Post by Brett Peto
I started my position with the Lake County Forest Preserves in northern Illinois in 2017. By the end of 2018, I had visited 45 of our 65 locations. Each time I returned from a new spot, I circled it on a map at my desk. Their names were just as diverse as the habitats within. Old School, Lakewood, Middlefork Savanna, Singing Hills, Cuba Marsh. Oak woodlands and savannas, prairies, sedge meadows, marshes, wetlands.
In mid-January, it felt like a good time to circle another name: Heron Creek in Lake Zurich, Illinois. It surprised me that I’d never walked its trails. A 242-acre preserve home to rolling woodlands, fields, the Indian Creek basin, and more than 116 species of birds, Heron Creek is closer to our General Offices than several sites I had been to. It was even roughly on my route to and from work. So toward the end of January, I took myself, some winter weather gear, and a few cameras there to explore.
From the easternmost parking lot near Shelter A, I traveled the trails in Heron Creek’s southern half, following a 1.1-mile loop that climbed and descended the landscape more than I expected. Apart from exchanging good mornings with a visitor walking her dog, I didn’t see another soul for the next few hours. Just the land, my equipment, and myself.
There was a kind of quiet I’ve only noticed during or after a heavy snowfall. The sounds of traffic were nearly erased by the snow and my increasing distance from the road.
In a small thought, I realized much of what I think of as the noise of civilization and development is really the noise of traffic. People wear earplugs and install thick windows against it. With it mostly removed, though, whatever broke the silence seemed more purposeful.
Two mallards (Anas platyrhynchos) quacking, flapping above the tree canopy. The slow flow of Indian Creek’s not-yet-frozen bends. My steps punching through the crunchy surface of the snow. And something I’d never heard before, or at least not that I could recall: freezing rain falling on a pin oak (Quercus palustris) whose leaves were largely still intact. Its neighbors had lost theirs months ago. The falling rain sounded as if a gust of wind were blowing within the branches of just this one tree, never leaving the crown, redirecting back inward at its edges.
Like maples, hickories, and cottonwoods, most species of oak are deciduous. However, some individual oaks hold their leaves through the winter. This is called marcescence. Along with several oak species, American beech (Fagus grandifolia) and ironwood (Ostrya virginiana) frequently display marcescence.
It’s caused by incomplete development of the abscission zone, a region of specialized cells that forms at the base of the petiole, or stalk, of leaves. With shorter days in autumn, a number of chemical changes occur within the abscission zone. Two distinct layers of cells form, eventually separating the petiole from the branch and letting the leaf fall. In marcescent trees, this process is usually delayed until early spring, when expanding buds push last year’s leaves to the ground. During winter, snow or wind can rip certain leaves off, but they hadn’t done so to this particular oak.
Despite the solitude, I noticed evidence of others having been there before me. Boot prints and cross-country skiing tracks marked each path in zigzag patterns. Small holes peppered the trunk of a standing dead tree, likely the handiwork of woodpeckers foraging for wood-boring insects. White-tailed deer (Odocoileus virginianus) tracks cut across the trail west-to-east, a pile of scat midway through the visible hoof prints.
You have to work a little more to spot wildlife in the winter. Many animals are harder to see due to lower activity levels and protective coloration. I experienced this when I spotted a great blue heron (Ardea herodias) from about 100 yards away. It was standing perfectly still on the frozen surface of Indian Creek, so still that I couldn’t determine what I was seeing at first. The bird’s blue-gray plumage blended well with the blue-gray ice it perched on. My long lens was in my camera bag, though. Could I swap lenses quietly enough? I had to try.
Midway through, both lenses in my hands, the heron cocked its head, spread its six-foot wingspan, and took off gracefully, flying northwest. By the time I clicked the long lens into place, the heron was indistinguishable among the trees. I followed the trail in its direction, but neither saw nor heard any sign of it. After 15 minutes of searching, I paused on a bridge over Indian Creek. East of the bridge, it was frozen; west, flowing. Thin shelves of ice hung over the water, which cast dark forms as it slipped and dipped beneath the ice. It was a mesmerizing Rorschach test. What exactly had I seen today? More than I thought.
Winter can seem to some like a monotonous season. The color palette can be limited; the cycles of snow and ice can feel limiting. But as I see more of the world in winter, I see more in the world in winter. There are 19 preserves still to circle on the map at my desk, and I intend to circle them. However your map may look, I hope you circle more of it in this new year.