Frog Chorus

November 21, 2005

We can often recognize people we know by the sounds of their voices. One researcher visited a pond at night to find out whether frogs can, too.

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Transcript

BOB HIRSHON (host):
Recognizing your neighbor’s ribbit. I’m Bob Hirshon and this is Science Update.

[frog chorus]

HIRSHON:
Every bullfrog has its own distinctive voice—and bullfrogs on a noisy pond know each other’s voices well. That’s according to University of Minnesota behavioral ecologist Mark Bee. He tested this by playing computer-generated frog calls on a pond crowded with territorial male bullfrogs. When the frogs would get used to one call, he would change the pitch.

MARK BEE (University of Minnesota):
This would cause the frogs to immediately orient toward the speaker, begin giving aggressive calls again, and approach toward the speaker…

HIRSHON:
…as if the changed call belonged to a totally new rival. Since bigger bullfrogs have lower-pitched calls, Bee says recognizing neighbors by pitch is a useful way for frogs to size up their competition.
I’m Bob Hirshon, for AAAS, the science society.