Get to know groundhogs

Post by Jen Berlinghof

Late last summer, I literally watched a groundhog (Marmota monax) fatten up before my eyes. He’d made a burrow in the field outside my office window and frequently visited the rain gardens around the Edward L. Ryerson Welcome Center in Riverwoods, part of the Lake County Forest Preserves in northern Illinois. We watched him scamper back and forth, snipping flower tops here and there, always with a mouth crammed full of flora.

Fast forward to early February, and as I look out across the same field, now dotted with small snow drifts punctuated by tufts of grasses gone tawny, I think about that groundhog curled tight in his burrow and deep in hibernation, oblivious to the hubbub of a day in his honor.

Groundhogs (Marmota monax) are active during daytime, particularly early morning and late afternoon. Stock photo.
Groundhogs (Marmota monax) are active during daytime, particularly early morning and late afternoon. Stock photo.

February 2 is about halfway between the winter solstice and the spring equinox. Historically, people have celebrated this seasonal crossroads in many ways. Groundhog Day in the United States is best described as a case of mistaken identity. It stems from a Germanic tradition involving hedgehogs and badgers as weather predictors for farmers. When German settlers arrived in Pennsylvania, they carried on this custom, substituting groundhogs, which were plentiful in the Keystone State.

While groundhogs can’t predict the weather, they do have other notable traits. It seems that we humans can’t quite agree on what to call them. Two common nicknames are woodchuck (which derives from a Native American word, wuchak) and whistle-pig (an homage to the high-pitched squeaks they use to signal danger). Groundhogs are rodents, and in fact, they’re Lake County’s largest squirrel, weighing in at up to 15 pounds. They can be seen swimming and climbing trees to elude predators such as raptors and coyotes (Canis latrans), which threaten to detour them away from their main focuses of food, architecture, and mating.

Except for mating season, groundhogs are solitary and spend the summer and early fall bulking up on a mostly plant-based diet, with some slugs and grubs as occasional ingredients. During this time, they also use their powerful front claws to create complex burrows. Their underground abodes have multiple entrance holes and can stretch up to 50 feet over several levels with numerous chambers. They even have a dedicated restroom chamber.

Once temperatures drop in late fall, groundhogs retreat alone to these palatial homes and begin hibernation. Unlike other animals that merely hunker down for cold bouts in the winter, groundhogs are true hibernators. They oscillate between short periods of arousal and long periods of torpor. In this altered state, groundhogs lose up to a third of their body weight. Their heart rate plunges from 80 to five beats per minute and their body temperature falls from 98 to 38 degrees Fahrenheit, about the same as inside a refrigerator.

Male groundhogs emerge from their dens temporarily in early February, then reemerge in March to mate. Stock photo.
Male groundhogs emerge from their dens temporarily in early February, then reemerge in March to mate. Stock photo.

Male groundhogs will wake up for one of these moments of arousal and emerge from their dens, typically sometime in February, to stumble sleepily around making house calls to the females living in their two-to-three-acre territory. It’s more a first date than anything else, but weather forecasting certainly isn’t on the radar for these rodents. The males eventually head back to their own burrows for another round of torpor before they emerge again to mate in early spring.

At the burrow I’ve been keeping tabs on, there are no tracks or signs of this groundhog rendezvous yet. But like the end of winter, whether it’s six weeks longer or not, my groundhog friend’s reemergence is one more thing to look forward to this spring.

A groundhog walks across a fallen tree. Photo © Tim Elliott.
A groundhog walks across a fallen tree in spring. Photo © Tim Elliott.

Get close to a real groundhog, make some tracks, and test your trivia knowledge at our Groundhog or Woodchuck? Drop In program, February 2, 11 am–4 pm. Learn more about one of Lake County’s few true mammal hibernators. FREE. No registration required. All ages welcome. Meet at the Edward L. Ryerson Welcome Center.

Monogamous minks? Not quite.

Post by Brett Peto. All mink images and footage by John D. Kavc.

