The Spring Peeper – A Tiny Frog with a Big Sound

Last week my wife and I were riding bikes on some rural roads, past fields and woods. At one point, up ahead we heard the unforgettable sound of the spring peepers – hundreds of tiny frogs sounding like loud sleigh bells ringing through the woods. It was deafening!  It was even more deafening when we cupped our ears with our hands making “deer ears”. If you live anywhere east of the Mississippi River, you should be familiar with this annual chorus of frogs this time of year!  Often in our family we say, “Have you heard the peepers yet?” This early spring songster has quite a story to tell.

Male Spring Peeper (Pseudacris crucifer) with vocal sac inflated as it sings.

While the spring peeper, Pseudacris crucifer, is the most famous of all the chirping frogs, they’re not the only species native to North America. Spring peepers belong to a group of frogs known as “chorus frogs” and live in the eastern half of N. Am. (from Northern FL to Canada). The easiest way to identify them is by their chirping (the monotonous sleigh bell sound).  Be careful for there is another frog, the chorus frog that sounds like the noise that you make when you run your fingernail over a fine-toothed comb.

Peepers make their way in March from their winter shelters under forest logs and leaf litter to ponds and pools of water on the forest floor. Their famous lusty songs are males filling the spring nights (and often days) in their efforts to bring the late-sleeping lady friends to the breeding ponds and pools of water. These vocal creatures are no bigger than a human thumb and are masters of camouflage.  Virtually the only way to spot one is to slowly home in on its loud peeping and catch a hint of movement as the frog’s inflated vocal sac pulsates with song. Even that can be maddeningly difficult, since these little singers have a habit of becoming instantly silent when an intruder approaches.  It has always amazed me how quickly and completely the whole jangling chorus can stop, even when I am still several yards from the nearest peep.  It may be that the frogs don’t see me coming but rather feel the vibrations of my footsteps through the ground.

Here are some other facts about our beloved spring peepers.

  • The nightly chorus from peepers on warm spring nights is actually a peeper mating ritual. Females are drawn to their male chirping suitors.  After they mate, the female lays eggs underwater. Those eggs hatch in about 12 days.
  • Spring peepers have the ability to start producing their own “antifreeze” to help preserve the most essential organs.  Up to 70% of the frog’s body can freeze, to the point that the heart stops pumping and the frog appears to be dead.  Once they wake up and thaw a bit, they will go through a period of healing before resuming their normal lives.
  • These small frogs feed on small bugs like ants or small beetles.
  • Peepers can be easily identified by a dark X-shaped marking across their backs.  Other species of “chorus frogs” have spotted or striped markings.

Perhaps at the writing of this blog, the peepers might have finished their remarkable singing.  However, I hope that you all take time to listen to the warm spring nights for these amazing little pond/marsh/forest songsters. You might also begin asking your family members or friends, “Have you heard the peepers yet?”


This post was by Teacher Peter Manzelmann, our on-campus naturalist who teaches students of all ages outdoor studies.