Bramblings display behaviour sexual dimorphism, in which the males and females of the same species differ in appearance.
The male brambling has a jet black head during the summer (its breeding season) as well as a brown body, black wings and a black tail. Its long white rump and orange breast are particularly noticeable when in flight. The bill is black, or occasionally blue-grey.
However in wintertime, the male brambling has a mottled grey-brown head, dark brown wings and the bill is a pale yellow/orange colour with a black tip.
The female’s appearance is very similar to the non-breeding male though it is plainer in colour and has a more subdued orange breast and shoulders.
Juveniles look very similar to the female except the rump and belly are a tinged dull yellow, and it has a brown tinged head and upper parts.