Swans are the largest of the waterfowl and, some believe, the most beautiful. Males are called cobs, females are pens, and the young are cygnets.

There are nine species of swans. The Whooper, Trumpeter, Tundra, Mute, Bewick's, and Jankowski's live in the northern hemisphere; the Black-necked, Black, and Coscoroba live in the southern.

The most commonly seen member of the group is the Mute Swan. Its curving neck that has the most vertebra (23) of any bird.