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#431568

22-597: In 2004 and 2005 thousands of black-necked swans in the Carlos Anwandter Nature Sanctuary in Chile died or migrated away following major contamination by a newly opened CELCO pulp mill located near the city of Mariquina and Cruces River which feeds the wetlands. By August 2005, the birds in the sanctuary had been "wiped out"; only four birds could be observed from a population formerly estimated at 5,000 birds. Autopsies on dead swans attributed

44-501: A document signed the tourism company's CELCO was exempted from all responsibility involving the contamination of Cruces River. CELCO also promised to pay $ 2 million monthly each of the coming three years to promote tourism. Also, a local resident group was formed named Accion por los Cisnes ("Action for the Swans"). This kept up a constant complaint to the government officials about the issue and looked for environmental reparation. In 2014

66-492: A pair. Males also give "a musical 'hooee-hoo-hoo'." Black-necked swans can contract avian influenza . In March 2023 influenza A virus subtype H5N1 was detected in black-necked swan populations in Carlos Anwandter Nature Sanctuary , Chile and Estación Tapia , Uruguay. As on May 30, 2023, three more black-necked swans were found dead due to influenza H5N1 in Lagoa da Mangueira , Taim Ecological Station , Brasil. This raises

88-410: A ship and end up being carried to the ship's destination. While many vagrant birds do not survive, if sufficient numbers wander to a new area they can establish new populations. Many isolated oceanic islands are home to species that are descended from landbirds blown out to sea, Hawaiian honeycreepers and Darwin's finches being prominent examples. Vagrancy in insects is recorded from many groups—it

110-465: A wingspan of 135 to 177 cm (53 to 70 in). Males weigh 4.6 to 8.7 kg (10 to 19 lb) and females 3.5 to 4.4 kg (7.7 to 9.7 lb). The sexes are alike. Adults' body plumage is white and the neck and head black; the latter usually has a white stripe behind the eye. They have a prominent red knob at the base of their bill. Juveniles are grayish rather than white and lack the knob until their third or fourth year. The black-necked swan

132-528: Is reverse migration , where the birds migrate in the opposite direction to that expected (say, flying north-west instead of south-east). The causes of this are unknown, but genetic mutation or other anomaly relating to the bird's magnetic sensibilities is suspected. Other birds are sent off course by storms, such as some North American birds blown across the Atlantic Ocean to Europe. Birds can also be blown out to sea, become physically exhausted, land on

154-511: Is almost entirely vegetarian. It feeds on aquatic plants like Chara , Potamogeton , Typha ; algae such as Aphantotece and Rhyzoclonium ; and presumably small numbers of aquatic invertebrates. In parts of Chile its principal food is Egeria densa . It forages mostly by immersing its head and neck and by surface feeding, but also upends to reach deeper. In times of drought it has been observed grazing in meadows and pastures. The black-necked swan's breeding season varies geographically. In

176-560: Is found in the southern tier of South America. It nests from Tierra del Fuego north to central Chile, Uruguay, and Rio Grande do Sul in extreme southern Brazil. It withdraws from the southern half of Argentina in winter and is then found as far north as Brazil's São Paulo state. It is a year-round resident of the Falkland Islands. Vagrants have been found on Juan Fernández Island , the South Orkney Islands ,

198-438: Is four to eight eggs. Males guard females during the 34- to 36-day incubation period. Captive nestlings fledged about 100 days after hatch. [REDACTED] The black-necked swan is mostly silent outside the breeding season. During that time, both sexes give a "soft, musical 'Whee-whee-whee' with the accent on the initial syllable", repeating it to challenge intruders. The call is also used to maintain contact between members of

220-551: Is particularly well-studied in butterflies and moths , and dragonflies . In mammals, vagrancy has been recorded for bats, pinniped seals, whales, manatees, belugas, cougars, and more. Vagrancy has been recorded for sea turtles , snakes (e.g. Pelamis platura ), crocodilians, and probably also occurs in lizards. It therefore seems to be a fairly widespread phenomenon in reptiles. Saltwater crocodiles are especially prone to vagrancy, with individuals occasionally being recorded in odd places including Fiji , Iwo Jima , and even

242-490: The Falkland Islands . The black-necked swan has occasionally been placed by itself in the genus Sthenelides . Its closest relatives are the black swan ( C. atratus ) and mute swan ( C. olor ). It is monotypic . The black-necked swan is the only member of its genus that breeds in the neotropics and is the largest waterfowl native to South America. Adults are 102 to 124 cm (40 to 49 in) long with

