Males' bills are black with an upper base that is bluish gray. Adult males in the winter look similar to how they do in the summer, except that the white markings on the wings are broader, the feathers of the back are edged with gray, the rump and upper tail coverts are washed with olive or gray and their flanks are tinged with an olive color. Immature males have similar characteristics with females, however, the immature male's head is mostly black by its first spring, while the female's is only black when it is very old. It takes two years for a juvenile to reach full plumage. Females are, on average, smaller than the males.
Adult females have olive-gray under parts and top of the head with dark streaks on the back.
There is no brown present on the body. The body color becomes yellowish on the rump and upper tail coverts. They also have two wing bars, as opposed to the male's one wing bar. The female's throat is sometimes spotted, clouded, or washed with black. Old females usually have a completely black throat.