Bristle curlew
| Bristle curlew | ||||||||
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Curlew ( Numenius tahitiensis ) |
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| Systematics | ||||||||
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| Scientific name | ||||||||
| Numenius tahitiensis | ||||||||
| ( Gmelin , 1789) |
The bristle-thighed curlew ( Numenius tahitiensis ) is a monotypic bird from the kind of curlews and one of the three endemic bird species in Alaska . The population is estimated at around 7000 animals.
description
This bird has a head-to-trunk length of 40 to 44 centimeters. About seven to nine centimeters are allotted to the beak. The wingspan is 80 to 90 centimeters. The weight varies between 350 and 550 grams.
Just like other curlews, the females are slightly larger and have longer bills. The typical downward curved beak has a pink base and a dark tip in summer. In winter the whole beak is dark. With all types of plumage, the animal has gray legs, a light beige underside and a light tail with dark horizontal stripes. The upper plumage sections are dark brown with gray shades and sand-colored dots. A dark line of eyes clearly stands out from its bright surroundings. The underside of the wings is more red-brown and the upper side is gray-blue.
Distribution and migration behavior
The curlew breeds in the Alaskan tundra near the mouth of the Yukon River and on the Seward Peninsula . It is a migratory bird that flies over Japan to the tropical islands of Oceania such as Hawaii , Tonga , Fiji or French Polynesia in autumn . He flies at least 4000 km non-stop and sometimes up to 6000 km.
behavior
The bristle curlew has a very unusual food spectrum for curlews. Like all curlews, they eat insects and spiders, but also fruits and even flowers. They also eat lizards, small mammals and even carrion, and they also take the eggs of seabirds , which they occasionally peck from under nesting birds. Common curlews usually break the shell by dropping the eggs on the ground. Bristle curlews have also been observed dropping stones on the eggs.
The nests, in which the greenish eggs with brown dots are laid, lie in depressions in the ground and are padded with moss. When the chicks are around five weeks old, the adults move south and leave the young behind until they have consumed enough food to move to their winter quarters themselves. The young then stay in the winter quarters for up to three years before they come back to Alaska. Research has shown that up to 50 percent of curlews lose their ability to fly when moulting in Hawaii, which sets them apart from all other plover species .
history
The first bristle curlew was caught in Tahiti in 1769 during James Cook's first voyage . The scientific name of the animal is based on this fact. For 150 years it was unclear about the breeding areas until a nest of the bird was found in the mountains surrounding the lower reaches of the Yukon on June 12, 1948.
supporting documents
literature
- Richard Sale: A Complete Guide to Arctic Wildlife , published by Christopher Helm, London 2006, ISBN 0-7136-7039-8
Web links
- Numenius tahitiensis onthe IUCN 2013 Red List of Threatened Species . 2. Listed by: BirdLife International, 2012. Retrieved January 14, 2014.