[order] ANSERIFORMES | [family] Anatidae | [latin] Cygnus melancoryphus | [authority] Molina, 1782 | [UK] Black-necked Swan | [FR] Cygne a cou noir | [DE] Schwarzhals-Schwan | [ES] Cisne Cuellinegro | [NL] Zwarthalszwaan
Swans, genus Cygnus, are birds of the family Anatidae, which also includes geese and ducks. Swans are grouped with the closely related geese in the subfamily Anserinae where they form the tribe Cygnini. Sometimes, they are considered a distinct subfamily, Cygninae. There are six to seven species of swan in the genus Cygnus; in addition there is another species known as the Coscoroba Swan, although this species is no longer considered related to the true swans. All evidence suggests that the genus Cygnus evolved in Europe or western Eurasia during the Miocene, spreading all over the Northern Hemisphere until the Pliocene. When the southern species branched off is not known. The Mute Swan apparently is closest to the Southern Hemisphere Cygnus (del Hoyo et al., eds, Handbook of the Birds of the World); its habits of carrying the neck curved (not straight) and the wings fluffed (not flush) as well as its bill color and knob indicate that its closest living relative is actually the Black Swan. Given the biogeography and appearance of the subgenus Olor it seems likely that these are of a more recent origin, as evidence shows by their modern ranges (which were mostly uninhabitable during the last ice age) and great similarity between the taxa.
Large solid white body with a long, velvety black neck and a white stripe across the eye. The bill is grey with a large, flesh-pink knob at the base. The legs and feet are also pink. Female is the same as the male, only slightly smaller.
Listen to the sound of Black-necked Swan
Copyright remark: Most sounds derived from xeno-canto
South America : Southern Cone. Southern South America including areas of Brazil, Bolivia and Patagonia. They are also found on the Falkland Islands.
This bird inhabits mostly costal areas, as well as inland lakes. Black-necked swans can be found in both marine and freshwater areas with an abundance of vegetation.
Black-necked swans mate for life, becoming very territorial and aggressive during nesting. These swans, which are normally very social, become very defensive and will pursue any intruder that ventures near their nest, attempting to bite or beat them with their wings. Black-necked swans are typically very quiet birds, but during their breeding season both sexes are extremely vocal. The male swan courts the female through a series of calls and head tilts. During breeding season, the red knob at the base of the beak of the male swan becomes dark scarlet and enlarged. The breeding season lasts from July to September with females laying four to six eggs at a time, up to three times a season. The female swan, known as a pen, is the only one who can sit on the eggs, while the male protects the nest and brings her food. After around 36 days the eggs hatch and the cygnets are dependent on their parents for their first year of life, fledging after a period of about 90 days. Black-necked swans are unique in that both of the parents carry their young on their back continuously for the first three weeks of life. This bird molts once a year, males and females at different times. The female swan becomes flightless soon after breeding, spending her time incubating the eggs. The males molt only after the female is finished. The swans do this at different times so that one of the parents is always ready to defend their young.
They submerge their head and neck while feeding on choice aquatic vegetation. Their bills have serrated edges that filter out small food items from the water. Their rough tongue aids with the grasping and tearing of plants. Due to their long necks, they can feed on pond bottoms. Diet consits of Aquatic vegetation, including stone warts, pond weeds and algae, insects, small invertebrates and fish spawn
copyright: Anna Motis
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size may be moderately small to large, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The black-necked swan has a fairly stable population and is common in many areas of its range. They are hunted for their down which is used for clothing and cold weather bedding. Although the demand is decreasing, these swans are also hunted for food. Habitat loss, including draining of many marsh and wetland areas, continues to be the largest threat to this species.
They tend to reside in large flocks (up to 5,000 birds) during the non-breeding season, but when breeding they split into highly territorial pairs. During non-breeding months, many of these swans can be found in Uruguay and southern Brazil. The breeding season initiates a migration south to areas such as Patagonia and the Falkland Islands.