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 Pacific. They are absent from the North Atlantic, although fossil remains of short-tailed albatross show they lived there up to the Pleistocene, and occasional vagrants are found. Generally, the group depends on cold water currents for their foraging and nesting grounds. The geographically outlying genus Phoebastria which includes 3 North Pacific species and an equatorial (Galapagos) species exploits the California, Alaska, Oyashio and Humboldt currents, nesting on major oceanic islands near those currents.
Great albatrosses are among the largest of flying birds, with wingspans reaching up to and bodies over in length. The albatrosses are usually regarded as falling into four genera, but disagreement exists over the number of species.
Albatrosses are highly efficient in the air, using dynamic soaring and slope soaring to cover great distances with little exertion. They feed on squid, fish, and krill by either scavenging, surface seizing, or diving. Albatrosses are colonial, nesting for the most part on remote oceanic islands, often with several species nesting together. Pair bonds between males and females form over several years, with the use of "ritualised dances", and last for the life of the pair. A breeding season can take over a year from laying to fledging, with a single egg laid in each breeding attempt. A Laysan albatross named Wisdom on Midway Island is the oldest-known wild bird in the world. She was first banded in 1956 by Chandler Robbins.
Of the 22 species of albatrosses recognised by the IUCN, 21 are listed as at some level of concern. Two species are Critically Endangered, seven species are Endangered, six species are Vulnerable, and six species are Near Threatened. Populations have declined in the past due to harvesting for feathers. Albatrosses are threatened by introduced species, such as rats and feral cats that attack eggs, chicks, and nesting adults; by pollution; by a serious decline in fish stocks in many regions largely due to overfishing; and by longline fishing. Longline fisheries pose the greatest threat, as birds are attracted to the bait, become hooked on the lines, and drown. Stakeholders such as governments, conservation organisations, and people in the fishing industry are all working toward reducing this phenomenon.
Etymology The name "Albatross" is derived from the Arabic or (a pelican; literally, "the diver"), which travelled to English via the Portuguese form Alcatraz ("gannet"), which is also the origin of the name of the former prison Alcatraz. The Oxford English Dictionary notes that the word Alcatraz was originally applied to the frigatebird; the modification to albatross was perhaps influenced by Latin , meaning "white", in contrast to frigatebirds, which are black. They were once commonly known as goonie birds or gooney birds, particularly those of the North Pacific. In the Southern Hemisphere, the name mollymawk is still well established in some areas, which is a corrupted form of , an old Dutch name for the northern fulmar. The name Diomedea, assigned to the albatrosses by Linnaeus, references the mythical metamorphosis of the companions of the Greek warrior Diomedes into birds. Finally, the name for the order, Procellariiformes, comes from the Latin word meaning "a violent wind" or "a storm".
Taxonomy and evolution
The "albatross" designation comprises between 13 and 24 species (the number is still a matter of some debate, with 21 being the most commonly accepted number) in four genera. These genera are the great albatrosses (Diomedea), the mollymawks (Thalassarche), the North Pacific albatrosses (Phoebastria), and the sooty albatrosses or sooties (Phoebetria). The North Pacific albatrosses are considered to be a sister taxon to the great albatrosses, while the sooty albatrosses are considered closer to the mollymawks.
The taxonomy of the albatross group has been a source of much debate. The Sibley-Ahlquist taxonomy places seabirds, birds of prey, and many others in a greatly enlarged order, the Ciconiiformes, whereas the ornithological organisations in North America, Europe, South Africa, Australia, and New Zealand retain the more traditional order Procellariiformes. The albatrosses can be separated from the other Procellariiformes both genetically and through morphological characteristics, size, their legs, and the arrangement of their nasal tubes (see below: Morphology and flight).
Within the family, the assignment of genera has been debated for over 100 years. Originally placed into a single genus, Diomedea, they were rearranged by Reichenbach into four different genera in 1852, then lumped back together and split apart again several times, acquiring 12 different genus names in total (though never more than eight at one time) by 1965 (Diomedea, Phoebastria, Thalassarche, Phoebetria, Thalassageron, Diomedella, Nealbatrus, Rhothonia, Julietata, Galapagornis, Laysanornis, and Penthirenia).
By 1965, in an attempt to bring some order back to the classification of albatrosses, they were lumped into two genera, Phoebetria (the sooty albatrosses, which most closely seemed to resemble the procellarids and were at the time considered "primitive" ) and Diomedea (the rest). Though a case was made for the simplification of the family (particularly the nomenclature), the classification was based on the morphological analysis by Elliott Coues in 1866, and paid little attention to more recent studies and even ignored some of Coues's suggestions.
