Adult Male:
The male has a prominent eyebrow stripe extending from the forehead to the nape of the neck, and several long crest feathers on the sides of the white head. The area in front of the eye and the stripe below the eye are white, with a slight yellowish-brown tinge in front of and above the eye. The forehead and crown are steel-green, while the nape is blue with a purplish sheen. The long crest feathers on the nape have a brownish-red base with a purplish sheen, and the tips are green with a blue sheen. The chin is white. The long feathers on the sides of the neck are fresh brown with a narrow white stripe running down the center of the feather. The back and the wing coverts are brownish-purple with a slight bronze sheen. The tail is dark brown, with a slight greenish sheen on the central tail feathers. The shoulders are dark brown with a blue or green sheen; the outermost shoulder feathers are white with black edges.
The innermost secondary flight feathers have tips that broaden into a sail-like shape, colored fresh brown. The outermost secondary flight feathers are dark brown, with a green sheen on the outer vane and white edges at the tip. The primary flight feathers are dark brown with silvery-white edges on the outer vane and a slight greenish sheen on the inner vane. The breast is brown with a purplish sheen. The feathers on the sides of the breast have brown bases and black and white stripes at the tips, forming two black and two white curved stripes on the sides of the breast. The abdomen is white. The flanks and thighs are yellowish-brown with fine dark brown streaks. The undertail coverts are white. In winter, the male’s plumage closely resembles that of the female.
Female:
The female has a gray head and crest. A narrow white stripe extends from the forehead to the nape. The sides of the head are pale gray, gradually transitioning to white on the chin, throat, and upper neck. The remainder of the back and wing coverts are brown, with varying degrees of gray. The under-neck, breast, and flanks are brown, similar to the back, with a pale mark near the tip of each feather. The remainder of the abdomen is white. The primary flight feathers are brown with a green sheen and white edges at the tips. The two innermost secondary flight feathers form a dark green mirror bordered by black and white edges. The innermost secondary feathers are brown. The eyes are dark brown with a pale yellow ring around the outside. The bill is pale reddish-brown. The legs are reddish-yellow, with a pale black membrane between the toes.
Measurements:
- Male: Wing: 223 – 240 mm; Tail: 108 – 122 mm; Tarsus: 33 – 36 mm; Bill: 27 – 31 mm.
- Female: Wing: 170 – 194 mm; Bill: 26 – 30 mm.
Distribution:
The Mandarin Duck is distributed in Central and Northern China, and Japan. In winter, they migrate to Southern China.
In Vietnam, this species has only been recorded during the winter season in the Lai Chau region.