ITHACA, N.Y. -- In a recent series of studies, Cornell University neurobiologists are showing why females of some avian species choose suitors with the most elaborate courtship songs: Fancy singers have more elaborate brain structures (to learn singing and other life skills), brains that the females hope their offspring will inherit.
Reports linking sexual selection on the basis of song and the "heritability" of bigger brain structures in three different bird species were published this year by Cornell scientists in the Journal of Neurobiology , with European sedge warblers; Behavioral Neuroscience , cowbirds; and most recently in Proceedings of the Royal Society (Biological Sciences) with zebra finches.
While the Cornell scientists hesitate to extend their avian neuroscience discoveries to the evolution and amorous affairs of homo sapiens , the leader of the studies says it helps to think in human motivational terms.
"An elaborate bird song is like a Grand Cherokee in the driveway or an M.D. after the name -- a kind of shorthand for all the desirable qualities that a female wants in a mate and wants passed along to the children," said Timothy J. DeVoogd, professor of psychology and of neurobiology and behavior at Cornell. "Of course these birds are not scholars of evolutionary theory. They don't think Darwin's principle of sexual selection when they make up their minds about which male sings best. Nevertheless, their choices will have an immediate impact on the success of their parenting and, in a longer-term, evolutionary sense, on the success and survivability of their kin for generations to come."
When male birds render their courtship song, a certain amount of bragging is implied, according to DeVoogd. It's as if the males are saying: "I know where the food sources are located around here. I know how to find nesting areas that are hidden from predators. I can defend our territory ag
Contact: Roger Segelken
Cornell University News Service