Ancient DNA elucidates the controversy about the flightless island hens (Gallinula sp.) of Tristan da Cunha

Abstract

A persistent controversy surrounds the flightless island hen of Tristan da Cunha, Gallinula nesiotis, Some believe that it became extinct by the end of the 19th century. Others suppose that is still inhabits Tristan. There is no consensus about Gallinula comeri, the name introduced for the flightless moorhen from the nearby island of Gough. On the basis of DNA sequencing of both recently collected and historical material, we conclude that G. neslotis and G. comeri are different taxa, that G. nesiotis indeed became extinct, and that G. comeri now inhabits both islands. This study confirms that among gallinules seemingly radical adaptations (such as the loss of flight) can readily evolve in parallel on different island, while conspicous changes in other morphological characters fail to occur. © 2008 Groenenberg et al.