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Albatross | | | | | |
Albatrosses are large seabirds in the biological family Diomedeidae of the order Procellariiformes (the tubenoses). Albatrosses are among the largest of flying birds, and the great albatrosses (genus Diomedea) have the largest wingspans of any extant (living) birds. They are closely related to the procellariids, storm-petrels, and diving-petrels, all of which also are part of the Procellariiformes. Some systematists recognize another order, Ciconiiformes, instead of Procellariiformes (see Taxonomy and evolution)
Albatrosses range widely in the Southern Ocean (South Pole Ocean or Antarctic Ocean) and the North Pacific Ocean. They are generally absent from the North Atlantic Ocean, althoughfossil remains show they once occurred there too and occasional vagrants are encountered.
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 ritualized dances, and will 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.
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.
The albatrosses are usually regarded as falling into four genera, but there is disagreement over the number of species. The four genera are the great albatrosses (Diomedea), the mollymawks (Thalassarche), the North Pacific albatrosses (Phoebastria), and the sooty albatrosses or sooties (Phoebetria).
Of the 21 species of albatrosses recognized by the IUCN, 19 are threatened with extinction. Numbers of albatrosses have declined in the past due to harvesting for feathers, but today the 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 long-line fishing. Long-line fisheries pose the greatest threat, as feeding birds are attracted to the bait and become hooked on the lines and drown. Governments, conservation organizations and fishermen are all working towards reducing this by-catch.
Morphology and flight

Unlike most Procellariiformes, albatrosses, like this Black-footed Albatross, can walk well on land.
The albatrosses are a group of large to very large birds; they are the largest of the procellariiformes.
The bill (beak) is large, strong and sharp-edged, 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 name. These tubes allow the albatrosses to have an acute sense of smell, an unusual ability for birds. Like other Procellariiformes, they use this olfactory ability while foraging in order to locate potential food sources (Lequette et al. 1989). 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.
The feet have no hind toe and the three anterior toes are completely webbed. The legs are strong for Procellariiformes, in fact, almost unique among the order in that they and the giant petrels are able to walk well on land.
The adult plumage of most of the albatrosses is usually some variation of dark upper-wing and back, white undersides, often compared to that of a gull. Of these, the species range from the Southern Royal Albatross which is almost completely white except for the ends and trailing edges of the wings in fully mature males, to the Amsterdam Albatross which has an almost juvenile-like breeding plumage with a great deal of brown, particularly a strong brown band around the chest. Several species of mollymawks and North Pacific albatrosses have face markings like eye patches, or have gray or yellow on the head and nape. Three albatross species, the Black-footed Albatross and the two sooty albatrosses, vary completely from the usual patterns and are almost entirely dark brown (or dark gray in places in the case of the Light-mantled Sooty Albatross). Albatrosses take several years to get their full adult breeding plumage.
The wingspans of the largest great albatrosses (genus Diomedea) are the greatest of any bird, exceeding 340 cm (over 11 feet), although the other species' wingspans are considerably smaller. The wings are stiff and cambered, with thickened streamlined leading edges.
Albatrosses travel huge distances with two techniques used by many long-winged seabirds, dynamic soaring and slope soaring. Dynamic soaring enables them to minimize the effort needed by gliding across wave fronts gaining energy from the vertical wind gradient. Slope soaring is more straightforward: the albatross turns to the wind, gaining height, from where it can then glide back down to the sea. Albatross have high glide ratios, around 1:22 to 1:23, meaning that for every meter they drop, they can travel forward 22 meters. They are aided in soaring by a shoulder-lock, a sheet of tendon that locks the wing when fully extended, allowing the wing to be kept up and out without any muscle expenditure, a morphological adaptation they share with the giant petrels (Pennycuick 1982). Albatrosses combine these soaring techniques with the use of predictable weather systems; albatrosses in the southern hemisphere flying north from their colonies will take a clockwise route, and those flying south will fly counterclockwise (Tickell 2000).

