On a recent walk through Ryerson Woods, the leaves of Virginia creeper shone bright red as they crawled around an oak tree. Intermingled were the yellow leaves of the poison ivy plant.
These are among the varying hues you can see on an autumn day in Illinois. But there’s a lot more going on with nature than changing leaf color. Listen carefully, and you will hear the subtle conversations of autumn.
At Ryerson Woods, short, low-pitched chips came from the upper and lower branches of oaks and other tree species. Occasionally, a loud “chuck” sounded from the forest floor, while a few metallic “chinks” emanated from the understory.
These are the sounds of migratory birds in autumn, precisely hundreds of yellow-rumped warblers, a few hermit thrushes and a dozen or more white-throated sparrows. These songbirds, which gave long phrases and haunting melodies in spring, are much more subdued this time of year.
They aren’t looking for a mate or setting up nesting territory. They are looking for food and keeping in touch with their brethren, with whom they will alight from the treetops at night to continue migrating. Trained ears can discern the single-note calls, which vary in tone quality, pitch, and duration.
Occasionally some of these migratory species will actually sing in autumn. The most vocal are the young white-throated sparrows that hatched in summer farther north and are practicing the songs they heard their parents sing.
It’s a softer, more tentative song compared with the vociferous “Oh sweet Canada, Canada ” the adults belt out in spring. Listening for the young of the year try to sing is one of my favorite autumn nature experiences. It makes me smile when the young seem to stumble on certain notes.
One vocalization that’s not nearly as pleasant is the insistent, repeated single-syllable “gulp” call of an eastern chipmunk in autumn. They communicate in spring as well, but in fall, their conversations can last 10 or 15 minutes long.
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One theory is that the chipmunks are gathering nuts and seeds to store beneath the ground for winter, and they are telling other chipmunks to stay away. “Go get your own food and hide it somewhere else,” they are saying. In winter, the chipmunks enter into a deep sleep in underground burrows, waking up every once in a while to munch on the food they’ve gathered.
The chipmunks are likely also giving what’s called an “aerial predator alarm call,” according to Lang Elliott, a professional nature recordist. Hawks migrate in autumn, so it makes sense we’d hear more alarmed chipmunks this time of year.
Amid the chipping warblers and scolding chipmunks, we also heard a faint ringing “peep,” a few times.
It was the sound of a 1.5-inch-long tree frog, specifically a spring peeper. In early spring, the peepers fill the woodlands near small ponds with jingle-bell-like mating songs. But once in a while in autumn, a peeper gives an occasional softer sound called a “fall echo.”
Scientists posit that these calls are a seasonal response to the weather. The amount of daylight, cool temperatures, and intermittent rain in autumn mimic what happens in spring when the peepers actively court and mate. That may trigger the males to vocalize.
In fact, in fall, the males are full of sperm, and the eggs in females are almost as large and developed as they will be in the spring, according to Kiley Briggs, a writer for the Orianne Society, a reptile and amphibian conservation organization.
In winter, spring peepers’ metabolism slows so much that they almost freeze solid. They remain almost lifeless, buried beneath logs and at the bottom of a shallow pond. In spring, as soon as they thaw out, they need to be ready to breed.
On that mid-October day, we also heard a few crickets rubbing their forewings together while cicadas flexed and relaxed membranes on their abdomens to create mating sounds. These insects call less frequently than they did in summer. But they are having their last hurrah, mating before they die, so that eggs laid underground by females can overwinter and hatch next spring.
The first hard frost marks the end of noise-making for crickets and cicadas. The spring peepers will then be tucked in their frozen state, and many of the migratory songbirds will be living down South where insects are active.
Still, winter will bring with it new and welcome sounds, like the “pips” of the juncos who arrived here recently. The goldfinches, who are here year-round, will continue to chatter “perchickeree,” reminding me of the continuum of spring to summer to fall to winter and back to spring again.
Sheryl DeVore has worked as a full-time and freelance reporter, editor, and photographer for the baiduhai and its subsidiaries. She’s the author of several books on nature and the environment, and co-author of “Birds of the Midwest,” to be published by Timber Press in 2027. Send story ideas and thoughts to [email protected].