Chatham rail


The Chatham rail is an extinct flightless species of bird in the family Rallidae. It was endemic to Chatham, Mangere and Pitt Islands, in the Chatham archipelago of New Zealand. Genetic similarity with the Dieffenbach's rail is why many view this species as part of the genus Gallirallus.
The Chatham rail and the Dieffenbach's rail, both flightless, were sympatric on the Chatham Islands. Their sympatry suggests parallel evolution after separate colonisation of the Chatham Islands by a common volant ancestor, presumably the Buff-banded rail.
The Chatham rail was first discovered on Mangere in 1871, and 26 specimens collected there are known from museum collections. It became extinct on the island between 1896 and 1900. The species is also known from 19th century bones from Chatham and Pitt Islands. It is likely to have occurred in scrubland and tussock grass.

Extinction

Its extinction was presumably caused by predation by rats and cats, habitat destruction to provide sheep pasture, and from grazing by goats and rabbits. On Chatham and Pitt Islands, Olson has suggested that its extinction resulted from competition with the larger Dieffenbach's rail, but this has been refuted later when the two species have been shown to have been sympatric on Mangere.