Taking off is one of the main times albatrosses use flapping in order to fly, and is the most energetically demanding part of a journey.
Albatrosses are so well adapted to this lifestyle that their heart rates while flying are close to their basal heart rate when resting. This efficiency is such that the most energetically demanding aspect of a foraging trip is not the distance covered, but the landings, take-offs and hunting they undertake having found a food source (Weimerskirch et al. 2000). This efficient, long-distance traveling underlies the albatross's success as a long-distance forager, covering great distances and expending little energy looking for patchily distributed food sources.
Their adaptation to gliding flight makes them dependent on wind and waves, however, as their long wings are ill-suited to powered flight and most species lack the muscles and energy to undertake sustained flapping flight. Albatrosses in calm seas are forced to rest on the ocean's surface until the wind picks up again. They also sleep while resting on the surface (and not while on the wing as is sometimes thought). The North Pacific albatrosses can use a flight style known as flap-gliding, where the bird progresses by bursts of flapping followed by gliding (Warham 1996). When taking off, albatrosses need to take a run up to allow enough air to move under the wing to provide lift.
Distribution and range at sea

The distribution of albatrosses across the world.
Most albatrosses range in the southern hemisphere from Antarctica to Australia, South Africa, and South America. The exceptions to this are the four North Pacific albatrosses, of which three occur exclusively in the North Pacific, from Hawaii to Japan, Alaska, and California; and one, the Waved Albatross, breeds in the Galapagos Islands and feeds off the coast of South America. The need for wind in order to glide is the reason albatrosses are for the most part confined to higher latitudes; being unsuited to sustained flapping flight makes crossing the doldrums extremely difficult. The exception, the Waved Albatross, is able to live in the equatorial waters around the Galapagos Islands because of the cool waters of the Humboldt Current and the resulting winds.

Albatrosses range over huge areas of ocean and regularly circle the globe.
It is not known for certain why the albatrosses became extinct in the North Atlantic, although rising sea levels due to an interglacial warming period are thought to have submerged the site of a Short-tailed Albatross colony that has been excavated in Bermuda (Olson and Hearty 2003). Some southern species have occasionally turned up as vagrants in the North Atlantic and can become exiled, remaining there for decades. One of these exiles, a Black-browed Albatross, returned to Northern Gannet (a seabird) colonies in Scotland for many years in a lonely attempt to breed (Cocker and Mabey 2005).
The use of satellite tracking is teaching scientists a great deal about the way albatrosses forage across the ocean in order to find food. They undertake no annual migration, but disperse widely after breeding, in the case of southern hemisphere species, often undertaking circumpolar trips (Croxall et al. 2005). There is also evidence that there is separation of the ranges of different species at sea. A comparison of the foraging niches of two related species that breed on Campbell Island, the Campbell Albatross and the Grey-headed Albatross, showed the Campbell Albatross primarily fed over the Campbell Plateau whereas the Grey-Headed Albatross fed in more pelagic, oceanic waters. Wandering Albatrosses also react strongly to bathymetry, feeding only in waters deeper than 1000 m (3281 feet); so rigidly did the satellite plots match this contour that one scientist remarked, "It almost appears as if the birds notice and obey a 'No Entry' sign where the water shallows to less than 1000 m" (Brooke 2004). There is also evidence of different ranges for the two sexes of the same species; a study of Tristan Albatrosses breeding on Gough Island showed that males foraged to the west of Gough and females to the east.
Albatrosses are colonial, usually nesting on isolated islands. Where colonies are on larger landmasses, they are found on exposed headlands with good approaches from the sea in several directions, like the colony on the Otago Peninsula in Dunedin, New Zealand. Colonies vary from the very dense aggregations favored by the mollymawks (Black-browed Albatross colonies on the Falkland Islands have densities of 70 nests per 100 m²) to the much looser groups and widely spaced individual nests favored by the sooty and great albatrosses. All albatross colonies are on islands that historically were free of land mammals.
Diet
The albatross diet is dominated by cephalopods, fish, and crustaceans (such as krill), although they will also scavenge carrion (carcasses of a dead animal) and feed on other zooplanktonbeyond krill (Tickell 2000). It should be noted that for most species, a comprehensive understanding of diet is only known for the breeding season, when the albatrosses regularly return to land and study is possible. The importance of each of these food sources varies from species to species, and even from population to population; some concentrate on squid alone, others take more krill or fish. Of the two albatross species found in Hawaii, one, the Black-footed Albatross, takes mostly fish while the Laysan feeds on squid.

