The Black Swan, Cygnus atratus, is a large waterbird which breeds mainly in the southeast and southwest regions of Australia. The New Zealand Swan ( Cygnus atratus sumnerensis) is an Extinct Swan from the Chatham Islands and the South Island of New In Biology and Ecology, extinction is the cessation of existence of a Species or group of taxa. In Scientific nomenclature, synonyms are different Scientific names used for a single Taxon. For a topic outline on this subject see List of basic Australia topics. The Black Swan was formerly placed into a monotypic genus, Chenopis. Monotypic is an adjective that refers to a taxonomic group with only one type: In Botany, "monotypic" means that a Taxon has only
‘Swan’ is the common gender term, but ‘cob’ for a male and ‘pen’ for a female are also used, as is ‘cygnet’ for the young. Swans are Birds of the family Anatidae, which also includes geese and Ducks Swans are grouped with the closely related geese in  Collective nouns include a ‘bank’ (on the ground) and a ‘wedge’ (in flight). In Linguistics, a collective noun is a word used to define a group of objects where "objects" can be People, Animals Inanimate things  Black Swans can be found singly, or in loose companies numbering into the hundreds or even thousands. 
Black Swans are mostly black feathered, with a line of white flight feathers of the wing edges that sometimes show when at rest, and are conspicuous in flight. Feathers are one of the epidermal growths that form the distinctive outer covering or Plumage, on Birds They are considered the most complex integumentary structures The bill is bright red, with a pale bar and tip; and legs and feet are greyish-black. Anatomy Stegosaurus --> Beaks can vary significantly in size and shape from species to species Cobs (males) are slightly larger than pens (females), with a longer and straighter bill. Cygnets (immature birds) are a greyish-brown with pale-edged feathers. 
A mature Black Swan measures between 1. 1 and 1. 4 metres in length and weighs 6-9 kg. Its wing span, in flight, is between 1. 6 and 2 metres.  The neck is long (relatively the longest neck among the swans) and curved in an "S".
The Black Swan utters a musical and far reaching bugle-like sound, called either on the water or in flight, as well as a range of softer crooning notes. It can also whistle, especially when disturbed while breeding and nesting. 
The Black Swan is unlike any other Australian bird, although in poor light and at long range it may be confused with a magpie-goose in flight. The Magpie-goose, Anseranas semipalmata, is a Waterbird Species found in Australia and New Guinea. However the Black Swan can be distinguished by its much longer neck and slower wing beat. 
The species has a large range, with figures between one to ten million km² given as the extent of occurrence. The current global population of the Black Swan is estimated to be up to 500,000 individuals. No threat of extinction, or significant decline in population has been identified in this numerous and widespread bird. 
The Black Swan is common in the wetlands of south western and eastern Australia and adjacent coastal islands. In the south west the range ecompasses an area between North West Cape, Cape Leeuwin and Eucla; while in the east it covers are large region bounded by the Atherton Tableland, the Eyre Peninsula and Tasmania, with the Murray Darling Basin supporting very large populations of Black Swans. North West Cape is a large peninsula of land in the north west coast of Western Australia. Cape Leeuwin (ˈluːwɪn —) is the most south-westerly mainland point of the Australian Continent, in the state of Western Australia. Eucla is the easternmost locality in Western Australia, located in the Goldfields-Esperance region of Western Australia along the Eyre Highway The Atherton Tableland is a fertile plateau which is part of the Great Dividing Range in Queensland, Australia. Eyre Peninsula is a triangular Peninsula in South Australia. It is bounded on the east by Spencer Gulf, the west by the Great Australian Bight Tasmania is an Australian island and state of the same name It is located south of the eastern side of the Continent, being separated from it by Bass The Murray-Darling Basin is 3375km long drains one-seventh of the Australian land mass and is currently by far the most significant agricultural area in Australia  It is uncommon in central and northern Australia.
