The Black-necked Swan (Cygnus melancoryphus) is the largest waterfowl native to South America.

Males are 115 to 140 cm (45 to 55 in) and weigh 4.5-6.7 kg (10-14.8 lbs); females are 100 to 124 cm (39 to 49 in) and weigh 3.5-4.4 kg (7.7–9.7 lbs).

[1] The wingspan ranges from 135 to 177 cm (53 to 70 in).

[2] The body plumage is white with a black neck, head and greyish bill. It has a red knob near the base of the bill and white stripe behind eye.