by Carl Strang
When I began to study singing insects a few years ago, one of my hopes was that I would be able to develop protocols for a monitoring program. I was a participant in the dragonfly monitoring group, and I was aware of hearing-based monitoring programs for frogs and breeding birds. In subsequent years I have found that there is no clear way to comprehensive, all-species monitoring of singing insects. Because of the odd pitch ranges and harmonics, different people hear insect songs differently. For example, older people like me begin to lose their capacity to hear higher pitches, and need to rely on devices like the expensive Songfinder to hear some species. There are many insect songs to learn, in comparison to relatively few frogs and toads. Though the number of breeding bird species is greater, birds are popular. Few people will make the kind of effort needed to learn so many insect songs.
I was interested, therefore, to learn of a group in the New York City area which has come up with a different approach to singing insect monitoring. They call it the Cricket Crawl. They selected a date, September 11, on which they asked people to go out at night and listen to insect songs for one minute at one or more places, then report locations and species heard to the web site. Key to their plan was limiting the focus to seven species of insects with loud, distinctive songs that nearly everyone can hear. They acknowledged that others “form the background of soft churrs and trills that emanate from a series of different small ground and tree crickets.”
While results are not complete as of this writing, Sam Droege and other organizers immediately picked several patterns from the data. For instance, the fall field cricket (photo above of a female) proved to be the species most tolerant of the broad range of urban environmental conditions. The most common katydid was the greater anglewing (photo below).
The species of greatest interest was the common true katydid, which historical data indicated at one time had become scarce or even extirpated locally. The September survey found several local populations, some of which may have become established from eggs transported on nursery stock from other parts of the country.
As I continue to ponder possibilities for insect song monitoring, the success of the Cricket Crawl will remain in mind as worth considering.