Thalassarche cauta in flight - SE Tasmania

The shy albatross, also known as shy mollymawk, (''Thalassarche cauta'', formerly ''Diomedea cauta''), is a medium-sized albatross that breeds on three remote islands off the coast of

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

, Australia, in the southern

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...

. Its lifespan is about 60 years, and it has been seen as far afield as

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...

and the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

coast of the United States. , 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 Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

albatross. Some authorities call this species the white-capped albatross, but the

White-capped albatross 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 caut ...

is generally the common name given to ''Thalassarche cauta steadi''.

Taxonomy

This

mollymawk 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 Sout ...

was once considered to be the same

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

as the Salvin's albatross, ''Thalassarche salvini'' and the

Chatham albatross The Chatham albatross (''Thalassarche eremita''), also known as the Chatham mollymawk or Chatham Island mollymawk,Robertson, C. J. R. (2003) is a medium-sized black-and-white albatross which breeds only on The Pyramid, a large rock stack in th ...

, ''Thalassarche eremita'', but they were split around 2004. In 1998, Robertson and Nunn suggested a four-way split including the

white-capped albatross 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 caut ...

, ''Thalassarche steadi''.Robertson, C. J. R. & Nunn, G. B. (1998) The three-way split was accepted by Brooke in 2004,Brooke, M (2004) the ACAP in 2006,ACAP (2006) SACC in 2008,Remsen Jr., J. V. (2004)Remsen Jr., J. V. (2005)Remsen Jr., J. V. (2008) and BirdLife International by 2000.BirdLife International (2008b)

James Clements James Franklin "Jim" Clements (October 31, 1927 – June 9, 2005) was an American ornithologist, author and businessman. He was born in New York, United States. He married Mary Norton and they had two sons. His second marriage, which lasted 14 ...

was the last major holdout on the three-way splitClements, J. (2007) but later accepted it. The fourth split, ''steadi'', was only accepted by the ACAP in 2006, and BirdLife International in 2008. Finally, following Brooke, this species was shifted from ''Diomedea'' to ''Thalassarche'', which was generally agreed upon by most experts. Some authorities, notably the

American Ornithological Society The American Ornithological Society (AOS) is an ornithological organization based in the United States. The society was formed in October 2016 by the merger of the American Ornithologists' Union (AOU) and the Cooper Ornithological Society. Its m ...

, call this species the white-capped albatross.Remsen Jr., J. V. (2008)(a) Mollymawks belong to the albatross family,

Diomedeidae Albatrosses, of the biological family Diomedeidae, are large seabirds related to the procellariids, storm petrels, and diving petrels in the order Procellariiformes (the tubenoses). They range widely in the Southern Ocean and the North Pacif ...

, which shares the order

Procellariiformes Procellariiformes is an order (biology), order of seabirds that comprises four family (biology), families: the albatrosses, the Procellariidae, petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still call ...

with

shearwater Shearwaters are medium-sized long-winged seabirds in the petrel family Procellariidae. They have a global marine distribution, but are most common in temperate and cold waters, and are pelagic outside the breeding season. Description These tub ...

fulmar The fulmars are tubenosed seabirds of the family Procellariidae. The family consists of two extant species and two extinct fossil species from the Miocene. Fulmars superficially resemble gulls, but are readily distinguished by their flight on ...

storm petrel Storm-petrel may refer to one of two bird families, both in the order Procellariiformes, once treated as the same family. The two families are: * Northern storm petrels (''Hydrobatidae'') are found in the Northern Hemisphere, although some speci ...

s, and

diving petrel The diving petrels form a genus, ''Pelecanoides'', of seabirds in the family Procellariidae. There are four very similar species of diving petrels, distinguished only by small differences in the coloration of their plumage, habitat, and bill co ...

s. Procellariiformes have certain identifying features. They have nasal passages that attach to the upper bill, called

naricorns A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called tur ...

(although the nostrils on the albatross are on the sides of the bill). The bills are also unique in that they are split into between seven and nine horny plates. They produce a stomach oil made up of

wax ester A wax ester (WE) is an ester of a fatty acid and a fatty alcohol. Wax esters comprise the main components of three commercially important waxes: carnauba wax, candelilla wax, and beeswax.. Wax esters are formed by combining one fatty acid with on ...

s and

triglycerides A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids (from ''tri-'' and ''glyceride''). Triglycerides are the main constituents of body fat in humans and other vertebrates, as we ...

that is stored in the

proventriculus The proventriculus is part of the digestive system of birds.Encarta World English Dictionary orth American Edition(2007). ''Proventriculus''. Source: (accessed: December 18, 2007) An analogous organ exists in invertebrates and insects. Birds Th ...

. This is used against predators as well as an energy-rich food source for chicks and for the adults during their long flights. They also have a

salt gland The salt gland is an organ for excreting excess salts. It is found in the cartilaginous fishes subclass elasmobranchii (sharks, rays, and skates), seabirds, and some reptiles. Salt glands can be found in the rectum of sharks. Birds and reptiles ...

that is situated above the nasal passage and helps desalinate their bodies, required due to the high amount of ocean water that they imbibe. It excretes a high saline solution from their nose. Within Australia, the bird is still shown as ''Diomedea cauta'', ''Diomedea cauta cauta'', or ''Thalassarche cauta cauta'' in some legislation and databases.

