According to the scientists, the finding offers broader insight into the role that traits learned by males play in sexual success.
In an article in the September 22, 2002, Proceedings of the Royal Society of London: Biological Sciences (now online), biologists led by Duke University Professor of Biology Stephen Nowicki reported studies in which they tested the mating response of female song sparrows to songs of captive-raised males. Importantly, the scientists had analyzed the males' songs in detail to determine the degree of accuracy with which the males copied songs they attempted to learn. They found that the females preferred those songs that came closest to wild-type songs they heard when young and presumably learned as models. The scientists' research was sponsored by the National Science Foundation.
According to Nowicki, he and his colleagues in the field have long theorized that female songbirds pay attention to male song as an indicator of fitness.
"We've developed experimental evidence that there is a link between early stress, male brain development and song-learning," he said.
"But until now, experimental and field observations showing that females were interested in song only contrasted the presence or absence of song, or relatively gross features of song, like the size of the repertoire. This is the first study to explicitly demonstrate that females care about song-learning quality," he said.
To test the effects of fine differences in song quality on female response, the researchers trained captive-reared male song sparrows to sing by exposing them to the recorded so
Contact: Dennis Meredith