Any of many species of wild or domestic web-footed birds that live in or near water. As with so many things culinary, the Chinese are credited with being the first to raise ducks for food. Today's domestic ducks are all descendants of either of two species — the mallard or the muscovy duck. Comprising about half the domesticated ducks in the United States are the white-feathered, full-breasted Long Island ducks, known for their dark, succulent flesh. These direct descendents of the Peking duck (a variety of mallard) are all the progeny of three ducks and a drake brought from Peking on a clipper ship in 1873. Besides Long Island, the locations most widely known for the cultivation of superior ducks are Peking (now known as Beijing) and Rouen, France. Since most ducks are marketed while still quite young and tender, the words "duck" and "duckling" are interchangeable. Broilers and fryers are less than 8 weeks old, roasters no more than 16 weeks old. Domestic ducks can weigh between 3 and 5 1/2 pounds; the older ducks are generally larger. Fresh duck is available from late spring through early winter, but generally only in regions where ducks are raised. Almost 90 percent of ducks that reach market are frozen and available year-round. The government grades duck quality with USDA classifications A, B and C. The highest grade is A, and is usually what is found in markets. Grade B ducks are less meaty and well finished; grade C ducks are usually used for commercial purposes. The grade stamp can be found within a shield on the package wrapping or sometimes on a tag attached to the bird's wing. When buying fresh duck, choose one with a broad, fairly plump breast; the skin should be elastic, not saggy. For frozen birds, make sure the packaging is tight and unbroken. Fresh duck can be stored, loosely covered, in the coldest section of the refrigerator for 2 to 3 days. Remove any giblets from the body cavity and store separately. Frozen duck should be thawed in the refrigerator; it can take from 24 to 36 hours, depending on the size of the bird. Do not refreeze duck once it's been thawed. Duck can be prepared in a variety of manners including roasting, braising, broiling, and so on. Though higher in fat than other domestic birds, it is a good source of protein and iron. For information about wild duck, see game birds.