White-wings are among the heaviest and largest of all ducks. Like all scoters, these birds move along our coasts in loose flocks, stringing into irregular, wavy lines. Drakes can be distinguished from other scoters by two white patches on their head and bright color of the bill. Flight is strong, direct, usually close to the waves. In flight, drakes appear all black except for the flash of the slight gray underwing and the bright yellow swelling at the base of the upper bill.
Scoters feed on mullusks, crabs, and some fish and very little vegetation.