Coscoroba swan
The coscoroba swan ("Coscoroba coscoroba") is a species of waterfowl endemic to southern South America. It is the smallest of the birds called “swans”, but still a large species of waterfowl. It belongs to the subfamily Anserinae in the family of ducks, swans, and geese, Anatidae. It is placed in the monotypic genus "Coscoroba". The coscoroba swan is traditionally considered as an early branch from the common ancestor leading to true geese and swans, and recent genetic studies have associated a phylogenetic relationship between this species and the Cape Barren goose ("Cereopsis novaehollandiae") as sister groups. Description. Male  coscoroba swans weigh and females weigh . The length is from and the wingspan is . They have 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 lacks the patch of bare skin between the eyes and beak typical of swans . They look like a very small swan in body and look like a goose in the head. Eggs 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 Distribution and habitat. 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, Bolivia, Uruguay and the southeast tip of Brazil. Its habitat is well-vegetated swamps and lagoons. Its population  is estimated at 10,000–25,000 birds. It also has an ancient route to the Pantanal of Brazil and has been seen in large flocks in the Nhecolandia and Rio Negro regions. Coscoroba swans have escaped or been deliberately released in to Florida, USA, but there is no evidence that the population is breeding and may only persist due to continuing releases or escapes. Behavior. The coscoroba swan feeds on various plant matter, small aquatic insects, and small fish. The female incubates the eggs, while the male stands guard and aggressively helps to protect the fledglings against predators after hatching. Coscoroba swans  live to an age of approximately twenty years.