Cygnus olormute swan

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Geographic Range

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)

Habitat

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)

  • Aquatic Biomes
  • lakes and ponds
  • rivers and streams
  • coastal

Physical Description

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)

  • Sexual Dimorphism
  • male larger
  • Range mass
    7600 to 14300 g
    267.84 to 503.96 oz
  • Range length
    144 to 158 cm
    56.69 to 62.20 in
  • Range wingspan
    2 to 2.5 m
    6.56 to 8.20 ft

Reproduction

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.

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
  • Average eggs per season
    5
    AnAge
  • 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

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

Lifespan/Longevity

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
    Bird Banding Laboratory

Behavior

There is no mass migration, though in winter there may be gatherings numbering more than 100 individuals in open salt water. When swimming, a mute swan holds its neck in a graceful curve with the bill pointing downward, as opposed to other swans, which carry their bills level and necks erect. Top flight speed is 50 to 55 mph.

(Granlund, McPeek and Adams, 1994; Reilly, 1968; Terres, 1980; http://www.airtime.co.uk/users/cygnus/muteswan.htm)

Home Range

Mute swans set up large territories of 4 to 10 acres, which can include an entire small lake or pond.

Communication and Perception

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.

Food Habits

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

Predation

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.

Ecosystem Roles

Mute swans impact aquatic vegetation communities through their grazing.

Economic Importance for Humans: Positive

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

Economic Importance for Humans: Negative

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

Conservation Status

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)

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Alicia Ivory (author), University of Michigan-Ann Arbor.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

estuarine

an area where a freshwater river meets the ocean and tidal influences result in fluctuations in salinity.

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

freshwater

mainly lives in water that is not salty.

herbivore

An animal that eats mainly plants or parts of plants.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

marsh

marshes are wetland areas often dominated by grasses and reeds.

migratory

makes seasonal movements between breeding and wintering grounds

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

visual

uses sight to communicate

young precocial

young are relatively well-developed when born

References

Granlund, J., McPeek, G., and Adams, R. The Birds of Michigan. Indiana University Press, Indianapolis, 1994.

Halton, W. http://www.airtime.co.uk/users/cygnus/muteswan.htm

Reilly, E. The Audubon Illustrated Handbook of American Birds. McGraw-Hill Book Company, New York, 1968.

Terres, J. The Audubon Society Encyclopedia of North American Birds. Alfred A. Knoph, New York, 1980.

http://aztec.inre.asu.edu/phxzoo/swanmute.html