Mute Swan

Cygnus olor

A Mute Swan
Photo courtesy of Ray Desjardins of Feather Lake

The Mute Swan is the common swan of parks and estates. It is native across Europe and Asia and has been introduced in many other areas, including parts of North America. In England, all Mute Swans were considered the property of the Crown until the 18th century. Actually, they're still considered the property of the crown, but you're no longer hung for killing one.

Mutes can be distinguished from other white swans by the triangular naked black area in front of the eyes and the black knob above the deep orange bill. The fleshy knob on the head of these swans is more prominent on the males. An adult male (the cob) can weigh 25 lb (10.5 kg) and an adult female (the pen) 21 lb (9 kg). Usually juveniles are pale gray with gray legs, which become black in adulthood, but there is a European population, known as leucistic or Polish Mutes, in which the cygnets are white with pinkish legs. Both forms may occur in a single clutch as the coloring is a result of a sex-linked recessive gene.

Although quieter than some other species, it is by no means mute. Among its vocalizations are a loud snort when annoyed, shrill trumpeting when really angry, and an aggressive hiss. They are the most territorial of the swans and two males will fight viciously if one intrudes on another's turf. Nesting territories can cover 4-10 acres and are reoccupied by the same pair year after year. In breeding season they can be quite aggressive to people approaching the nesting area, and their large size makes them somewhat dangerous in this situation, so it is best to avoid them at that time.

The nest consists of a large pile of vegetation, usually by the shore of a body of water. A nest may be up to 4 meters (15 ft) in diameter. The chalky greenish-blue eggs are laid at intervals of 48 hours and a clutch averages 5-6 eggs. Incubation can last 35-41 days, with the pen doing most of the sitting. The cygnets can't fly til 120-150 days of age.

Some Mute Swans have been recorded to live past 30 years of age.