Mute Swan

Cygnus olor

Mute Swan - Adult

Stefan Berndtsson/Flickr/CC by 2.0

The mute swan is commonly associated with romance because of its stark white beauty, graceful swimming, and the fact that it mates for life. Yet there are many things most people don’t know about this swan, including that it is not native to North America and it can be one of the most aggressive waterfowl.

Common Name: Mute Swan, Cygnet (juvenile)
Scientific Name: Cygnus olor
Scientific Family: Anatidae

Appearance and Identification

The mute swan is very distinctive with its long neck and white plumage, but several other swans and geese can look very similar. Knowing the field marks to check on this bird can help birders feel confident with its identification.

  • Bill: Large and straight, spatulate shape, orange with black basal knob at base
  • Size: 56-60 inches long with 90-inch wingspan, heavy body, very long neck
  • Colors: White, black, orange, brown, gray
  • Markings: Genders are identical with all white plumage, though the long neck, which is often held in an S-curve, may show a buff or brown wash from dirt or plant debris. The orange bill has a black edge and tip. The bare-skinned lores are black, as are the eyes, legs, and webbed feet. Juveniles look similar to adults, but have a brownish wash on the plumage, especially on the head, neck, and wings. As they mature, their plumage may appear more mottled. Juvenile birds have a gray-black bill.

Foods, Diet, and Foraging

These swans are herbivorous and eat only aquatic plants and grain. They may skim the surface of the water to collect floating morsels, or can tip up to stretch their necks under the water and search out food in mud or sand, or to nibble at algae. They will also forage on land, grazing as they walk.

Habitat and Migration

Mute swans are native to Europe and Asia, and they have been heavily domesticated in Europe and introduced as domestic waterfowl for estates, parks, and gardens throughout North America. Released birds have formed feral populations around the Great Lakes as well as the North Atlantic coast from Massachusetts south to Virginia. The occasional released bird or pair may be found nearly anywhere, typically near large open areas of water including lakes, large ponds, sheltered bays, bogs, and marshes. They can be found in both freshwater and brackish habitats. Mute swans in Europe may migrate to the Middle East in winter, but North American birds typically do not migrate.

Vocalizations

Despite their name, these birds are not really mute. Adult birds are usually silent but will use hisses, barks, and rattling snorts when threatened, and juvenile birds have additional whining calls to attract attention.

Behavior

Mute swans are graceful on the water but can appear awkward and ungainly in flight and on land. These are very aggressive birds when defending their territory and nesting sites, and they will charge and attack large birds and mammals, including humans, that they perceive to be a threat. When swimming, they may hold their wings over their backs in a puffed up position to advertise their strength, and the neck may be held in a strong S-curve as an aggressive posture. In flight, mute swans hold their necks out straight and the legs and feet extend to the end of the tail.

Reproduction

Mute swans are monogamous and believed to mate for life. The pair will work together to create a mound of plant material in shallow water for the nest. Both parents incubate the 2-10 gray or blue-green stained eggs for 36-38 days, and both parents help watch over the precocial young until the birds’ first flight at 100-150 days. Young birds learn to swim and forage within a day of hatching. Mated pairs raise one brood per year.

Attracting Mute Swans

These are not backyard birds but they can be a common site in parks and gardens that include large water features. Mute swans will approach picnickers and visitors in hopes of handouts, but it is not wise to feed them, since bread is not healthy for swans, ducks, or geese. Furthermore, these large birds can become aggressive quickly and are best left alone.

Conservation

Mute swans are not considered threatened or endangered, and in fact may be culled or closely monitored in some areas to be sure they do not become dangerously invasive. They are subject to several threats common to many waterfowl, however, including toxic pollution of waterways, fishing line tangles, and lead poisoning from sunken pellets or fishing gear. Mute swans are occasionally shot as well, often because they may be confused with other swan species that can be legally hunted.

Similar Birds

  • Tundra Swan (Cygnus columbianus)
  • Trumpeter Swan (Cygnus buccinator)
  • Snow Goose (Anser caerulescens)