Adult Male:
The crown, back, wing feathers, wing coverts, flanks, and tail feathers are dark yellowish-brown. The wing coverts exhibit spots and narrow, white, horizontal barring. The outer edge of the first primary feather is white. The forehead, area in front of the eyes, sides of the head and neck, front of the neck, and the breast are rufous-brown. The chin, throat, and mid-belly are pale white. The remaining parts of the belly, under the tail, flanks, and underwings are dark brown with broad, white, horizontal stripes.
Adult Female:
Resembles the male, but differs in that the forehead is yellowish-green, and overall, the back and belly are lighter in color.
Juvenile:
Resembles the female, but differs in that the white color on the belly is modified: the front of the neck and the breast are white, but the upper breast has a broad, horizontal rufous-brown band. The bill is dark brown, with a slightly paler tip on the lower mandible. The legs are pale reddish-brown.
Measurements:
Wing Length:
- Male: 122 – 130 mm
- Female: 116.7 – 122 mm
Distribution:
This species nests in Northeast Asia. During the winter, it migrates south to Malaysia and Indonesia. In Vietnam, the species is found in the northern part of the country (Son Tay) and the Mekong Delta during the winter.