Size: L: 20 cm. Wt: 40 g. Males and females are similar. This species is somewhat seasonally dimorphic, with the winter plumage being of similar pattern, but paler, than breeding plumage.

Breeding Adult: wings and back blackish, with dark buff feather-tips, giving heavily scalloped appearance; head, nape, and breast buffy, with fine, dark streaking, and paler face; belly and undertail coverts white; bill short, straight, black; legs blackish

Winter Adult: similar to breeding adult, but paler overall; feather-tips on back whitish

Juvenile: wings and back as in winter adult, but head and breast as in breeding adult; all other features similar to all adults