Friday, August 29, 2014

Who's that Croaking!

Report from a FrogWatch Volunteer at the Vinton Park Pond
By Jeanette Kreiser

At the Vinton Park Pond, right by the Somerset Town Pool, a lone bullfrog (apparently) calls for a mate while American toads provide a more continuous background din. As part of FrogWatch USA, a national citizen science program of the Association of Zoos and Aquariums to monitor the frog and toad populations across the United States, I have been spending three minutes one night a week for the past several months listening at the pond for the calls of various species of frogs and toads, and some additional minutes recording my findings on the web at the Fieldscope site, http://frogwatch.fieldscope.org.

I have been part of the Montgomery County chapter of the program, conducted under the aegis of the Montgomery County Department of Environmental Protection. After a one-hour classroom session in January and an additional hour of training in the field in early March, supplemented with further online listening sessions at my home to learn the calls of the different species of frogs and toads native to this area, I began my weekly three-minute evening vigils as soon as temperatures were above freezing.

The first weeks were discouraging.  There were no sounds at all coming from our pond—even when, in early March, I had just heard a multitude of spring peepers a half-hour earlier at a pond in Rockville where the March training session was conducted. After three very quiet weekly evening sessions at the pond, I was beginning to think that our town was devoid of frogs, and that my frog monitoring was going to be a very uneventful and unproductive effort.

Finally, one afternoon in late April, while taking the cut-through from Friendship Heights to Somerset, I heard my first calls at the Town pond which I identified as those from American toads. The next week, a lone bullfrog added deep bass notes to the toads’ higher trills. Several weeks later, the American toad calls ceased and sounds that resembled the strumming on a comb’s teeth—the call of the upland chorus frog—began, with the bullfrog’s voice continuing its regular deep croak.

Concerned that there seemed to be a lone (and lonely?) bullfrog, I began an e-mail conversation with the Somerset Mayor and some Town Council members, as well as some members of the town’s Environmental Committee, about whether there was a way that the Town might provide some additional bullfrogs in the pond.

But the idea was dropped when we contacted the Montgomery County Department of Environmental Protection, which discouraged the introduction of populations in general, and warned that bullfrogs were known to be very aggressive and would very likely drive out the other species of frogs in the pond environs. Further, it seemed best to leave the frog to his own devices. Rather than lonely, he might well have been most happy to be the sole male, with the likelihood being that there were females, who do not croak, available in the pond area.


My vigil will continue into the summer.  I hope that I will be able to report that there are other species of frogs and toads croaking in our pond and woods.