Jump to content

Albatross: Difference between revisions

From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
m Reverted 1 edit by 205.235.40.151 identified as vandalism to last revision by Synthebot. (TW)
its all wrong
Line 1: Line 1:
{{otheruses1|the bird family}}
{{Taxobox
| name = Albatross
| image = Short tailed albatross.jpeg
| image_width = 200px
| image_caption = [[Short-tailed Albatross]] (''Phoebastria albatrus'')
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| classis = [[Bird|Aves]]
| ordo = [[Procellariiformes]]
| familia = '''Diomedeidae'''
| familia_authority = [[George Robert Gray|G.R. Gray]], 1840
| subdivision_ranks = Genera
| subdivision =
''[[Diomedea]]''<br />
''[[Thalassarche]]''<br />
''[[Phoebastria]]''<br />
''[[Phoebetria]]''
|
| range_map = Albatrosses distribution map.png
| range_map_width = 200px
| range_map_caption = Global range

}}

'''Albatrosses''', of the biological [[family (biology)|family]] '''Diomedeidae''', are large [[seabird]]s allied to the [[procellariidae|procellariids]], [[storm-petrel]]s and [[diving-petrel]]s in the order [[Procellariiformes]] (the tubenoses). They range widely in the [[Southern Ocean]] and the North [[Pacific Ocean|Pacific]]. They are absent from the North [[Atlantic Ocean|Atlantic]], although [[fossil]] remains show they once occurred there too and occasional vagrants turn up. Albatrosses are amongst the largest of [[bird flight|flying]] birds, and the [[great albatross]]es ([[genus (biology)|genus]] ''Diomedea'') have the largest wingspans of any [[extant taxon|extant]] birds. The albatrosses are usually regarded as falling into four genera, but there is disagreement 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 [[seabird colony|colonial]], nesting for the most part on remote oceanic islands, often with several species nesting together. [[Pair bond]]s between males and females form over several years, with the use of 'ritualised dances', and will last for the life of the pair. A [[breeding season]] can take over a year from laying to [[fledge|fledging]], with a single [[egg (biology)|egg]] laid in each breeding attempt.

Of the 21 species of albatrosses recognised by the [[World Conservation Union|IUCN]], 19 are threatened with [[extinction]]. Numbers of albatrosses have declined in the past due to harvesting for [[feather]]s, but today the albatrosses are threatened by [[introduced species]] such as [[rat]]s and [[feral cat]]s 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 (luring substance)|bait]], become hooked on the lines, and drown. Identified [[Stakeholder (general)|stakeholders]] such as governments, conservation organisations and people in the fishing industry are all working towards reducing this [[bycatch]].

==Albatross biology==
===Taxonomy and evolution===
The albatrosses comprise between 13 and 24 [[species]] (the number of species is still a matter of some debate, 21 being the most commonly accepted number) in 4 genera. The four genera are the [[great albatross]]es (''Diomedea''), the [[mollymawk]]s (''Thalassarche''), the [[North Pacific albatross]]es (''Phoebastria''), and the [[sooty albatross]]es or sooties (''Phoebetria''). Of the four genera, 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 a great deal of debate. The [[Sibley-Ahlquist taxonomy]] places seabirds, [[bird of prey|birds of prey]] and many others in a greatly enlarged order [[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 [[genetics|genetically]] and through morphological characteristics, size, their legs and the arrangement of their nasal tubes (''see Morphology and flight'').

Within the family the assignment of genera has been debated for over a hundred years. Originally placed into a single genus, ''Diomedea'', they were rearranged by [[Ludwig Reichenbach|Reichenbach]] into four different genera in 1852, then [[Lumpers and splitters|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).<ref>Alexander, W. B., Fleming C. A., Falla R. A., Kuroda N. H., Jouanin C., Rowan M. K., Murphy R. C., Serventy D. L., Salomonsen F., Tickell W. L. N., Voous K. H., Warham J., Watson G. E., Winterbottom J. M., and Bourne W. R. P. 1965. "Correspondence: The families and genera of the petrels and their names." ''Ibis'' '''107''': 401–5.</ref> Though there was a case for the simplification of the family (particularly the nomenclature), the classification was based on the morphological analysis of [[Elliott Coues]] in 1866, and paid little attention to more recent studies and even ignored some of Coues's suggestions.

