Definition that contains tundra swan
- cygnus columbianus bewickii Eurasian subspecies of tundra swan; smaller than the whooper
- cygnus columbianus columbianus North American subspecies of tundra swan having a soft whistling note
- whistling swan North American subspecies of tundra swan having a soft whistling note
- bewick's swan Eurasian subspecies of tundra swan; smaller than the whooper