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40-496: (Redirected from Lake Alexandrina ) Alexandrina may refer to: Lakes [ edit ] Lake Alexandrina (New Zealand) Lake Alexandrina (South Australia) Other uses [ edit ] Bibliotheca Alexandrina , a library and cultural centre in Alexandria, Egypt Alexandrina (name) , a feminine name Alexandrina Council , a local government area covering land on

80-479: 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

120-425: 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

160-582: A length of 7.2 kilometres (4.5 mi). Its shores are flat. The maximum water depth in the lake is reported to be 27 metres (89 ft). The lake catchment has landscape that provides for plentiful wildlife but also has extensive cultivation which brings in a lot of nutrients, enriching the lake's with phosphorus . The lake's annual balance is contributed by surface streams: 5.72 million m (27%), overland flows: 1.11 million m (5%), ground water sources: 10.1 million m (48%) and precipitation: 4.11 million m (20%). The storage in

200-485: 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

240-597: 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

280-495: 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 was introduced to various countries as an ornamental bird in

320-471: A valid Crown Protected Area . The threats to the lake waters that were identified in the 1980s were the regular occurrence of algal ( Anabaena ) blooms, which were a result of high nutrient levels of phosphorus, survival of wildlife, and recreational fishery. It was assessed by measurements that nearly 50% of the phosphorus was contributed by groundwater, with 32% from surface water inflows and only 3–9% from hut settlements. This resulted in poor quality of

360-470: 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

400-739: Is different from Wikidata All article disambiguation pages All disambiguation pages Lake Alexandrina (New Zealand) Categorised as a Canterbury High County lake in the Mackenzie Basin , it lies a short distance from Lake Tekapo while also being connected to it. Lake Alexandrina is approached from the State Highway 8 via the Godley Peaks Road. The lake, located at an altitude of 732 metres (2,402 ft), covers an area of 640 hectares (1,600 acres) with width of 0.9 kilometres (0.56 mi) and extending to

440-572: 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

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480-636: 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

520-728: 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

560-402: 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

600-544: 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

640-732: 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

680-450: 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

720-560: The Mackenzie District Council under a District Plan 1997, under the title "Lake Side Protection Area around Lake Alexandrina". Progressively implemented since 1985, the redeeming feature of these actions is that the heavy algal blooms of the 1980s are now infrequent and limited to a frequency occurrence of once in three years. In 1881, 10,000 trout were brought to Mackenzie country and released into Lake Alexandrina, as well as some other lakes, creeks and streams. After

760-434: 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

800-413: 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

840-521: 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 ,

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880-523: 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

920-616: The first 50 metres of the outlet stream, and urged holidaymakers to keep their distance, to avoid disturbing the birds. The breeding of the Elodea canadensis species has been inhibited at Lake Alexandrina because of the steep slopes on the east and west sides of the lake, as well as turbulence caused by high winds of 10–14 m/s. The lake has plentiful stocks of brown trout, rainbow trout and salmon, which are well known to fishing enthusiasts. The trout are not found in abundance because of overfishing and inadequate spawning duration. However,

960-409: The fish do grow to a large size, especially the trout, each weighing as much as 2.5 kilograms (5.5 lb) on an average. Some of prize catch could be of 4.5 kilograms (9.9 lb) weight for rainbows and 6.3 kilograms (14 lb) for brown variety trout (which generally are found along the shores of the lake where flies and insects abound). Lake Alexandrina is one of New Zealand's Scenic Reserves,

1000-578: The lake catchment, underground sources, grazing on the periphery of the lake, human habitations around the lake, aerial spray and stocking in the trout-spawning streams. The lake catchment is biologically rich, with 45 species of birds, which include the Australasian crested grebe , shoveler and scaup . The Australian shoveller is a common bird seen in the lake area, as well as black swans and ducks . Six species of waterbirds have been recorded in total. Paradise shelducks flock here during

1040-479: The lake lasts four years. The lake has been classified as mesotrophic type. Chlorophyll levels of 0.4–3.8 mg/1 have recorded during observations carried out between November 1978 and March 1979. The total phosphorus at 1 m depth was 0.009–0.015 mg/L as measured in March 1979. The reasons attributed to high nutrient content and consequent high degree of phosphorus levels are due to nutrients entering from

1080-465: The lake waters and subsequently, measures to check the phosphorus content in the lake received priority attention of the Government of New Zealand . In order to take adequate remedial measures to check the inflow of nutrients into the lake, which had raised the phosphorus content in the lake waters to unacceptable levels, in 1984, the "Lake Alexandrina Steering Committee" was set up which identified

1120-436: The lake; restrictions on fertiliser use for agriculture; access to streams for spawning activities and to establish a "deer fence" on the northern end of the wetland; stop all activities related to cultivation on the shores of the lake; stop building of the hut settlements around the lake; install individual household effluent storage or septic tanks; and diversion of sewage outside the catchment. These measures were implemented by

1160-515: The problem areas causing deterioration of water quality as due to phosphorus as also from the hut settlements at the outlet and south end, and from agricultural sources. The Taranaki Catchment Commission and the Waitaki Catchment Commission , who examined this issue in 1987, also concluded that though the inflows exceeded outflows, but they did not contribute to the storage due to the high sediment contribution which vitiated

1200-526: 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

1240-466: The storage. Consequent to their study of recorded high total phosphorus levels causing the blooms and creating threats to wildlife and the recreational fisheries, the Commission prescribed interim management guidelines such as: Total cessation of aerial top dressing within 500 metres (1,600 ft) of the eastern shore and 800 metres (2,600 ft) of the western shore and around the flow sources into

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1280-556: The summer season, seeking sanctuary when they become flightless during their moult . Freshwater snails Potamopyrgus antipodarum have also been analysed in the basin area. For example, studies in 1994 found that there are more male snails in the lake's shallow water than females, and that snails are sicker in shallow water than deep water. In December 2021, the Department of Conservation reported that over 60 breeding pairs of Australasian crested grebes had established nests in

1320-466: 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

1360-399: The trout grew and prospered, fishing licenses were issued. Lake Alexandrina, now known for its attraction to fisherman, has a small number of fisherman's huts clustered at each end of the lake and near the outlet. Rowing boats are the only mode of transport on the lake as sail and motor boats are prohibited. Black swans The black swan ( Cygnus atratus ) is a large waterbird ,

1400-512: 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

1440-634: The west side of Lake Alexandrina in South Australia See also [ edit ] Alexandrine (disambiguation) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Alexandrina . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Alexandrina&oldid=1185994217 " Category : Disambiguation pages Hidden categories: Short description

1480-630: 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

1520-436: 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

1560-655: 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

1600-669: 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

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