The Whooper Swan (Cygnus cygnus) is a species of bird (Aves) in the family Anatidae (Ducks, Geese, and Waterfowl) and order Anseriformes (Ducks).
Cygnus atratus
Cygnus melancoryphus
Cygnus olor
Cygnus buccinator
Cygnus columbianus
Cygnus cygnus