White-capped albatross | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Procellariiformes |
Family: | Diomedeidae |
Genus: | Thalassarche |
Species: | |
Subspecies: | T. c. steadi |
Trinomial name | |
Thalassarche cauta steadi | |
The white-capped albatross (Thalassarche cauta steadi) is a mollymawk that breeds on the islands off of New Zealand. Not all experts agree that this form should be recognized as a separate species from the shy albatross, Thalassarche cauta. It is a medium-sized black, slate gray, and white albatross and is the largest of the mollymawks.[ citation needed ]
Mollymawks are a type of albatross that belong to family Diomedeidae of the order Procellariiformes, along with shearwaters, fulmars, storm petrels, and diving petrels. They share certain identifying features. First, they have nasal passages that attach to the upper bill called naricorns. Although the nostrils on the albatross are on the sides of the bill. The bills of Procellariiformes are also unique in that they are split into between seven and nine horny plates. Finally, they produce a stomach oil made up of wax esters and triglycerides that is stored in the proventriculus. This is used against predators as well as an energy rich food source for chicks and for the adults during their long flights. [2] They also have a salt gland that is situated above the nasal passage and helps desalinate their bodies, due to the high amount of ocean water that they imbibe. It excretes a high saline solution from their nose. [3]
The white-capped albatross is part of a greater complex of albatrosses consisting of the shy albatross, Thasassarche cauta, Salvin's albatross, Thalassarche salvini, and Chatham albatross, Thalassarche eremita. In 1998, Robertson and Nunn recommended a four-way split, [4] some experts agreed. BirdLife International agreed in 2007, [5] ACAP agreed in 2006, [6] and Brooke agreed in 2004. [7] The SACC agreed to a three-way split, leaving steadi, the white-capped albatross grouped with the shy albatross. [8] [9] [10] The Clements taxonomy [11] has yet to agree on any of these splits. Finally, following Brooke, this species was shifted from Diomedea to Thalassarche, which was generally agreed upon by most experts.
The white-capped albatross averages 90 to 99 cm (35–39 in) in length, with a wingspan of 220 to 256 cm (87–101 in). [12] It weighs 3.4 to 4.4 kg (7.5–9.7 lb) [13] It has a bold white cap that contrasts with a pale silver gray face and a darker brow. Some adults have a white back with brown tipped feathers. [14] They have a dark gray mantle and a black tail. Most of the rest of the body is white. Its bill is pale gray to blue with a yellow tip. Juveniles have a gray bill with a dark tip, and their head is darker, with gray to the collar.
Location | Population | Date | Trend |
---|---|---|---|
Disappointment Island | 72,000 pairs | 1993 | |
Auckland Island | 3,000 pairs | ||
Antipodes Island | 50—100 pairs | 1994 | |
Adams Island | 100 pairs | ||
Total | 150,000 | 1993 | Stable |
They are endemic to the islands off the coast of New Zealand, with a population of 75,000 breeding pairs, estimated in 2007, [15] [16] and 350,000 to 375,000 total birds. [17] Disappointment Island has a massive colony whose sheer numbers comprise the dominant feature of the island, with a mean of 63,856 breeding pairs (when corrected for non-breeders) based on surveys conducted from 2009-2017. [18] [19] Auckland Island has 3,000 pairs, Adams Island (Auckland Islands) has 100 pairs, [17] [20] and Bollons Island (Antipodes Islands) has 100 pairs. [21]
Juvenile and non-breeding birds are believed to forage in the southwestern Atlantic [22] and a recent DNA test of a South Georgia bird confirmed it. [23] Also, using different techniques, scientists have proven that they forage off the coast of southwestern Africa. [24] [25] [26] Juveniles are also believed to go as far as the south Atlantic and the southwestern Indian Ocean.
They are a surface feeder, but may utilize shallow dives for their food which is fish, cephalopods, tunicates, and crustacea. [5]
The white-capped albatross breeds annually on rocks on small islands. [5]
The IUCN classifies this species as near threatened, [1] with an occurrence range of 77,700,000 km2 (30,000,000 sq mi) and a breeding range of 22 km2 (8.5 sq mi). The largest threat for this bird is longline and trawl fisheries. [16] Net monitor cables were responsible for large numbers of deaths; however, they were phased out in 1992. [17] [20] Commercial exploitation of squid in Bass Strait may present a threat by reducing the food supply. Also, pigs on Auckland Island reduced nesting from 1972–1982, and feral cats also take small number of chicks. [17] [20] [27]
Since 2006, Auckland Island birds have been tracked, and this will continue. [25]
The black-browed albatross, also known as the black-browed mollymawk, is a large seabird of the albatross family Diomedeidae; it is the most widespread and common member of its family.
The Chatham albatross, also known as the Chatham mollymawk or Chatham Island mollymawk, is a medium-sized black-and-white albatross which breeds only on The Pyramid, a large rock stack in the Chatham Islands, New Zealand (Aotearoa). It is sometimes treated as a subspecies of the shy albatross Thalassarche cauta. It is the smallest of the shy albatross group.
The Antipodes Subantarctic Islands tundra ecoregion, within the tundra biome, includes five remote island groups in the Pacific Ocean south of New Zealand: the Bounty Islands, Auckland Islands, Antipodes Islands and Campbell Island groups of New Zealand, and Macquarie Island of Australia.
