20.5 - 22 cm. 60 g. Bill black, long, straight, slender. Eyebrow, belly, flanks and rump white. Feathers that cover upperwings gray. Wings black above, below white with grayish edgings. Tail feathers pale gray, white at base. Non-breeding plumage (August-March): Crown and back pale gray. Auricular zone dusky. Face, foreneck and chest white. Legs yellow. In breeding season males and females are different (April-July). Male: Smaller than the female. Gray crown. Nape white. Sides of neck dark cinnamon less contrasting. Throat white chest and upper-chest pale cinnamon. Back patterned grayish, black and reddish. Legs black. Female: Back mask extends as broad stripe down sides of neck becoming chestnut on sides of chest. Cheeks and crown grayish blue. Nape white with a median reddish-brown stripe. Throat white, foreneck and upperchest deep cinnamon. Back grayish-blue with 2 chestnut Vs. Legs black. Juveniles are similar to non-breeding adults, but crown, nape and upperparts dark brown, neatly edged pale cinnamon to whitish; foreneck washed buffy cinnamon; legs yellowish.