The mute swan (Cygnus olor) is a species of swan and a member of the waterfowl family Anatidae. It is native to much of Eurosiberia, and (as a rare winter visitor) the far north of Africa. It is an introduced species in North America, home to the largest populations outside of its native range, with additional smaller introductions in Australasia and southern Africa. The name 'mute' derives from it being less vocal than other swan species. Measuring 125 to 160 cm (49 to 63 in) in length, this large swan is wholly white in plumage with an orange beak bordered with black. It is recognizable by its pronounced knob atop the beak, which is larger in males.
Mute swans nest on large mounds that they build with waterside vegetation in shallow water on islands in the middle or at the very edge of a lake. They are monogamous and often reuse the same nest each year, restoring or rebuilding it as needed. Male and female swans share the care of the nest, and once the cygnets are fledged it is not uncommon to see whole families looking for food. They feed on a wide range of vegetation, both submerged aquatic plants which they reach with their long necks, and by grazing on land. The food commonly includes agricultural crop plants such as oilseed rape and wheat, and feeding flocks in the winter may cause significant crop damage, often as much through trampling with their large webbed feet, as through direct consumption. It will also feed on small proportions of aquatic insects, fish and frogs.
The mute swan is found naturally mainly in temperate areas of Europe then across the Palearctic as far east as Primorsky Krai, near Sidemi.
It is partially migratory throughout northern latitudes in Europe and Asia, as far south as North Africa and the Mediterranean. It is known and recorded to have nested in Iceland and is a vagrant to that area as well as to Bermuda, according to the UN Environment Programme chart of international status chart of bird species, which places it in 70 countries, breeding in 49 countries, and vagrant in 16 countries. While most of the current population in Japan is introduced, mute swans are depicted on scrolls more than 1,000 years old, and wild birds from the mainland Asian population still occur rarely in winter. Natural migrants to Japan usually occur along with whooper and sometimes Bewick's swans.
The mute swan is protected in most of its range, but this has not prevented illegal hunting and poaching. It is often kept in captivity outside its natural range, as a decoration for parks and ponds, and escapes have happened. The descendants of such birds have become naturalised in the eastern United States and Great Lakes, much as the Canada goose has done in Europe.