[[Image:Albatross phylogeny.svg|thumb|right|250px|Phylogenetic relationships of the 4 albatross genera. Based on Nunn et al 1996.]]More recent 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 that there were four, not two, monophyletic groups within the albatrosses.<ref>Nunn, G. B., Cooper, J., Jouventin, P., Robertson, C. J. R. and Robertson G. G. (1996) "Evolutionary relationships among extant albatrosses (Procellariiformes: Diomedeidae) established from complete cytochrome-b gene sequences". ''Auk'' '''113''': 784–801. [http://elibrary.unm.edu/sora/Auk/v113n04/p0784-p0801.pdf]</ref> 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''. Both the [[British Ornithologists' Union]] and the South African authorities split the albatrosses into four genera as Nunn suggested, and the change has been accepted by the majority of researchers.
[[Image:Albatros ceja negra - paso drake - noviembre 2005.jpg|thumb|250px|left|Black-browed Albatross, a [[mollymawk]].]]
While there is some agreement on the number of genera, there is less agreement 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.<ref name = "Double">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</ref>

Based on the work on albatross genera, Robertson and Nunn went on in 1998 to propose a revised taxonomy with 24 different species,<ref>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,</ref> compared to the 14 then accepted. This interim taxonomy elevated many established [[subspecies]] to full species, but was criticised for not using, in every case, [[peer review]]ed 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 [[microsatellite]]s 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.<ref>Burg, T.M., & Croxall, J.P., (2004) "Global population structure and taxonomy of the wandering albatross species complex". ''Molecular Ecology'' '''13''': 2345–2355.</ref> For the most part, an interim taxonomy of 21 species is accepted by the [[IUCN]] and many other researchers, though by no means all &mdash; 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]]),<ref>Penhallurick, J. and Wink, M. (2004). "Analysis of the taxonomy and nomenclature of the Procellariiformes based on complete nucleotide sequences of the mitochondrial cytochrome b gene." ''Emu'' '''104''': 125–147.</ref> although this paper was itself controversial.<ref name = "Double"/><ref>Rheindt, F. E. & Austin, J., (2005) "Major analytical and conceptual shortcomings in a recent taxonomic revision of the Procellariiformes - A reply to Penhallurick and Wink (2004), ''Emu'' '''105''': 181–186 [http://www.publish.csiro.au/?act=view_file&file_id=MU04039.pdf] </ref> On all sides, there is the widespread agreement on the need for further research to clarify the issue.

[[Sibley-Ahlquist taxonomy|Sibley and Ahlquist's]] molecular study of the [[evolution]] of the bird families has put the [[Adaptive radiation|radiation]] of the [[Procellariiformes]] in the [[Oligocene]] period (35&ndash;30 million years ago), 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 (unit)|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 (genus)|Manu]]'' (early Oligocene of [[New Zealand]]), and an undescribed form from the Late Oligocene of [[South Carolina]]. Similar to the last was ''Plotornis'', formerly often considered a petrel but 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.<ref name = "Brooke">Brooke, M. (2004). ''Albatrosses And Petrels Across The World'' Oxford University Press, Oxford, UK ISBN 0-19-850125-0</ref>
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 Albatross]]es have been uncovered on the island of [[Bermuda]],<ref name = "olson">Olson, S.L., Hearty, P.J. (2003) "Probable extirpation of a breeding colony of Short-tailed Albatross (''Phoebastria albatrus'') on Bermuda by Pleistocene sea-level rise." ''Proceedings of the National Academy of Science'' '''100''': (22) 12825–12829.</ref> 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]]. See the genus accounts for more data on fossil species.

===Morphology and flight===
[[Image:Black footed albatross.jpg|thumb|199px|Unlike most Procellariiformes, albatrosses, like this Black-footed Albatross, can walk well on land.]]
The albatrosses are a group of large to very large [[bird]]s; they are the largest of the procellariiformes. The [[beak|bill]] 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 (biology)|order]] its former name. 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. 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.<ref>Lequette, B., Verheyden, C., Jowentin, P. (1989) "Olfaction in Subantarctic seabirds: Its phylogenetic and ecological significance" ''The Condor'' '''91''': 732-135. [http://scholar.google.com/url?sa=U&q=http://elibrary.unm.edu/sora/Condor/files/issues/v091n03/p0732-p0735.pdf]</ref> The feet have no hind toe and the three anterior toes are completely webbed. The legs are strong for Procellariiformes, in fact, almost uniquely amongst the order in that they and the [[giant petrel]]s 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 [[mollymawk]]s and [[North Pacific albatross]]es have face markings like eye patches or have grey or yellow on the head and nape. Three albatross species, the [[Black-footed Albatross]] and the two [[sooty albatross]]es, vary completely from the usual patterns and are almost entirely dark brown (or dark grey in places in the case of the [[Light-mantled Sooty Albatross]]). Albatrosses take several years to get their full adult breeding plumage.

