wood of dead trees.

Woolly Bear Caterpillars:  Freezing Solid!

Woolly Bear Caterpillars are the larval stage of the somewhat drab  Isabella Tiger Moth (Pyrrharctia isabella). These caterpillars, by the way,  don’t predict winter by their bands; they simply molt throughout the summer “becoming less black and more reddish as …winter approaches” (Bernd Heinrich, Winter World).  

Wooly bear
Woolly Bear Caterpillars freeze solid during the winter by supercooling and producing glucose, which works like anti-freeze, and then thaw in the spring to continue their life cycle.

In the fall, they curl up under leaf litter and survive the cold by a combination of supercooling (lowering their body temperature, even below 32 F!) and producing the glucose which functions as anti-freeze – just  like the spring frogs in a previous blog. They can even survive thawing and re-freezing throughout the winter! Their pupae can’t survive the cold, so they wait until late in March before thawing and beginning to spin their cocoons. Continue reading THIS WEEK AT BEAR CREEK: A Chickadee’s “Bed,” plus Insects Alive in Our Wintry World