The Coscoroba Swan (Coscoroba coscoroba) is a species of waterfowl inhabiting southern South America. It is the smallest of the birds called "swans", but still a large species of waterfowl, averaging 4.2 kg (9.3 lbs), 1 m (3.3 ft) long and 1.57 m (5.2 ft) across the wings. It belongs to the subfamily Anserinae in the family of ducks, swans, and geese, Anatidae. It is placed in the monotypic genus Coscoroba.
Male Coscoroba Swans weigh 3.8–5.4 kg (8.4–12 lb) and females weigh 3.2–4.5 kg (7.1–9.9 lb). Length is from 87.5 to 115 cm (34.4 to 45 in) and wingspan is 155 to 160 cm (61 to 63 in). has white plumage except for black tips to the outer six primary feathers, although this black is often barely visible on the closed wing. In flight, the black wing tips are conspicuous. The bird has a red beak, legs and feet. They look somewhat more like geese than swans. The female looks almost identical to the male. The cygnet is a patchy color, with brown and gray hues. The Coscoroba Swan is also lacking the black mask that other swans have where their lores are between the eyes and beak. They look like a very small swan in body and look like a goose in the head.Eggs have a measure 89 X 61 mm, with averages of 82 to 94 53 to 67 mm, with an average weight of 170 grams and range from 129 to 203 grams
The Coscoroba Swan breeds in South America from southern Chile and central Argentina south to Tierra del Fuego and the Falkland Islands. In winter it flies north to central Chile, northern Argentina, Uruguay and the south east tip of Brazil. Its habitat is well-vegetated swamps and lagoons. Its population is estimated as 10,000–25,000 birds.
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