By Bill Cook, Michigan State University Extension
Most of us are aware that many birds claim territory with songs and calls. Robins and cardinals might top the list for the most frequently recognized spring migrants. However, as the frogs and toads emerge from their overwintering habitats, their voices are among the favorites. The woodland frogs begin the annual serenade.
Chorus frogs (Pseudacris triceriata), spring peepers (Pseudacris crucifer) and wood frogs (Rana sylvatica) can be heard in those crepuscular times (dawn and dusk).
Nearly as soon as the ground surface thaws and even when there is still snow on the ground, the chorus frogs make a call that’s reminiscent of running a fingernail along a stiff comb. Often the first to make itself heard in the spring, they can be easily distinguished from the louder spring peepers and wood frogs.
The peepers, particularly, can make a cacophony of sound heard from the inside of speeding cars, even with music playing! Passing through those wetlands might seem a bit like a visitation from an alien world. They might be the best-known northern frog.
Wood frogs are also among the first debuts of spring. Their calls can be distinguished by a rapid thrup-thrup-thrup that sounds a bit like rubber slipping across rubber. Populations of wood frogs are known to sound like a large of group of people, all talking at once.
Soon to follow the chorus frogs, peepers and woodies are the American toads (Bufo americanus). These marvelous sounds are high-pitched trills that last around 15-20 seconds. A neighboring toad will sing at a slightly different pitch. Many toads will sound like a choir of sopranos or like science fiction laser guns!
Gray treefrogs (Hyla versicolor) can be heard from springtime and into the fall. Their sound is often mistaken for that of a bird. It’s a bubbly sound, sort of like blowing a straw into a glass of water, only a much higher pitch. These are also the frogs that can appear on window sills during the summer. They can be colored gray, brown or green.
Northern leopard frogs (Rana pipiens) make a rapid clicking sound as well as a rubber-stretching sound or, maybe, a slow, creaky rocking chair. Sometimes, they sound like the rapid taps of a sapsucker on hollow wood. The pickerel frog (Rana palustris) has a similar call, a bit more like a giant zipper.
Later into the spring and into the summer, green frogs (Rana clamitans) announce themselves with a flat note that is a bit like a single strum on a loose banjo string. Green frogs, bullfrogs, and leopard frogs are generally associated with ponds.
Bullfrogs (Rana catesbiana) are aptly named for their calls, which, indeed, resemble the moaning of bulls in the field. It’s a low-pitched, short moo that is usually repeated several times in sequence.
Of course, all of these northern frogs and toads, including some not mentioned here, are associated with water and begin as tadpoles. Many of them, especially the woodland frogs, are associated with vernal pools. These pools are essentially ephemeral spring puddles in the woods. Besides frogs, vernal pools sport many other interesting critters, such as salamanders and fairy shrimp.
Learning the various sounds of frogs and toads is fairly easy with the numerous audio clips found on the internet. Without much practice, identifying species and population sizes can be fun spring activities. The Michigan DNR has some fun information about our frogs and toads including audio clips.
