Gray-headed albatross
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Gray-headed albatross ( Thalassarche chrysostoma ) |
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| ( Forster , 1785) |
The gray-headed albatross ( Thalassarche chrysostoma ) is a breeding bird belonging to the albatrosses of the Sub -Antarctic and the maritime-Antarctic zone. He is one of the smaller albatrosses. The species is classified as endangered (" vulnerable ") by the IUCN .
Appearance
The gray-headed albatross reaches a body length of 70 to 85 centimeters and a wingspan of 200 to 215 centimeters. The weight is 2.6 to 4.35 kilograms. Females are, on average, slightly smaller and lighter than males. Otherwise there is no noticeable sexual dimorphism .
Gray-headed albatrosses are generally built compactly. Due to their black and white plumage and gray head, they can only be confused with young black -browed albatrosses and Campbell's albatrosses . Distinguishing features in flight are the shorter and slimmer wings, the more rounded head and the shorter neck.
In adult gray-headed albatrosses the head and neck are gray, the upper side of the wings is smoke brown, the tail is dark gray, the underside and upper tail-coverts are white. The beak is glossy black with a bright yellow line on the lower and upper beak. The yellow line on the upper beak narrows towards the tip of the beak. The yellow markings at the base of the beak are wide in the lower beak and taper off in the front quarter of the beak.
Young birds also have a gray head, but the forehead and cheeks are lighter in color. The beak is dark gray-brown to brown-black. The lower wings are still dark.
Distribution area
The breeding areas of the gray-headed albatross are off Tierra del Fuego, on South Georgia , the Prince Edward Islands , Marion Island , the Crozet Islands , the Kerguelen , Macquarie , on the Auckland Islands on Enderby Island and on Campbell Island . Outside of the breeding season, the gray-headed albatross stays mainly over cool sea waters. In the region of the Humboldt Current , the gray-headed albatross occasionally reaches the 15th southern parallel. On their forays, the species, like almost all albatross species, occurs in a circumpolar manner around the Antarctic in the entire Southern Ocean . For example, they are often seen in the Drake Passage and adjacent marine areas. A gray-headed albatross from South Georgia flew once around the earth in just 46 days and then circled the world again to provide the chick with food during the breeding season.
food
The diet consists of cephalopods , fish as well as krill and occasionally carrion. The species usually eats from the surface of the water, but sometimes appears shallow. Near the Falkland Islands , gray-headed albatrosses also occasionally follow ships - a behavior that is rarely observed in other regions.
Reproduction
Gray-headed albatrosses breed successfully for the first time at the age of 13. The breeding season begins in late September to October. Gray-headed albatrosses are colony breeders and usually build their nests on the grassy edges of cliffs. They are often associated with other albatrosses. The nest consists of earth, grass and roots with a shallow hollow in the middle. The clutch consists of an egg. The egg is white-shelled with fine red-brown spots. It is incubated for 69 to 78 days. The young bird fledged after about 140 days. Both parent birds are involved in the breeding and rearing of the young birds. Gray-headed albatrosses only breed every other year.
supporting documents
literature
- Hadoram Shirihai: A Complete Guide to Antarctic Wildlife - The Birds and Marine Mammals of the Antarctic Continent and Southern Ocean , Alula Press, Degerby 2002, ISBN 951-98947-0-5
- James McQuilken: The Mists of Time. Spitzbergen.de-Verlag, 2012.
Web links
- Thalassarche chrysostoma in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 2 of 2009.
Single receipts
- ↑ Shirihai, p. 121
- ^ Galapagos of the Southern Ocean from Dunedin | Polar cruises. Retrieved September 29, 2018 .
- ↑ Christian Walther: ANTARCTICA . 10th edition. Conrad-Stein-Verlag, 2018, ISBN 978-3-86686-965-3 , p. 255 .
- ↑ Feathered frequent flyers: Around the world in 46 days . In: Spiegel Online . January 17, 2005 ( spiegel.de [accessed September 19, 2018]).
- ↑ James McQuilken: The Mists of Time . Ed .: Rolf Stange. 1st edition. Spitzbergen.de, 2012, ISBN 978-3-937903-15-6 , pp. 137 .
- ↑ Shirihai, p. 122 and p. 123
- ^ Shirihai, p. 123