Extinct birds of New Zealand, Part 4 – Rails

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.

Mounted chick of Chatham Island rail (Cabalus modestus). Te Papa Collections Online OR.001371

Mounted chick of Chatham Island rail (Cabalus modestus). Te Papa Collections Online OR.001371

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.

Skull of North Island takahe (Porphyrio mantelli). Te Papa Collections Online S.024736

Skull of North Island takahe (Porphyrio mantelli). Te Papa Collections Online S.024736

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.

Mounted chick of Chatham Island rail. Te Papa Collections Online OR.001371

Composite image of left tarsometatarsal bones of snipe-rail (Capellirallus karamu) and Hodgens’ waterhen (Gallinula hodgenorum). Te Papa Collections Online S.024712 & S.025594

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.

Chatham Island coot (Fulica chathamensis). Te Papa Collections Online OR.007937

Chatham Island coot (Fulica chathamensis). Te Papa Collections Online OR.007937

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.

Chatham Island rail (Cabalus modestus). Te Papa Collections Online S.031754

Chatham Island rail (Cabalus modestus). Te Papa Collections Online S.031754

 

Dieffenbach’s rail. Te Papa Collections Online S.032195

Dieffenbach’s rail (Gallirallus dieffenbachii). Te Papa Collections Online S.032195

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.

Hawkins’ rail (Diaphorapteryx hawkinsi). Te Papa Collections Online OR.007967

Hawkins’ rail (Diaphorapteryx hawkinsi). Te Papa Collections Online OR.007967

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:

Extinct birds of New Zealand Part 1 – A diverse menagerie, sadly departed

Extinct birds of New Zealand Part 2 – Songbirds

Extinct birds of New Zealand Part 3 – Waterfowl

Extinct birds of New Zealand, Part 5 – Moa

For more information, check out these bird groups on New Zealand Birds Online:

Birds extinct since human contact

Birds extinct since European contact

or visit the Blood Earth Fire | Whāngai Whenua Ahi Kā exhibition at Te Papa

Recently extinct New Zealand rails: Dieffenbach’s rail, Chatham Island rail, snipe-rail, Hawkins’ rail, Hodgens’ waterhen, North Island takahe, New Zealand coot, Chatham Island coot.

2 Responses

  1. Dave

    Hi, I was writing about the demise of ground dwelling birds due to the introduction of pests by Humans this morning, came across your post – very interesting read.

    I believe you have ambitious plans in NZ to eradicate predatory pests that are killing your native birds, I hope that goes ahead and you are able to save remaining species going forward.

    Reply
    • Colin Miskelly

      Thanks for your comments Dave

      Yes, it is a very ambitious goal. But even the lesser steps along the way (e.g. stated objectives of removing all predators from several large islands near the two main islands) will greatly benefit many vulnerable bird and reptile species.

      Cheers
      Colin

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