The duck is an AQUATIC BIRD with short legs, webbed feet and narrow, pointed wings. A few island species are unable to fly, but most are good sailors and are migratory. A subspecies of Common Eider (Somateria mollissima), which breeds in Hudson Bay and James Bay, is almost sedentary as it winters in Hudson Bay. The duck, like the goose and the swan, belongs to the Anatidae family, which has 158 living species and a few recently extinct. Ducks are found all over the world.