Yes, it’s almost that time of year. American mink (Neovison vison) mating season. I know, I’ve been waiting for it, too. February is celebrated for human romance: fancy dinner dates, shiny gifts, and long walks on the Des Plaines River Trail. But it’s useful to step out of our human-focused perspective once in a while. And thanks to our comprehensive Wildlife Monitoring Program, we know minks live in the Lake County Forest Preserves in northern Illinois. So, let’s examine why humans aren’t the only species that looks forward to February 14.

A mink (Neovison vison) peeks over a fallen tree. Photo © John D. Kavc.
A mink (Neovison vison) peeks over a fallen tree. Photo © John D. Kavc.
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Finding the right angle

This gallery contains 10 photos.

Post by Brett Peto

I keep thinking about angles. Not the kind you measure with a protractor, but those you measure with your mind. The angle of a story, a conversation, or a project. Photography, of course, uses physical angles—where’s the camera pointed? is the sun directly overhead or is it the sweet time of golden hour?—but the best photos make you want to see even more. They make you want to break open the frame and soak in every bit of the Lake County Forest Preserves in northern Illinois.

Since it’s nearly the end of 2019, I thought I’d turn 180 degrees and peruse the photos uploaded to our group Flickr pool since January 1. Suffice to say: we’re spoiled. Spoiled with the beauty of Lake County’s flora, fauna, and natural areas, and the talent of the photographers who capture it for everyone to see. Trees and shrubs in their bright fall wardrobes on either side of a trail draining into a vanishing point. A sandhill crane (Grus canadensis) with both wings up like a paper airplane as it dashes to take off. A whirlpool of stars spun around a rich blue sky over a tranquil wetland.

I’ve gathered these moments plus seven more below, but that’s only a small taste. I encourage you to browse the rest of the visual buffet as we make the turn out of the 2010s into the 2020s. And, hey! You might become inclined to upload that shot living on your phone, camera, or computer.

"Night Moves." Photo © reddog1975.
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Give thanks for turkey vultures

Post by Jen Berlinghof

Come late November, most of us have turkeys on the brain. But a different type of turkey is taking to the skies at this time of year on its annual migration south: the turkey vulture (Cathartes aura). You can spot them in the sky or on the ground in the Lake County Forest Preserves in northern Illinois.

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Go take a hike

Post by Nan Buckardt

Everyone has one! At least, anyone who regularly hikes in the Lake County Forest Preserves in northern Illinois has one: a favorite trail. It might be the trail near your home or the one that reminds you of a secret only-I-know-about-this spot growing up. Maybe it holds a special memory. Whatever the reason, something about it always sparks joy in your heart.

I’ve been thinking about trails a lot this fall as I’ve hiked those selected for this year’s Hike Lake County (HLC) program. HLC has encouraged folks for 20-plus years to explore seven of 12 designated trails between mid-August and November 30. More than 200 miles of trails thread through dozens of preserves countywide, so the diversity of choices isn’t necessarily a big surprise, but it is a big benefit to residents and visitors.

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A different kind of autumn apple

Post by Jen Berlinghof

Fall is the time of harvest here in the Midwest. Golden stacks of hay bales, farmer’s markets teeming with end-of-season produce, and above all, apples. But step away from the orchard and into an oak woodland and you’ll find a different kind of autumn apple: an oak apple gall. What looks like a small, lime-green, spotted apple dangling from an oak leaf is not a fruit at all, but rather a secret abode for a tiny wasp.

There are more than 50 species of oak apple gall wasps in North America. Each one creates a unique fruit-like structure that protects and feeds its eggs and larvae as they develop. Lately, I’ve been finding many dried, spent brown husks created by the larger empty oak apple wasp (Amphibolips quercusinanis) around the Lake County Forest Preserves in northern Illinois.

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The din of the dog days

Post by Jen Berlinghof

The dog days of summer are a bounty for the senses. We see the lemon-yellow of whorled sunflower blooms, taste the ripe flavor of a homegrown tomato, smell the spicy sweetness of bee balm flowers, feel the heat of the day and the cool of the evening. Yet the most quintessential sensation of these end-of-summer days is hearing the overwhelming cacophony of cicada songs around the Lake County Forest Preserves in northern Illinois.

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