Note to editors: A photo of Steve Nowicki is available on the University Photography ftp site at ftp://152.3.242.19/pub/ . The filename is Nowicki.
He may be reached at (919) 684-6950, snowicki@duke.edu

DURHAM, N.C. -- When male songbirds sing to attract mates, the quality of their song might directly portray their fitness, say Duke University biologists in advancing a new theory of how birdsong serves as a mating signal. Their theory holds that female birds carefully analyze a male's song quality to judge how well he has overcome the stress of early life and how effective a mate he will be.

The researchers, Associate Professor of Zoology Steve Nowicki and research associates Susan Peters and Jeffrey Podos, discussed their theory in an article in the latest (dated February) issue of American Zoologist. Their research is sponsored by the National Science Foundation.

"This hypothesis has to do with the fact that song is a learned trait," Nowicki said, "And that this learning is supported by specific regions of the brain that develop during a particular period when the young bird is most likely to undergo stress." Such stress, Nowicki said, might consist of the nutritional stress a nestling faces during the rapid growth period songbirds typically face early in life, or perhaps stress resulting from the effects of parasites.

"Males that have more complex songs -- or songs that females prefer -- went through the learning process better, because their brains developed better. It's because they were better nourished or less stressed during this critical period in the late nestling, early fledgling phase."

Thus, said Nowicki, the song quality, in essence, tells the story of a male bird's life, not only how fit he is, but how well his parents raised him.

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Contact: Dennis Meredith
Dennis@dukenews.duke.edu
919-681-8054
Duke University
4-May-1998