Female Barrow’s Goldeneyes have gray bodies, brown heads, and yellow eyes. They can be very difficult to distinguish from the female Common Goldeneyes. The bill of the female Common Goldeneye is larger and mostly black with a yellow tip, while the Barrow’s bill is smaller and mostly yellow. Male Barrow’s Goldeneyes have iridescent purple heads that look black when not in the sun, and prominent, crescent-shaped white spots on each side of the head at the base of the bill. Their bellies and flanks are white, and their rumps are black. Their backs are mostly black with white spots. Their bills are solid black. Juveniles are mostly gray with brownish heads similar to females, but with less differentiation between the head and body colors. Consult a field guide or an experienced observer; consider range and habitat; and study nearby males to help determine which species is present.