Common Goldeneye
Bucephala clangula
The common goldeneye or simply goldeneye (Bucephala clangula) is a medium-sized sea duck of the genus Bucephala, the goldeneyes. Its closest relative is the similar Barrow's goldeneye. Adult males have a dark head with a greenish gloss and a circular white patch below the eye, a dark back and a white neck and belly. Adult females have a brown head and a mostly grey body. Their legs and feet are orange-yellow.
Two subspecies are generally recognized, the nominate Eurasian subspecies Bucephala clangula clangula and the North American B. c. americana. americana has a longer and thicker bill than clangula. Common goldeneyes are aggressive and territorial ducks, and have elaborate courtship displays.