What does one think may be a Swan? Swans are birds of the Anatidae within the Cygnus. The English word 'swan', springs from Indo European root 'swen' (to sound, to sing) Swan is that the largest waterfowl species of the Anserinae, Anatidae (order Anseriformes). Most swans are classified within the Cygnus. Swans are gracefully long-necked, heavy-bodied, big-footed birds that glide majestically when swimming and fly with slow wingbeats and with necks outstretched.
They migrate in diagonal formation or V-formation at great heights, and no other waterfowl moves as fast on the water or within the air. Swans feed by dabbling (not diving) in shallows for aquatic plants. Swimming or standing, the mute (C. olor) and black (C. atratus) swans often tuck one foot over the rear. Male swans, called cobs, and females, called pens, look alike. Legend to the contrary, swans utter a spread of sounds from the windpipe, which in some species is looped within the breastbone (as in cranes); even the Cygnus olor, the smallest amount vocal species, often hisses, makes soft snoring sounds, or grunts sharply. Swans are sociable except in breeding season. They mate for all times.
Courtship involves mutual bill dipping or head-to-head posturing. The pen incubates, on the average, a half-dozen pale unmarked eggs on a heap of vegetation while the cob keeps close guard; in some species he takes his turn at brooding. After repulsing an enemy, swans utter a triumph note, as geese do. The young, called cygnets, emerge short-necked and thickly downed; though capable of running and swimming a couple of hours after hatching, they're carefully tended for several months; in some species they'll ride about on their mother’s back. Immature birds wear mottled gray or brown plumage for 2 or more years. Swans mature within the third or fourth year and live perhaps 20 years within the wild and 50 years or more in captivity. Of the seven or eight species—some of them probably races of a species, as indicated below by scientific names in parentheses—five are all-white, black-legged birds of the Northern Hemisphere: the Cygnus olor, with a black knob at the bottom of its orange bill, curved posture of the neck, and aggressive wing arching; the trumpeter (C. cygnus buccinator), named for its far-carrying low-pitched call and having an all-black bill; the whooper (C. cygnus cygnus), a loud bird with black bill having a conspicuous yellow base; the similar but smaller and quieter Bewick’s swan (C. columbianus bewickii), of which Jankowski’s swan (C. columbianus jankowskii) could also be merely the eastern race; and therefore the Cygnus columbianus columbianus (C. columbianus columbianus), named for its voice and having a black bill with, usually, alittle yellow spot near the attention.
Some ornithologists (especially within the United States) place the last four swans within the genus Olor, reserving Cygnus for the Cygnus olor. Once threatened with extinction—fewer than 100 birds were counted within the us in 1935—the trumpeter has made a robust comeback within the national parks of the western us and Canada, but the entire population within the mid-1970s was only about 2,000. it's the most important swan—about 1.7 metres (5.5 feet) long, with a 3-metre (10-foot) wingspan—but it weighs but the Cygnus olor, which at 23 kg (50 pounds) is that the heaviest carinate.