by Carl Strang
Waterfall Glen is DuPage County’s most biologically diverse forest preserve. It has the greatest topographic variety, the greatest geological variety, the greatest mix of plant communities, covers hundreds of acres and therefore harbors more species than any other preserve. I had a few specific places I wanted to check for singing insects on my most recent visit there, and will need two posts to describe that afternoon sensibly. My first stop was Sawmill Creek.
In particular I hoped to find variegated ground crickets there. I hadn’t noticed any unusual songs along that stream before, for instance during the Roger Raccoon Club’s creek walks, but I hadn’t known then that the variegated ground cricket is a habitat specialist found on pebbly or sandy stream edges. In DuPage County, covered with tens to hundreds of feet of clay-rich glacial till, the one stream most likely to match this habitat description was Sawmill Creek, which has pebbly banks and in places flows right over the exposed Silurian dolomite bedrock. I struck out, though. I heard no trilling species other than Say’s trigs and Carolina ground crickets, even with the SongFinder, and so my tentative conclusion is that this little-studied ground cricket lives elsewhere than DuPage County.
Next I checked out low wet areas in the western part of Waterfall Glen’s forest, some reduced to muddy patches and others still ponded at this point in the season.
Here I was listening for two other ground cricket species, the spotted and sphagnum ground crickets. The latter was the longest shot, as there was no sphagnum moss, but sometimes species have a broader habitat range than the literature suggests. This time, though, I heard no new species in that part of the forest.
As I followed the trail back to my car I got one very good break, however. I heard a meadow katydid’s buzzing song coming from the edge of the woods about 20 feet away. It wasn’t as loud as a black-legged meadow katydid, and anyway the habitat was high and dry. As I approached the singer I realized I recognized the song. Sure enough, it was a long-spurred meadow katydid.
The long pointy teeth on the cerci confirmed the ID.
This finding was a source of great relief. A few posts ago I mentioned that my failure to hear some of these singing at Blackwell Forest Preserve (except when I wore the SongFinder) had me wondering if my hearing was failing rapidly. Such clearly is not the case. So, what was going on at Blackwell? At some point I’ll have to see if I can find out. Incidentally, at both the Blackwell and the Waterfall Glen locations for long-spurreds there were no coniferous plants present, so here is one of those examples of hints in the literature being misleading.