The Black-necked Swan (Cygnus melancoryphus) is the largest waterfowl native to South America.The body plumage is white with a black neck, head and greyish bill.
jBlack-necked swans (Cygnus melancoryphus) are a bird species belonging to the anseriforme order and to the Anatidae family native to South America. They are easily recognisable thanks to their head and long black neck and their completely white body.
Plumage is the same in males and females, but males are slightly bigger than females. Adults’ neck and head are completely black, but there is a white line going from their beak to the centre of their eyes and finishing at the back of their head. All the rest is white. Their facial skin and the caruncle on their beak are red. Their legs are pink.
They shed yearly, at the end of the breeding season and before migrating to the North. They can live 7 years in captivity. Some specimens got to live up to 20 years.
They can be found in lakes and lagoons and along the seashores. They can be easily seen in the marshland or in water reservoirs where they can find waterweed and plankton. We could say this bird is very aquatic if we compare it to other kind of swans. They can live at the sea level or at up to 4000 feet high.
Their geographical distribution goes from southern Brazil to Tierra del Fuego. During austral springs and summers they breed in Chile, Paraguay, Argentina, Uruguay and the Falklands. During this period, some specimens reach the Beagle Channel ― in southern Ilha Grande, Tierra de Fuego ― and Juan-Fernández islands (Chile). They migrate to the North in winter. Then, they are easily seen in Paraguay, Rio Grande do Sul, Santa Catarina and the Brazilian state of Paraná.
They eat waterweed, other water plants and insects. They put their beak into the water and filter it. They open it and close it slightly so the water can flow in the inside. They also put their head and their neck into the water while their body stays outside.
They are able to fly during a lot of time. Starting the journey and landing on water is difficult for them. They make sounds similar to whistles when they fly or swim.
Swans are monogamous. Once they find a partner, they find it for good. If the couple breaks because of the death of one of them, the living one will reject any other possible partner.
They make their nests of weeds next to lakes and lagoons. They lay from three to seven cream-colored eggs that are incubated by the female during 34-36 days. Males are always near to the nest in order to protect the laying and may attack ferociously those animals getting too close to the eggs or the chicks. They are able to breed in captivity.