The Black Swan’s preferred habitat extends across fresh, brackish and salt water lakes, swamps and rivers with underwater and emergent vegetation for food and nesting materials. Permanent wetlands are preferred, including ornamental lakes, but Black Swans can also be found in flooded pastures and tidal mudflats, and occasionally on the open sea near islands or the shore. A wetland is an area of Land consisting of Soil that is Saturated with Moisture, such as a Swamp, Marsh, or Bog 
Black Swans were once thought to be sedentary, but the species is now known to be highly nomadic. There is no set migratory pattern, but rather opportunistic responses to either rainfall or drought. In high rainfall years, emigration occurs from the south west and south east into the interior, with a reverse immigration to these heartlands in drier years. When rain does fall in the arid central regions, Black Swans will migrate to these areas to nest and raise their young. However, should dry conditions return before the young have been raised, the adult birds will abandon the nests and their eggs or cygnets and return to wetter areas. 
Black Swans, like many other water fowl, lose all their flight feathers at once when they moult after breeding, and they are unable to fly for about a month. During this time they will usually settle on large, open waters for safety. 
Prior to the arrival of the Māori in New Zealand, a sub-species of the Black Swan known as the New Zealand Swan had developed in the islands, but was apparently hunted to extinction. This article discusses the Māori people of New Zealand For their language see Māori language, and for other meanings see Māori (disambiguation. New Zealand is an Island country in the south-western Pacific Ocean comprising two main landmasses (the North Island and the South Island In Zoology, as in other branches of Biology, subspecies is the Taxonomic rank immediately subordinate to a Species. The New Zealand Swan ( Cygnus atratus sumnerensis) is an Extinct Swan from the Chatham Islands and the South Island of New In Biology and Ecology, extinction is the cessation of existence of a Species or group of taxa. In 1864 the Australian Black Swan was introduced to New Zealand as an ornamental waterfowl, and populations are now common on larger coastal or inland lakes, especially Rotorua Lakes, Lake Wairarapa and Lake Ellesmere, and the Chatham Islands. Year 1864 ( MDCCCLXIV) was a Leap year starting on Friday (link will display the full calendar of the Gregorian Calendar (or a Leap year Lake Rotorua is the second largest Lake in the North Island of New Zealand by surface area and covers 7878 ha. Lake Wairarapa is a Lake at the southern end of the North Island of New Zealand, 50 kilometers east of Wellington. Lake Ellesmere is located in the Canterbury region of the South Island of New Zealand. The Archipelago of the Chatham Islands ( Rekohu in the Moriori language and Wharekauri in the Māori language) is a territory  Black Swans have also naturally flown to New Zealand, leading some people to consider them a native rather than exotic species, although the present population appears to be largely descended from deliberate introductions. 
The Black Swan is also very popular as an ornamental waterbird in Western Europe, especially Britain, and escapes are commonly reported. See also Kingdom of Great Britain Great Britain (Breatainn Mhòr Prydain Fawr Breten Veur Graet Breetain is the larger of the two main islands As yet the population in Britain is not considered to be self-sustaining and so the species is not afforded admission to the official British List, but the Wildfowl and Wetlands Trust have recorded a maximum of nine breeding pairs in the UK in 2001, with an estimate of 43 feral birds in 2003/04 (though that is undoubtedly an under-estimate given the level of monitoring undertaken). The Wildfowl and Wetlands Trust is a Wildfowl and Wetland conservation charity in the United Kingdom.
When swimming, Black Swans hold their necks arched or erect, and often carry their feathers or wings raised in an aggressive display. In flight, a wedge of Black Swans will form as a line or a V, with the individual birds flying strongly with undulating long necks, making whistling sounds with their wings and baying, bugling or trumpeting calls. 
Generally, Black Swans nest in the wetter winter months (February to September), occasionally in large colonies. A typical clutch contains 4 to 8 greenish-white eggs that are incubated for about 35-40 days.  After hatching the cygnets are tended by the parents for about 6 months until fledging, and may ride on their parent's back for longer trips into deeper water. 
