Mute Swan

The Mute Swan is one of the largest flying birds in Europe and Asia, familiar for its graceful S-curved neck posture and orange bill with a black basal knob. Introduced populations are also well established in North America and elsewhere.

Adult Mute Swan feathers are pure white and notably large, with primaries and secondaries stiff and strongly built to support the bird's considerable weight in flight; the wings produce an audible throbbing or singing sound in flight due to the shape and vibration of these flight feathers, unlike the largely silent flight of geese. Body feathers are dense, curved, and pure white, without any of the grey or buff tones seen in immature birds. Cygnet down and early feathers are grey-brown, gradually replaced with white plumage over the first year.

Sexes look identical in plumage, though males (cobs) average larger with a bigger bill knob. Juveniles (cygnets) are grey-brown, molting gradually into white first-winter plumage with grey-brown remnants persisting into the second year in some birds. Adults undergo a complete molt in late summer, becoming flightless for several weeks.

Mute Swans favor lakes, slow rivers, and estuaries with abundant aquatic vegetation, and are equally at home on rural waters and urban park ponds. Native to much of Europe and central Asia, they have been introduced and become established in North America, Australia, and elsewhere, generally remaining resident or making only short-distance movements.

Mute Swans graze on aquatic plants both by dabbling and by upending in shallow water, and can be highly territorial and aggressive in defense of nests and cygnets, hissing loudly at intruders. Despite the name, they are not silent, producing grunts, hisses, and snorting calls, though they lack the loud trumpeting calls of some other swan species. Nests are large mounds of vegetation built at the water's edge. IUCN status is Least Concern.