Misplaced Pages

Black swan

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
#791208

61-496: The black swan ( Cygnus atratus ) is a large waterbird , a species of swan which breeds mainly in the southeast and southwest regions of Australia . Within Australia, the black swan is nomadic, with erratic migration patterns dependent on climatic conditions. It is a large bird with black plumage and a red bill . It is a monogamous breeder, with both partners sharing incubation and cygnet -rearing duties. The black swan

122-403: A sock from one's foot by grabbing the open end and pulling it over itself. The snake's skin is often left in one piece after the moulting process, including the discarded brille (ocular scale), so that the moult is vital for maintaining the animal's quality of vision. The skins of lizards , in contrast, generally fall off in pieces. Both frogs and salamanders moult regularly and consume

183-426: A bird's body weight, it takes a large amount of energy to replace them. For this reason, moults often occur immediately after the breeding season, but while food is still abundant. The plumage produced during this time is called postnuptial plumage. Prenuptial moulting occurs in red-collared widowbirds where the males replace their nonbreeding plumage with breeding plumage. It is thought that large birds can advance

244-451: A body weight loss of 25 to 35%, which stimulates the hen to lose her feathers, but also reinvigorates egg-production. Some flocks may be force-moulted several times. In 2003, more than 75% of all flocks were force-moulted in the US. Other methods of inducing a moult include low-density diets (e.g. grape pomace, cotton seed meal, alfalfa meal) or dietary manipulation to create an imbalance of

305-659: A broad and elongated general body plan. Diving species vary from this in being rounder. Extant species range in size from the cotton pygmy goose , at as little as 26.5 cm (10.5 in) and 164 g (5.8 oz), to the trumpeter swan , at as much as 183 cm (6 ft) and 17.2 kg (38 lb). The largest anatid ever known is the extinct flightless Garganornis ballmanni at 22 kg (49 lb). The wings are short and pointed, and supported by strong wing muscles that generate rapid beats in flight . They typically have long necks, although this varies in degree between species. The legs are short, strong, and set far to

366-479: 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 'Australianness'. The black swan is featured on the flag, and is both the state bird and state emblem of Western Australia ; it also appears in

427-422: A greyish-brown with pale-edged feathers. Mature black swans measure between 110 and 142 centimetres (43 and 56 in) in length and weigh 3.7–9 kilograms (8.2–19.8 lb). Their wing span is between 1.6 and 2 metres (5.2 and 6.6 ft). The neck is long (relatively the longest neck among the swans) and curved in an "S"-shape. The black swan utters a musical and far reaching bugle-like sound, called either on

488-571: A later moulting period. Some species of bird become flightless during an annual "wing moult" and must seek a protected habitat with a reliable food supply during that time. While the plumage may appear thin or uneven during the moult, the bird's general shape is maintained despite the loss of apparently many feathers; bald spots are typically signs of unrelated illnesses, such as gross injuries, parasites, feather pecking (especially in commercial poultry), or (in pet birds) feather plucking . Some birds will drop feathers, especially tail feathers, in what

549-483: 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 escapees are commonly reported. 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

610-487: A new partner the following year, whereas the larger swans, geese and some of the more territorial ducks maintain pair bonds over a number of years, and even for life in some species. However, forced extrapair copulation among anatids is common, occurring in 55 species in 17 genera. Anatidae is a large proportion of the 3% of bird species to possess a penis , though they vary significantly in size, shape, and surface elaboration. Most species are adapted for copulation on

671-706: A number of other ducks occasionally lay eggs in the nests of conspecifics (members of the same species) in addition to raising their own broods. Duck, eider, and goose feathers and down have long been popular for bedspreads, pillows, sleeping bags, and coats. The members of this family also have long been used for food. Humans have had a long relationship with ducks, geese, and swans; they are important economically and culturally to humans, and several duck species have benefited from an association with people. However, some anatids are agricultural pests , and have acted as vectors for zoonoses such as avian influenza . Since 1600, five species of ducks have become extinct due to

SECTION 10

#1732771996792

732-404: A particular nutrient(s). The most important among these include manipulation of minerals including sodium (Na), calcium (Ca), iodine (I) and zinc (Zn), with full or partially reduced dietary intakes. Squamates periodically engage in moulting, as their skin is scaly . The most familiar example of moulting in such reptiles is when snakes "shed their skin". This is usually achieved by

