Barrow’s goldeneyes are chunky mid-sized sea ducks with short necks, a relatively large rounded head, and a short gray-black bill. Males are markedly larger than females; males are about 48 cm (19 in) and females about 43 cm (17 in). Spring weights for males average 1278 g (2.8 lbs.) and 818 g (1.8 lbs.) for females.
Sea Duck Information Series fact sheet
Species Knowledge Summary and Information Needs (PDF)