The [[wingspan]]s of the largest great albatrosses (genus ''Diomedea'') are the largest of any bird, exceeding 340&nbsp;cm (over 11&nbsp;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 minimise 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 ratio]]s, around 22:1 to 23:1, meaning that for every metre they drop, they can travel forward 22 metres. 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 outstretched without any muscle expenditure, a morphological adaptation they share with the giant petrels.<ref>Pennycuick, C. J. (1982). "The flight of petrels and albatrosses (Procellariiformes), observed in South Georgia and its vicinity". ''Philosophical Transactions of the Royal Society of London B'' '''300''': 75–106.</ref>

[[Image:Phoebastria albatrus1.jpg|thumb|250px|left|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 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]].<ref name ="tick">Tickell, W.L.N. (2000). ''Albatrosses''. Sussex:Pica Press, ISBN 1-873403-94-1</ref> Albatrosses are so well adapted to this lifestyle that their [[heart rate]]s 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.<ref>Weimerskirch H, Guionnet T, Martin J, Shaffer SA, Costa DP. (2000) "Fast and fuel efficient? Optimal use of wind by flying albatrosses." ''Proc Biol Sci'' '''267''': (1455) 1869–74. </ref> This efficient long-distance travelling 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.<ref name ="war">Warham, J. (1996). ''The Behaviour, Population, Biology and Physiology of the Petrels''. London:Academic Press, ISBN 0-12-735415-8</ref> When taking off, albatrosses need to take a run up to allow enough air to move under the wing to provide [[Lift (force)|lift]].

===Distribution and range at sea===
[[Image:Diomedeidae distribution.png|thumb|left|200px|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, California and Alaska; 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 [[equator]]ial waters around the Galapagos Islands because of the cool waters of the [[Humboldt Current]] and the resulting winds.

[[Image:Albatross shape.png|thumb|right|200px|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 level]]s 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.<ref name = "olson"/> Some southern species have occasionally turned up as [[Vagrancy in birds|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|gannet]] colonies in [[Scotland]] for many years in a lonely attempt to breed.<ref name = "Brit">Cocker, M., & Mabey, R., (2005) ''Birds Britannica'' London:Chatto & Windus, ISBN 0-7011-6907-9</ref>

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 [[bird migration|migration]], but disperse widely after breeding, in the case of southern hemisphere species, often undertaking [[circumpolar]] trips.<ref>Croxall, J. P., Silk, J.R.D., Phillips, R.A., Afanasyev, V., Briggs, D.R., (2005) "Global Circumnavigations: Tracking year-round ranges of nonbreeding Albatrosses" ''Science'' '''307''': 249–250.</ref> There is also evidence that there is separation of the ranges of different species at sea. A comparison of the foraging [[ecological niche|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 Albatross]]es also react strongly to [[bathymetry]], feeding only in waters deeper than 1000&nbsp;m (3281&nbsp;ft); 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&nbsp;m".<ref name = "Brooke"/> There is also evidence of different ranges for the two sexes of the same species; a study of [[Tristan Albatross]]es breeding on [[Gough Island]] showed that males foraged to the west of Gough and females to the east.{{see also|List of albatross breeding locations}}

===Diet===
The albatross diet is predominantly [[cephalopod]]s, [[fish]] and [[crustacean]]s, although they will also scavenge [[carrion]] and feed on other [[zooplankton]].<ref name ="tick"/> 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 Albatross|Laysan]] feeds on squid.

