Its thighs and flanks are black, as is its cere and legs. In flight the male has white wings underneath with black barring on the primaries and secondary flight feathers, and light streaking on the underwing coverts.
Its hindquarters and flanks are black, as is its abdomen and legs. In flight, the male has white wings beneath with black stripes on the primary and secondary flight feathers, and light streaking on the underwing covers.