Research by Gary Nunn of the American Museum of Natural History (1996) and other researchers around the world studied the mitochondrial DNA of all 14 accepted species, finding four, not two, monophyletic groups within the albatrosses. They proposed the resurrection of two of the old genus names, Phoebastria for the North Pacific albatrosses and Thalassarche for the mollymawks, with the great albatrosses retaining Diomedea and the sooty albatrosses staying in Phoebetria.
While some agree on the number of genera, fewer agree on the number of species. Historically, up to 80 different taxa have been described by different researchers; most of these were incorrectly identified juvenile birds.Double, M.C. & Chambers, G.K., (2004). "The need for the parties to the Agreement on Albatrosses and Petrels (ACAP) to establish a robust, defendable and transparent decision-making process for the construction and maintenance of their species lists ". Proceedings of the Scientific Meeting of Agreement on Albatrosses and Petrels (ACAP), Hobart, Australia, 8–9 November 2004
Based on the work on albatross genera, Robertson and Nunn went on in 1998 to propose a revised taxonomy with 24 different species,Robertson, C. J. R. and Nunn, G. B. (1998) "Towards a new taxonomy for albatrosses" in: Proceedings First International Conference on the Biology and Conservation of Albatrosses, G.Robertson & R.Gales (Eds), Chipping Norton:Surrey Beatty & Sons, 13–19, compared to the 14 then accepted. This expanded taxonomy elevated many established subspecies to full species, but was criticised for not using, in every case, peer reviewed information to justify the splits. Since then, further studies have in some instances supported or disproved the splits; a 2004 paper analysing the mitochondrial DNA and microsatellites agreed with the conclusion that the Antipodean albatross and the Tristan albatross were distinct from the wandering albatross, per Robertson and Nunn, but found that the suggested Gibson's albatross, Diomedea gibsoni, was not distinct from the Antipodean albatross. For the most part, an interim taxonomy of 21 species is accepted by ITIS and many other researchers, though by no means all—in 2004 Penhallurick and Wink called for the number of species to be reduced to 13 (including the lumping of the Amsterdam albatross with the wandering albatross), although this paper was itself controversial.
Sibley and Ahlquist's molecular study of the evolution of the bird families has put the radiation of the Procellariiformes in the Oligocene period 35–30 million years ago (Mya), though this group probably originated earlier, with a fossil sometimes attributed to the order, a seabird known as Tytthostonyx, being found in late Cretaceous rocks (70 Mya). The molecular evidence suggests that the storm petrels were the first to diverge from the ancestral stock, and the albatrosses next, with the procellarids and diving petrels separating later. The earliest fossil albatrosses were found in Eocene to Oligocene rocks, although some of these are only tentatively assigned to the family and none appear to be particularly close to the living forms. They are Murunkus (Middle Eocene of Uzbekistan), Manu (early Oligocene of New Zealand), and an undescribed form from the Late Oligocene of South Carolina. The oldest widely accepted fossil albatross is Tydea septentrionalis from the early Oligocene of Belgium. Diomedavus knapptonensis is smaller than all extant albatrosses and was found in late Oligocene strata of Washington State, U.S. Plotornis was formerly often considered a petrel but is now accepted as an albatross. It is from the Middle Miocene of France, a time when the split between the four modern genera was already underway as evidenced by Phoebastria californica and Diomedea milleri, both being mid-Miocene species from Sharktooth Hill, California. These show that the split between the great albatrosses and the North Pacific albatrosses occurred by 15 Mya. Similar fossil finds in the Southern Hemisphere put the split between the sooties and mollymawks at 10 Mya.Brooke, M. (2004). Albatrosses and Petrels Across the World Oxford University Press, Oxford, UK
The fossil record of the albatrosses in the Northern Hemisphere is more complete than that of the Southern, and many fossil forms of albatross have been found in the North Atlantic, which today has no albatrosses. The remains of a colony of short-tailed albatrosses have been uncovered on the island of Bermuda, and the majority of fossil albatrosses from the North Atlantic have been of the genus Phoebastria (the North Pacific albatrosses); one, Phoebastria anglica, has been found in deposits in both North Carolina and England. Due to convergent evolution in particular of the leg and foot bones, remains of the prehistoric pseudotooth birds (Pelagornithidae) may be mistaken for those of extinct albatrosses; Manu may be such a case, and quite certainly the supposed giant albatross femur from the Early Pleistocene Dainichi Formation at Kakegawa, Japan, actually is from one of the last pseudotooth birds. Aldiomedes angustirostris was a uniquely narrow-beaked species from the Pliocene of New Zealand.
Morphology and flight
The albatrosses are a group of large to very large birds; they are the largest of the Procellariiformes. The bill is large, strong, and sharp-edged, with the upper mandible terminating in a large hook. This bill is composed of several horny plates, and along the sides are the two "tubes", long nostrils that give the order its former name (Tubinares, or tubenoses). The tubes of all albatrosses are along the sides of the bill, unlike the rest of the Procellariiformes, where the tubes run along the top of the bill.