Trumpeter swans in the Madison River in Yellowstone National Park, WY in the winter. The Trumpeter Swan (Cygnus buccinator) is the heaviest bird native to North America.
The Mute Swan (Cygnus olor) is a species of swan, and thus a member of the duck, goose and swan family Anatidae. It is native to much of Europe and Asia, and (as a rare winter visitor) the far north of Africa. It is also an introduced species in North America, Australasia and southern Africa.