[[Image:Light sooty albatross flying.jpg|thumb|245px|left|Light-mantled Sooty Albatrosses regularly dive in order to feed and can dive to below 12&nbsp;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,<ref>Croxall, J.P. & Prince, P.A. (1994). "Dead or alive, night or day: how do albatrosses catch squid?" ''Antarctic Science'' '''6''': 155–162.</ref> and include mid-water species likely to be beyond the reach of albatross, suggesting that, for some species (like the [[Wandering Albatross]]), [[Scavenger|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-eating [[whale]]s ([[sperm whale]]s, [[pilot whale]]s and [[Southern Bottlenose Whale]]s). 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 metre, some species, like the [[Light-mantled Sooty Albatross]], have a mean diving depth of almost 5&nbsp;m and can dive as deep as 12.5&nbsp;m.<ref>Prince, P.A., Huin, N., Weimerskirch, H., (1994) "Diving depths of albatrosses" ''Antarctic Science'' '''6''': (''3'') 353–354.</ref> In addition to surface feeding and diving, they have now also been observed plunge diving from the air to snatch prey.<ref>Cobley, N.D., (1996) "An observation of live prey capture by a Black-browed Albatross ''Diomedea melanophrys'' " ''Marine Ornithology'' '''24''': 45–46.[http://www.marineornithology.org/PDF/24/24_10.pdf]</ref>

===Breeding and dancing===
[[Image:Wandering dance.jpg|thumb|300px|right|Wandering Albatrosses are colonial but have large widely spaced territories. Here a pair performs their famous breeding dance.]]
Albatrosses are [[seabird colony|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 favoured by the mollymawks ([[Black-browed Albatross]] colonies on the [[Falkland Islands]] have densities of 70 nests per 100&nbsp;m²) to the much looser groups and widely spaced individual nests favoured by the sooty and great albatrosses. All albatross colonies are on islands that historically were free of land [[mammal]]s. Albatrosses are highly [[philopatry|philopatric]], meaning they will usually return to their natal colony to breed. This tendency to return to their point of origin to breed 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 metres.<ref>Fisher, H.I., (1976) "Some dynamics of a breeding colony of Laysan Albatrosses. ''Wilson Bulletin'' '''88''': 121–142.</ref>

Like most seabirds, albatrosses are [[R/K selection theory|K-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 [[Bird ringing|ringed]] as an adult and survived for another 51 years, giving it an estimated age of 61.<ref>Robertson, C.J.R. (1993). "Survival and longevity of the Northern Royal Albatross ''Diomedea epomophora sanfordi'' at Taiaroa Head" 1937–93. ''Emu'' '''93''': 269–276.</ref> 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.

[[Image:LAAL adult sky call.jpg|thumb|left|250px|Sky-pointing is one of the stereotyped actions of Laysan Albatross breeding dances.]]
Albatrosses reach [[sexual maturity]] slowly, 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 10 years for some species). Young non-breeders will attend a colony prior to beginning to breed, spending many years practising the elaborate breeding rituals and "dances" that the family is famous for.<ref>Jouventin, P., Monicault, G. de & Blosseville, J.M. (1981) "La danse de l'albatros, ''Phoebetria fusca''". ''Behaviour'' '''78''': 43–80.</ref> Birds arriving back at the colony for the first time already have the stereotyped behaviours that compose albatross [[language]], but can neither "read" that behaviour as exhibited by other birds nor respond appropriately.<ref name ="tick"/> 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 behaviour involves synchronised performances of various actions such as [[personal grooming|preening]], pointing, calling, bill clacking, staring, and combinations of such behaviours (like the sky-call).<ref>Pickering, S.P.C., & Berrow, S.D., (2001) "Courtship behaviour of the Wandering Albatross ''Diomedea exulans'' at Bird Island, South Georgia" ''Marine Ornithology'' '''29''': 29–37 [http://www.marineornithology.org/PDF/29_1/29_1_6.pdf]</ref> 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 held to undertake these elaborate and painstaking rituals to ensure that the appropriate partner has been chosen and to perfect partner recognition, 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.<ref name = "Brooke"/> The great albatrosses (like the [[Wandering Albatross]]) take over a year to raise a chick from laying to [[fledge|fledging]]. Albatrosses lay a single [[egg (biology)|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.

[[Image:Albatross chick at Northwest Hawaiian Islands National Monument, Midway Atoll, 2007March01.jpg|thumb|250px|An albatross chick at [[Northwest Hawaiian Islands National Monument]], [[Midway Atoll]].]]
All the southern albatrosses create large [[nest]]s 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&nbsp;m, sometimes causing it to lose the egg.<ref>Anderson, D.J. & Cruz, F. (1998) "Biology and management of the Waved Albatross at the Galapagos Islands. Pp.105–109 in ''Albatross Biology and Conservation'' (Roberston, G. & Gales, R. eds) Chipping Norton:Surrey Beatty and & Sons ISBN 0-949324-82-5 </ref> 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.<ref>Warham, J. (1990) ''The Petrels - Their Ecology and Breeding Systems'' London:Academic Press. </ref>

After hatching, the chick is brooded and guarded for three weeks until it is large enough to defend and [[thermoregulation|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% of their body weight (around 600 g). The meals are composed of both fresh [[squid]], [[fish]] and [[krill]], as well as [[stomach oil]], an [[food energy|energy]]-rich food that is lighter to carry than undigested prey items.<ref>Warham, J. (1976) "The incidence, function and ecological significance of petrel stomach oils." ''Proceedings of the New Zealand Ecological Society'' '''24''': 84–93 [http://www.nzes.org.nz/nzje/free_issues/ProNZES24_84.pdf]</ref> 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.

