Wisconsin Sea Grant Frogs: Field Guide

Spring Peeper Frog
(Pseudacris crucifer crucifer)

Call: A high-pitched, rising "peep!" given about one per second; a male peeper may also give a lower-pitched trilled whistle, usually when another male has moved too close to its calling site

Size: 2-3.7 cm in length (0.8-1.5 inches)

Coloring:
Brown, tan or gray with dark slanting stripes on the back that usually form an X-shaped mark; the belly is white, yellowish or cream colored; this frog has some color-changing ability and can darken or lighten, depending on its mood or the surroundings

Habitat:
Found in temporary and permanent ponds, marshes, floodings, and ditches; after the breeding season they move into woodlands, old fields or shrubby areas; common throughout the Great Lakes region, except in the far north along northeastern Lake Superior.

Confusing Species:
Striped Chorus Frogs have a light upper lip line and lengthwise stripes, instead of the X-like marking, on the back; Cricket Frogs are wartier and have a dark stripe on the inner thigh.

Breeding: Late March into May

FACT: Spring Peepers have large "vocal sacs" under their chins. They pump these sacs full of air until they look like a full balloon, then let out a mighty "peep" while discharging the air. The easiest way to see calling Peepers is to look for their shiny vocal sacs, which look like 25-cent pieces, inflating and deflating as they call.

The loud, peeping chorus of Spring Peepers means winter is finally coming to an end. These little frogs are among the very first to call and breed in the spring, often starting while there is still snow on the ground and ice on the lakes.

Did you know?

A spring pond full of peeping Peepers can sound like sleigh bells jingling -- only louder. Sometimes peepers make their calls while sitting under clumps of grass or in cracks or crevices in the earth. This position allows them to amplify the call, and also can create an effective ventriloquism: the frog sound seems to come from somewhere other than where the frog actually is!

copyright 2001 University of Wisconsin Sea Grant Institute