Size: L: 30 cm. Wt: 300g. Males and females similar. This species is seasonally dimorphic.
Breeding Adult: head black, with golden plumes behind the eyes; neck and back black; flanks chestnut; belly white; bill long, thick, black; eyes red
Winter Adult: head mostly dusky, without plumes, and with whitish "chinstrap"; back of neck and back dusky or blackish; front of neck, breast, and flanks greyish or whitish; bill long, thick, black; eyes red
Juvenile: similar to winter adult