[[Image:BFAL Adult w chick.jpg|thumb|left|190px|Albatrosses brood young chicks until they are large enough to defend themselves and thermoregulate.]]
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.<ref name ="delhoyo">Carboneras, C. (1992) "Family Diomedeidae (Albatross)" in ''Handbook of Birds of the World'' Vol 1. Barcelona:Lynx Edicions, ISBN 84-87334-10-5</ref> 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 behaviour, a genetically coded navigation route, which helps young birds when they are first out at sea.<ref>Åkesson, S., & Weimerskirch, H., (2005) "Albatross Long-Distance Navigation: Comparing Adults And Juveniles" ''Journal of Navigation'' '''58''': 365–373.</ref>

==Albatrosses and humans==
===Etymology===
The name ''albatross'' is derived from the [[Arabic language|Arabic]] ''al-câdous'' or ''al-ġaţţās'' (a [[pelican]]; literally, "the diver"), which travelled to English via the [[Portuguese language|Portuguese]] form ''alcatraz'' ("[[gannet]]"), which is also the origin of the title of the former prison, [[Alcatraz]]. The ''[[Oxford English Dictionary|OED]]'' 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.<ref name ="tick"/> The Portuguese word ''albatroz'' is of [[English language|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 language|Dutch]] name for the [[Northern Fulmar]]. The name ''Diomedea'', assigned to the albatrosses by [[Carolus Linnaeus|Linnaeus]], references the mythical metamorphosis of the companions of the Greek warrior [[Diomedes]] into birds.

===Albatrosses and culture===
[[Image:Royal Albatross near Dunedin.jpg|thumb|150px|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".<ref name ="delhoyo"/> 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 (metaphor)|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 [[urban legend|myth]] that sailors believe it disastrous to shoot or harm an albatross; in truth, however, sailors regularly killed and ate them,<ref name = "Brit"/> but they were often regarded as the souls of lost sailors. More recently, they have become part of [[popular culture]], for example, in a [[Monty Python]] [[Albatross (Monty Python sketch)|sketch]], and in the movie ''[[Serenity (film)|Serenity]]''. The [[Royal Air Force]] also use an image of an albatross on their officer's cap badge as did the former [[Air Ministry]]. Despite popular opinion that the bird is some sort of eagle, the characteristics of the albatross are clearly visible. There were efforts during the 1930's and 1940's to make the bird appear more like an eagle and ultimately more war like, but the [[Royal College of Arms]] still recognises the bird as an Albatross in a displayed pose with its head turned to the right.
[[Image:Albatroz - Panorama 1837.jpg|thumb|left|200px|''' "Albatroz" - Woodcut from the journal "O Panorama" 1837 edition''' (''From the Dr. Nuno Carvalho de Sousa Private Collections - Lisbon)]]''
Albatrosses are popular birds for [[birdwatching|birdwatchers]] and their colonies popular destinations for [[ecotourism|ecotourists]]. Regular birdwatching trips are taken out of many coastal towns and cities, like [[Monterey, New South Wales|Monterey]], [[Kaikoura]], [[Wollongong]] and [[Sydney]], to see [[pelagic]] [[seabird]]s, 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,<ref name = "Brooke"/> and more isolated colonies are regular attractions on cruises to sub-Antarctic islands.

===Threats and conservation===
In spite of often being accorded legendary status, albatrosses have not escaped either indirect or direct pressure from humans. Early encounters with albatrosses by [[Polynesia]]ns and [[Aleut]] Indians resulted in hunting and in some cases extirpation from some islands (such as [[Easter Island]]). As [[European ethnic groups|European]]s began sailing the world, they too began to hunt albatross, "fishing" for them from boats to serve at the table or blasting them for sport.<ref>Safina, C. (2002) ''Eye of the Albatross: Visions of Hope and Survival'' New York:Henry Holt & Company ISBN 0-8050-6229-7</ref> This sport reached its peak on emigration lines bound for [[Australia]], and only died down when ships became too fast to fish from, and regulations stopped the discharge of weapons for safety reasons. In the 19th century, albatross colonies, particularly those in the North Pacific, were harvested for the feather trade, leading to the near extinction of the [[Short-tailed Albatross]].

