Cheep and cheat on the wing

October 1, 2005

THEY say personality is more important than looks for women, but try telling that to the North American barn swallow.

Scientists found that female barn swallows will not hesitate to cheat on their partners if they spy a more handsome suitor.

The female bird constantly compares the appearance of her mate with that of other males. Should a more attractive proposition come along, they are likely to set up a secret love nest.

Researchers were able to influence the birds' mating habits by painting the throats, breast and belly feathers of randomly selected males with a red marker.

As far as the female North American barn swallow is concerned, a red breast is best.

Rebecca Safran, of Cornell University, who led the study, said: "The bad news for male swallows is the mating game is never over. It is dynamic and continual. This is something that most humans can relate to."

All 30 females studied during the research remained socially paired with their original mates. But at the same time they were sexually active with other males. DNA tests showed that males with enhanced colour fathered a substantially larger percentage of offspring in their second nests.

Dr Safran, whose findings appear in the journal Science, said: "The study shows that the females are paying close attention to these signals and that they respond quickly to changes in their mate's appearance."

The findings may point to why evolution has allowed decorations such as the peacock's tail or a deer's antlers to remain.

