Birds: Mute Swan

By far the most familiar of Ireland's three swan species, the Mute Swan is the only one that is with us year-round; the other two, namely the Whooper and Bewick's Swans, are strictly winter visitors.

By far the most familiar of Ireland's three swan species, the Mute Swan is the only one that is with us year-round; the other two, namely the Whooper and Bewick's Swans, are strictly winter visitors.  A frequent sight on lakes and rivers around the country, it is also a common resident of parks, ponds and canals in urban areas, and can become quite tame.

At 150cm in length, the Mute Swan is Ireland's largest bird, and indeed is one of the heaviest flying birds in the world.  It shares its snow-white plumage and extremely long, graceful neck with our other swans, but is easily distinguished by its orange, not yellow, beak with a prominent black bump, or “knob”, at the base. This bump is larger on males than on females.  Juvenile birds are much browner overall, and tend to have grey bills.

Mainly vegetarian, Mute Swans feed primarily on pondweed, algae and other aquatic plants, though they also frequently graze on grass and will, sometimes, eat water-dwelling insects and snails.  Their long necks enable them to feed in deeper water than any other non-diving Irish species.

It is true that this species is far less vocal than other swans, though it is not strictly mute: it makes a rasping hissing noise when agitated, and youngsters can make high-pitched whistling sounds.  Mute Swans also make a highly distinctive pulsating musical “whoosh” noise in flight, though this is not produced vocally. The sound is made by air passing over specially-shaped flight feathers, which appear to have evolved specifically for this purpose.