Forest Preserve District of Cook County, Illinois
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Spring Frogs
Nature Bulletin No. 6  March 17, 1945
Forest Preserve District of Cook County
Clayton F. Smith, President
Dr. David H. Thompson, Zoologist

The CRICKET FROG and the SPRING PEEPER are among the first of the winter sleepers to come out of hibernation and greet the new year, On March 10, a few were found at McGinnis Slough, near Orland Park, where the sun had melted the ice and warmed the water along the shore. A week later the ice was all gone and they were singing in full chorus. If it freezes again, they will crawl back under the logs, leaves and trash where they spent the winter.

Both of these frogs are tiny -- about the size of a lima bean. The cricket frog has a rough skin and a dark triangle between the eyes. The spring peeper' s skin is smooth with a large dark-colored X on the back. The male frog does all the singing, blowing up the loose skin at his throat into a small balloon to serve as an amplifier. The cricket frog gets its name from the song of the male, which is a rapid series of staccato chirps -- as sharp as a note struck on a xylophone. The spring peeper's voice is a drawn-out "pe-e-e-ep", sounding like that of a cold hungry baby chick.

These frogs sing both day and night when it is warm, and often can be heard for a quarter of a mile. As you walk toward a pond or ditch where dozens of them, seeming to be trying to drown out each other, they suddenly shut up and sink out of sight in the water. They are very wary, but if you "freeze" on the spot, and wait, soon they will stick their heads out, inflate their throats, and tune up. But they are very hard to see and harder to catch.

The female come to the singing males and soon afterwards little bits of jelly, each containing an egg, may be seen stuck to weeds, twigs, and leaves just under the surface of the water. During the next week or so, the eggs develop into tiny tadpoles, the jelly swells and dissolves, and the tadpoles swim away to begin eating. If a few eggs can be found on a twig or leaf, and placed in a dish of water, you can watch the daily development of the eggs and the hatching of the tadpoles.

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