Natural Events

By Jack MacRae

Here’s what’s debuting on nature’s stage in Chicago Wilderness

Early Fall

Merlin Migration

Few people study merlin migrations. Peregrines get all the research dough, it seems. Beginning in September and lasting into October, hundreds of merlins—small, fast falcons—will rocket down the Lake Michigan shoreline. They’re headed south from their summer home north of Lake Superior. Merlins are reported to be antagonistic toward other raptors during migration. Spectacular, acrobatic flyers, merlins share the same prey—birds as peregrine falcons yet employ a different hunting strategy. Peregrines stoop on their unsuspecting prey from above; merlins chase down fleeing birds from behind like a heat-seeking missile.

Tasty Grass

Little bluestem is a righteous grass of dry hilltops, and one of the dominant grasses of the grasslands. During autumn, the plant is no longer little or blue. A hot-weather specialist, little bluestem bolts to 3 or 4 feet by the end of the summer. When the days shorten, it turns an attractive shade of burnt sienna. (Check your Crayola 64-color box.) Little bluestem adds much to a habitat by providing abundant shelter and a good deal of food. Field sparrows, with their smallish beaks, find the little seeds of the little bluestem a key addition to their diet as autumn turns into winter.

Middle Fall

Squirrels Fly Straight

During the fall, law-abiding flying squirrels prepare a nice warm home in the oak woods. But last October (and continuing through December), a gang of nine flying squirrels were caught breaking and entering into the attic of a suburban house in Glen Ellyn. Although 100 percent guilty, the court understood the situation (a desperate family in need of shelter) and ruled with compassion. The squirrels were sentenced to spend the winter in a warm, quiet location (the Willowbrook Wildlife Center). They were fed balanced meals of Lab Diet 5001, plus nine tablespoons of mealworms each day, perfect for developing young flying squirrels. The following spring, the group was released into a suitable oak habitat. Following tradition, they were released with their own new nest box, provided by the warden-naturalist. These squirrels were lucky McGruff the Crime Dog wasn’t involved in the case!

Secret Serpent

The first Kirtland’s water snake ever recorded in the scientific literature came from the Chicago Wilderness. The description came from Robert Kennicott who named it after his mentor, Jared Kirtland. (Kirtland also had a warbler named for him). Kirtland’s water snakes remain active relatively late into the season; they’ve been seen as late as mid-November. This doesn’t mean they’re easy to find. Highly secretive and living on the fringes of wet prairies and meadows, they are rarely seen above ground and may only come out at night. Oddly, unlike the more common northern water snake, Kirtland’s are extremely difficult to keep in captivity.

Late Fall

Bittersweet Sensation

Climbing bittersweet is a twisting, woody vine that climbs rope-like on trees and old fences. It is perhaps best known for its use in floral arrangements. The dried fruit clusters of climbing bittersweet—a unique combination of orange, yellow, and scarlet—are an attractive addition to many Thanksgiving centerpieces. The fruit matures on the vine and turns orange during the fall. Following a hard frost, the capsules split open and expose the bright red, berry-like center that contains the actual seeds. My mother thought the colors so pleasing she brought a sprig of dried bittersweet into the kitchen store and asked for a countertop in that exact color.

At one time common on rural roadside fences, climbing bittersweet has been disappearing from the Chicago Wilderness. Habitat loss and weed control along roadsides are partly to blame. So is the harvest for floral decorations. Yet it is still growing nicely in the dunes of Chicago Wilderness where it acts as a sand stabilizer. And according to my trusty copy of Plants of the Chicago Region (or “Swink and Wilhelm”), a healthy stand recently grew along the old towpath of the historic Illinois and Michigan Canal east of Morris.