Adult Plumage:
Summer Plumage: The crown is gray, rufous-brown, or rufous. The posterior crown and nape feature broad, dark brown bands interspersed with rufous. The back varies from brown, rufous, yellowish-rufous to gray, with numerous irregular black streaks that gradually transition to rufous-black on the flanks and upper tail. The throat is pale white. The underparts are pale rufous tinged with gray or pale white, and marked with black horizontal streaks; the undertail coverts have white tips. Both sides of the breast have numerous large brown or rufous streaks. The area in front of the eyes is dark brown. The wing feathers are dark brown, with the first primary feather having rufous edges, and subsequent feathers exhibiting horizontal rufous or rufous-brown streaks. The tail feathers are black with grayish-white tips, and both sides of the tail have horizontal rufous streaks.
Winter Plumage: Similar to the summer plumage but appears duller. Eyes are dark brown. The beak is dark brown with a reddish tinge at the base. The legs are green or pale gray.
Measurements:
- Wing: 183 – 230 mm; Tail: 80 – 90 mm; Tarsus (leg): 36 – 41 mm; Beak: 69 – 84 mm
Distribution:
The species is distributed in Northern Europe and Asia, southward to Japan, Northern China, and the Himalayas. During the winter, it migrates southward to Africa, India, Myanmar, and Indochina.
In Vietnam, this species can be found in winter throughout the plains as well as the mountainous regions, from Thừa Thiên Huế northwards.