Chatham raven
| Chatham raven | ||||||||||||
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skull |
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| Corvus moriorum | ||||||||||||
| ( Forbes , 1892) |
The Chatham Raven ( Corvus moriorum ) is an extinct species of bird in the family Corvidae . It occurred in the Chatham Islands and is known only from subfossil material. The type epithet refers to the Moriori , the first settlers on the Chatham Islands. The type material was discovered in January 1892 by Henry Ogg Forbes .
features
The Chatham raven was the largest known corvid in the Australasian region and believed to be the fourth or fifth largest songbird in the world. Henry Ogg Forbes described him as about one and a half times the size of the hooded crow . The weight was 950 to 1000 grams. The relatively long tarsometatarsus probably indicates an adaptation for better walking or running on the ground. Like all ravens and crows, however, he was also good at flying. The palatine bone was more ossified than in the common ravens or the American crows of the northern hemisphere. The Chatham raven had a long, broad beak that was not as curved as the beak of the Hawaiian crow ( Corvus hawaiiensis ).
The New Holland crow ( C. coronoides ) is probably the closest living species, the original sister species is probably the New Zealand Maori crow ( C. antipodum ).
Way of life
Most of the bones were found on the shores of the Chatham Islands. It is therefore possible that the ravens visited the penguin and fur seal colonies or looked for food in the Wadden Sea.
die out
The cause and timing of the extinction are still unclear. Many bones have been found in the Moriori clam mounds , so it can be assumed that the species was hunted. If the Chatham raven was a ground breeder, it would have been easy for the introduced rats to chase the chicks.
literature
- BJ Gill (2003): Osteometry and systematics of the extinct New Zealand ravens (Aves: Corvidae: Corvus) In: Journal of Systematic Palaeontology , 1, pp. 43-58 doi : 10.1017 / S1477201903001019
- A. Tennyson and P. Martinson: Extinct birds of New Zealand. Te Papa Press, 2006, ISBN 0-909010-21-8
- Trevor H. Worthy , Richard Holdaway: The Lost World of the Moa. Prehistoric Life of New Zealand. Indiana University Press, Bloomington 2002, ISBN 0-253-34034-9 .
- William Plane Pycraft (1911): On the skeleton of Palaeocorax moriorum . In: Novitates Zoologicae 18: p. 123-128
Web links
- Chatham Islands Raven. Corvus moriorum. by Paul Martinson. Illustration from the book Extinct Birds of New Zealand by Alan Tennyson, Te Papa Press, Wellington, 2006