Adult Bird:
The plumage is generally a yellowish-brown with numerous black and brown streaks and bars. The forehead and crown are black. The long feathers on the nape have pale yellowish-brown tips mixed with pale black streaks. The sides of the head are yellowish-brown. A blackish-brown streak extends from the mouth to below the cheeks. The chin and throat are pale yellowish-brown with a longitudinal brownish streak down the center. This streak extends to below the neck. The sides of the neck are pale yellowish-brown with sparse blackish-brown bars.
The back is brownish-yellow with broad black and blackish-brown bars and streaks. The shoulders, wing coverts, and tail are similar to the back, but the streaks and bars are narrower. The wings are blackish-brown with brownish-yellow bars. The feathers on the chest are pale yellowish-brown with a large blackish-brown streak down the center of each feather; towards the abdomen, these brown streaks become narrower and almost disappear on the underside. The thighs are pale yellowish-brown.
Juvenile Bird:
The plumage is a lighter yellowish-brown, and the blackish-brown markings are darker. The eyes are yellow or brownish-yellow. The bill is pale yellowish-green with a darker ridge. The legs are pale yellowish-green. The bare skin around the eyes is pale green tinged with blue.
Measurements:
- Wing: 300 – 360 mm
- Tail: 95 – 116 mm
- Tarsus: 90 – 100 mm
- Bill: 60 – 75 mm
Distribution:
The species is distributed in temperate regions of Europe and Asia; it migrates south in winter.
In Vietnam, the species is common in winter in Ha Tay, Ha Bac, and around Hanoi.