swan

Swans are large waterfowl in the genus Cygnus, within the family Anatidae of the order Anseriformes. The six widely recognized species are the mute swan (Cygnus olor), whooper swan (Cygnus cygnus), trumpeter swan (Cygnus buccinator), black swan (Cygnus atratus), Bewick's swan (Cygnus bewickii), and tundra swan (Cygnus columbianus). They are among the largest flying birds, with long necks, strong wings, and predominantly white plumage in most species; the black swan is an exception with dark plumage and a red bill.

Swans inhabit lakes, rivers, and coastal estuaries across the Northern Hemisphere and Australia, with some populations undertaking long migrations. They feed mainly on aquatic vegetation, including pondweed and water lilies, and may supplement their diet with grains or small invertebrates, especially in winter.

Pairs often form for life and defend nesting sites vigorously. Nests are built near water from reeds and grasses, and females typically lay 4–7 eggs. Incubation lasts about a month, after which the downy cygnets fledge and accompany the parents for several months. Swans are strong fliers and may travel thousands of kilometers during migration, often flying in a line or V-formation.

Conservation status varies by species; most populations are stable or increasing due to habitat protection. Some populations face threats from habitat loss, pollution, and lead exposure. In culture, swans are symbols of beauty, grace, and loyalty.