by Carl Strang
One of my favorite adventures was a solo sea kayak circumnavigation of Isle Royale in 1996. Islands have relatively few species, and this helped me to solve a puzzle that had bothered me for several years. I had been hearing a strange animal sound in late summers into autumns, a high-pitched intermittent call that sounded vaguely cricket- or frog-like. I hadn’t heard it in DuPage County, but in a variety of locations in the eastern U.S. I patiently had stalked these mystery animals several times without success. Then I found I was hearing the calls on Isle Royale. I also was seeing numbers of spring peepers.
Finally my brain made a testable connection. I knew a couple peeper locations in DuPage, and realized I had not gone into them late in the season. When I went there after returning from Isle Royale I heard the sounds. So that was the source of the sound, but I still have not figured out nor have I found an enlightening reference, which would explain why a spring peeper would peep in the autumn.