Boreal Chorus Frog (video)

Boreal Chorus Frog calling from the shelter of a tangle of dead plants, 3/3/2021

If you look closely at the picture above you can see a small frog tucked under the triangle of dead plant stems with his throat ballooned out to amplify the sound of his call.  This was one of a handful of boreal chorus frogs (Pseudacris maculata) that was calling along with the huge chorus of spring peepers at the Homer Lake Wetland on 3/3/21.  The numbers of chorus frogs will grow in the coming days and may even come to rival the number of spring peepers, though the high shrill peeps of the peepers will still probably dominate the audioscape.  

If you take a look at the short video below, you will hear and see the chorus frog above doing his best to be heard above the din of the spring peepers. You will be able to tell the sound of the chorus frog because his throat enlarges with each of his calls and his call is very different from that of the spring peepers. The call of the chorus frogs is usually compared to the sound of a person running a finger over the teeth of a comb. 

The boreal chorus frog is a relative of the spring peeper and about the same size. If you happen to spot one of these small frogs, the spring peepers have an X on their backs whereas the chorus frogs have three lines running down their backs.

You might wonder how we know that this frog is a "he."  We know because, as in so much of the animal kingdom, it is the males that must attract the attention of the females. Male frogs do this by calling.

You might also notice that neither the spring peepers nor the chorus frogs say "ribbit." The pacific treefrog, found in Southern California makes the "ribbit" sound. When early movie makers based in Hollywood needed night sounds, they went out and recorded sounds which included the pacific treefrog. This then became a common way of describing frog calls, despite the fact that, for example, none of the twenty species of frogs and toads found in Illinois make that sound at all.