The Tristan albatross (''Diomedea dabbenena'') is a large

seabird Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same enviro ...

from the

albatross 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 Pacifi ...

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

. One of the

great albatross The great albatrosses are seabirds in the genus ''Diomedea'' in the albatross family. The genus ''Diomedea'' formerly included all albatrosses except the sooty albatrosses, but in 1996 the genus was split, with the mollymawks and the North Paci ...

es of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

''Diomedea'', it was only widely recognised as a full

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 ...

in 1998.

Taxonomy

Albatrosses belong to the 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 Pacifi ...

of the order

Procellariiformes Procellariiformes is an order of seabirds that comprises four families: the albatrosses, the petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still called tubenoses in English, procellariiforms are of ...

, along with

shearwater Shearwaters are medium-sized long-winged seabirds in the petrel family Procellariidae The family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the diving petrels, the prions, and the shearwa ...

s, petrels, storm petrels, 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 con ...

s. They share certain identifying features. First, 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 turbi ...

, 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 7 and 9 horny plates. Albatrosses also 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 o ...

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 The ...

. This is used against predators as well as an energy rich food source for chicks and for the adults during their long flights. While not all scientists believe it is a full species with some retaining it as a

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of the

wandering albatross The wandering albatross, snowy albatross, white-winged albatross or goonie (''Diomedea exulans'') is a large seabird from the family Diomedeidae, which has a circumpolar range in the Southern Ocean. It was the last species of albatross to be descr ...

, a 2004 study of the

mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...

of the wandering albatross

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

supported the split. Other studies have shown it to be the most

genetically Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar working in ...

distinct member of the wandering albatross superspecies.Brooke, M. (2004) This may be due to it diverging from their common ancestor before all its relatives, or because it underwent particularly strong

genetic drift Genetic drift, also known as allelic drift or the Wright effect, is the change in the frequency of an existing gene variant (allele) in a population due to random chance. Genetic drift may cause gene variants to disappear completely and there ...

. Among the major experts, BirdLife International has split this species, Clements has not yet,Clements, J. (2007) and the SACC has a proposal on the table to split it.Remsen Jr., J. V. (2009)

Etymology

''Diomedea'' refers to

Diomedes Diomedes (Jones, Daniel; Roach, Peter, James Hartman and Jane Setter, eds. ''Cambridge English Pronouncing Dictionary''. 17th edition. Cambridge UP, 2006.) or Diomede (; grc-gre, Διομήδης, Diomēdēs, "god-like cunning" or "advised by ...

, whose companions turned to birds.

Description

It is practically indistinguishable from the wandering albatross at sea; the Tristan albatross is smaller and has a slightly darker back. The Tristan albatross is and has a wingspan of up to . The Tristan albatross also never attains the full white

plumage Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...

of the wandering albatross, and its bill is about shorter.BirdLife International (2008a)

Behavior

The Tristan albatross feeds on fish and

cephalopods A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, an ...

. They breed biennially and will nest in wet heath from in elevation. They are

monogamous Monogamy ( ) is a form of Dyad (sociology), dyadic Intimate relationship, relationship in which an individual has only one Significant other, partner during their lifetime. Alternately, only one partner at any one time (Monogamy#Serial monogamy, ...

, and do not start breeding until they are about 10 years old.Double, M. C. (2003)

Range and habitat

Due to the difficulty in distinguishing them from wandering albatrosses, their distribution at sea is still not fully known, but the use of satellite tracking has shown that they forage widely in the South

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

, with males foraging west of the breeding islands towards

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

and females to the east towards

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

. There have been sightings near

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

and also off the coast of

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. Tristan albatrosses are

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 elsew ...

to the islands of the

Tristan da Cunha Tristan da Cunha (), colloquially Tristan, is a remote group of volcanic islands in the South Atlantic Ocean. It is the most remote inhabited archipelago in the world, lying approximately from Cape Town in South Africa, from Saint Helena ...

group and more specifically

Gough Island upright=1.3, Map of Gough island Gough Island ( ), also known historically as Gonçalo Álvares, is a rugged volcanic island in the South Atlantic Ocean. It is a dependency of Tristan da Cunha and part of the British overseas territory of Sain ...

. The majority of the world's population nest on

, around 1500 pairs. On some years a pair breeds on

Inaccessible Island Inaccessible Island is a volcanic island located in the South Atlantic Ocean, south-west of Tristan da Cunha. Its highest point, Cairn Peak, reaches , and the island is in area. The volcano was last active six million years ago and is curren ...

Conservation

They were formerly threatened by

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...

, rats, cats and pigs, but these have now been removed from their breeding islands. However, this resulted in the population of

mice A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

, ''

Mus musculus Mus or MUS may refer to: Abbreviations * MUS, the NATO country code for Mauritius * MUS, the IATA airport code for Minami Torishima Airport * MUS, abbreviation for the Centre for Modern Urban Studies on Campus The Hague, Leiden University, Neth ...

'', increasing to the point where they would eat and kill albatross chicks en masse. Even though the chicks are huge compared to the mice, they do not know how to defend themselves appropriately. Today the main threat to the species is believed to be

long-line fishing Longline fishing, or longlining, is a commercial fishing angling technique that uses a long ''main line'' with baited hooks attached at intervals via short branch lines called ''snoods'' or ''gangions''.Gough Gough ( ) is a surname. The surname probably derives from the Welsh (English: "red"), given as a nickname to someone with red hair or a red complexion or as a reduced form of the Irish McGough which itself is an Anglicized form of Gaelic , a patro ...

has decreased by 28% over 46 years, whereas population modelling predicts annual decline rates of 2.9–5.3%. More recent modelling, conducted over three generations since 1980, suggests a decline equivalent to a >96% reduction in population size over three generations, since declines began. The rate of decline is therefore placed here in the band of 80–100% over three generations (86 years). Formerly classified as an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

,Lee, J. (2008) it was suspected to be more threatened than generally assumed and undergoing a marked decline. Following the evaluation of its status, this was found to be correct, and the Tristan albatross was consequently uplisted to Critically Endangered status in 2008. They have an occurrence range of and a breeding range of .

Footnotes

References

* * * * * * * * * * *

External links

BirdLife Species Factsheet.
{{Taxonbar, from=Q1419906

Tristan albatross The Tristan albatross (''Diomedea dabbenena'') is a large seabird from the albatross family. One of the great albatrosses of the genus ''Diomedea'', it was only widely recognised as a full species in 1998. Taxonomy Albatrosses belong to the fami ...

Birds of islands of the Atlantic Ocean Birds of subantarctic islands Fauna of Gough Island Endemic fauna of Tristan da Cunha