Leopards and tigers and bears!

Post by Jen Berlinghof

Around the first frost is the best time for spotting bears in the Lake County Forest Preserves in northern Illinois…woolly bears, that is! These fuzzy caterpillars succumb to a late fall wanderlust and can often be found traversing trails and roads, as well as climbing vegetation and nibbling a last few bites before winter sets in. They belong to the subfamily Arctiinae, commonly known as tiger moths. Their scientific name stems from the ancient Greek word arktos (“bear”), for the appearance of their hairy larvae.

A woolly bear caterpillar (Pyrrharctia isabella) found along the Des Plaines River Trail. Photo © Lake County Forest Preserves.

Any ten-year-old child can probably identify the most common woolly bear larva in the area, the isabella tiger moth (Pyrrharctia isabella). It boasts orange and black bristles in a banded pattern. That same child may also try to convince you this critter can predict the severity of the coming winter by looking at the length of the caterpillar’s bands of bristles. But just as groundhogs can’t truly predict the spring, moth larvae cannot predict the winter. After each molt, a stripe of the black setae (stiff hairs) is replaced by orange setae. This makes the orange band broadest in the last instar, or stage of larval development.

The author holds a giant leopard moth caterpillar (Hypercompe scribonia) in her hand. Photo © Lake County Forest Preserves.

I found another type of woolly bear caterpillar on a recent hike at Ryerson Woods (Riverwoods) that might be less familiar to folks. The larva of the giant leopard moth (Hypercompe scribonia) sports shiny black bristles separated by red inter-segments. Like the isabella moth larva, this giant woolly bear lacks stinging spines and doesn’t bite. When alarmed, it curls up into a tight ball, displaying its setae like little swords that can irritate the skin and mucous membranes of potential predators. This defensive posture also makes its bright red inter-segments prominent, a literal “red flag” to warn predators they’re unpalatable.

In its defensive posture, a giant leopard moth caterpillar displays its stiff setae and red inter-segments. Photo © Donald W. Hall.

Once these woolly bears have gorged themselves on asters, milkweed, sunflowers, violets, and even dandelions—and almost finished growing as larvae—they ramble on to find a suitable spot under leaves or logs to wait out the winter. Unlike most moth larvae that spend our freezing months tucked inside a pupal “sleeping bag,” in general tiger moths overwinter as nearly full-grown caterpillars, pumping glycerol through their bodies to keep their cells from freezing solid. They then emerge in spring to munch a bit more before creating a cocoon and completing metamorphosis.

The familiar orange-and-black woolly bear caterpillar emerges in spring as an adult isabella tiger moth. Photo © Patrick Randall.

An adult giant leopard moth. Photo © Christopher J. Williams.

As the sun sets earlier in the final days of fall and winter approaches, take these last moments to try to find these fascinating larvae before they hide away and press pause on their development. Discover new trails with our Hike Lake County Challenge before it ends on November 30. Then, come spring, look for the adult moths when both larvae and people emerge to explore the new season.

Happy birthday to our hawk

Post by Jen Berlinghof

This year marks the 100th anniversary of the Migratory Bird Treaty Act, a landmark law that protects bird species worldwide. To honor and celebrate this milestone, organizations and citizens have teamed up to designate 2018 the “Year of the Bird.” We at the Lake County Forest Preserves in Lake County, Illinois are celebrating another bird-related milestone this year as our education red-tailed hawk (Buteo jamaicensis) turns 30 years old.

Our education red-tailed hawk (Buteo jamaicensis) turned 30 years old this year. Photo © Joel Sartore/National Geographic Photo Ark.

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Summer “buzz kill”

Post by Jen Berlinghof

The sun had set, the campfire was doused, and the food was stashed away for the night as my sons and I tucked ourselves into our sleeping bag cocoons, thoroughly exhausted in a way one can only be from a day spent entirely outdoors. Still, sleep would not come easily. The whirling drone of thousands of annual cicadas buzzed through the nylon walls of our tent loud enough to overpower our fatigue. I lay awake, thinking it odd the cicadas would be calling after dark, when I caught a hint of the rising full moon through the ceiling screen and realized they were staying up late to party with the extra light. One of my boys groaned, “Isn’t there anything that can stop these CICADAS?” As a matter of fact, the next day we found just the thing: a cicada killer wasp (Sphecius speciosus).

The author holds a dead cicada killer wasp in her palm. Photo © Lake County Forest Preserves.

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“Toadally” awesome!

Post by Jen Berlinghof

Last week, our Wetland Explorers summer nature campers went wild…in a good way! We were hiking along the Des Plaines River Trail when we came upon a major toad hatch-out. Hundreds of dime-sized toadlets took over the trail, prompting shrieks of excitement from the campers. The kids scurried around, scooping up handfuls of toads, trying to save all the hopping and popping amphibians from potentially hazardous bike tires and hiking boots along the trail.

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A tale of two squirrels

Post by Jen Berlinghof and Allison Frederick

Everywhere you look this time of year, animals are tending to nests during spring’s baby season. Squirrels are very active at this time with the bounties of spring. Food reserves from winter are low, and energy demands are high with young in the drey (their leafy, treetop summer homes) demanding to be fed. So, squirrels turn from their habits of digging for winter caches and begin eating buds, flowers, fungi and lichens. They will take advantage of almost ANY food source at this time of year!

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In search of river otters

Guest post by Andrew Rutter

I had just finished my time as a Masters student at Southern Illinois University with the Cooperative Wildlife Research Lab, studying river otter (Lontra canadensis) ecology, when I took my first full-time position as a wildlife biologist with the Lake County Forest Preserve District in Illinois.

Having spent the last two years of my life entirely focused on river otters, I figured my time studying the species was at an end. Although my research team and I found them to be relatively abundant where we focused our research efforts in southern Illinois, I did not expect the same to be true farther north in Lake County.

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“Submarine cottages”

Post by Jen Berlinghof

Late spring and early summer are busy seasons for children visiting the Lake County Forest Preserves for pond study programs. The shorelines of ponds pulse with the excitement of students, nets in hand, ready to discover the macroinvertebrates teeming under the water’s surface. The most delightful find this season by students has to be what Henry David Thoreau once called the “submarine cottages” of caddisfly larvae.

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