Female birds sing more often than previously thought
IBL-researcher Katharina Riebel, together with international collaborators, published a remarkable finding in Nature Communications on the prevalence of female birdsong.
Most birds that you can hear singing now outside in the Netherlands are males. They typically sing to keep male competitors away from important resources such as food, mates or nesting sites. Female birds can vocalize, but typically just utter some simple calls. However, there are some female songbirds that sing in our gardens.
Female robins are receptive for the seductive power of male acoustic ornaments during the breeding season in spring, but join in during song contests over individual territory boundaries during winter. Then, female robins turn out to be fully capable of fighting off males and females with their acoustic armaments. These gender conditions in robins appear less exceptional when investigated globally.
Katharina Riebel and collaborators performed an extensive survey of female singing tendencies across songbird species from all over the world and used so-called ancestral state reconstruction. They were able to show that female song is present in 71% of surveyed species, including 32 families, and that females must have sang in the common ancestor of all modern songbirds.
These results reverse the classical assumptions about the evolution of elaborate song and sex differences in birds. They also stress that understanding of evolutionary processes cannot always come from just studying the birds around us here in the western world.
Furthermore, although we should never translate biological insights directly to moral standards, we may also learn from this study that we should never assume any male bias as the inevitable default.