7-1-2016 HONG KONG - COSCOROBA SWAN (Coscoroba coscoroba)

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.

Male coscoroba swans weigh 3.8–5.4 kg (8.4–11.9 lb) and females weigh 3.2–4.5 kg (7.1–9.9 lb). The length is from 87.5 to 115 cm (34.4 to 45.3 in) and the wingspan is 155 to 160 cm (61 to 63 in). 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.