BOB HIRSHON (host):
Interspecies confusion…I’m Bob Hirshon and this is Science Update.
Some birds lay their eggs in the nests of other species, saving themselves the trouble of having to raise their own young. But this poses a problem: how do their offspring learn to recognize and mate with members of their own species? Boston University ornithologist Mike Sorenson says female redhead ducks often lay their eggs in the nests of the canvasback duck.
MIKE SORENSON (Boston University):
If you raise a male with females of the other species, and then give him a choice the following spring of females of both species, he will very actively court and pursue females of the same species he was reared with.
He and his colleagues aren’t sure yet how the ducks end up mating with the right species. They think that habitat differences between the species, and the female canvasbacks’ disinterest in male redheads may help sort out the confusion. I’m Bob Hirshon, for AAAS, the science society.