793-596: A related species of swan known as the New Zealand swan had developed there, but was apparently hunted to extinction . 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 , Lake Ellesmere / Te Waihora , and the Chatham Islands . Black swans have also naturally flown to New Zealand, leading scientists to consider them

854-405: A thin and sensitive layer of skin on top (which has a leathery feel when touched). For most species, the shape of the bill tends to be more flattened to a greater or lesser extent. These contain serrated lamellae which are particularly well defined in the filter-feeding species. Their feathers are excellent at shedding water due to special oils. Many of the ducks display sexual dimorphism , with

915-431: A year, although many moult twice and a few three times each year. It is generally a slow process: birds rarely shed all their feathers at any one time. The bird must retain sufficient feathers to regulate its body temperature and repel moisture. The number and area of feathers that are shed varies. In some moulting periods, a bird may renew only the feathers on the head and body, shedding the wing and tail feathers during

976-569: Is a process by which an animal casts off parts of its body to serve some beneficial purpose, either at specific times of the year, or at specific points in its life cycle. In medieval times, it was also known as "mewing" (from the French verb "muer", to moult), a term that lives on in the name of Britain's Royal Mews where the King's hawks used to be kept during moulting time before becoming horse stables after Tudor times. Moulting can involve shedding

1037-469: Is a regional symbol of both Western Australia , where it is native, and the English town of Dawlish , where it is an introduced species. Black swans are black-feathered birds, with white flight feathers. The bill is bright red, with a pale bar and tip; and legs and feet are greyish-black. Cobs (males) are slightly larger than pens (females), with a longer and straighter bill. Cygnets (immature birds) are

1098-422: Is called a "fright moult". The process of moulting in birds is as follows: First, the bird begins to shed some old feathers, then pin feathers grow in to replace the old feathers. As the pin feathers become full feathers, other feathers are shed. This is a cyclical process that occurs in many phases. It is usually symmetrical , with feather loss equal on each side of the body. Because feathers make up 4–12% of

1159-566: Is marked by ritualised displays by both sexes. If eggs accidentally roll out of the nest both sexes will retrieve the egg using the neck (in other swan species only the female performs this feat). Like all swans, black swans will aggressively defend their nests with their wings and beaks. After hatching, the cygnets are tended by the parents for about nine months until fledging. Cygnets may ride on their parent's back for longer trips into deeper water, but black swans undertake this behaviour less frequently than mute and black-necked swans. The black swan

1220-635: Is protected in New South Wales, Australia under the National Parks and Wildlife Act 1974 (s.5). The Black Swan is fully protected in all states and territories of Australia and must not be shot. It is evaluated as Least Concern on the IUCN Red List of Threatened Species. The black swan was a literary or artistic image among Europeans even before their arrival in Australia. Cultural reference has been based on symbolic contrast and as

1281-665: Is small, mtDNA results must be considered with caution. While a comprehensive review of the Anatidae which unites all evidence into a robust phylogeny is still lacking, the reasons for the confusing data are at least clear: As demonstrated by the Late Cretaceous fossil Vegavis iaai —an early modern waterbird which belonged to an extinct lineage—the Anatidae are an ancient group among the modern birds. Their earliest direct ancestors, though not documented by fossils yet, likewise can be assumed to have been contemporaries with

SECTION 20

#1732771996792

1342-723: Is so well associated with the town that the bird has been the town's emblem for forty years. There are also wild populations in Japan , having originally been imported during 1950–1960. Black swans have been reported in Florida , but there is no evidence that they are breeding; persistent sightings may be due to continual releases or escapes. Orange County, California reported black swans in Lake Forest , Irvine and Newport Beach on October 5, 2020, and Santa Ana in December 2021 in

1403-402: 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. It also favors permanent wetlands , including ornamental lakes, but can also be found in flooded pastures and tidal mudflats, and occasionally on the open sea near islands or

1464-542: Is unlike any other Australian bird, although in poor light and at long range it may be confused with a magpie goose in flight. However, the black swan can be distinguished by its much longer neck and slower wing beat. One captive population of black swans in Lakeland, Florida has produced a few individuals which are a light mottled grey colour instead of black. White black swans are also known to exist; these individuals, which are leucistic , are believed to occur rarely in

1525-731: 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 2003–2004. A small population of black swans exists on the River Thames at Marlow , on the brook running through the small town of Dawlish in Devon , near the River Itchen, Hampshire , and the River Tees near Stockton on Tees . The Dawlish population

