Short-tailed albatross

from Wikipedia, the free encyclopedia
Short-tailed albatross
Short tailed Albatross1.jpg

Short-tailed albatross ( Phoebastria albatrus )

Systematics
Class : Birds (aves)
Order : Tubular noses (Procellariiformes)
Family : Albatrosses (Diomedeidae)
Genre : Phoebastria
Type : Short-tailed albatross
Scientific name
Phoebastria albatrus
( Pallas , 1769)

The short-tailed albatross ( Phoebastria albatrus , Syn .: Diomedea albatrus), also called Steller's albatross , is a rare species from the albatross family (Diomedeidae). The species used to be assigned to the genus Diomedea .

The short-tailed albatross is the largest albatross in the northern hemisphere with a wingspan of just over two meters. He is a skilled glider pilot who is also agile on the ground. In the breeding ground, it is an outspoken colony bird, while it is less sociable during migrations across the sea. During his wanderings he roams the entire northern part of the Pacific.

Short-tailed albatrosses were thought to be extinct in 1949, but individual individuals were rediscovered in 1951. By placing it under protection, the population has now recovered to around 2,400 individuals. The IUCN classified the way since 1994, no longer as endangered ( endangered ), but as endangered ( vulnerable ) a.

Appearance

Characteristics of adult short-tailed albatrosses

Short-tailed albatrosses show no sexual or seasonal dimorphism . Adult short-tailed albatrosses have almost completely white body plumage, only on the head and neck the plumage is overlaid with dark yellow. The top of the wing edges are black-brown, the undersides of the wings are white. The tail is white with a black-brown end band. Contrary to what the name suggests, the tail is no shorter than that of other Phoebastria species. The beak is light pink to flesh colored, while the end of the beak is light blue. The legs are either also pink-flesh-colored or bluish-white. The plumage is moulted once a year. This full moult sets in after the breeding season.

The short-tailed albatross has a wingspan of around 215 centimeters, the wing length averages 56 centimeters. The beak is between 11.7 and 15.7 inches long.

Fledglings

Newly hatched young have a dark, downy dress with a gray tint. Their legs and beak are black. Her second dune dress is chocolate brown, with the underside of the body being a little lighter. In the following years, the plumage becomes lighter and lighter with age. Even young birds have pale pink beaks with a bluish tip. The legs are flesh-colored with a bluish tinge.

Occurrence

The short-tailed albatross lives in the North Pacific. Today it breeds mainly on the Japanese island of Torishima in the southern part of the Izu Islands in the East China Sea and to a lesser extent on one of the Senkaku Islands , which is also located in the south of the East China Sea. It used to breed on several of the Bonin Islands , on Oki-daitō , Ryūkyū Islands and the Penghu Islands . Overall, it is assumed that there were nine breeding colonies in the past. In 2011 a young bird was hatched for the first time on the Midway Atoll .

During its migrations, the short-tailed albatross reached the southern limit of 18 ° north latitude on the Asian coast, 10 ° north latitude in the central Pacific and the southern tip of California in the east of its migration area at times when it was still more numerous. The northern limit of his migrations was the southern part of the Chukchi Sea . It used to be quite numerous in the outskirts of its migration area. For example, the kitchen waste of the indigenous people of the Aleutians contained many remains of this species of albatross.

food

Short-tailed albatrosses eat cephalopods , fish and crabs, as well as waste that is thrown overboard. While searching for food, they fly over larger areas of water and then settle on the surface of the water when they discover food objects there.

Reproduction

Like other albatross species, short-tailed albatrosses only become sexually mature after several years of life. However, birds that are not yet able to reproduce also visit the breeding islands in their second year of life. They are monogamous birds that prefer to breed on small, rugged islands from which they can easily be blown up.

On today's most important breeding island Torishima, the adult birds arrive in October. The courtship ritual is short, it contains bows and loud clatter of bills as elements. The nest is just a simple hollow that is covered with dry grass. Short-tailed albatrosses only lay one egg per reproductive period. The oval egg weighs an average of 375 grams and has a light, ash-gray shell with yellow streaks and dark spots on the blunt pole.