Description

The shy albatross averages in length, wingspan,Dunn, Jon L. & Alderfer, Jonathan (2006) and in weight. Alongside its similarly sized sister species, the Salvin's albatross, this species is considered the largest of the mollymawks or the small albatrosses. It is a black, white and slate-grey bird with the characteristic black thumb mark at the base of the leading edge of the underwing. Adults have a white forehead and a crown, which is bordered on the bottom with a dark eyebrow and pale grey face. Its mantle, tail and upperwing are grey-black, and the rest is white. Its bill is grey-yellow with a prominent yellow culmen and yellow tip.BirdLife International (2008a) It has a lifespan of about 60 years.

Behaviour

Feeding

The shy albatross feeds by a combination surface-seizing and some pursuit diving – it has been recorded diving as deep as . Fish, cephalopods, crustacea, and

tunicates A tunicate is a marine invertebrate animal, a member of the subphylum Tunicata (). It is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one tim ...

are the sustenance for this species.Hedd, A. & Gales, R. (2001)

Reproduction

The shy albatross breeds on rocky islands and builds mounded nests of soil, grass, and roots. They lay one egg in the second half of September.

Flight endurance

Some shy albatross are able to fly in 24 hours.

Range and habitat

The shy albatross is

breeder to Australia and it breeds on three island colonies off Tasmania, in the southern Indian Ocean: Albatross Island, Pedra Branca, and the Mewstone.Hedd, A., et al. (2001a)Garnett, S. T. & Crowley, G. M. (2000)BirdLife International (2004)Baker, G. B., et al. (2007) It is the only albatross endemic to Australia. Juvenile birds are known to fly as far as

; otherwise, non-breeding birds can be found throughout the southern oceans, but specifics are hard to determine due to their similarity to the other species.Double, M. C. , et al. (2003) It is sometimes found off the

coast of the United States.

Conservation

The IUCN classifies this species as

near threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify f ...

, with an occurrence range of . The population from an estimate in 2007 was 25,500 breeding birds with 5,100 pairs on Albatross Island, 270 pairs on Pedra Branca, and 7,380 on the Mewstone. Historically, they were exploited for their feathers, and by 1909 there were only 300 pairs left on Albatross Island.Johnstone, G. W., et al. (1975) Today,

longline fishing Longline fishing, or longlining, is a commercial fishing angling technique that uses a long ''main line'' with fish bait, baited fish hook, hooks attached at intervals via short branch lines called ''snoods'' or ''gangions''.< ...

still impacts this species but their numbers have been maintained despite this threat. They also had an avian pox outbreak on Albatross Island that has impacted their numbers slightly.Woods, R. & Gales, R. (2008) Finally, the

Australasian gannet The Australasian gannet (''Morus serrator''), also known as the Australian gannet or tākapu, is a large seabird of the booby and gannet family, Sulidae. Adults are mostly white, with black flight feathers at the wingtips and lining the trailin ...

, ''Morus serrator'' is the primary threat to their survival. In June 2020, the

Australian Government The Australian Government, also known as the Commonwealth Government, is the national government of Australia, a federal parliamentary constitutional monarchy. Like other Westminster-style systems of government, the Australian Government ...

changed the status of the bird under the ''

Environment Protection and Biodiversity Conservation Act 1999 The ''Environment Protection and Biodiversity Conservation Act 1999'' (Cth) is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and cult ...

'' from "Vulnerable" to "Endangered", with the bird facing the main threats from

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...

and fisheries (as bycatch victims, either caught in

trawling Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different spec ...

nets, or on hooks in the longline fishing industry), as well as disease and competition with other seabirds. The change in status is not considered to be due to poor management. Listings under state and territory legislation were mostly still "vulnerable" at this time. The bird can only be monitored on Albatross Island, as the other two islands are inaccessible, but there are thought to be 15,000 pairs of shy albatross left.

Footnotes

References

* *Alsop III, Fred J.(2001). ''Smithsonian Birds of North America''.

Dorling Kindersley Dorling Kindersley Limited (branded as DK) is a British multinational publishing company specialising in illustrated reference books for adults and children in 63 languages. It is part of Penguin Random House, a subsidiary of German media co ...

* * * * * * * * * * * * * * * * * * * * *Woods, R. & Gales, R. (2008), ''in litt.''

External links

* * Shy Albatross
Species text in The Atlas of Southern African Birds
{{Taxonbar, from=Q1262700

shy albatross The shy albatross, also known as shy mollymawk, (''Thalassarche cauta'', formerly ''Diomedea cauta''), is a medium-sized albatross that breeds on three remote islands off the coast of Tasmania, Australia, in the southern Indian Ocean. Its li ...

Birds of South Australia Birds of Tasmania Birds of Victoria (Australia) Birds of Western Australia Birds of the Indian Ocean