Swans are birds in the genus Cygnus, located in the family Anatidae, making them close relatives to ducks and geese. These waterfowl originated in the Old World, and they have since spread to many regions across the globe, congregating around lakes, rivers, and streams. The distinctive appearance of swans is perceived as quite attractive by many people, earning the birds a special place in folklore.

Swans have muscular, heavy bodies, large webbed feet, and long, slender necks. They are among the largest and heaviest of all waterbirds, and they vary in color from pure white to black. While many people associate swans with the color white, swans in the Southern Hemisphere tend to be more brown or mottled in color, although they share the graceful movement and familiar appearance of their Northern Hemisphere cousins.

These birds famously mate for life, although divorces do sometimes occur, and they raise clutches of three to eight young, known as cygnets until they mature into adult swans. Male swans, incidentally, are known as cobs, while lady swans are called pens. The history of swans and humans is quite old, as swans have been domesticated as ornamental and companion birds for centuries in Europe and Asia, and in some regions swans have also been eaten, with some cultures reserving swan meat for the consumption of royalty only.

Swans feed on aquatic plants which they churn up from the bottom of shallow waterways. This can make the birds into noxious pests, as they will substantially disturb waterways in a quest for food. In areas where the swan is not native, imported birds have been known to displace local species by destroying the habitat, muddying the water, and frightening other birds off with their large size and ferocity.

Although swans look quite graceful and peaceful from a distance, the birds can be quite vicious. They are sometimes used as guard animals, like their goose cousins, and they are especially aggressive around nests and young. Because swans are large and strong, they can deal out some severe bruises with their heavy wings. The best thing to do when attacked by a swan is to back away from the area, in the hopes of moving away from the territory the swan is defending.

Some well known swan species include black swans, mute swans, whistling swans, trumpeter swans, and whooper swans. As you might imagine from some of these colorful common names, some swans make very distinctive and unusual noises.