Parent: Anatidae (Ducks)

└─ Cygnus (Swans)

└─── Cygnus atratus (Black swan)

└─── Cygnus buccinator (Trumpeter swan)

└─── Cygnus columbianus (Tundra swan)

└─── Cygnus cygnus (Whooper swan)

└─── Cygnus melancoryphus (Black-necked swan)

└─── Cygnus olor (Mute swan)