Salvin's albatross (Thalassarche salvini) 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.
Taxonomy
Mollymawks are a type of albatross that belong to the family Diomedeidae in 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, unlike other tubenosed seabirds. The bills of Procellariiformes are also unique in that they are split into between seven and nine horny plates. 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.[3] Finally, they 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.[4]
Salvin's albatross is about 90 cm (35 in) and 2.56 m (8.4 ft) across the wings. It weighs 3.3–4.9 kg (7.3–10.8 lb) and is, alongside the shy albatross, the largest of the mollymawk or small albatross group.[13] The adult bird has a silver-grey crown. Its face, upper throat, and upper mantle are grey, and its back, upperwing, and tail are grey-black. It has a white rump and underparts with a black thumbmark on underwing and black narrow leading and trailing edges on the wing and black wing tips. Its bill is pale grey-green with a pale yellow upper ridge, and a bright yellow tip on the upper mandible, and a dark spot on the tip of the lower mandible. The juveniles have more extensive grey areas and a blue-grey bill with black tips on both mandibles.[6] It can be distinguished from the Chatham albatross by its larger size and grey bill, and from the shy albatross by the greyer head. Such differences can be difficult to pick out at sea, however, and this explains the under-representation of this species in at-sea surveys.
Behavior
Feeding
Salvin's albatross feeds mainly on fish and cephalopods.[14]
It breeds mainly on small rocky islands with little vegetation,[15] and the nest is a pedestal made of mud, feathers, and bird bones.[16] A single egg is laid in September, and incubated by both parents until early November. The chicks fledge after about 4 months.
At sea they range from South Africa across to Australia and as far east as the coast of South America. In the early 2000s, an adult Salvin's albatross was seen by a fisheries observer 700-800mi north of the Hawaiian islands. This sighting was supported by a photograph.[citation needed]
Conservation
The IUCN classifies this species as vulnerable[1] with longline fisheries and trawlers responsible for small numbers of deaths, although trawlers are responsible for more than half of those killed. The world population is currently estimated to be around 61,500 birds in 1998,[21][22] which suggests a decline in the species since earlier studies (although differences in methods make direct comparisons difficult). There are 30,750 pairs, in 1998, on the Bounty Islands, compared to 76,000 pairs in 1978.[16] There were 650 pairs on the Snares Islands, and 4 pairs were recorded on Île des Pingouins in the Crozet Islands.[7][17] Single chicks have been observed on The Pyramid and Forty-fours Island in 2007.[23]
ACAP (2007). "ACAP species". ACAP. Archived from the original on January 5, 2009. Retrieved 22 Feb 2009.
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Brooke, M. (2004). "Procellariidae". Albatrosses And Petrels Across The World. Oxford, UK: Oxford University Press. ISBN0-19-850125-0.
Clark, G.; Booth, A. M.; Amey, J. (1998). Unpublished Report. Invercargill, N.Z: NZ Department of Conservation.{{cite journal}}: CS1 maint: untitled periodical (link)
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Croxall, J. P.; Gales, R. (1998). "Assessment of the conservation status of albatrosses". In Robertson, G.; Gales, R. (eds.). Albatross biology and conservation. Chipping Norton, Australia: Surrey Beatty & Sons.
Double, M. C. (2003). "Procellariiformes (Tubenosed Seabirds)". In Hutchins, Michael; Jackson, Jerome A.; Bock, Walter J.; Olendorf, Donna (eds.). Grzimek's Animal Life Encyclopedia. Vol. 8 Birds I Tinamous and Ratites to Hoatzins. Joseph E. Trumpey, Chief Scientific Illustrator (2nd ed.). Farmington Hills, MI: Gale Group. pp. 107–111. ISBN0-7876-5784-0.
Ehrlich, Paul R.; Dobkin, David, S.; Wheye, Darryl (1988). The Birders Handbook (First ed.). New York, NY: Simon & Schuster. pp. 29–31. ISBN0-671-65989-8.{{cite book}}: CS1 maint: multiple names: authors list (link)
Jouventin, P. (1990). "Shy Albatrosses Diomedea cauta salvini breeding on Penguin Island, Crozet Archipelago, Indian Ocean". Ibis. 132: 126–127. doi:10.1111/j.1474-919x.1990.tb01026.x.
Marchant, S.; Higgins, P. J. (31 August 1991). Handbook of Australian, New Zealand and Antarctic birds, 1: ratites to ducks. Melbourne, Australia: Oxford University Press. ISBN978-0-19-553068-1.
Miskelly, C. M.; Bester, A. J.; Bell, M. (2006). "Additions to the Chatham Islands' bird list, with further records of vagrant and colonising bird species". Notornis (53): 215–230.
Robertson, C. J. R.; Nunn, G. B. (1998). "Towards a new taxonomy for albatrosses". In Robertson, G.; Gales, R. (eds.). Albatross biology and conservation. Chipping Norton, Australia: Surrey Beatty & Sons. pp. 13–19.
Robertson, C. J. R. (2008) in litt
Robertson, C. J. R.; van Tets, G. F. (1982). "The status of birds at the Bounty Islands". Notornis (29): 311–336.
Taylor, G. A. (2000). "Action plan for seabird conservation in New Zealand. Wellington: Department of Conservation". Threatened Species Occasional Publication (16).