(Santa Barbara, Calif.) More modest male displays attract the females when it comes to brown-headed cowbirds, contrary to sexual selection theory, according to UC Santa Barbara researchers Adrian O'Loghlen and Stephen Rothstein. Their findings are published May 2 in the open access journal PLoS ONE.
While sexual selection theory predicts that females should find more flamboyant displays the most sexually attractive, the opposite holds true for brown-headed cowbirds, a small songbird common in North America. Using audiovisual recordings of displaying males shown to captive females, the scientists found that the less intense the wing spreading, feather puffing, and bowing were during a display, the more sexually interested the female would be.
Although cowbirds have been studied for years, it hadn't really been noticed that displays directed at females were different in intensity than those directed at other males," said O'Loghlen, a research scientist in the Department of Ecology, Evolution and Marine Biology. However, technical advances in the area of audiovisual recordings made it possible for the researchers to investigate the brown-headed cowbirds's display behaviors in greater depth. O'Loghlen and Rothstein, a professor of Zoology, are the first to use AV technology to study the sexual responses of female songbirds to male displays.
Several things factor into cowbird displays, said O'Loghlen. For one thing, displays are typically targeted directly toward another cowbird. The display is a coordinated song and dance, with the bird singing as it puffs its feathers, spreads its wings, and bows. While earlier experiments had shown that female cowbirds are sexually responsive to some male songs and not to others (for example, they prefer local over foreign song types), this study shows that they also respond to the visual display that usually accompanies cowbird song.
"With these new audiovisual techniques we have deve
|Contact: Sonia Fernandez|
University of California - Santa Barbara