Adult Plumage:
The entire head, neck, part of the upper back, chest, and upper abdomen are white. Each feather has a narrow, longitudinal band of dark brown or faint black down the center. The first primary flight feathers are black, with the base of the feathers, from the notch inward, being brown with black edges. Towards the inner part of the wing, these feathers gradually transition to a rufous-brown color. The remaining plumage is entirely rufous-brown. The tail feathers have narrow, horizontal bars of dark brown on the inner vane.
Juvenile Plumage:
The plumage is brown, with the tips of the feathers being paler and the feather shafts black. The head and neck are paler, with the feather tips having broad rufous-brown markings. The ears are dark brown. The chin and throat are rufous-brown. The belly is rufous with broad rufous-brown streaks. The center of the abdomen and the area under the tail are rufous, with black feather shafts. There are also intermediate plumage forms. The eyes are brown. The beak is blue-gray, with the ridge and tip of the beak being paler and sometimes pale yellow. The skin at the base of the beak is yellow. The legs are pale yellow or pale yellowish-gray.
Measurements:
- Wings: 355 – 399 mm
- Tail: 188 – 207 mm
- Tarsus: 52 – 59 mm
- Beak: 32 – 35 mm
Distribution:
The species is distributed in Indochina, Thailand, Myanmar, and Java.
Vietnam:
This species is found in Bắc Cạn (Ba Be Lake), Quảng Trị, Thừa Thiên, and near Saigon.