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264-701: The Sea of Japan . The term vagrant is also used of plants (e.g. Gleason and Cronquist, 1991), to refer to a plant that is growing far away from its species' usual range (especially north of its range) with the connotation of being a temporary population. In the context of lichens, a vagrant form or species occurs unattached to a substrate ("loose"), not necessarily outside its range. Another definition (de Lange & Molloy, 1995) defined vagrant species in New Zealand flora – although could also be applied for any given region. Their definition was, "taxa whose presence within

286-645: The South Shetland Islands , and the Antarctic Peninsula . The black-necked swan inhabits freshwater marshes and swamps, shallow lakes, brackish lagoons , and sheltered coastal sites. On the mainland of South America, it is often found near human habitation but shuns built-up areas in the Falklands. It is generally found at low elevations but non-breeding flocks can be found as high as 900 to 1,250 metres (3,000 to 4,100 ft) in

308-666: The Andes of southern Argentina. The wetlands created in Chile by the 1960 Valdivia earthquake , such as Carlos Anwandter Nature Sanctuary on the Cruces River , have become important population centers for the black-necked swan. The population in this sanctuary has fluctuated widely over the years, reaching a low of 214 in January 2008 and a peak of 22,419 in May 2020 before plumbing to 2,782 in May 2022. The black-necked swan's diet

330-853: The Northern Hemisphere, adult birds (possibly inexperienced younger adults) of many species are known to continue past their normal breeding range during their spring migration and end up in areas further north (such birds are termed spring overshoots ). In autumn, some young birds, instead of heading to their usual wintering grounds, take "incorrect" courses and migrate through areas which are not on their normal migration path. For example, Siberian passerines which normally winter in Southeast Asia are commonly found in Northwest Europe , e.g. Arctic warblers in Britain. This

352-505: The company to pledge to adopt cleaner technologies. The plant reopened two months later at limited production capacity. Even in 2006 the Latin American water tribunal recommended to close down the mill. In July 2007 CELCO agreed to pay $ 614 million Chilean pesos to Valdivian tourism companies to avoid legal actions for supposed losses of the tourism sector of Valdivia due to contamination of Carlos Anwandter Nature Sanctuary. In

374-461: The creation of a wetland research with community engagement. 39°33′57″S 72°54′00″W  /  39.5657°S 72.8999°W  / -39.5657; -72.8999 Black-necked swan The black-necked swan ( Cygnus melancoryphus ) is a species of waterfowl in the tribe Cygnini of the subfamily Anserinae . It is found in Argentina , Brazil , Chile , Uruguay , and

396-553: The deaths to high levels of iron and other metals polluting the water. The company had been dumping dioxins and heavy metals into the river illegally from a wastetube that had not been approved by the authorities. The plant was closed in 2005 after the company's lawyers reportedly produced a misleading environmental study regarding pollution on the Cruces River. The scandal prompted Celco's chief executive to resign in June 2005 and

418-425: The far south of its range, it breeds from July to November but ends as early as September in the northern parts. In the Falklands, it breeds between August and November. The exact timing of breeding appears dependent on rainfall. The species is believed to form long-term pair bonds. Its nest is a mound of vegetation constructed by both members of a pair on a small islet or partially floating in a reedbed. The clutch size

440-590: The population is estimated at 50,000. Vagrancy (biology) Vagrancy is a phenomenon in biology whereby an individual animal (usually a bird ) appears well outside its normal range ; they are known as vagrants . The term accidental is sometimes also used. There are a number of poorly understood factors which might cause an animal to become a vagrant, including internal causes such as navigatory errors (endogenous vagrancy) and external causes such as severe weather (exogenous vagrancy). Vagrancy events may lead to colonisation and eventually to speciation. In

462-427: The state of defense council filed against CELCO in a lawsuit. The Civil Court of Valdivia ordered CELCO a series of measures to repair and mitigate the damage to the wetland. The first was to conduct a biological and chemical study about the actual situation. They were also to create an artificial wetland upon the river from where the dumping was made. Then there was to be five years of environmental impact monitoring, and

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484-552: The total at that station to 63. The IUCN has assessed the black-necked swan as being of Least Concern. It has a very large range, and though its population size is not known, it is believed to be stable. No immediate threats have been identified. It is widespread and generally common. Large-scale hunting in the 18th and 19th centuries extirpated it from much of Chile but it has recolonized those areas. Some egg collecting and hunting still occur, however. The species occurs in several protected areas in mainland Argentina, in which country

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