On the other hand, we have a new player this year, the "common true katydid." Southern Wisconsin is at the northern limit of these creatures' range, and until a couple of years ago, we had never heard them hereabout. We first heard them on the north side of Milwaukee, when walking on a summer's evening near the campus of Mount Mary College, which stands in a handsome oak grove. The entire grounds reverberated with a strange metallic quacking noise that could be heard blocks away, although, strangely, the invisible noisemakers seemed limited to that area, and were not, for example, accross the street. For a couple of years that was the only place we heard them, but they have now moved into our neighborhood. How they get here is a mystery, since info I can find on the web says they are "nearly" flightless, which seems most peculiar for a species that chiefly inhabits the tops of hardwood trees. We can target three individuals in our neighborhood within a block or so, so but no others. I can't imagine how they mate, since none of them seem to be inclined to leave the particular tree they have set up shop in (unlike crickets, both males and females sing--). Also unlike crickets, their noise does not seem to increase in rate with the heat, and they vary rythyms, usually squalking in triplets, but varying with rests or double notes. They are quite loud close up, although fortunately the noise of one does not carry too far. You can hear roughly what one sounds here:
Also interestingly, like some bird species, katydids have "regional dialects" maning the same species has different song patterns dependin on where found. Ours are "northern."