Size: L: 35 cm. Wt: 300-500g. Males and females are similar. This species is seasonally dimorphic.

Breeding: head black, with golden "horns" extending back from eyes; neck, breast and flanks chestnut; back black; belly white; bill straight blackish, with pale tip; eyes red

Winter: crown, nape, back of neck, and dusky; no horns present; cheeks, throat, front of neck, flanks, and belly white; bill blackish; eyes red

Juvenile: similar to winter adult

Nestling: precocial and downy; body longitudinally striped blackish and white; pink spot on crown; throat tinted buff