Male goldeneyes have black heads and backs and white sides, females brown heads and gray bodies. Their bills are short and high for a duck. Not surprisingly, they have bright yellow eyes. The males of the two species can be distinguished easily by the shape of the white spot before the eye and the relative amount of black on the back. Females are more similar, but their head shapes are different, Barrow's with a higher forehead and puffier crown. During late winter and spring, the bill of a female Barrow's turns orange, making identification easy.
Goldeneyes have relatively large heads and short necks, giving them a bull-headed look in flight. In fact, Bucephala means bull-headed. The males have big white wing patches, the females smaller patches. The wings of the males in both species whistle loudly in flight, and hunters call them "whistlers." We don't know the significance of the wing whistling.
Goldeneyes are aquatic predators, diving to the bottom to forage for invertebrate prey. Barrow's seem to specialize in bivalves, while Commons eat just about anything, including a variety of mollusks and crustaceans. This is manifested in their occurrence in winter. Commons are pretty much everywhere in salt water and fairly common in fresh water, as there is always something to eat.
Like most of our wintering waterfowl, these ducks pair in the winter, so by spring they are all in pairs, showy black and white males and more subdued brown and gray females. But there are still unmated males, so wherever goldeneyes hang out, watch for their spectacular courtship displays. The males throw their heads back while vocalizing and scoot forward on the water.
Both species nest in old woodpecker holes and tree crevices on freshwater lakes. Barrow's is fairly common on mountain lakes all across the Pacific Northwest, while Common is a more northerly species, relatively rare as far south as Washington.