by Carl Strang
The south unit of Illinois Beach State Park is closed. I found that out when I arrived there, having taken a vacation day and driven the hour and a half or so it takes to reach Zion. That squelched singing insect research Plan A, though it turned out for the best, as we’ll see. I would not be able to achieve all my goals, but I could at least try to find gray ground crickets at the north unit.
Between the parking lot and Lake Michigan, this grassy area is protected enough from wind and waves to support tall prairie grasses including big and little bluestem, and Indian grass, as well as a few forbs. The soil appears to be nearly pure sand. All I was hearing at the parking lot were some fall field crickets and Allard’s ground crickets, but I followed a path toward the beach and soon, in the sandy prairie shown in the photo, was hearing scattered gray ground crickets. I kept hoping I might see one out on the path, but no such luck, and I didn’t want to be too intrusive at an area that already gets much use. I’ll hope for a photo opportunity some other time.
The gray ground cricket’s song is distinctive, though in part that is because of the connection to the habitat. There was one place where an Allard’s was singing close enough to a gray to allow a direct comparison. Both ground crickets have long trills, but that of Allard’s is noticeably slower, the individual notes fully distinguishable if a little too rapid to count. The gray ground cricket’s trill is much more rapid, though still audibly composed of distinct notes (i.e. they don’t blend into a single tone). The song is higher pitched than that of Allard’s. In addition, the gray incorporates characteristic pauses here and there. A recording can be found on-line here.
It was only mid-day, so I decided to check another Lake County site on my fall research list, which I had thought would have to happen on another day. I’ll report on that tomorrow.