Muscovy Duck is a large and heavily-built, black duck of tropical rivers, ponds and marshes. Muscovy Duck commonly is kept in captivity, and feral populations and free ranging domestic type muscovies now occur well outside its original range (Donkin 1989), which extends from extreme southern Texas and northern Mexico south to northern Argentina. Wild Muscovy also is heavily hunted, and can be very wary; where hunted, these ducks most often are detected in the early morning or late evening when seen flying to and from feeding areas. In flight, Muscovy Duck appears massive, with broad wings and tail; the upperwing coverts of adults are white, and form a broad white wing patch in flight. The diet of Muscovy Duck includes a variety of grains, aquatic vegetation, fruits, nuts, small fish, insects, and crabs. The sexes are similar in plumage, but males are significantly larger than females. Despite its large size, Muscovy Ducks are partially arboreal, roosting in trees, and nesting in tree cavities and nest boxes.