Environmental Almanac

October a month of dramatic change in central Illinois

From the departure of monarch butterflies to the arrival of dark-eyed juncos and the onset of cold weather, change is in the air
Tight profile shot of a songbird, light below and gray above, with a patch of yellow on its shoulder. Blurred background of orange and yellow maple leaves.

Yellow-rumped warblers and fall colors both arrive in October. Rob Kanter

Although the bright sunshine and warm days of this week make it tempting to think otherwise, the month of October promises dramatic changes for the natural world in central Illinois.

In urban areas, the acorns and walnuts that have already fallen add new challenges walking and cycling. Grey squirrels are in a constant frenzy, trying to figure out how to store the surplus of food available to them now. If you find walnuts stuck in your flower pots or wedged into odd places around your house or even on your car, blame the squirrels.

For now, chimney swifts still enliven the skies throughout the day, chipping to one another as they swoop and glide in pursuit of insects. But somewhere around the middle of the month they’ll head for South America, not to be seen again here until mid-April. 

Over in Indiana migrating sandhill cranes have just begun to arrive at the Jasper-Pulaski Fish and Wildlife Area. As of now there are only a handful of these magnificent birds at the site, but their numbers will increase over the next six weeks until they peak at nearly 20,000 in mid-November.

The cranes will move on to spend the winter in Georgia and Florida, but the smaller, cold-hardy birds that come down from the north to stay in Illinois for the winter will also arrive in October. If you keep an eye out you’re likely to see the season’s first dark-eyed juncos at your feeder before the month is over, and some white-throated sparrows have already arrived.

Insect life, which is still so abundant now, will also be scarce in a few short weeks. Migratory species, including monarch butterflies and assorted dragonflies, will have moved on by the time November arrives. Adults of other insect species will die off with the coming of frost, to be survived by eggs or larvae capable of withstanding the winter.

Frogs and toads will continue to fatten up on insects while they can, but over the course of the month they’ll be moving toward the edges of lakes and ponds. After a cold snap or two, they’ll burrow into the mud for protection from freezing as they hibernate through the winter.

In places where prairie remains or has been restored, this year’s flower show is mostly over, save for goldenrods and asters. Now is the time for the seeds of most plants to ripen and disperse. Adapted as they are for long life, the perennial grasses and flowers of the prairie will send the energy they have produced through the growing season below ground. It’s a good time to recall that much of the life of the prairie exists beneath the surface, where a deep, dense tangle of roots rhizomes and other structures mirrors the growth aboveground in depth and complexity.

I guess it goes without saying, but October is also the month for appreciating forests in the Midwest. Why not give yourself and your family the gift of a walk in the woods at Allerton Park this month? Or hit the trails for some leaf-peeping and wildlife watching at Turkey Run State Park in Indiana.

Winter will provide us with all sorts of reasons to stay indoors before you know it. Until then, though, let’s make use of whatever time and good weather we’ve got.