Picky female sparrows may be more unfaithful

Picky female sparrows may be more unfaithful, new Imperial research suggests. Cheating on social partners is common in birds, and there are clear benefits to males who can raise more offspring without investing in their care. For females, however, the drivers are less obvious.

The researchers tested if females who swap mates (divorce) more often were also more likely to cheat on their partners and produce young, known as "extra-pair offspring." They monitored the divorce rates of female house sparrows Passer domesticus, and the paternity of their young, finding females who swap mates more frequently were also more likely to cheat—but did not have greater proportions of extra-pair offspring. This implies that genes controlling female mate choice may also control infidelity.

The paper, "Divorce is linked with extra-pair paternity in a monogamous passerine" was published in the Journal of Avian Biology.

Jamie Dunning, lead author and Ph.D. student from Imperial's Department of Life Sciences, said, "Although it is common for female birds to cheat on their partners in the wild, why they do this has long been debated. Here we tested if genes that control infidelity may also control other behaviors, like switching social mates. The results here are a good step towards a better understanding on this intriguing social behavior."