New Findings About Bird Songs And Calls

National Wildlife, April-May, 1999

Instrument Included

Birds apparently come equipped with partially preprogrammed "instruments." That's the conclusion of researchers who studied the sound-producing organ, or syrinx, of the zebra finch. They found that a steady change in air flow through the syrinx can generate a complex sequence of sounds. Still, like all musicians, birds must learn their songs and practice their instruments.

Nasal Is for Girl

People can't hear a difference between the songs of female and male northern cardinals. But a study of their songs' harmonics has found that the females, rare among songbirds for singing at all, use more overtones. The effect is somewhat nasal, and the cardinals can hear it: In an experiment, males tried to attack the source of a recorded male song, and females returned the song of a female. Scientists theorize hormone levels cause the difference in sound.

I'm Over Here!

If you've ever marveled at the way you can hear a conversation at a loud party, you might appreciate the similar hearing ability of king penguin chicks when their parents return from foraging at sea. Among tens of thousands of birds milling about and calling, the chicks locate their parents by sound. Now French researchers have found that a chick can locate a parent's calls when the mingled surrounding noise is as much as six decibels louder.