Adult Plumage:
Summer Plumage: Forehead and a small band above the eyes are pale rufous. Crown and upper back are pale black, each feather edged with rufous; the back feathers also have white streaks. Lower back, flanks, central upper tail, and central tail feathers are pale black with paler edges. Sides of the flanks and sides of the upper tail are white. Wing coverts are brownish-gray with a dark spot in the middle of each feather. Tips of the greater wing coverts are white. Primary feathers are pale black with white shafts. Secondary feathers are dark gray with white edges. Sides of the head, throat, and front of the neck are rufous, many feathers having a very narrow white edge. Breast, flanks, and sometimes the thighs and under tail coverts have dark spots.
Winter Plumage: Back is brownish-gray; the shafts of the feathers on the crown have black streaks, and the feathers on the upper back are edged with white. Greater wing coverts are gray with white feather tips, forming a white band across the wing. Belly is white, occasionally with a pale brown tinge on the breast. Eyes are brown. Beak and legs are pale black.
Measurements:
- Wings: 90 – 107 mm; Tail: 43 – 47 mm; Tarsus: 19 – 21 mm; Beak: 16 – 19 mm.
Distribution:
This species nests in Siberia and Japan. It migrates to South China, Indochina, Burma, Malaysia, and Australia in the winter.
Occurrence in Vietnam:
Flocks are observed flying over in early winter and early summer in the Central Coast region (Hue) and in Southern Vietnam.