Whooper swans require large areas of water to live in, especially when they are still growing because their body weight cannot be supported by their legs for extended periods.

The whooper swan spends much of its time swimming, straining the water for food, or eating plants that grow on the bottom.

Whooper swans can migrate hundreds or even thousands of miles to their wintering sites in southern Europe and eastern Asia.

Whooper swans pair for life, and their cygnets stay with them all winter; they are sometimes joined by offspring from previous years.

[10] Whooper swans that signaled with these movements in large groups were found to be able to convince their flock to follow them 61% of the time.

Observational evidence indicates that a swan whose mate is paying attention to and participates in its partner's signals will be more likely to follow through with the flight.

[10] They are very noisy; the calls are strident, similar to those of Bewick's swan but more resonant and lower-pitched on average: kloo-kloo-kloo in groups of three or four.

[citation needed] The global spread of H5N1 reached the UK in April 2006 in the form of a dead whooper swan found in Scotland.