[[Image:Albatross hook.jpg|thumb|250px|left|This Black-browed Albatross has been hooked on a long-line.]]Of the 21 albatross species recognised by IUCN on their [[IUCN Red List|Red List]], 19 are threatened, and the other two are ''near threatened''.<ref>IUCN, 2004. [http://www.iucnredlist.org/search/search.php?freetext=Albatross&modifier=phrase&criteria=wholedb&taxa_species=1&redlistCategory%5B%5D=allex&redlistAssessyear%5B%5D=all&country%5B%5D=all&aquatic%5B%5D=all&regions%5B%5D=all&habitats%5B%5D=all&threats%5B%5D=all&Submit.x=104&Submit.y=16 Red List: Albatross Species]. Retrieved [[July 27]], [[2007]].</ref> Two species (as recognised by the IUCN) are considered critically [[endangered species|endangered]]: the [[Amsterdam Albatross]] and the [[Chatham Albatross]]. One of the main threats is commercial [[long-line fishing]],<ref>Brothers NP. 1991. "Albatross mortality and associated bait loss in the Japanese longline fishery in the southern ocean." ''Biological Conservation'' '''55''': 255–268.</ref> as the albatrosses and other [[seabird]]s which will readily feed on [[offal]] are attracted to the set bait become hooked on the lines and drown. An estimated 100,000 albatross per year are killed in this fashion. Unregulated [[pirate]] fisheries exacerbate the problem.

On [[Midway Atoll]], collisions between [[Laysan Albatross]] and aircraft have resulted in human and bird deaths as well as severe disruptions in military flight operations. Studies were made in the late 1950s and early 1960s that examined the results of control methods such as the killing of birds, the leveling and clearing of land to eliminate updrafts and the destruction of annual nesting sites.<ref>{{cite journal |last=Fisher |first=Harvey I. |year=1966 |month=May |title=Airplane-Albatross Collisions on Midway Atoll |journal=The Condor |volume=68 |issue=3 |pages=229-242 |url=http://links.jstor.org/sici?sici=0010-5422(196605%2F06)68%3A3%3C229%3AACOMA%3E2.0.CO%3B2-I |accessdate= 2007-12-16}}</ref> Tall structures such as traffic control and radio towers killed 3000 birds in flight collisions during 1964-1965 before the towers were taken down. Closure of Naval Air Facility Midway Island in 1993 eliminated the problem of collisions with military aircraft. Recent reductions in human activity on the island have helped reduce bird deaths, though lead paint pollution near military buildings continues to poison birds by ingestion.<ref>[http://www.audubon2.org/watchlist/viewSpecies.jsp?id=118 Audubon Watchlist. ''Laysan Albatross (Phoebastria immutabilis)'']</ref>

Another threat to albatrosses is [[introduced species]], such as rats or [[feral cat]]s, which directly attack the albatross or its chicks and eggs. Albatrosses have evolved to breed on islands where land mammals are absent and have not evolved defences against them. Even species as small as mice can be detrimental; on [[Gough Island]] the chicks of [[Tristan Albatross]]es are attacked and eaten alive by introduced [[house mouse|house mice]] that are almost 300 times smaller than they are.<ref>BBC News, 2005. [http://news.bbc.co.uk/1/hi/sci/tech/4708899.stm Albatross chicks attacked by mice]. Retrieved [[March 6]], [[2006]].</ref> Introduced species can have other indirect effects: [[cattle]] overgrazed essential cover on [[Amsterdam Island]] threatening the Amsterdam Albatross; on other islands introduced plants reduce potential nesting habitat.

