Female song is widespread in songbirds, despite being considered to be a predominantly male trait, and females sang in the common ancestor of modern songbirds. These findings are reported in a study published this week in Nature Communications.
Bird song is commonly seen as a male trait used to attract females and compete with rivals; while female birds that sing are viewed as rare and atypical. Songbirds are a diverse group known for learning complex songs.
Karan Odom and colleagues conduct an extensive survey of the occurrence of female song in songbirds and find that female song is present in 71% of the surveyed species. Mapping song traits on a songbird evolutionary tree the team show that it is likely that females sang in the ancestor of all songbirds. These results challenge the classic view that differences in male and female song are due to sexual selection, and raise the possibility that broader forces such as natural and social selection shaped the evolution of this elaborate trait.