Bill Thrune - USFWS
Spring's Journey North
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Signs of Spring: February 2, 1998
Sounds of Spring
Spring makes itself known not only by new sights but also through new sounds. One unmistakable spring sound is
the croaking and calling of frogs, which will soon raise a chorus in the wetlands, stream sides, and woodlands
across North America. This year, we ask your help in LISTENING for the arrival of spring. Four frog species--known
for early spring singing--will be included in this study. We're eager to hear from you--as soon as you hear from
| Report the FIRST Frogs you hear singing this spring to
Listen for the:
Which frogs live near you? Check any field guide to amphibians where you'll find a range map for these species.
The Journey North WWW site will soon have range maps for each frog, thanks to Macalester
College. In addition, the frog calls for our 4 frogs will be provided, courtesy of the
Library of Natural Sounds at Cornell University.
First Frogs to Signal Spring
One of the first frog species to start calling in the Eastern U.S. and Canada is the Spring Peeper. They're tiny
frogs, between ¾ and 1 1/4 inches in length. Because they are so small, Peepers are nearly impossible to
see, yet they can ALWAYS be heard whenever they're singing. The voice of one Peeper sounds like a short, high-pitched
whistle. But when a group of Spring Peepers is calling together they sound like jingle bells on a winter sleigh.
Paul Moler, wildlife biologist with Florida Game and Fish Commission reports that Spring Peepers can be heard in
Florida as early as December. In northern latitudes, Jim Yaki from Ontario, Canada reports first observations of
Spring Peepers in March and sometimes as late as April. If you live somewhere between Florida and Ontario, Canada,
you should soon be able to hear Peepers within this range of time.
Frog Facts of Life
While Spring Peepers are one of the earliest frogs to sing, they're not the only frogs you may hear calling. Why
do you think frogs make such a raucous in the spring?
Don Forestor, Amphibean biologist at Towsend State University in Maryland states that it's the male frogs you hear,
and they croak like crazy in the spring to attract females of their species. Because there are so many different
kinds of frogs, each species must have its own distinct call in order to attract the right mates. In fact, frogs'
ears are specially "tuned" to absorb the mid-point of the pitch of the call of their particular species.
For example, ears of female Spring Peepers are specifically tuned to absorb the mid-point of the pitch of the male
Watch for more news and information about frogs over the course of the spring. In the meantime, learn more about
frogs by checking into some of the following sites:
Frog sites on the WWW
The Next Signs of Spring Update Will be Posted on February 16, 1998