May 2, 2010 in western Kentucky:
Major thunderstorms and gusty winds have raged across western Kentucky for the last three days, effectively delaying my work with birds. The one payoff: a couple of decent “frog nights” where I was able to collect some nice video and sound recordings.
On the night of May 1, I visited the Obion Creek Wildlife Management Area in the Mississippi lowlands near Milburn, Kentucky. There I focused my attention on a group of Upland Chorus Frogs (Pseudacris feriarum) calling from the edge of a flooded field next to the parking lot. Although a storm was blowing in and lightning was causing me some concern, I was able to get some very nice video clips (ultimately, a lightning strike nearby sent me packing!). Here are some highlights:
The call of the Upland Chorus Frog is described as a clicking trill that sounds like someone running their finger across the teeth of a comb. It is quite similar to the calls of a number of other chorus frogs, including the Midland Chorus Frog (Pseudacris triseriata) of the upper Midwest, the Boreal Chorus Frog (Pseudacris maculata) that ranges north into Canada, the New Jersey Chorus Frog (Pseudacris kalmi) found in New Jersey and surrounding areas, the Cajun Chorus Frog (Pseudacris fouquettei) of the mid-South, and the Southern Chorus Frog (Pseudacris nigrita) of the southeastern states. The calls of these species vary with regard to pulse rate (timing of clicks within a call), but they are exceedingly difficult to identify in the field because their pulse rates vary with temperature.
In the background of the video, you can hear a large chorus of Cope’s Gray Treefrogs (Hyla chrysoscelis). Here is the mix of sound of the two species, as I heard it when I pulled into the parking lot. Listen also for the occasional nasal calls of a single Fowler’s Toad:
Chorus of Upland Chorus Frogs, Cope’s Gray Treefrogs, and one Fowler’s Toad, Obion Wildlife Management Area hear Milburn, Kentucky, 10:30 pm, May 2, 2010.