Wisconsin Frogs Don't Croak!
- Jackie Scharfenberg, Retired DNR Naturalist
- May 14
- 2 min read
Visit a local pond or lake this spring into summer, and you’ll hear peeps, trills, twangs and deep jug-o-rums, but no croaks or ribits! Look closely among the bushes and reeds along the water’s edge and you may just spy these noise makers, the frogs.
DID YOU KNOW?
Wisconsin is home to eleven species of frogs and one toad, which makes learning their calls easier than learning the songs of the hundreds of bird species in our state.
HOW DO THEY MAKE THOSE SOUNDS?
Frogs and toads make sounds by closing their nostrils and pushing air from their lungs over their vocal cords and through the windpipe into the air sac. The air sac located below the chin, when inflated, sometimes pokes out on both sides, but most often to the front depending on the species. The air sac acts like a resonance chamber, which magnifies the sound making it louder. The glottis, or opening into the lungs, controls the flow of air and the call’s sound. Think of how your lips modifies how air goes in and out of your mouth.
Frogs are one of the true circular breathers. When calling, a frog expands its air sac with air from the lungs. Then the air is forced from the air sac back into the lungs in a circular path. This allows frogs to call continuously, even if they are underwater.
WHY DO THEY MAKE THOSE CALLS?
Mostly during the cover of darkness, male frogs and toads do all that singing hoping to attract mates. Each kind of frog sings when the water reaches the perfect temperature, and stops when it warms up too much. The green frogs and bullfrogs will sing all summer, since they sing not only to attract the girls, but to also mark their territories.
WHERE DO THEY LIVE?
Green frogs and bullfrogs hang out in permanent water bodies like lakes, because their tadpoles take two or three years before they morph into adults. The best place to look for the other frogs is in temporary ponds or other water holes that don’t have fish (remember, fish eat little tadpoles). They will complete their transition from tadpoles to adults in just one season.
FROG SPECIES IN WISCONSIN
Below is a list of the frogs found in our area along with the toad, their calls and when to listen for them.
Late March to Mid-May (water temperature around 50oF)
Wood Frog: raspy “lick it up” or quack
Northern Spring Peeper: shrill and repetitious “peep”
Western Chorus Frog: like a fingernail run overa plastic comb
Late April to late May (water temperature around 60oF)
Leopard Frog: loud, broken snore, like rubbing a finger over an inflated balloon
Pickerel Frog: snore-like call shorter and less broken than the Leopard’s
Eastern Gray Treefrog: short, melodic trill
Cope’s Gray Treefrog: short, raspy trill
American Toad: uninterrupted trill even tone lasting up to 30 seconds
Late May to July (water temperature above 70oF)
Green Frog: “gung-gung-gung,” like plucking a loose banjo string
Bullfrog: low, slow “jug-o-rum”
Hope you have some grand adventures listening and searching for our most boisterous noise makers.
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