The colloquial name for web-footed fowl that live on or near water. They are members of the family Anatidae, which also contains geese and swans. Strictly speaking, ducks are female; the males are drakes, and have the more elaborate plumage. Wild and domestic ducks are prized for their meat, eggs, and feathers. All domestic ducks are descended from two breeds, the mallard and the muscovy. The muscovy is of South American origin and thus relatively new to European and North Americans; mallards however have known in Asia and Europe since ancient times. The popular domesticated white, full-breasted Long Island ducks, consumed across North America, are all descendants of three ducks and a drake brought from Beijing to New York on a clipper ship in 1873.

Ducks can be divided into three groups: surface-feeding or puddle ducks, diving ducks, and fish-eating ducks. Surface feeding ducks include mallards, wood ducks, black ducks and teal; they live in quiet waters such as ponds and marshes and take wing straight up. Diving ducks like canvasbacks, scaup, scoter, eider, and redhead live in bays, rivers, and lakes; they "walk" for a distance across the surface of the water before taking off. The fish-eaters are mergansers; they have slender serrated bills and live on open water such as oceans and large lakes.

Most common in parks in my city are mallards; the drakes have a green head and neck with a white ring around it, white tails, and blue patches on their wings; the females are more drab. Wood ducks nest in hollow trees. The various types of teal are small and fly very quickly. Canvasbacks have a chestnut-coloured head and neck, black bill and chest, and whitish back; they're fast fliers and good divers, and also favourite of hunters because they're very tasty. The eiders live in northern countries and line their nests with soft down that is collected to make quilts and pillows. The mergansers (sheldrakes or sawbills) are usually crested; their diet of fish gives their flesh an unpleasant taste, so hunters call them "trash ducks".

An internet search on ducks turns up a plethora of sites on duck hunting, a popular "sport" in North America and Europe. Generally this involves a man with a gun, duck decoys, and a device (a duck call) which simulates the voice of the duck being hunted. Often dogs - retrievers - are used to fetch the (hopefully) dead duck from where it fell and bring it back to the hunter. In North America duck-hunting season is in the fall; most ducks are taking off on their long migratory flights at this time, and the skies are filled with flying targets for those who find picking live animals out of the sky a worthy pastime. Hunters of duck and other waterfowl are a powerful lobby group for the preservation of wetlands, a prime duck habitat.

Ducks bought in the supermarket have been raised and slaughtered for food, not hunted; such birds do not enjoy a long life, being killed between 8 and 16 weeks of age, so they can also be called ducklings. Unlike chickens, all duck flesh is dark; the breast is dark, tender, and lean, while the leg is firm and tough. Ducks are generally covered with a generous layer of fat, which makes them very tasty but also very fatty. Whole duck can be slow-roasted at a low temperature, which will render off some of the copious fat and yield tender meat and crispy skin; Chinese barbecued duck is prepared in this way, and it is delicious. Duck confit is cooked slowly in its own fat and then stored completely covered with that fat; prepared in this way, duck will keep for months. (Don't worry, the fat is scraped off before serving.) Boneless duck breasts can be seared and finished off in a hot oven for 10 minutes or so, till the flesh is just pink.
Joy of Cooking
Ducks Unlimited