A striking medium-sized duck. Widespread across much of North America, Europe, and Asia, where it is found in a variety of wetland habitats. Breeds on lakes, ponds, and marshes, and winters on inland lakes and rivers or coastal bays and nearshore waters. Adult males have a black head with circular white patch at the base of the bill and a mostly white body with limited black. Females and first-year males have gray body and chocolate brown head. Bright yellow eyes usually stand out on all but first-year females. Very similar to Barrow’s Goldeneye. Males are easiest: Common has less black on the back, lacks a dark spur on the side, and has a circular (not crescent-shaped) white patch on the face. Females can be very difficult. Common usually has a dark bill with a small yellow patch near the tip, but rarely can have an entirely dull yellowish bill like Barrow’s. Head and bill shape are important: Common has more evenly rounded head with a peak in the center of the crown, and a longer, straighter-edged bill.