Light-mantled Sooty Albatrosses regularly dive in order to feed and can dive to below 12 m.
The use of dataloggers at sea that record ingestion of water against time (providing a likely time of feeding) suggest that albatross predominantly feed during the day. Analysis of the squid beaks regurgitated by albatrosses has shown that many of the squid eaten are too large to have been caught alive (Croxall and Prince 1994) and include mid-water species likely to be beyond the reach of albatross, suggesting that, for some species (like the Wandering Albatross), scavenged squid may be an important part of the diet. The source of these dead squid is a matter of debate; some certainly comes from squid fisheries, but in nature it primarily comes from the die-off that occurs after squid spawning and the vomit of squid-eatingwhales (sperm whales, pilot whales and Southern Bottlenose Whales). The diet of other species, like the Black-browed Albatross or the Grey-headed Albatross, is rich with smaller species of squid that tend to sink after death, and scavenging is not assumed to play a large role in their diet.
Until recently, it was thought that albatross were predominantly surface feeders, swimming at the surface and snapping up squid and fish pushed to the surface by currents, predators, or death. The deployment of capillary depth recorders, which record the maximum dive depth undertaken by a bird (between attaching it to a bird and recovering it when it returns to land), has shown that while some species, like the Wandering Albatross, do not dive deeper than a meter, some species, like the Light-mantled Sooty Albatross, have a mean diving depth of almost 5 m and can dive as deep as 12.5 m (Prince et al. 1994). In addition to surface feeding and diving, they have now also been observed plunge diving from the air to snatch prey (Cobley 1996).
Breeding

Wandering Albatrosses are colonial but have large widely spaced territories. Here a pair performs their famous breeding dance.
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Albatrosses are highly philopatric, meaning they will usually return to their natal colony to breed. This tendency to return is so strong that a study of Laysan Albatross showed that the average distance between hatching site and the site where a bird established its own territory was 22 meters (Fisher 1976).
Like most seabirds, albatrosses are K-selected (rather than R-selected) with regard to their life history, meaning they live much longer than other birds, they delay breeding for longer, and invest more effort into fewer young. Albatrosses are very long lived; most species survive upwards of 50 years, the oldest recorded being a Northern Royal Albatross that was ringed as an adult and survived for another 51 years, giving it an estimated age of 61 (Robertson 1993). Given that most albatross ringing projects are considerably younger than that, it is thought likely that other species will prove to live that long and even longer.

Sky-pointing is one of the stereotyped actions of Laysan Albatross breeding dances.
Albatrosses reach sexual maturity after about five years, but even once they have reached maturity, they will not begin to breed for another couple of years (even up to ten years for some species). Young non-breeders will attend a colony prior to beginning to breed, spending many years practicing the elaborate breeding rituals and "dances" for which the family is famous (Jouventin et al. 1981). Birds arriving back at the colony for the first time already have the stereotyped behaviors that compose albatross language, but can neither "read" that behavior as exhibited by other birds nor respond appropriately (Tickle 2000). After a period of trial and error learning, the young birds learn the syntax and perfect the dances. This language is mastered more rapidly if the younger birds are around older birds.
The repertoire of mating behavior involves synchronized performances of various actions such as preening, pointing, calling, bill clacking, staring, and combinations of such behaviors (like the sky-call) (Pickering and Barrow 2001). When a bird first returns to the colony, it will dance with many partners, but after a number of years the number of birds an individual will interact with drops, until one partner is chosen and a pair is formed. They then continue to perfect an individual language that will eventually be unique to that one pair. Having established a pair bond that will last for life, however, most of that dance will never be used ever again.
Albatrosses are thought to undertake these elaborate and painstaking rituals to ensure that the correct partner has been chosen and to perfect recognition of their partner, as egg laying and chick rearing is a huge investment. Even species that can complete an egg-laying cycle in under a year seldom lay eggs in consecutive years (Brooke 2004). The great albatrosses (like the Wandering Albatross) take over a year to raise a chick from laying to fledging. Albatrosses lay a single egg in a breeding season; if the egg is lost to predators or accidentally broken, then no further breeding attempts are made that year. The "divorce" of a pair is a rare occurrence, usually only happening after several years of breeding failure.
All the southern albatrosses create large nests for their egg, whereas the three species in the north Pacific make more rudimentary nests. The Waved Albatross, on the other hand, makes no nest and will even move its egg around the pair's territory, as much as 50 m, sometimes causing it to lose the egg (Anderson and Cruz 1998). In all albatross species, both parents incubate the egg in stints that last between one day and three weeks. Incubation lasts around 70 to 80 days (longer for the larger albatrosses), the longest incubation period of any bird. It can be an energetically demanding process, with the adult losing as much as 83 g of body weight a day (Warham 1990).

