Size: L: 20 cm. Wt: 60 g. Males and females are similar. This species is seasonally dimorphic.
Breeding Adult: wings and back blackish brown, with light chestnut or buff feather-tips; head and breast rusty, with blackish spotting; belly and undertail coverts whitish; bill long, thick, straight, black; legs black
Winter Adult: head and upperparts pale grey, with black wingtips; underparts white; bill and legs as in breeding adult
Juvenile: wings and back blackish, with buffy or whitish feather-tips;head pale buff, with dusky crown and nape; breast whitish, with buffy wash; belly and undertail coverts white; bill and legs as in adults