The Common Goldeneye (Bucephala clangula) is a medium-sized sea duck. Adult males ranges from 45–52 cm (18–21 inches) and from 888 to 1400 grams (1.9 to 3.1 lbs), while females range from 40–50 cm (16–20 inches) and from 500 to 1182 grams (1.1 to 2.6 lbs). The species is aptly named for its golden-yellow eye.