[[Image:Laysan albatross chick remains.jpg|thumb|250px|The remains of this Laysan Albatross chick show the plastic ingested before death, including a bottle cap and lighter.]]Ingestion of [[plastic]] [[flotsam]] is another problem, one faced by many seabirds. The amount of plastic in the seas has increased dramatically since the first record in the 1960s, coming from waste discarded by ships, offshore dumping, litter on beaches and waste washed to sea by rivers. It is impossible to digest and takes up space in the stomach or [[gizzard]] that should be used for food, or can cause an obstruction that starves the bird directly. Studies of birds in the North Pacific have shown that ingestion of plastics results in declining [[body weight]] and body condition.<ref>Spear, L.B., Ainley, D.G. & Ribic, C.A. (1995). "Incidence of plastic in seabirds from the tropical Pacific, 1984–91: relation with distribution of species, sex, age, season, year and body weight." ''Marine Environmental Research'' '''40''': 123–146. </ref> This plastic is sometimes regurgitated and fed to chicks; a study of [[Laysan Albatross]] chicks on [[Midway Atoll]] showed large amounts of ingested plastic in naturally dead chicks compared to healthy chicks killed in accidents.<ref>Auman, H.J., Ludwig, J.P., Giesy, J.P., Colborn, T., (1997) "Plastic ingestion by Laysan Albatross chicks on Sand Island, Midway Atoll, in 1994 and 1995." in ''Albatross Biology and Conservation'', (ed by G. Robinson and R. Gales). Surrey Beatty & Sons:Chipping Norton. Pp. 239-44 [http://www.mindfully.org/Plastic/Ocean/Albatross-Plastic-Ingestion1997.htm]</ref> While not the direct cause of death, this plastic causes physiological stress and causes the chick to feel full during feedings, reducing its food intake and the chances of survival.

Scientists and conservationists (most importantly [[BirdLife International]] and their partners, who run the Save the Albatross campaign) are working with governments and [[fishermen]] to find solutions to the threats albatrosses face. Techniques such as setting long-line bait at night, dying the bait blue, setting the bait underwater, increasing the amount of weight on lines and using bird scarers can all reduce the seabird by-catch.<ref>Food and Agriculture Organisation (1999) "The incidental catch of seabirds by longline fisheries: worldwide review and technical guidelines for mitigation. FAO Fisheries Circular No.937. Food and Agriculture Organization of the United Nations, Rome. [http://www.fao.org/documents/show_cdr.asp?url_file=/DOCREP/005/W9817E/W9817E00.HTM]</ref> For example, a collaborative study between scientists and fishermen in [[New Zealand]] successfully tested an underwater setting device for long-liners which set the lines below the reach of vulnerable albatross species.<ref>O'Toole, Decland & Molloy, Janice (2000) "Preliminary performance assessment of an underwater line setting device for pelagic longline fishing" ''New Zealand Journal of Marine and Freshwater Research'' '''34''': 455–461. [http://www.rsnz.org/publish/nzjmfr/2000/36.pdf]</ref> The use of some of these techniques in the [[Patagonian Toothfish]] fishery in the [[Falkland Islands]] is thought to have reduced the number of [[Black-browed Albatross]] taken by the fleet in the last 10 years.<ref>Reid, A.T., Sullivan, B.J., Pompert, J., Enticott, J.W., Black, A.D., (2004) "Seabird mortality associated with Patagonian Toothfish (''Dissostichus eleginoides'') longliners in Falkland Islands waters." ''Emu'' '''104''': (4) 317–325.</ref> Conservationists have also worked on the field of [[island restoration]], removing introduced species that threaten native wildlife, which protects albatrosses from introduced predators.

One important step towards protecting albatrosses and other [[seabird]]s is the 2001 [[treaty]] the [[Agreement on the Conservation of Albatrosses and Petrels]], which came into force in 2004 and has been ratified by eight countries, [[Australia]], [[Ecuador]], [[New Zealand]], [[Spain]], [[South Africa]], [[France]], [[Peru]] and the [[United Kingdom]]. The treaty requires these countries to take specific actions to reduce by-catch, pollution and to remove introduced species from nesting islands. The treaty has also been signed but not ratified by another three countries, [[Argentina]], [[Brazil]] and [[Chile]].

