Chatham Albatross (Thalassarche eremita)

Chatham Albatross

[order] PROCELLARIIFORMES | [family] Diomedeidae | [latin] Thalassarche eremita | [authority] Murphy, 1930 | [UK] Chatham Albatross | [FR] Albatros des Chatham | [DE] Chatham Albatros | [ES] Albatros de Chatham | [NL] Chathamalbatros

Subspecies

Genus Species subspecies Region Range
Thalassarche eremita PO Chatham Is, NZ

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

Medium-sized, black-and-white albatross with dark thumbmark at base of leading edge of underwing. Adult has dark grey crown, face and throat. Dark grey upper mantle. Grey-black back, upperwing and tail. White rump. White underparts with black thumbmark, narrow leading and trailing wing edges, and wing tip. Yellow bill with dark spot at tip of lower mandible. Juvenile, grey areas more extensive and blue-grey bill has black tips to both mandibles

Listen to the sound of Chatham Albatross

[audio:http://www.planetofbirds.com/MASTER/PROCELLARIIFORMES/Diomedeidae/sounds/Chatham Albatross.mp3]

Copyright remark: Most sounds derived from xeno-canto

recorded by Frank Lambert


wingspan min.: 210 cm wingspan max.: 240 cm
size min.: 88 cm size max.: 92 cm
incubation min.: 68 days incubation max.: 72 days
fledging min.: 130 days fledging max.: 140 days
broods: 1   eggs min.: 1  
      eggs max.: 1  

Range

Pacific Ocean : Chatham Islands, NZ. Race cauta occurs commonly off S Australia and South Africa, but migratory strategy and route not well known; race salvini moves E to W coast of S America, where is common in zone of Humboldt Current; race eremita virtually sedentary, dispersing only to waters around Chatham Is; breeding adults of migratory races probably do not disperse far from nesting grounds. Records in N Hemisphere off Pacific coast of N America (Washington) and in N Red Sea (Elat, Israel).

Habitat

It usually nests on rocky ledges and steep slopes. At sea the species appears to be largely pelagic, showing less preference for waters along the continental shelf than congeners.

Reproduction

Eggs are laid September-October, hatching November-December and fledging in March-April. The earliest recorded breeding age is seven years, but birds return to the colony at the age of four. Due to the difficult access of the Pyramid islet, and the frequently challenging sea and weather conditions surrounding it, the Chatham albatross remains one of the least known of the world’s albatross species. It is thought to lay a single egg every year, in August or September, and incubate it for 66 to 72 days. The egg hatches between October and December, and the chick is thought to fledge between February and April. Incubation of the egg and feeding of the chick is carried out by both parents, in five day stints.

Feeding habits

The diet has not been well studied but it is thought to feed mostly on cephalopods and fish

Conservation

This species has been downlisted as there is no evidence of ongoing habitat degradation at its one breeding site (The Pyramid) and the global population is either stable or increasing. It remains Vulnerable as it has a very small breeding range rendering it susceptible to stochastic events and human impacts.
Thalassarche eremita breeds only on The Pyramid, a large rock stack in the Chatham Islands, New Zealand. Aerial photographs indicated that the breeding population was between 3,200 and 4,200 pairs, but ground counts between 1999-2003 and in 2007 revealed c.5,300 occupied sites. Counts in recent years and aerial photographs from as 1973, 1974 and 1991 suggest that the population is stable.
Chatham Albatross status Vulnerable

Migration

Satellite tracking (1997-1999) and other observations indicate that it disperses within the south Pacific Ocean west to Tasmania and east to Chile and Peru. During April-July (the non-breeding season) birds migrate to the south-west coast of South America and transit northwards with the Humboldt Current into Peruvian coastal waters, as far north as 6 degrees S. Up to 90% of the wintering time (3-4 months) is spent in the territorial waters of Chile and Peru, which, based on at-sea data collected between 1980 and 1995, support c.73% of the estimated global population.

Distribution map

Chatham Albatross distribution range map

Leave a Reply