Fall 2004

By Jack MacRae

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

Red bat. Photo by Rob Curtis, The Early Birder.

EARLY FALL

Red Bats in Morning
In early autumn, small groups of migrating red bats funnel along the Lake Michigan shoreline as they head south to spend the winter in the southern U.S. After flying all night, the exhausted bats head ashore at daybreak. Once over land, fatigued red bats become easy targets for predators. Early morning nature watchers have seen gulls, crows, and peregrine falcons all having a bite of bat for breakfast on the beach.

Predators aren't the only danger to the bats. I remember when my old volleyball teammate and mighty fine mammalogist Bob Timm spent a few years documenting the migrating bats that were killed when they collided with McCormick Place windows in downtown Chicago. Sadly, he and other scientists collected more than 70 bats — including 43 red bats — over eight years.

Free Bird
Once upon a time, during a local harvest fest in a quaint Chicago Wilderness town, a small flock of common nighthawks treated the crowd to an entertaining air show. The nighthawks were attracted to moths that were drawn by the bright lights of the stage. Coincidently, the music was provided by a Lynyrd Skynyrd cover band, playing a passable version of "Freebird"!

	Common nighthawk. Photo by Rob Curtis, The Early Birder.

Nighthawks are common in our skies during early fall. From mid-August to early October, they often fill the dusky sky snatching bugs and uttering their peent calls to keep in contact with one another. As neotropical migrants, nighthawks must fill up on flying insects for their long trip to Argentina, where they'll spend the winter hanging out with the gauchos.

MIDDLE FALL

Swift Moves
Chimney swifts should be grateful for miserly landlords who won't turn on the heat until November 1. As long as the chimneys remain cool and dark, the swifts will gather together to roost safely inside.

The average departure date for these birds from our area is October 6. Readers should try to catch their legendary act before the swifts depart for Peru. Their rapid, full-tilt entry into the chimneys is an amazing sight. At times, more than 100 swifts may rush into a chimney in a matter of seconds. During the first week of October, this spectacle takes place around 6:25 p.m. in those wonderful red brick chimneys of older schools and factories.

Bottle gentian. Photo by Gene Burda, Root Resources.

Bee in the Bottle
The late-blooming bottle gentian, found in moist prairies and savannas, has a unique appearance — the flowers look like blue, pleated sausages. The tight clusters of blue-violet flowers grow on top of the stem and provide bumblebees with an exclusive, late-season supply of nectar. Only these robust bees are capable of forcing their way through the closed petals and crawling into the chamber of rich pollen. Bottle gentians are in bloom during September and October.

Little Kings
Eastern milk snakes like to live under the cover of logs and boards. But on warm, blue-sky afternoons in autumn, I have found them basking on a grassy path under some noisy high-tension wires. There is a nice stand of oaks and the remains of an old farm there, the perfect habitat for the Eastern milk snake. Some researchers believe old stone foundations may be important hibernating sites for the species.

Eastern milk snakes are members of the king snake family, the only king snake in Chicago Wilderness. Milk snakes have a rounded diet of mammals, birds, reptiles, amphibians, fish, eggs, and invertebrates, with a decided preference for rodents and snakes. Good gumbo, your majesty.

LATE FALL

Underground
To a cool chipmunk, a good stash is important. Unlike some other cheeky rodents, chipmunks don't put on an extra layer of fat when the nights grow longer. Rather, they depend more on a well-supplied cache of munchies for the long, cold, lonely winter.

By the end of autumn, chipmunks have gathered several pounds of seeds, bulbs, and assorted nuts and packed them into underground storage rooms. Chipmunks won't be entering hibernation and will need to eat to stay alive.