[order] PROCELLARIIFORMES | [family] Diomedeidae | [latin] Thalassarche chrysostoma | [authority] Forster, 1785 | [UK] Grey-headed Albatross | [FR] Albatros a tete grise | [DE] Graukopf-Albatros | [ES] Albatros Cabecigris | [NL] Grijskopalbatros
| Genus |
Species |
subspecies |
Region |
Range |
| Thalassarche |
chrysostoma |
|
SO |
widespread |
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.
Small albatross with dark ashy-grey head, throat and upper neck. Blackish upper wings, mantle and tail. White rump. White crescent behind eye. Black bill with bright yellow upper and lower ridges, shading to pink-orange at tip. White underparts. White underwing with much black on leading edge, less on trailing edge. Immature has mostly black bill and head, nape darker than adult, indistinct white eye-crescent, virtually no white on underwing. Underwing pattern distinguishes it from Buller’s Albatross T. bulleri (which has more yellow on bill), yellow-nosed species, and Shy Albatross T. cauta, Chatham Albatross T. eremita and Salvin’s Albatross T. salvini. Immatures difficult.
| wingspan min.: |
180 |
cm |
wingspan max.: |
220 |
cm |
| size min.: |
80 |
cm |
size max.: |
82 |
cm |
| incubation min.: |
69 |
days |
incubation max.: |
75 |
days |
| fledging min.: |
135 |
days |
fledging max.: |
145 |
days |
| broods: |
1 |
|
eggs min.: |
1 |
|
| |
|
|
eggs max.: |
1 |
|
Southern Ocean : widespread. Thalassarche chrysostoma has a circumpolar distribution over cold subantarctic and Antarctic waters. It breeds on South Georgia (Georgias del Sur), Islas Diego Ramirez and Ildefonso (Chile), Prince Edward and Marion Islands (South Africa), Crozet Islands, Kerguelen Islands (French Southern Territories), Campbell Island (New Zealand) and Macquarie Island (Australia). The annual breeding Pacific Oceanpulation is c.99,000 pairs, equivalent to a total Pacific Oceanpulation of c.250,000 mature individuals in this biennially breeding bird. Approximately half the global Pacific Oceanpulation occurs on South Georgia. Its range at sea while breeding lies largely within or south of the Antarctic Pacific Oceanlar Frontal Zone.
It breeds on steep slopes or cliffs, generally with tussock-grass. During the non-breeding season it is entirely pelagic.
This species is a biennially breeder, although 5.4% and 1% of successful breeders on Marion Island and Bird Island respectively, attempt to breed annually. Birds return to colonies between late September and early October, laying occurs in October and chicks hatch by December. Chicks fledge from April to May, returning to breeding colonies at the earliest at 3 years of age but generally at 6 or 7 years old. First breeding can begin as early as 7 years old, but the average age on Campbell Island is 13.5 years old and the modal age on South Georgia is 12 years old. A single egg is laid in a large nest and incubated for 72 days. Chicks fledgw after 141 days. If a pair of has managed to successfully raise a chick it will not breed in the following year. During this time spent away from the colony they can cover great distances, often circling the globe several times.
It feeds by surface-seizing but can also dive up to depths of 6m. Substantial segregation in foraging areas is apparent for male and female Grey-headed Albatross during incubation at South Georgia, with males travelling on average further than females. At Iles Kerguelen, Campbell Island and South Georgia (Islas Georgias del Sur), the species is principally an oceanic forager, concentrating in the Antarctic Polar Frontal Zone and associated oceanic upwellings. However, in years of low availability, chick-rearing birds from South Georgia (Islas Georgias del Sur) forage mainly in Antarctic shelf-slope waters around the South Shetland Islands and the Antarctic Peninsula. On Marion Island, incubating birds foraged in the Sub-tropical Frontal Zone and the Subantarctic Zone in association with what are most likely eddies. In contrast, during chick rearing, foraging was concentrated in the Subantarctic and Polar Frontal Zones to the south-west of the island, also in association with eddies. Its diet is variable with locality and year. It feeds mainly on cephalopods and fish, but crustaceans, carrion and lampreys are locally important
This species is classified as Vulnerable because it is declining at a rapid rate over three generations (90 years), probably largely owing to incidental mortality on longline fisheries. If the severe declines observed at some sites also occur elsewhere, the species would warrant uplisting to Endangered.
Disperses widely over Southern Ocean, mostly between 65 degrees and 35 degrees South, reaching 15 degrees South in zone of Humboldt Current. No reliable records from N orthern Hemisphere.
