Incomplete Reproductive Isolation Following Host Shift In Brood Parasitic Indigobirds

Distributed across sub-Saharan Africa, ten species of brood parasitic indigobirds reproduce by laying their eggs in the nests of other birds.


Because both male and female indigobirds learn host songs, populations associated with different hosts are behaviourally isolated from one another, allowing for rapid speciation whenever a new host is colonized. We used genetic parentage analyses to test this model for two indigobird host races, recently derived and morphologically indistinguishable populations that mimic the songs of different hosts.


Perhaps due to imperfect fidelity in host choice by the female parasites, reproductive isolation between the two host races is incomplete, suggesting that divergent natural or sexual selection is needed to complete the speciation process in indigobirds.


Proceedings of the Royal Society B: Biological Sciences


Proceedings B is the Royal Society's flagship biological research journal, dedicated to the rapid publication and broad dissemination of high-quality research papers, reviews and comment and reply papers. The scope of journal is diverse and is especially strong in organismal biology.


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