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.
|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|
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.