By August, the heat and humidity are taking a toll on most birds and mammals, including humans. The morning brings half-hearted tunes from robins and cardinals but bird song is otherwise limited to the occasional rant of a jay or crow, the twitter of energetic swifts and the evening peents of the nighthawks. Even the drone of lawnmowers has become less common as the grass has slowed its growth and suburbanites have lost their enthusiasm for yard work.
In contrast, insects, oblivious to the heat, have assumed the choral duties. Annual cicadas, frantic to find a mate during their brief lives, call from the broadleaf trees, their irritating but nostalgic tune rising and falling in unison. A variety of beetles and grasshoppers join this late summer chorus and evening brings a substantial contribution from the fiddlers: crickets and katydids. The latter insects sing until morning, their scratchy tunes a classic feature of Midwestern, August nights.
Before long, the cool nights of September will suppress the insect chorus and the first hard freeze will officially end their run. By then, the birds and mammals are reinvigorated and the calls of owls, coyotes and migrant waterfowl propel us into autumn.