Adult Male:
Summer Plumage: Head, neck, and belly black, with feathers slightly edged with pale gray, except on the flanks and belly, where feathers are edged with wider pale white. Feathers on the nape, back, scapulars, and wing coverts dark brown or pale black, edged with leaden gray. Rump and uppertail coverts brown, edged with pale brown. Outermost wing coverts dark brown, edged with rufous. Flight feathers pale dark brown, the outer web of the first primary white, the inner flight feathers edged with pale brown. Undertail coverts rufous or whitish tinged with rufous, with few brown transverse bands. Winter Plumage: Similar to the female.
Female:
Before the eye and around the eye, a mixture of dark brown and pale rufous brown. Crown brown. Feathers on the back, scapulars, tail, and wing coverts dark brown edged with wide rufous. Flight feathers dark brown, the outer web of the first primary white. Belly pale rufous brown with narrow brown streaks. Chin and throat pale white tinged with rufous. Undertail coverts rufous with pale dark brown bars. Eyes bright red, beak and fleshy comb blood-red, beak tip yellow. Legs pale greenish-brown.
Measurements:
Wing: 180 – 217 mm; Tail: 77 – 83 mm; Tarsus: 75 – 77 mm; Bill: 37 – 38 mm.
Distribution:
The species is widely distributed in Southeast Asia: from India to China, the Philippines, and northward to Korea. In Vietnam, this species is found throughout the plains from North to South.