Swan

Swans are large water birds of the Anatidae family, which also includes ducks and geese. Sometimes swans are lumped with geese in the subfamily Anserinae.

Swans mate for life; the number of eggs in each clutch varies both within and among swan species.

Young swans are known as cygnets, from the Latin word for swan, cygnus.

Most species of swan are white, but Australia is home to a species known as the Black Swan (Cygnus atratus), which is black with a red beak and white patches under its wings. The black swan is the official state emblem of Western Australia.

The following are examples:

Genus Cygnus

• Mute Swan, Cygnus olor, is a common Eurasian species, often semi-domesticated; descendants of domestic flocks have been naturalized in the eastern United States.

Mute Swans

• Whooper Swan[?], Cygnus cygnus migrates from Iceland and Arctic Europe to western Europe in winter.
• Tundra Swan, Cygnus columbianus is a relatively small swan which has two major subspecies
  • Bewick's Swan, Cygnus columbianus bewickii is the Eurasian form which migrates from Arctic Russia to western Europe in winter. The reserves of the Royal Society for the Protection of Birds and of the Wildfowl and Wetlands Trust in Britain are important for Bewick's and Whooper Swans.
  • Whistling Swan, Cygnus columbianus columbianus is the North American race, which is sometimes considered a separate species from Bewick's swan.
• Trumpeter Swan[?], Cygnus buccinator is a North American species which was hunted almost to extinction but has since recovered: it is perhaps the heaviest flying animal at 17 kilograms (38 pounds).
• Black Swan, Cygnus atratus of Australia
• Black-necked Swan, Cygnus melanocoryphus of South America, formerly Sthenelides melanocorypha.

Genus Coscoroba

• Coscoroba Swan[?], Coscoroba coscoroba, also of South America

The Anseriformes and rails are ancestral to neognathous birds, and should follow ratites and tinamous in bird classification systems. See the chart below

For further taxonomic comments, see also Sibley-Ahlquist taxonomy.