Swan (redirected from Cisne)

swan, common name for a large aquatic bird of both hemispheres, related to ducks and geese. It has a long, gracefully curved neck and an extremely long, convoluted trachea which makes possible its far-carrying calls. The orange-billed white trumpeter swan, Cygnus buccinator, seen in parks, is the mute swan, of Old World origin. It breeds in the wild state in parts of Europe, Asia, and the United States. During the breeding season it has a trumpetlike note, softer in the tame birds. The whistling swan migrates from the arctic to Mexico. Conservation measures saved the almost extinct trumpeter swan of North America, the largest species. Wild species in Europe include the whooper (or whooping) and the Bewick swans. The black swan, Chenopis atrata, is native to Australia, and the black-necked swan, Cygnus melancoriphus, to South America. The black swan has been domesticated. Swans are classified in the phylum Chordata, subphylum Vertebrata, class Aves, order Anseriformes, family Anatidae.

Bibliography

See study by P. Scott and the Wildfowl Trust (1972).

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swan

Mute swan (Cygnus olor) and cygnet

(credit: Arthur W. Ambler—The National Audubon Society Collection/Photo Researchers)

Long-necked, heavy-bodied, big-footed waterfowl (genus Cygnus, family Anatidae). Among waterfowl, swans are the largest and fastest, both swimming and flying; at about 50 lbs (23 kg), the mute swan (C. olor) is the heaviest flying bird. Swans dabble in shallows for aquatic plants. Five all-white, black-legged species live in the Northern Hemisphere; a black and a black-necked species live in the Southern Hemisphere. Males (cobs) and females (pens) look alike. Swans mate for life. The cob keeps guard while the pen incubates, on average, six eggs on a heap of vegetation; the young (cygnets) are tended for several months. Their graceful form when swimming has made swans emblems of beauty for centuries.

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swan

any large aquatic bird of the genera Cygnus and Coscoroba, having a long neck and usually a white plumage: family Anatidae, order Anseriformes

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Swan¹

Sir Joseph Wilson. 1828--1914, English physicist and chemist, who developed the incandescent electric light (1880) independently of Edison

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Swan²

a river in SW Western Australia, rising as the Avon northeast of Narrogin and flowing northwest and west to the Indian Ocean below Perth. Length: about 240 km (150 miles)

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swan [swän]

(vertebrate zoology)

Any of several species of large waterfowl comprising the subfamily Anatinae; they are herbivorous stout-bodied forms with long necks and spatulate bills.

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Swan [swän]

(astronomy)

Cygnus

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Swan 

a bird of the family Anatidae of the order Anseriformes. It measures up to 180 cm long and weighs up to 13 kg. The length of the neck is equal to or exceeds the length of the body. There are six species, combined into two genera: black swans (Chenopsis) and true swans (Cygnus).

The genus Chenopsis comprises one species, the black swan (Ch. atrata), which is distributed in Australia and Tasmania and is acclimatized in New Zealand. The genus Cygnus comprises five species, one of which is distributed in the subarctic regions, two in Europe and Asia, one in North America, and one in South America.

In the USSR there are three species of true swans: the mute swan, the whooper swan, and Bewick’s swan. The mute swan (C. olor) is the largest of all the swans. The male has a black knob on its bill. The bird is distributed in some parts of the southeast European Plain and in Kazakhstan, Middle Asia, and Western Siberia. The whooper swan (C. cygnus), somewhat smaller than the mute swan, is widely distributed except in the tundra. However, it is becoming increasingly rare everywhere. Bewick’s swan (C. bewicki) measures about 120 cm long and weighs up to 7 kg. It inhabits the tundra. Swans that nest in the USSR winter on the seas, sometimes even in the north, and more rarely on freshwater lakes in the south.

Swans settle on large lakes in reed thickets. The nests are bulky, and they are built by both the male and female on the shore, next to the water. Five to seven eggs, although sometimes as many as 12, are laid per clutch, and they are incubated by the female for 35 to 40 days. The male guards the female and the cygnets. Swans generally mate for many years. They swim well but cannot dive and therefore feed only in shallow waters. They eat aquatic and littoral plants and sometimes aquatic invertebrates.

Swans are often kept on ponds in parks. They have some commercial significance in the northern USSR; elsewhere, hunting them is prohibited.

REFERENCE

Ptitsy Sovetskogo Soiuza, vol. 4. Edited by G. P. Dement’ev and N. A. Gladkov. Moscow, 1952.

A. I. IVANOV