1586-519: The archipelago contains as Anseriformes Branta geese and their descendants, and the moa-nalos as mentioned above. The following taxa, although certainly new species, cannot be assigned even to subfamily; that Kauaʻi is the oldest of the large Hawaiian Islands, meaning the species may have been evolving in isolation for nearly 10  mya (since the Late Miocene ), does not help in determining their affinities: Similarly, Branta rhuax from

1647-586: The coat of arms and other iconography of the state's institutions. The Black Swan was the sole postage stamp design of Western Australia from 1854 to 1902. The Noongar People of the South-West of Australia call the black swan Kooldjak along the West and South-West coast, Gooldjak in the South East and it is sometimes referred to as maali in language schools. Anatidae The Anatidae are

1708-656: The common bulbul , breeding seasonality is weak at the population level, instead moult can show high seasonality with individuals probably under strong selection to match moult with peak environmental conditions. A 2023 paleontological analysis concluded that moulting probably evolved late in the evolutionary lineage of birds. In some countries, flocks of commercial layer hens are force-moulted to reinvigorate egg-laying. This usually involves complete withdrawal of their food and sometimes water for 7–14 days or up to 28 days under experimental conditions, which presumably reflect standard farming practice in some countries. This causes

1769-478: The epidermis (skin), pelage ( hair , feathers , fur , wool ), or other external layer. In some groups, other body parts may be shed, for example, the entire exoskeleton in arthropods , including the wings in some insects . In birds , moulting is the periodic replacement of feathers by shedding old feathers while producing new ones. Feathers are dead structures at maturity which are gradually abraded and need to be replaced. Adult birds moult at least once

1830-529: The family was introduced by the English zoologist William Elford Leach in a guide to the contents of the British Museum published in 1819. While the status of the Anatidae as a family is straightforward, and which species properly belong to it is little debated, the relationships of the different tribes and subfamilies within it are poorly understood. The listing in the box at right should be regarded as simply one of several possible ways of organising

1891-420: The mergansers , are primarily piscivorous , and have serrated bills to help them catch fish. In a number of species, the young include a high proportion of invertebrates in their diets, but become purely herbivorous as adults. The anatids are generally seasonal and monogamous breeders. The level of monogamy varies within the family; many of the smaller ducks only maintain the bond for a single season and find

Black swan - Misplaced Pages Continue

1952-450: The Anatidae and is now placed in its own family, Anseranatidae ). They are generally herbivorous and are monogamous breeders. A number of species undertake annual migrations . A few species have been domesticated for agriculture, and many others are hunted for food and recreation. Five species have become extinct since 1600, and many more are threatened with extinction . The ducks, geese, and swans are small- to large-sized birds with

2013-634: The Anatidae may be considered to consist of three subfamilies (ducks, geese, and swans, essentially) which contain the groups as presented here as tribes , with the swans separated as subfamily Cygninae , the goose subfamily Anserinae also containing the whistling ducks, and the Anatinae containing all other clades . For the living and recently extinct members of each genus, see the article List of Anatidae species . From subfossil bones found on Kauaʻi ( Hawaiian Islands ), two enigmatic waterfowl are known. The living and assignable prehistoric avifauna of

2074-474: The Big Island of Hawaiʻi , and a gigantic goose-like anatid from Oʻahu are known only from very incomplete, and in the former case much damaged, bone fragments. The former has been alleged to be a shelduck, but this was generally dismissed because of the damage to the material and biogeographic considerations. The long-legged Kauaʻi bird, however, hints at the possibility of a former tadornine presence on

2135-623: The ability to fly, and were vulnerable to human hunting pressure and introduced species . Other extinctions and declines are attributable to overhunting, habitat loss and modification, and hybridisation with introduced ducks (for example the introduced ruddy duck swamping the white-headed duck in Europe). Numerous governments and conservation and hunting organisations have made considerable progress in protecting ducks and duck populations through habitat protection and creation, laws and protection, and captive-breeding programmes. The name Anatidae for

2196-426: The activities of humans, and subfossil remains have shown that humans caused numerous extinctions in prehistory. Today, many more are considered threatened . Most of the historic and prehistoric extinctions were insular species, vulnerable due to small populations (often endemic to a single island), and island tameness . Evolving on islands that lacked predators, these species lost antipredator behaviours, as well as

