Swan, a migratory water bird related to ducks and geese. Larger than the goose, the swan may attain a length of five feet (1.5 m) or more. Its long, graceful, arched neck allows it to dip into the water and gather the aquatic plants and seeds that form the major part of its diet. The male swan, called a cob, is larger than the female, or pen. The young, called cygnets, have bluish-gray or brownish feathers. With the exception of the black-necked swan and the black swan, the plumage of adults is white.Swans are large migratory water birds related to ducks and geese.
Swans gather in flocks, and a mated pair may stay together for life. The nest is usually a wide mass of rushes and reeds, lined with down, built near the water's edge. The female lays two to seven whitish eggs, each about four inches (10 cm) long.
Swans usually do mate for life. But there are times when a swan does take a new mate. A swan may take a new mate if its partner gets lost or dies.
Swans choose mates when they are 2 to 3 years old. A swan begins its courtship by displaying, or showing off, to another swan. Swans display while facing each other. They dip and turn their heads. Swans may also “kiss” bills. When swans kiss, their necks form a heart shape.
Many swan pairs set up territories. A pair picks a territory where there is a lot of food and a safe place to build a nest. Swans defend their territories fiercely. They fight off an intruder by bumping it and hitting it with their wings. When the intruder leaves, the swan pair celebrates. They call loudly and face each other with raised wings.
There are seven species of swans. The tundra swan nests in arctic regions of North America and Eurasia and winters in temperate regions. The tundra swan grows to a length of about 55 inches (1.4 m). It has a black bill, usually with a yellow spot at the base. The tundra swan has a high-pitched call. Tundra swans of North America are also called whistling swans ; those of Eurasia, Bewick's swans .
The trumpeter swan was once close to extinction, but through conservation measures its numbers have increased. Largest of the swans, trumpeters can reach a length of more than 70 inches (1.8 m) and a weight of more than 30 pounds (14 kg). They have black bills and give a deep, hornlike call. These birds nest mostly in Alaska and winter in Canada. Smaller flocks are found south of Canada in a few parts of the western United States.
Trumpeter swans sound off with trumpetlike calls. How do they do this? A trumpeter swan has a very long neck. Inside the neck is a long trachea (TRAY kee uh), or windpipe. The trachea is so long that it even winds around the trumpeter’s chest bone. It lets a trumpeter swan make its deep, hornlike calls. Trumpeter swans are the loudest of all swimming birds.
Pairs of trumpeter swans set up large territories. They need their loud calls to stay in touch with each other. Their calls are also a way to say: “Stay out of our territory!”
Swans are very vocal birds. The trumpeter swan, the whistling swan, and the whooper swan are all named for their calls. So you might think that the mute swan is mute, or silent. But even mute swans hiss, snort, and give off trumpetlike notes.
The domesticated mute, or common, swan is the species commonly seen in parks. It has an orange bill with a black knob at its base. The mute swan is native to Eurasia and has been successfully introduced into North America and Australia. Despite its name, it is not mute; it occasionally gives a barklike call. The black-necked swan is native to southern South America. It is white with a black neck; its bill is red. The black swan is native to Australia. It has a bright red bill and is entirely black except for white wing feathers that are visible only during flight. The whooper swan, of Eurasia, has a black and yellow bill. The coscoroba swan, of South America, is the smallest swan; it grows to a length of about 30 inches (76 cm).
The tradition that a dying swan produces a beautiful song—the “swan song”—is without basis in fact.
Swimming birds can be found on every continent—including Antarctica. Swans, however, live on just five continents. These swimming birds prefer places that have mild or cool climates. Swans do not live in Africa, where the temperatures get very hot. And they do not live in Antarctica, where temperatures are too cold.
There are seven species, or kinds, of swans. Four species live in the Northern Hemisphere, and three species live in the Southern Hemisphere.
Where a swan lives tells you a little bit about it. For example, swans that live in the Northern Hemisphere have only white feathers. Swans that live in South America have either black wing tips or black necks. Australian swans are nearly all black. Northern swans are also larger than southern swans.