The mollymawks are a group of medium-sized albatrosses that form the genus Thalassarche. The name has sometimes been used for the genus Phoebetria as well, but these are usually called sooty albatrosses. They are restricted to the Southern Hemisphere, where they are the most common of the albatrosses. They were long considered to be in the same genus as the great albatrosses, Diomedea, but a study of their mitochondrial DNA showed that they are a monophyletic taxon related to the sooty albatrosses, and they were placed in their own genus.
Salvin's albatross or Salvin's mollymawk, is a large seabird that breeds mainly on the Bounty Islands of New Zealand, with scant amounts on islands across the Southern Ocean. A medium-sized mollymawk, it was long considered to be a subspecies of the shy albatross.
The sooty albatross, also known to sailors as the Quaker, is a species of marine bird belonging to the albatross family Diomedeidae. It is a medium-sized albatross that sports a sooty-brown or sooty-black color. It can be found in the southern Atlantic Ocean, the southern Indian Ocean, and the Southern Ocean. This bird scavenges for squid, fish, and carrion. Like other albatrosses, these birds mate for life and return to the same breeding spots every season. A single pair will mate every other year on a variety of islands in the southern Atlantic Ocean and the southern Indian Ocean islands. This bird is an endangered species and conservation efforts are taking place.
The grey-headed albatross also known as the gray-headed mollymawk, is a large seabird from the albatross family. It has a circumpolar distribution, nesting on isolated islands in the Southern Ocean and feeding at high latitudes, further south than any of the other mollymawks. Its name derives from its ashy-gray head, throat and upper neck.
The Agreement on the Conservation of Albatrosses and Petrels (ACAP) is a legally binding international agreement signed in 2001 and entered into force on 1 February 2004 when South Africa ratified as the fifth Party to the Agreement.
The shy albatross, also known as shy mollymawk, is a medium-sized albatross that breeds on three remote islands off the coast of Tasmania, Australia, in the southern Indian Ocean. Its lifespan is about 60 years, and it has been seen as far afield as South Africa and the Pacific coast of the United States. As of June 2020, the species is listed as "Endangered" in Australia; there are thought to be 15,000 pairs of shy albatross left. It is Australia's only endemic albatross.
Buller's albatross or Buller's mollymawk, is a small mollymawk in the albatross family.
The Campbell albatross or Campbell mollymawk, is a medium-sized mollymawk in the albatross family. It breeds only on Campbell Island and the associated islet of Jeanette Marie, in a small New Zealand island group in the South Pacific. It is sometimes considered a subspecies of the black-browed albatross. It is a medium-sized black and white albatross with a pale yellow iris.
The Indian yellow-nosed albatross is a member of the albatross family, and is the smallest of the mollymawks. In 2004, BirdLife International split this species from the Atlantic yellow-nosed albatross; however Clements has not split it yet, and the SACC has not either, but recognises the need for a proposal.
The Antipodean albatross is a large seabird in the albatross family. Antipodean albatrosses are smaller than snowy albatrosses, and breed in predominantly brown plumage, but are otherwise difficult to distinguish from young snowy albatrosses.
The Atlantic yellow-nosed albatross is a large seabird in the albatross family Diomedeidae.
The southern royal albatross or toroa, is a large seabird from the albatross family. At an average wingspan of above 3 m (9.8 ft), it is one of the two largest species of albatross, together with the wandering albatross. Recent studies indicate that the southern royal albatross may, on average, be somewhat larger than the wandering albatross in mass and have a similar wingspan, although other sources indicate roughly similar size for the two species and the wandering species may have a larger average wingspan in some colonies.
Albatrosses, of the biological family Diomedeidae, are large seabirds related to the procellariids, storm petrels, and diving petrels in the order Procellariiformes. They range widely in the Southern Ocean and the North Pacific. They are absent from the North Atlantic, although fossil remains of short-tailed albatross show they once lived there up to the Pleistocene, and occasional vagrants are found. Great albatrosses are among the largest of flying birds, with wingspans reaching up to 2.5–3.5 metres (8.2–11.5 ft) and bodies over 1 metre (3.3 ft) in length. The albatrosses are usually regarded as falling into four genera, but disagreement exists over the number of species.
The white-chinned petrel also known as the Cape hen and shoemaker, is a large shearwater in the family Procellariidae. It ranges around the Southern Ocean as far north as southern Australia, Peru and Namibia, and breeds colonially on scattered islands. The white-chinned petrel was formerly considered to be conspecific with the spectacled petrel.
Disappointment Island is one of seven uninhabited islands in the Auckland Islands archipelago, in New Zealand. It is 475 kilometres (295 mi) south of the country's main South Island and 8 kilometres (5 mi) from the northwest end of Auckland Island. It is home to a large colony of white-capped albatrosses: about 65,000 pairs – nearly the entire world's population – nest there. Also on the island is the Auckland rail, endemic to the archipelago; once thought to be extinct, it was rediscovered in 1966.
Gerald Stanley Clark was a New Zealand sailor, writer and ornithologist. He is notable for his ornithological research work on subantarctic islands and for his circumnavigation of Antarctica in his self-built yacht Totorore.
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