==Species==
Current thinking divides the albatrosses into four genera. The number of species is a matter of some debate. The [[IUCN]] and [[BirdLife International]] among others recognise the interim taxonomy of 21 extant species, other authorities retain the more traditional 14 species, and one recent paper proposed a reduction to 13:
*[[Great albatrosses]] (''Diomedea'')
**[[Wandering Albatross]] '' D. exulans''
**[[Antipodean Albatross]] ''D. (exulans) antipodensis''
**[[Amsterdam Albatross]] ''D. (exulans) amsterdamensis''
**[[Tristan Albatross]] ''D. (exulans) dabbenena''
**[[Northern Royal Albatross]] ''D. (epomorpha) sanfordi''
**[[Southern Royal Albatross]] ''D. epomophora''
*[[North Pacific albatross]]es (''Phoebastria'')
**[[Waved Albatross]] ''P. irrorata''
**[[Short-tailed Albatross]] ''P. albatrus''
**[[Black-footed Albatross]] ''P. nigripes''
**[[Laysan Albatross]] ''P. immutabilis''
*[[Mollymawk]]s (''Thalassarche'')
**[[Black-browed Albatross]] ''T. melanophris ''
**[[Campbell Albatross]] ''T. (melanophris) impavida''
**[[Shy Albatross]] ''T. cauta''
**[[Chatham Albatross]] ''T. (cauta) eremita''
**[[Salvin's Albatross]] ''T. (cauta) salvini''
**[[Grey-headed Albatross]] ''T. chrysostoma''
**[[Atlantic Yellow-nosed Albatross]] ''T. chlororhynchos''
**[[Indian Yellow-nosed Albatross]] ''T. (chlororhynchos) carteri''
**[[Buller's Albatross]] ''T. bulleri''
*[[Sooty albatross]]es (''Phoebetria'')
**[[Dark-mantled Sooty Albatross]] ''P. fusca''
**[[Light-mantled Sooty Albatross]] ''P. palpebrata''.

==Notes and references==
{{reflist|2}}

==External links==
{{commonscat|Diomedeidae}}
{{Wikispecies|Diomedeidae}}
* {{ITIS|ID=174514|taxon=Diomedeidae|year=2006|date=4 May}}
* [http://www.birdsaustralia.com.au/hanzab/HANZAB_spp_list.pdf HANZAB complete species list] (Handbook of Australian, New Zealand and Antarctic Birds.)
*[http://www.birdlife.org/action/campaigns/save_the_albatross/ BirdLife International Save the Albatross campaign]
* [http://www.acap.aq/ The Agreement for the Conservation of Albatrosses and Petrels (ACAP)]
* [http://www.montereybay.com/creagrus/albatrosses.html Albatross: Don Roberson's family page]
* [http://www.birdlife.org/action/science/species/seabirds/tracking_ocean_wanderers.pdf Tracking Ocean Wanderers] The global distribution of albatrosses and petrels: Results from the Global Procellariiform Tracking Workshop, 1–5 September, 2003, Gordon’s Bay, South Africa. [[BirdLife International]]
* [http://ibc.hbw.com/ibc/phtml/familia.phtml?idFamilia=10 Albatross videos] on the Internet Bird Collection
*{{cite web | url = http://www.doc.govt.nz/upload/documents/science-and-technical/TSRP42.pdf| title = Recovery plan for albatrosses in the Chatham Islands 2001-2011| year = 2001 | publisher = Department of Conservation, Wellington, New Zealand | format = PDF | accessdate = 2007-09-28}}


{{featured article}}

[[Category:Albatrosses|*]]
[[Category:Bird families]]
[[Category:Heraldic birds]]
[[Category:Seabirds]]

{{Link FA|pt}}

[[ar:قطرس]]
[[bn:আলবাট্রস]]
[[cs:Albatrosovití]]
[[da:Albatrosser]]
[[de:Albatrosse]]
[[es:Diomedeidae]]
[[eo:Albatrosoj]]
[[fa:آلباتروس]]
[[fr:Diomedeinae]]
[[fy:Albatrossen]]
[[hr:Albatrosi]]
[[io:Albatroso]]
[[id:Albatros]]
[[it:Diomedeidae]]
[[he:אלבטרוסיים]]
[[ka:ალბატროსისებრნი]]
[[lt:Albatrosiniai]]
[[hu:Albatroszfélék]]
[[nl:Albatrossen]]
[[ja:アホウドリ亜科 (Sibley)]]
[[no:Albatrosser]]
[[pl:Albatrosy]]
[[pt:Diomedeidae]]
[[ro:Diomedeidae]]
[[ru:Альбатросовые]]
[[simple:Albatross]]
[[sk:Albatrosovité]]
[[fi:Albatrossit]]
[[sv:Albatrosser]]
[[ta:அல்பட்ரோஸ்]]
[[tr:Albatros]]
[[uk:Альбатроси]]
[[zh:信天翁科]]

Revision as of 16:17, 12 March 2008

Retrieved from "https://en.wikipedia.org/w/index.php?title=Albatross&oldid=197743177"