2257-731: The archipelago. The fossil record of anatids is extensive, but many prehistoric genera cannot be unequivocally assigned to present-day subfamilies for the reasons given above. For prehistoric species of extant genera, see the respective genus accounts. Dendrocheninae – a more advanced relative of the whistling-ducks or an ancestral relative of stifftail ducks paralleling whistling-ducks; if not extinct possibly belong in Oxyurinae (including Malacorhynchus ) Anserinae Tadorninae Anatinae Oxyurinae Incertae sedis Putative or disputed prehistoric anatids are: The Middle Oligocene Limicorallus (from Chelkar-Teniz ( Kazakhstan )

2318-479: The back of the body (more so in the more aquatic species), and have a leathery feel with a scaly texture. Combined with their body shape, this can make some species awkward on land, but they are stronger walkers than other marine and water birds such as grebes or petrels . They typically have webbed feet , though a few species such as the Nene have secondarily lost their webbing. The bills are made of soft keratin with

2379-429: The biological family of water birds that includes ducks , geese , and swans . The family has a cosmopolitan distribution , occurring on all the world's continents except Antarctica. These birds are adapted for swimming , floating on the water surface, and, in some cases, diving in at least shallow water. The family contains around 174 species in 43 genera (the magpie goose is no longer considered to be part of

2440-433: The care of the nest. A typical clutch contains four to eight greenish-white eggs that are incubated for about 35–40 days. Incubation begins after the laying of the last egg, to synchronise the hatching of the chicks. Prior to the commencement of incubation the parent will sit over the eggs without actually warming them. Both sexes incubate the eggs, with the female incubating at night. The change over between incubation periods

2501-412: The dominant foods. The exact composition varies with water level; in flood situations where normal foods are out of reach black swans will feed on pasture plants on shore. The black swan feeds in a similar manner to other swans. When feeding in shallow water it will dip its head and neck under the water and it is able to keep its head flat against the bottom while keeping its body horizontal. In deeper water

Black swan - Misplaced Pages Continue

2562-520: The extent of occurrence. The current global population is estimated to be up to 500,000 individuals. No threat of extinction or significant decline in population has been identified with this numerous and widespread bird. Black swans were first seen by Europeans in 1697, when Willem de Vlamingh 's expedition explored the Swan River , Western Australia . Before the arrival of the Māori in New Zealand ,

2623-518: The female after she lays the eggs. Generally, black swans in the Southern hemisphere nest in the wetter winter months (February to September), occasionally in large colonies. A black swan nest is essentially a large heap or mound of reeds, grasses and weeds between 1 and 1.5 metres (3– 4 + 1 ⁄ 2 feet) 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

2684-537: The males being more brightly coloured than the females (although the situation is reversed in species such as the paradise shelduck ). The swans, geese, and whistling-ducks lack sexually dimorphic plumage. Anatids are vocal birds, producing a range of quacks, honks, squeaks, and trumpeting sounds, depending on species; the female often has a deeper voice than the male. Anatids are generally herbivorous as adults, feeding on various water-plants, although some species also eat fish, molluscs, or aquatic arthropods. One group,

2745-445: The many species within the Anatidae; see discussion in the next section. The systematics of the Anatidae are in a state of flux. Previously divided into six subfamilies, a study of anatomical characters by Livezey suggests the Anatidae are better treated in nine subfamilies. This classification was popular in the late 1980s to 1990s. But mtDNA sequence analyses indicate, for example, the dabbling and diving ducks do not belong in

2806-424: The morphology of successive instars . A new skin can replace structures, such as by providing new external lenses for eyes. The new exoskeleton is initially soft but hardens after the moulting of the old exoskeleton. The old exoskeleton is called an exuviae . While moulting, insects cannot breathe. In the crustacean Ovalipes catharus molting must occur before they mate. Most dogs moult twice each year, in

2867-446: The moult of severely damaged feathers. Determining the process birds go through during moult can be useful in understanding breeding, migration and foraging strategies. One non-invasive method of studying moult in birds is through using field photography. The evolutionary and ecological forces driving moult can also be investigated using intrinsic markers such as stable hydrogen isotope ( δ2H ) analysis. In some tropical birds, such as

2928-412: The non-avian dinosaurs . The long period of evolution and shifts from one kind of waterbird lifestyle to another have obscured many plesiomorphies , while apparent apomorphies are quite often the result of parallel evolution , for example the "non-diving duck" type displayed by such unrelated genera as Dendrocygna , Amazonetta , and Cairina . For the fossil record, see below. Alternatively,

