This winter has been harsh in Lake County, Illinois, causing many of us to wish we could migrate to South America like some birds do, or hibernate in a cozy underground den like the groundhog. Alas, most of us just stick it out in the cold. It may offer consolation to know we are not the only animals active during these record-breaking cold, snowy days. It turns out there is a whole ecosystem teeming with life right under the snow.
Recently, scientists having been taking a closer look at life in the subnivean, which literally translates to “a place under the snow.” The space between the snow and the ground acts as a seasonal refuge for invertebrates, birds, and small mammals. Snow affords these small critters with remarkable insulation, and temperatures around 32 F regardless of the temperature above the snow. Biologist Bernd Heinrich explains the science underlying these insulating properties in the book Winter World: The Ingenuity of Animal Survival. “As long as both ice and water exist side by side, they constitute a thermostat keeping temperatures constant.” When water converts to ice crystals, heat releases. When ice turns into water, the process uses up heat.
Many years ago, while running along the Lake Michigan shoreline late on an evening in January, a feathered ghost appeared on top of a flag pole. It was the first time I had ever seen a snowy owl (Bubo scandiacus) and it stopped me in my tracks. This was the spark on that frozen night that lighted my fire of curiosity about birds. This winter, snowy owls have left their Arctic homes in record numbers, causing one of the largest irruptions (sudden increase) in northern Illinois in decades.
Although it seems natural to correlate the arrival of these boreal birds with the extremely cold, snowy winter northern Illinois is having, experts say the motivator is more likely linked to food. On their Arctic breeding grounds, snowy owls feast under 24-hour sunshine. Their food of choice is lemmings, small mammals with an extremely cyclical population. Bird expert Kenn Kaufman explains in a recent Audubon magazine article, that when the lemming population explodes, like it did last summer in northern Quebec, snowy owls have great breeding success, producing large broods of up to 11 chicks. As these chicks quickly grow into juvenile birds, the competition grows for the now dwindling numbers of lemmings. Thus, the young birds get nudged further and further away to find a meal, resulting in them moving to areas that mimic their treeless tundra home, such as the Lake Michigan shoreline. Continue reading →
Leaves throughout the forest glowed gold against a backdrop of graying sky as I left Ryerson Conservation Area yesterday afternoon. This morning—as I entered the same preserve along the same road—the dark, skeletal branches were completely visible, stripped of their vibrant leaves that now lay in muddied piles on the forest floor.
These days of November mark a change from crisp colors to muted tones, which offer the perfect backdrop for animals to hide using camouflage. Lake County Forest Preserve educators often teach the concept of camouflage during environmental programs, where students hike in search of animal hides and mounts that have been hidden along the trail. Teachers and scout leaders, peruse our variety of school and scout programs to find a great fit for your group this year. Following is a virtual version of our camouflage hike. Continue reading →
When most adults hear someone mention crayfish, what most likely comes to mind is a culinary dish rooted in the South. However, mention crayfish to a group of Summer Campers at the Lake County Forest Preserves, and you will see eyes light up and hands reach for pond-scooping nets and buckets while their minds contemplate questions of “how big?” and “how many?” During our hikes to the edge of a pond the campers exchange crayfish stories about the best techniques for catching these crustaceans, the size of earlier catches growing the closer we get to the water.
It comes as no surprise that in a place named “Lake County” you are never more than a stone’s throw away from water. Lake County, Illinois is scattered with thousands of acres of wetlands, dotted with over 170 lakes and rivers, crisscrossed with 400 miles of streams, and bordered by massive Lake Michigan. This year at the Lake County Forest Preserves, we are celebrating this wealth of water by exploring how Water Connects Lake County through educational programs and recreational opportunities.
One way water connects the critters of Lake County is through the magic of metamorphosis. Ponds, streams and other wetlands host and hide well-known animals in surprising forms. Take a look at the picture below. This is a type of insect found in most local bodies of water. Can you identify this creature?
Now that the icy days of January have arrived, everyone in my house has that cooped up feeling and needs to get outside for a view of the expansive winter sky. We need to breathe a bit of fresh air, regardless of how cold it might be. At dusk, my sons and I have been hiking a nearby trail that takes us through scrubby meadows and thickets. During these forays, the boys are often loud and boisterous—until they flush out a cottontail rabbit. They quickly hush. We spend the rest of the hike searching for “our” rabbit (or signs of it) as we crisscross the worn network of trails trodden with tracks.
Earlier this week, my husband came in from the yard with a mosquito on his forehead. Had it been summer, that little tag-along would never have made it so far—but not in December. In the colder months, critters that are commonplace during the Midwestern summer are often the farthest things from our minds. It always amazes me when the weather has been cold for an extended period, then, at the first sign of warmth, insects seem to magically reappear. Where have they been hiding? How did they survive the frigid air that makes me shiver in my sweater when I’m outdoors longer than a few minutes?
While we revel in the slow pace of these last dog days of summer, sipping one last lemonade on the porch or wandering down one last stretch of beach, there is another mammal pulsing with life that has no such concept of slowing down. One of the most abundant mammals in Illinois, the shrew lives its life entirely in the fast lane—tunneling about a foot below the ground’s surface.
There are three species of shrews that live in Lake County, Illinois. The most common species, and largest at about 4 inches long with a 1-inch tail, is the lead-colored short-tailed shrew (Blarina brevicauda). The short-tailed shrew lives in a variety of habitats from forests to grasslands and typically only lives 1-2 years.
The least shrew (Cryptotis parva), at about 3 inches long, can be distinguished by its cinnamon-colored fur and extremely short tail. Least shrews are most commonly found in open grassy areas. About the same size as the least shrew, the masked shrew (Sorex cinereus), appears grayish-brown with a longer tail and prefers low wet areas such as floodplains.
This time of the year brings dazzling firework shows high in the sky. But, look closer to the ground in grassy yards and woodlands, and you will catch that same sense of awe as a myriad of lights burst, creating nature’s very own fireworks display. Watching and catching fireflies is one of the most quintessential summer experiences in the Midwest. There is a giddiness in holding a creature in your hand and watching it glow before it flies away to join the show. Continue reading →