Size: L: 20 cm. Wt: 30-35 g. Males and females are dimorphic in color during the breeding season, with females being more intensely colored. This species is also seasonally dimorphic.
Breeding Male: upperparts dark brown, with tawny stripes and scalloping on wings, and rufous wash over back; head white, with broad, blackish-brown crown and eye-stripes, meeting at back of head and running down sides of neck, becoming chestnut on neck; throat and chin white; breast with dark, mottled brown and chestnut; belly white; bill dark; legs blackish
Breeding Female: upperparts dark slate, with two prominent chestnut-orange stripes along sides; head dark slate, with broken white eye-ring and white chin; throat, upper breast, and sides of neck chestnut; lower breast and flanks with broad, blackish streaks; belly white; bill and legs blackish
Winter Adult: upperparts slate blue, with two prominent white stripes along sides; head white, with dark slate on back of head and on nape; dark patch extends from back of eye, curving downward; throat, breast, and belly white; flanks dusky grey; bill and legs as in breeding adults
Juvenile: upperparts tawny brown, with two prominent, light chestnut stripes along sides; head white, with buffy forehead, dark crown and nape, and dark patch behind eye; throat white; breast with light brown wash; belly white; bill and legs as in adults