Albatrosses brood young chicks until they are large enough to defend themselves and thermoregulate.
After hatching, the chick is brooded and guarded for three weeks until it is large enough to defend and thermoregulate itself. During this period, the parents feed the chick small meals when they relieve each other from duty. After the brooding period is over, the chick is fed in regular intervals by both parents. The parents adopt alternative patterns of short and long foraging trips, providing meals that weigh around 12 percent of their body weight (around 600 g). The meals are composed of both fresh squid, fish, and krill, as well as stomach oil, an energy-rich food that is lighter to carry than undigested prey items (Warham 1976). This oil is created in a stomach organ known as a proventriculus from digested prey items by most tubenoses, and gives them their distinctive musty smell.
Albatross chicks take a long time to fledge. In the case of the great albatrosses, it can take up to 280 days; even for the smaller albatrosses, it takes anywhere between 140 and 170 days (Carboneras 1992). Like many seabirds, albatross chicks will gain enough weight to be heavier than their parents, and prior to fledging they use these reserves to build up body condition (particularly growing all their flight feathers), usually fledging at the same weight as their parents. Albatross chicks fledge on their own and receive no further help from their parents, who return to the nest after fledging, unaware their chick has left. Studies of juveniles dispersing at sea have suggested an innate migration behavior, a genetically coded navigation route, which helps young birds when they are first out at sea (Åkesson and Weimerskirch 2005).
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Etymology
The name albatross is derived from the Arabic al-câdous or al-ġaţţās (a pelican; literally, "the diver"), which traveled to English via the Portuguese form alcatraz ("gannet"), which is also the origin of the title of the former U.S. 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 albus, meaning "white," in contrast to frigatebirds, which are black (Tickell 2000). The Portuguese word albatroz is of English origin.
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 malle-mugge, 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.
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Albatrosses and humans
Albatrosses and culture

A Northern Royal Albatross in flight at the colony in Taiaroa Head, New Zealand.
Albatrosses have been described as "the most legendary of all birds" (Carboneras 1992). An albatross is a central emblem in The Rime of the Ancient Mariner by Samuel Taylor Coleridge; a captive albatross is also a metaphor for the poète maudit in a poem of Charles Baudelaire. It is from the former poem that the usage of albatross as a metaphor is derived; someone with a burden or obstacle is said to have 'an albatross around their neck', the punishment given in the poem to the mariner who killed the albatross. In part due to the poem, there is a widespread myth that sailors believe it disastrous to shoot or harm an albatross; in truth, however, sailors regularly killed and ate them (Cocker and Mabey 2005), but they were often regarded as the souls of lost sailors.
Albatrosses are popular birds for birdwatchers and their colonies popular destinations for ecotourists. Regular birdwatching trips are taken out of many coastal towns and cities, like Monterey and Wollongong in New South Wales, Kaikoura in New Zealand, and Sydney in Australia, where pelagic seabirds and albatrosses are easily attracted to these sightseeing boats by the deployment of fish oil into the sea. Visits to colonies can be very popular; the Northern Royal Albatross colony at Taiaroa Head in New Zealand attracts 40,000 visitors a year (Brooke 2004), and more isolated colonies are regular attractions on cruises to sub-Antarctic islands. albatrosses from introduced predators.
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