Herp Update: Recent Herp Activity — May 25, 2022
Recent Herp Activity
Along with the many choruses of Gray Treefrogs that people have been reporting, the extremely warm weather toward the end of last week even motivated a few American Bullfrogs to call here in the Lake Champlain Valley. They are the last of our frogs to call in the spring. Male American Bullfrogs set up and defend territories and hope to tempt the females into their territory through their calls. It is not the mad scramble you see with mating Wood Frogs.
On a field trip last Saturday, a couple of the students watched an American Bullfrog catch and eat a small Common Watersnake. We also have a photo in our database of a bullfrog eating a small Snapping Turtle. My wife Kris saw an American Bullfrog trying to catch a young weasel, and another bullfrog was found to have eaten a chipmunk. Bullfrogs are known as a gape-limited species. That simply means they will eat anything they can catch and fit into their mouths.
American Bullfrogs are not as common in Vermont as you might think. They appear to be missing from higher elevation towns and large sections of the NEK. We are in need of reports, photos, or tapes of American Bullfrogs from 96 Vermont towns. If you see one, please do take a photo and send in a report. If you hear one (a deep jug-o-rum), you can just record it (video on your cell phone) and send that in with your report. [Some files may be too large to submit way; you may email those if needed.]
Large Green Frogs are often mistaken for American Bullfrogs, but keep in mind that Green Frogs have dorsolateral ridges (folds of skin that run down either side of their backs) while American Bullfrogs do not. American Bullfrogs also have a more rounded mouth. I will attach a couple photos.
In the first two photos the American Bullfrog is on the right and the Green Frog is on the left. Look for the ridges and lack of ridges in the first photo (taken by Katie Reilley) and the mouth shape in the second photo (taken by April Hillman).
The last photo taken by Leah Farrell here in Salisbury shows a male Green Frog in amplexus (mating) with a female American Bullfrog. As far as I know, this does not result in any young.
Jim Andrews
“Anyone who believes that exponential growth can go on forever in a finite world is either a madman or an economist.” (Kenneth Boulding, 1973)
American Bullfrog on the right and Green Frog on the left. Photo taken by Katie Reilley and used with permission.
An American Bullfrog on the right and Green Frog on the left. Notice the mouth shape in this photo taken by April Hillman.
A male Green Frog in amplexus (mating) with a female American Bullfrog. Photo by Leah Farrell, Salisbury, Vermont.