2989-457: The same subfamily. While shortcomings certainly occur in Livezey's analysis, mtDNA is an unreliable source for phylogenetic information in many waterfowl (especially dabbling ducks) due to their ability to produce fertile hybrids , in rare cases possibly even beyond the level of genus (see for example the " Barbary duck "). Because the sample size of many molecular studies available to date

3050-525: The shore. The black swan was once thought to be sedentary, but 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 migration from 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

3111-435: The skin, with some species moulting in pieces and others in one piece. In arthropods , such as insects , arachnids and crustaceans , moulting is the shedding of the exoskeleton , which is often called its shell , typically to let the organism grow. This process is called ecdysis . Most Arthropoda with soft, flexible skins also undergo ecdysis. Ecdysis permits metamorphosis , the sometimes radical difference between

SECTION 50

#1732771996792

3172-413: The snake rubbing its head against a hard object, such as a rock (or between two rocks) or piece of wood, causing the already stretched skin to split. At this point, the snake continues to rub its skin on objects, causing the end nearest the head to peel back on itself, until the snake is able to crawl out of its skin, effectively turning the moulted skin inside-out. This is similar to how one might remove

3233-461: The swan up-ends to reach lower. Black swans are also able to filter feed at the water's surface. Like other swans, the black swan is largely monogamous , pairing for life (about 6% divorce rate). Recent studies have shown that around a third of all broods exhibit extra-pair paternity . An estimated one-quarter of all pairings are homosexual , mostly between males. They steal nests, or form temporary threesomes with females to obtain eggs, driving away

3294-464: The water only. They construct simple nests from whatever material is close at hand, often lining them with a layer of down plucked from the mother's breast. In most species, only the female incubates the eggs. The young are precocial , and are able to feed themselves from birth. One aberrant species, the black-headed duck , is an obligate brood parasite , laying its eggs in the nests of gulls and coots . While this species never raises its own young,

3355-509: 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. 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. The black swan

3416-627: The wild. The black swan is common in the wetlands of southwestern and eastern Australia and adjacent coastal islands. In the south west its range encompasses an area between North West Cape , Cape Leeuwin and Eucla ; while in the east it covers a large region bounded by the Atherton Tableland , the Eyre Peninsula and Tasmania , with the Murray Darling Basin supporting very large populations of black swans. It

3477-433: The young have been raised, the adult birds will abandon the nests and their eggs or cygnets and return to wetter areas. The black swan, like many other water fowl, loses all its flight feathers at once when it moults after breeding and is unable to fly for about a month. During this time it will usually settle on large, open waters for safety. The species has a large range, with figures between 1 and 10 million km given as

3538-650: The “Versailles on the Lake” apartment community. The "Lake Forest Keys” community bought the original swans about eight to ten years ago and since then there have been many births and gaggles from the original couple" according to a report in the Orange County Register . Black swans formerly resided in the vicinity of Lake Junaluska , a large lake in Waynesville, North Carolina . Black swans can also be found in mainland China. In 2018, one group of swans

3599-669: Was introduced to the Shenzhen University campus on an artificial lake in Guangdong Province . The black swan is almost exclusively herbivorous, and while there is some regional and seasonal variation, the diet is generally dominated by aquatic and marshland plants. In New South Wales the leaf of reedmace (genus Typha ) is the most important food of birds in wetlands, followed by submerged algae and aquatic plants such as Vallisneria . In Queensland, aquatic plants such as Potamogeton , stoneworts, and algae are

3660-509: Was introduced to various countries as an ornamental bird in the 1800s, but has managed to escape and form stable populations. Described scientifically by English naturalist John Latham in 1790, the black swan was formerly placed into a monotypic genus, Chenopis . Black swans can be found singly, or in loose companies numbering into the hundreds or even thousands. It is a popular bird in zoological gardens and bird collections, and escapees are sometimes seen outside their natural range. This bird

3721-446: Was sometimes considered an anserine. It is now recognized as a primitive cormorant . The middle Eocene Eonessa was formerly thought to belong to Anatidae, however reexamination of the holotype in 1978 resulted in the genus being placed as Aves incertae sedis . Moult In biology , moulting ( British English ), or molting ( American English ), also known as sloughing , shedding , or in many invertebrates , ecdysis ,

SECTION 60

#1732771996792
#791208