New Zealand oystercatcher
| New Zealand oystercatcher | ||||||||
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Mottled variant of the New Zealand oystercatcher |
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| Systematics | ||||||||
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| Scientific name | ||||||||
| Haematopus unicolor | ||||||||
| Forster , 1844 |
The New Zealand oystercatcher ( Haematopus unicolor ) is a species from the family of oystercatchers (Haematopodidae), which is limited in its distribution exclusively to New Zealand coastal regions. In the Maori language it is called "torea". No subspecies are distinguished.
description
Body measurements
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The New Zealand oystercatcher reaches a body length of 47 to 49 centimeters, of which around 10.6 centimeters are accounted for by the tail plumage. The beak is 8.2 to 9.2 inches long. Females tend to have a slightly longer beak. The wing measures 26.3 to 28.8 centimeters. The males weigh around 670 grams. The females are larger and weigh around 720 grams.
Adult birds
The species is polymorphic . This means that there are different gene variants that have different colors. The color of the underside can range from black and white spotted to mottled to pure black shapes. The further south you go, the darker the species becomes. All oystercatchers resident on the Stewart Islands are black. All color variants have a mottled band on the underside of the wing. The legs are pink. The beak is red and the eye ring is colored orange.
Fledglings
The color morphs can already be seen when the chicks hatch. The black parts of the plumage are generally more dull in young birds and tend to be brownish. In the young birds of the black color morphs, the feathers on the lower breast, the belly and the rump are narrowly lined with white. However, these feather edges wear off quickly and are no longer noticeable in somewhat older young birds.
distribution and habitat
The New Zealand oystercatcher is endemic to the coasts of New Zealand . It also inhabits islands near the coast, but it is not found on islands further off. It prefers sandy tears and is particularly common near river mouths and mussel beds. This type of oystercatcher is rare on pebble beaches. It is predominantly a resident bird that defends a territory all year round. Ringing data indicate, however, that New Zealand oystercatchers who are not yet sexually mature undertake further migrations until they form a pair bond and are then relatively loyal to their place. Young birds migrate an average of 36 kilometers from their place of birth. The furthest distance that could so far be detected using ringing data was 119 kilometers.
It is a common bird species in its area of distribution. Outside of the breeding season, it usually forms schools with the South Island oystercatcher .
nutrition
The New Zealand oystercatcher feeds primarily on mollusks, crabs, and sea worms. It is active during the day and at night, the time of day it searches for food is mainly determined by the tides. After heavy downpours, they sometimes go inland looking for food. With their powerful beak they are able to penetrate the shells of the prey.
Reproduction
The species lives monogamous and enters into a lifelong couple bond. During the breeding season, the couple defends their territory. They breed on the North Island , the South Island , the Stewart Islands, and the Chatham Islands . The nest is a hollow that is dug in the sand and sometimes covered with seaweed. It is built on the coast between rocks or on top of sand dunes.
The clutch consists of 2 to 3, sometimes up to 5 eggs. The eggs are greyish in color and have brown spots. The clutch is incubated for 25 to 32 days. The young birds fledge after about 6 weeks. Both parent birds are involved in the brood, the feeding of the nestlings and their management. The chicks are completely dependent on the parent birds for their first three weeks of life. Only at the age of 6 to seven weeks are they able to provide themselves with food independently. They are driven out of the territory by them three to four weeks after they have become independent from the parent birds.
The New Zealand oystercatcher can live to be over 27 years old.
Danger
The species is listed as "not endangered" in the IUCN Red List .
literature
- PJ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds , Volume 2, Raptors to Lapwings, Oxford University Press, Oxford 1993, ISBN 0-19-553069-1 .
Web links
- Haematopus unicolor in the endangered Red List species the IUCN 2011. Posted by: BirdLife International, 2009. Accessed November 17, 2011th
- Description of the species at Awana.co.nz
- Description of the species at Newzealandfauna.com
- Information on Art
- Internet encyclopedia on New Zealand
Single receipts
- ↑ a b Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 749.
- ↑ a b c d Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 748.
- ↑ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 755.
- ↑ a b c d Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 750.
- ↑ a b Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds . Volume 2, p. 751.