Adult Plumage Description:
Summer Plumage:
The summer plumage features a jet-black coloration from the forehead to the nape of the neck, with the forehead sometimes displaying white markings. The back exhibits a gray hue, which becomes slightly paler on the flanks, rump, and tail. The outer webs of the outermost tail feathers are nearly entirely white. The area encompassing the fore-eye region, cheeks, chin, and throat is white, transitioning to gray on the upper chest, and eventually turning black on the belly and under-tail coverts. The underwings and armpits are white.
Winter Plumage:
The winter plumage presents a white crown with black streaks. A black spot is present behind the eye. The belly is white, tinged with gray on the chest and upper throat. The eyes are dark brown. The beak is a vibrant orange-yellow, with a paler shade in winter and a brown tip. The legs are orange-yellow.
Measurements:
- Wing: 221 – 240 mm
- Tail: 145 – 152 mm
- Tarsus: 15 – 16 mm
- Bill: 32 – 40 mm
Distribution:
This species is distributed in Southern Vietnam, Laos, Thailand, Myanmar, and India.
Vietnam:
This species is found in Bà Rịa and Trà Vinh provinces.