A Black Swan nest is essentially a large heap or mound of reeds, grasses and weeds between 1 and 1. 5 metres in diameter and up to 1 metre high, in shallow water or on islands.  A nest is reused every year, restored or rebuilt as needed. Both parents share the care of the nest. Like other swans, the Black Swan is largely monogamous, pairing for life (about 6% divorce rate). Monogamy is the custom or condition of having only one mate in a Relationship, thus forming a Couple.  Recent studies have shown that around a third of all broods exhibit extra-pair paternity. Recent discoveries have led biologists to talk about the three varieties of Monogamy: social monogamy sexual monogamy and genetic monogamy 
A recent (2007) exhibition at the University of Oslo Natural History Museum in Norway called Against Nature? explored homosexual behaviours in a number of species, including Black Swans. The University of Oslo (Universitetet i Oslo Universitas Osloensis is the oldest and largest University in Norway, situated in the Norwegian capital Against Nature? is a controversial exhibition on Homosexuality in animals made by The Natural History Museum University of Oslo, Norway.
Several swan species exhibit lifelong homosocial behaviours, and the same phenomenon can also be found in a number of other water-birds, notably geese and flamingos, where it serves as a flexible life strategy. In Sociology, homosociality describes same-sex relationships that are not of a romantic and/or Sexual nature Goose (plural geese) is the English name for a considerable number of Birds belonging to the family Anatidae. Flamingos or flamingoes ( are gregarious Wading birds in the Genus Phoenicopterus and family
In swans, the pair is the central social unit. The birds reinforce the unit with frequent preening and sex. Should one die, the other will usually live out the remainder of its life alone. The pair builds nests, raise cygnets and defends a territory. Two cobs, being bigger and stronger than a cob and a pen, can hold down a larger territory, and provide their cygnets with more to eat.
Such same-sex pairs represent a major fitness bonus to a pen, and pens without partners will seek out these couples, have sex with one or other of the cobs and lay eggs in their nest. Fitness (often denoted w in Population genetics models is a central concept in evolutionary theory. She is then chased off, not being a part of the pair, and the cobs raise the cygnets themselves. Having access to more food the brood have up to ten times the survival rate of a brood with a heterosexual swan couple. From an evolutionary point of view, this is a very rewarding strategy for the cobs as well.
This situation only holds true as long as a nest and a territory is in short supply. The two males will have a fitness loss in that they (1) have no guarantee they are the actual fathers of the cygnets (not being bonded with the female) and (2) will anyway have to split reproduction between them.
A same-sex lifestyle will be advantageous in some situations, but not in others. However, having a partner is a requisite for building a nest and keeping a territory, and an opposite-sex partner may not always be available when forming pairs. Thus, the ability to form a male pair is a normal part of the Black Swans social behaviour and an example of a flexible life strategy in the species. 
Perhaps the most famous black swan is Petra, the swan who fell in love with a paddling boat in Germany and refused to migrate. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Petra has since fallen in and out of love with a male swan named Bruce and currently lives with her paddling boat at the Allwetter Zoo. Swans are Birds of the family Anatidae, which also includes geese and Ducks Swans are grouped with the closely related geese in 
The Black Swan is protected under the Australian National Parks and Wildlife Act, 1974.
The Black Swan is evaluated as Least Concern on the IUCN Red List of Threatened Species. The IUCN Red List of Threatened Species (also known as the IUCN Red List or Red Data List) created in 1963 is the world's most comprehensive inventory of the global
The black swan was a literary or artistic image, even before the discovery of Cygnus atratus. Black Swan emblems and popular culture deals with the uses which have been made of the image of the Black Swan such as Emblems Coins Logos Cultural reference has been based on symbolic contrast and as a distinctive motif. The Black Swan's role in Australian heraldry and culture extends to the first founding of the colonies in the eighteenth century. It has often been equated with antipodean identity, the contrast to the white swan of the northern hemisphere indicating 'Australianess'. The black swan is featured on the flag, and is both the state and bird emblem, of Western Australia; it also appears in the Coat of Arms and other iconography of the state's institutions. Western Australia is a state occupying the entire western third of the Australian continent. A coat of arms or armorial bearings (often just arms for short in European tradition is a design belonging to a particular person (or group of people
Swan with cygnets
earliest known illustration
Lake Burley Griffin, Australia