Auckland Sawyer
| Auckland Sawyer | ||||||||||||
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Aucklandsäger ( Mergus australis ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Mergus australis | ||||||||||||
| Hombron & Jacquinot , 1841 |
The Aucklandsäger ( Mergus australis ) is an extinct duck bird from the genus of the saws . The distribution area of this saw species was limited to New Zealand. Already the Māori , who colonized New Zealand from around 1000 AD, hunted this species so heavily that it was exterminated in the interior of New Zealand before the colonization of New Zealand by Europeans. The change in the habitat and the introduction of species such as pigs, sheep, goats, cats and dogs by the Europeans made the species completely extinct at the beginning of the 20th century.
description
The Aucklandsäger was a small type of sawyer and the only member of its genus that was found in New Zealand waters. According to some scientists, the short wings suggest that the species was only able to fly to a limited extent.
The Aucklandsäger reached a size of 58 centimeters and a weight of 900 grams. It looked a lot like a female goose saw , but it was smaller and darker. The head was auburn. The throat and fore-neck were rust-colored. The back, shoulders, and tail were blue-black. The wings were ash gray. The wings of the hand were black. The middle arm wings were white on the outside flags. The arm-swing covers showed white tips. The chest was dull gray with lighter crescent markings. The rest of the underside was mottled gray and white. The iris was dark brown. Legs and feet were reddish brown with a hint of pink. The beak was longer than other types of saws. The upper beak and the tip of the beak were black. The lower beak was yellow-orange. The male had a five to six centimeter long reddish brown head of feathers. The females had a shorter head.
In young birds, the head of feathers was even shorter and did not appear at all. The chicks were mostly dark brown to black on the upper side of the body. There were pale spots on the end of the trunk. The chin, throat and front chest were chestnut colored. There were chestnut-colored spots under the eyes on the face. Unlike other sawaws, the chicks had no white stripes on their faces.
distribution
Fossil bone finds suggest that the Auckland Sawyer existed in the past on mainland New Zealand, Stewart Island and the Auckland Islands . Most of the fossil remains have been found near the coast. However, the fossil remains of at least two individuals have also been excavated in Lake Poukawa . On the Chatham Islands , too, there are fossil bone finds of ducks that look very similar to those of the Aucklandsawer. A species of duck from Campbell Island , erroneously referred to by Robert McCormick as a sawyer around 1842 , which was wiped out by rats around 1840, could either be a population of the Campbell duck ( Anas nesiotis ) or one of the eyebrow ducks ( Anas superciliosa ) act.
Way of life
Based on the beak content of a killed bird, it was found that the Aucklandsäger fed on fish such as the lowland pike ( Galaxias brevipinnes ) and on aquatic invertebrates. Its beak was longer than that of other types of saws. He was an excellent diver, but a very poor flyer because of his short wings. The Aucklandsäger couple probably stayed together all year round. The breeding season was between November and December. The clutch consisted of at least five eggs.
die out
On the New Zealand mainland, the Aucklandsäger probably died out as early as the 13th or 14th century due to human stalking and rats. Excavations of māorischen middens have brought several bones this Sägerart to day, although otherwise fossil remains of this kind are rare. This is taken as evidence that Māori hunted this species deliberately. In the 19th century the Auckland Sawyer was only found in large numbers on the Auckland Islands. A few specimens survived in inaccessible areas on the north and east coast of New Zealand.
Around 1806, pigs were introduced to the sub-Arctic Auckland Islands, which depleted the Aucklanders' populations very strongly. In 1840 they were collected for the first time during the expedition of the two corvettes L'Astrolabe and La Zélee under the direction of Jules Dumont d'Urville and scientifically described in 1841. After 1850 cattle, goats and sheep destroyed the habitat of the sawmill. It is not known when dogs, cats and rats came to the islands. They accelerated the extermination of the Auckland Sawyer. In addition, 25 specimens were collected for museums, the last pair of which was shot by Lord Ranfurly on January 9, 1902 . It is now kept in the British Museum . In 1909 there was an unsuccessful search operation. In 1910 a reserve was established on the Auckland Islands. A final expedition in 1973 also failed, confirming fears that the species had long been extinct.
In the museums of the world 26 bellows, 3 complete skeletons, some skeletal remains and three bodies soaked in alcohol are kept. The National Museum of Ireland in Dublin also has a stuffed male.
supporting documents
Individual evidence
literature
- Errol Fuller: Extinct Birds. Oxford University Press 2000, ISBN 0-8160-1833-2
- David Day: The Doomsday Book of Animals. Ebury Press, London 1981, ISBN 0-670-27987-0
- B. Gill and P. Martinson: New Zealand's Extinct Birds. Random Century, Auckland, New Zealand 1991, ISBN 1-86941-147-1
- Janet Kear (Ed.): Ducks, Geese and Swans. Oxford University Press, 2005, ISBN 0-19-854645-9 .
- A. Tennyson and P. Martinson: Extinct birds of New Zealand. Te Papa Press, 2006, ISBN 0-909010-21-8
- McCormick, Robert (1842): A sketch of the Antarctic regions, embracing a few passing remarks, geographical and ornithological. Tasmanian Journal of Natural Sciences 1 (4): 241-247. PDF full text
- Williams, GR & Weller, MW (1974): Unsuccessful search for the Auckland Islands Merganser ( Mergus australis ). Notornis 21 (3): 246-249. PDF full text
Web links
- Mergus australis in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed on December 20 of 2008.
- New Zealand Birds Auckland Islands Merganser