The egg is incubated for 64 days. The chicks hatch from late December to early January. At first they feed the parent birds with pre-digested food, later they also receive fresh food. The young birds can fledge from the end of May.

Inventory and inventory development

BirdLife International sees the populations of the short-tailed albatross as endangered due to the geographically restricted breeding area (VU = vulnerable). For the years 2008/2009, the organization estimated the total population at 2,200–2,500 individuals, including 1,500–1,700 sexually mature animals.

The original population in the 19th century is estimated at more than 100,000 breeding pairs, which were distributed on at least 11 of the Izu and Bonin Islands in the Pacific south of Japan. Around the turn of the 20th century, the populations fell dramatically due to human influences (157 tons of their coveted feathers were exported from the islands between 1896 and 1906) and a volcanic eruption in 1902. The trade ban on the feathers of the short-tailed albatross issued in 1906 proved ineffective until the 1930s and two further volcanic eruptions in 1939 and 1941 brought the species to the brink of extinction. In 1949 the species was considered extinct; it was rediscovered two years later. In 1957, the short-tailed albatross was finally placed under protection on Torishima and the populations slowly recovered. In 2006 more than 400 breeding pairs were counted on Torishima again. An initiative by the United States Fish and Wildlife Service , in which animals were lured by dummies of short-tailed albatross and shouts spread over loudspeakers, has resulted in breeding success in the Midway Islands . In 2010 the inventory was again over 2,200 copies.

supporting documents

literature

  • VD Il'ičev & VE Flint (eds.): Handbook of birds of the Soviet Union - Volume 1: History of exploration, Gaviiformes, Podicipediformes, Procellariiformes . Aula Verlag, Wiesbaden 1985, ISBN 3-89104-414-3 .
  • C. Carboneras / F. Jutglar / GM Kirwan: Short-tailed Albatross (Diomedea albatrus) , in: Handbook of the Birds of the World Alive, ed. by J. del Hoyo / A. Elliott / J. Sargatal / DA Christie / E. de Juana, Barcelona 2014 (paid access; last accessed on July 26, 2014).
  • J. McQuilken: The Mists of Time . Spitzbergen.de-Verlag, Dassow.

Web links

Commons : Short-tailed albatross  - album with pictures, videos and audio files

Single receipts

  1. ↑ Il'ičev & Flint, Handbook of the Birds of the Soviet Union - Volume 1: Erforschungsgeschichte , Gaviiformes, Podicipediformes, Procellariiformes , Wiesbaden 1985, p. 289.
  2. ↑ a b IUCN website on the short-tailed albatross, accessed June 25, 2013
  3. ↑ a b Il'ičev & Flint, Handbook of the Birds of the Soviet Union - Volume 1: Erforschungsgeschichte , Gaviiformes, Podicipediformes, Procellariiformes , Wiesbaden 1985, p. 290.
  4. ↑ a b c Il'ičev & Flint, Handbook of the Birds of the Soviet Union - Volume 1: Erforschungsgeschichte , Gaviiformes, Podicipediformes, Procellariiformes , Wiesbaden 1985, p. 291.
  5. ↑ Il'ičev & Flint, Handbook of the Birds of the Soviet Union - Volume 1: History of Research, Gaviiformes, Podicipediformes, Procellariiformes , Wiesbaden 1985, p. 292.
  6. ↑ a b c Species factsheet: Phoebastria albatrus , in: BirdLife International (2014) IUCN Red List for birds (last accessed on July 26, 2014).
  7. ↑ On this and the following cf. C. Carboneras / F. Jutglar / GM Kirwan: Short-tailed Albatross (Diomedea albatrus) , in: Handbook of the Birds of the World Alive, ed. by J. del Hoyo / A. Elliott / J. Sargatal / DA Christie / E. de Juana, Barcelona 2014 (paid access; last accessed on July 26, 2014).
  8. ^ Jules Evens / Ian Tait, Introduction to California Birdlife , Berkeley [u. a.] 2005, p. 77.
  9. ↑ James McQuilken: The Mists of Time . Ed .: Rolf Stange. 1st edition. Spitzbergen.de, Dassow 2012, ISBN 978-3-937903-15-6 , pp. 137 .