Rails are a group of birds that include the familiar pukeko and weka, and also takahe, coots, and the small, secretive crakes that inhabit densely vegetated wetlands. At least 14 species of rails were living in New Zealand before human contact, eight of which have since been lost. As with all New Zealand’s extinct birds, the larger species were directly hunted, while smaller species succumbed to predation by introduced mammals.
Two extinct species of small rails from the Chatham Islands are known from skins collected by European naturalists, but the six other extinct New Zealand rail species are known only from their bones. A single specimen of Dieffenbach’s rail was collected on Chatham Island in 1840, with the specimen deposited in the British Museum. Te Papa holds one mounted specimen and a single study skin of the smaller Chatham Island rail, both taken on Mangere Island before cats were introduced there about 1890.
The North Island takahe was described from bones found in south Taranaki more than a year before the first live South Island takahe was captured in Fiordland. This remarkable sequence of events was part of the reason that takahe (Notornis) held so much mystique from the mid nineteenth century through to the rediscovery of the South Island takahe in the Murchison Mountains in 1948.
Among the extinct rails of New Zealand are two little-known flightless species which are represented in the Te Papa collection by limb bones only. The snipe-rail was a small, long-billed denizen of North Island forests – its bill was longer in relation to body size than any other rail worldwide. Hodgens’ waterhen was about a quarter the size of a pukeko, and was found in forests and around wetlands in both the North and South Islands.
Two large species of coots occurred in forests and wetlands of primeval New Zealand, with the New Zealand coot in the North and South Islands, and the Chatham Island coot confined to the main Chatham Island. Both species were probably capable of flight. The Chatham Island coot was the largest coot species known worldwide.
In addition to the coot, the Chatham Islands have lost three other rail species in the last 500 years. The Chatham Island rail and Dieffenbach’s rail were mentioned earlier in this blog, and both are represented by many bones in the Te Papa collection. Both were found throughout the island group, with the best preserved skulls found in a limestone cave on the shore of Te Whanga Lagoon on Chatham Island.
The fourth extinct rail species from the Chatham Islands was a much larger species, found on both Chatham and Pitt Islands. With an estimated bodyweight of about 2 kg, Hawkins’ rail was about twice the size of a weka. Although the bird was not seen by European naturalists, there are several intriguing accounts provided by Moriori elders in the nineteenth century that were apparently first-hand reminiscences about this bird.
Previous blogs in this series:
For more information, check out these bird groups on New Zealand Birds Online:
or visit the Blood Earth Fire | Whāngai Whenua Ahi Kā exhibition at Te Papa