Amsterdam Albatross (Diomedea amsterdamensis)

Amsterdam Albatross

[order] PROCELLARIIFORMES | [family] Diomedeidae | [latin] Diomedea amsterdamensis | [authority] Roux et al. 1983 | [UK] Amsterdam Albatross | [FR] Albatros d’ Amsterdam | [DE] Amsterdam Albatros | [ES] Albatros de la Amsterdam | [NL] Amsterdam-eilandalbatros

Subspecies

Genus Species subspecies Region Range
Diomedea amsterdamensis IO Amsterdam Island

Genus

Albatrosses are the ‘largest’ birds in terms of wingspan. Royal Abatrosses, for instance, may reach a wing span of almost 3.5m, which make them look like feathered sail plaines. They are also the largest members of the tubenose family. Only the smallest albatross species are equalled in size by the Giant Petrels (Macronectes). Albatrosses occur in all oceans, except the northern part of the Atlantic. In ancient times they were also present in that part of the world, but nowadays only an occasional straggler find its way to the North Atlantic. Most of the 24 species are Southern Hemisphere breeders, only three actually breed north of the Equator in the Pacific Ocean.
Albatross taxonomy is subject of discussion for a long time, and has been at times rather chaotic. Based on external characters: plumage patterns, tail shapes, bill structure (size, organization of the plates and coloration) albatrosses were, until recently, divided in 13-14 species in four ‘natural groups’: the Great Albatrosses, the Mollymawks, the North Pacific Albatrosses, grouped in the genus Diomedea and the Sooty Albatrosses Phoebastria. More recently DNA-analyses supports the division in four distinct groups but the were elevated to a generic status and has led to a splitting into 24 species: Great Albatrosses Diomedea (7 species), the Northern (Pacific) Albatrosses Phoebastria (4 species), the southern Mollymawks Thalassarche (11 species) and the Sooty Albatrosses Phoebetria (2 species). Recently this taxonomy is challenged by who proposed to lump some of the ‘species’ again based on their molecular analysis. Since then the discussion flared up and has not ended yet. Some list six species of Great Albatrosses, including two subspecies of Antipodian Albatross.

Physical charateristics

Huge albatross with brownish breeding plumage. Juvenile very similar to juvenile Wandering Albatross D. exulans. Adult has almost entirely chocolate-brown upperparts. White face mask and throat. Broad brown breast-band. White lower breast and belly with brown undertail-coverts. White underwing with dark tip


wingspan min.: 280 cm wingspan max.: 330 cm
size min.: 108 cm size max.: 113 cm
incubation min.: 78 days incubation max.: 82 days
fledging min.: 220 days fledging max.: 240 days
broods: 1   eggs min.: 1  
      eggs max.: 1  

Range

Indian Ocean : Amsterdam Island. Diomedea amsterdamensis breeds on the Plateau des Tourbieres on Amsterdam Island (French Southern Territories) in the southern Indian Ocean. It has a total Pacific Oceanpulation of c.130 birds including 80 mature individuals, with c.18-25 pairs breeding annually, showing an increase since 1984, when the first census was carried out

Habitat

Pelagic

Reproduction

Breeding is biennial (when successful) and is restricted to the central plateau of the island at 500-600 m, where only one breeding group is known. Pair-bonds are lifelong, and breeding begins in February. Most eggs are laid from late February to March, and chicks fledge in January-February the following year. Immature birds begin to return to breeding colonies between four and seven years after fledging but do not begin to breed until they are nine years of age.

Feeding habits

During the breeding season, birds forage both around Amsterdam Island and up to 2,200 km away in subtropical waters

Conservation

This species qualifies as Critically Endangered because it has an extremely small population, confined to a tiny area on one island. Although numbers have recently been increasing, a continuing decline is projected owing to the impact of a disease which is probably already causing chick mortality.
Degradation of breeding sites by introduced cattle has decreased the species’s range and population across the island. Human disturbance is presumably also to blame5. Introduced predators are a major threat, particularly feral cats. Interactions with longline fisheries around the island in the 1970s and early 1980s could also have contributed to a decline in the population. Today the population is threatened primarily by the potential spread of diseases (avian cholera and Erysipelothrix rhusiopathidae) that affect the Indian Yellow-nosed Albatross Thalassarche carteri population 3 km from the colony. Infection risks are very high and increased chick mortality over recent years suggests the population is already affected.
Amsterdam Albatross status Critically Endangered

Migration

Pelagic range unknown. Plumage similarities with immatures of D. exulans may cause confusion at sea. A few possible records off New Zealand.

Distribution map

Amsterdam Albatross distribution range map

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