Large scoter, with distinctive white patch on wing. Dark chocolate-brown overall; males are darker than females and have small white mark under eye. Note bill pattern: mostly yellow with a dark knob on top and a subtle pinkish tip. Females have two rounded white patches on face. Breeds on ponds, lakes, or rivers in woodland or tundra across much of northern Europe. Winters mainly in coastal waters, sometimes in large flocks. Occasionally found on large inland lakes during migration. Dives frequently, feeding on mollusks and crustaceans.