Birds who play away help lift gene pool

Photo / Amos Chapple

Female birds paired for life in apparently monogamous relationships seek out sex with other males to boost the genetic fitness of their offspring, scientists have discovered in an experiment involving warblers in the Seychelles.

Since the advent of DNA fingerprinting it has been possible to test the paternity of the offspring and, to the astonishment of scientists, many offspring appear to have been fathered by males other than the ones involved in rearing the brood.

Only one male helps the female to raise the brood and the infidelity could result in him abandoning the nest.

This led scientists to suggest the female was seeking better genes behind the back of her male partner to boost the genetic fitness of her offspring without the risk of losing the help of her male partner.

In the journal Molecular Ecology, it was revealed scientists had found evidence in support of this hypothesis by studying the lives and mating habits of 97 per cent of the warblers that live on the island of Cousin in the Seychelles, where the birds have been studied since 1997.

- INDEPENDENT