Mute swans have keen vision and hearing. Mute swans are usually silent, as the name suggests. Adults sometimes snort and make hissing noises or puppy-like barking notes or whistles, though the sounds are not far-reaching due to their straight trachea. Also, the sound of the wings during flight, which has been described as a musical throbbing or humming, is very audible. They also use visual displays as a form of communication, such as postures. For example, in an aggressive posture, males often arch their secondary wing feathers over the back.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
The successful introduction and consequent expansion of mute swans into North America has begun to pose significant concerns to native wildlife. Common loons (threatened in Michigan) and recently re-introduced trumpeter swans are two species of primary concern. The North American population of mute swans has been increasing steadily since its introduction. These birds are aggressive, and have been known to drive off such stubborn and similarly sized species as Canada geese and trumpeter swans. Wildlife managers seek to control non-native mute swans in areas where native wildlife is being threatened. (Granlund, McPeek, and Adams, 1994)
There was a high incidence of lead poisoning in the mute swans of Great Britain, caused by the swans' ingestion of discarded lead shot that became entangled in aquatic vegetation. Since this problem was discovered, it is no longer a major threat to mute swan populations in Britain. ( http://www.airtime.co.uk/users/cygnus/muteswan.htm)
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Swans may attack people who approach their nests too closely. There are records of them knocking boaters off of jet skis. An adult swan can seriously injure children.
In addition, mute swans are thought to pose a threat to native wildlife as a result of competition for food, territories, and nesting areas.
Negative Impacts: injures humans
Mute swans were domesticated for food in Britain. Markings on their feet indicated ownership. Eventual domestication saved the bird from becoming hunted to extinction there. Feathers were also used as quills for writing, the leathery web used for purses, and the wing bones for making whistles. ( http://www.airtime.co.uk.users/cygnus/muteswan/htm)
Positive Impacts: food ; body parts are source of valuable material
Mute swans impact aquatic vegetation communities through their grazing.
The diet of mute swans consists of aquatic vegetation, and small proportions of aquatic insects, fish, and frogs. Mute swans do not dive, instead they plunge their head and long neck below the water's surface. Swans feed in deeper waters than ducks and other waterfowl that share their habitat and thus do not compete with them directly for food. Rather, food is made more readily available to other birds by swans because parts of the plants they consume float to the surface while the swans are feeding. However, mute swans compete with other swans for food because they feed in similar ways. (Reilly, 1968; Terres, 1980; http://aztec.inre.asu.edu/phxzoo/swanmute.html)
Animal Foods: insects; mollusks; aquatic or marine worms
Plant Foods: leaves; roots and tubers; algae
Primary Diet: herbivore (Folivore )
Mute swans breed in the British Isles, north central Europe and north central Asia. They winter as far south as North Africa, the Near East, and to northwest India and Korea. They have been successfully introduced in North America, where they are a widespread species and permanent residents in many areas. (Reilly, 1968; Granlund, McPeek, and Adams, 1994)
Biogeographic Regions: nearctic (Introduced ); palearctic (Native ); ethiopian (Native )
Mute swans are the most common swans in the wild, in parks or on country estates in their native range. In winter, they are more common on marine waters. They live in well-sheltered bays, open marshes, lakes, and ponds. (Reilly, 1968; Terres, 1980)
Habitat Regions: temperate ; saltwater or marine ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams; coastal
Wetlands: marsh
Other Habitat Features: estuarine
The greatest age recorded for a banded mute swan was 19 years. In captivity, they have lived 30 to 40 years.
Range lifespan
Status: wild: 19 (high) years.
Range lifespan
Status: captivity: 30-40 (high) years.
Average lifespan
Status: wild: 321 months.
Mute swans are large birds, measuring 144 to 158 cm. The wingspan is 2 to 2.5 meters. The two sexes are alike in appearance, except that males are generally larger than females. The plumage is white. They are best distinguished from North American swans by the knob at the base of the upper bill, and the color of the bill itself, which is orange, with the tip and base colored black. The head and neck may sometimes be stained brown from water and mud containing iron. (Reilly, 1968; Terres, 1980)
Range mass: 7600 to 14300 g.
Range length: 144 to 158 cm.
Range wingspan: 2 to 2.5 m.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Mute swans are large and aggressive birds. As adults they are not often preyed on unless they are old or ill. Eggs and hatchlings are vulnerable to nest predation by raccoons, mink, and a wide variety of other medium to large-sized predators. But swan parents are typically present to protect their young.
Known Predators:
Adults are not paired for life, contrary to the stereotype of the 'pining swan' who has lost its mate. In fact, some have been observed to have as many as four mates, or even 'divorce' one mate in favor of another. However, established pairs are more successful breeders than non-established pairs and mute swans do form monogamous pairs for at least a season.
Mating System: monogamous
Mute swans rarely nest in colonies. Nest sites are selected and breeding begins in March or early April. These swans either build a new nest or use a previously constructed mound, such as a muskrat house. The nest is large, made of aquatic vegetation, and lined with feathers and down. It is built well above the normal water level in swampy places near a pond or lake. It is possible for clutches of 5 to 12 to occur, but 5 to 7 is most common. The eggs are pale gray to pale blue-green. Incubation lasts 36 to 38 days. The chicks are brownish gray (gradually turning white within the next 12 months) and only remain in the nest for one day. The male may often take the first-hatched cygnet to the water while the female continues to incubate the remaining eggs. They are able to fly in about 60 days. Chicks can ride on the backs of their parents or under their wings. By the following breeding season the parents drive the young away. The cygnets then join flocks of other non-breeding swans, and during this time molt their feathers, becoming flightless for a short period of time. In the next two years, the cygnets begin to bond with a mate and begin to look for suitable breeding territory. Swans do not begin to breed until about their third year. (Granlund, McPeek and Adams, 1994; Reilly, 1968; Terres, 1980; http://www.airtime.co.uk/users/cygnus/muteswan.htm; http://www.aztec.inre.asu.edu/phxzoo/swanmute.html)
Breeding interval: Mute swans breed once yearly.
Breeding season: Breeding begins in March and April.
Range eggs per season: 5 to 12.
Average eggs per season: 5-7.
Range time to hatching: 36 to 38 days.
Average fledging age: 60 days.
Average time to independence: 12 months.
Average age at sexual or reproductive maturity (female): 3 years.
Average age at sexual or reproductive maturity (male): 3 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average eggs per season: 5.
The sexes share incubation, though the female spends the majority of time sitting, and the male usually stands guard.
Even in semi-domestication, the nest is strongly defended; swans have been known to attack other waterfowl and even people. Blows from their powerful wings can be especially painful. They can be dangerous to children, and are capable of killing or maiming some of the larger predators.
Parental Investment: precocial ; pre-fertilization (Protecting: Female); pre-hatching/birth (Protecting: Male); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)
