Medium-sized, stocky shorebird found almost exclusively on coastal mudflats during migration, seldom inland. Distinctive adult in breeding plumage has a brick-orange upperwing patch, blackish back, and chest with black mottling. Duller nonbreeding and juvenile plumages are grayish brown above, white below, with grayish mottling in neck and upper breast. Smaller Red Knot much paler in nonbreeding plumage and has shorter bill. Flight call a sharp, whistled “kweet-kweet.”