Bird song prompts species split

August 21, 2003

The love of a familiar tune has prompted the evolution of many new species of indigobird, according to a study in the August 21, 2003 Nature. African indigobirds (Vidua spp.) lay their eggs among those of other species. A male, adult indigobird learns the songs of his firefinch hosts and uses them in his own courtship. A female, in turn, will only mate with males that sing the host melodies she learned as a youngster. Now, Michael D. Sorenson and colleagues have studied the genetic make-up of a range of indigobirds. They report that song recognition prompted the development of ten distinct indigobird species from a recent common ancestor. Single species classically diverge as individuals become geographically isolated. Here, the indigobird uses firefinch song as a kind of identification system. The different tunes effectively isolate populations of indigobirds, much like a geographical barrier, but with no spatial separation.

“Speciation by host switch in brood parasitic indigobirds,” Michael D. Sorenson, Kristina M. Sefc, Robert B. Payne, Nature, August 21, 2003

Abstract © 2003 Nature, contact: Michael D. Sorenson, Boston University