As the winter passes the upper plumage becomes worn and browner in colour, and the black bases of the breast-feathers larger
and more distinct.
After the spring moult the forehead, crown, nape, and hind neck are dark slaty grey ; the back, scapulars, and rump yellowish green ; the upper tail-coverts dark brown, with greenish margins ; the wings and tail as in winter, but with the margins of the feathers of the former decidedly yellow ; lores, cheeks, round the eye, and the ear-coverts black; traces of a narrow supercilium sometimes present ; the whole lower plumage very bright yellow, with concealed black bases to the feathers of the breast ; these bases become more conspicuous as the summer passes.
Female. In winter does not differ from the male ; in summer it has the upper green parts duller, the crown and nape very faintly tinged with slaty, and almost concolorous with the green back, the lower plumage less brilliant yellow, with the mottlings on the breast more developed, the lores, cheeks, and ear-coverts brown, not black, and the supercilium generally slightly developed and of a pale fulvous colour. As the summer goes on, the head becomes greyer owing to the green tips wearing away.
The young bird on first arrival in India has the entire upper plumage greyish brown, tinged with blue on the rump ; the upper tail-coverts black, edged with grey ; tail and wings as in the adult, but with the margins of the wing-feathers very pale and almost white ; a very broad and nearly white supercilium ; lores and ear- coverts greyish brown ; lower plumage white, with a row of brown spots on either side of the throat, meeting and forming a gorget across the breast.
During the winter a series of changes are undergone, tending to make the young resemble the adult, and the full plumage appears to be assumed by the first spring.
Iris brown ; bill blackish brown, the base of the lower mandible yellowish ; legs, feet, and claws dark horn-colour.
Length about 7 ; tail 3'1 ; wing 3-2 ; tarsus -9 ; bill from gape -7.
Distribution. A winter visitor to every portion of the Empire except the higher parts of the Himalayas, where this species is only found on migration. It occurs in winter in the Malay Peninsula. In summer it ranges to Northern Siberia, and it is also found according to season over a considerable portion of Europe and Africa.
The true M. cinereicapilla, a closely allied species, is confined to Southern Europe and portions of Africa.
834. Motacilla flava. The Blue-headed Wagtail.
Motacilla flava, Linn. Syst. Nat. i, p. 331 (1706) ; Sharpe, Cat. B. M. x, p. 516, pi. vi, figs. 3-5.
Budytes flava (Linn.), Hmne, Cat.uo. 593 ter (part.) ; Gates, B. B. i, p. 162.
Budytes beema (Syfas), Hume, S. F, x, p. 227 note.
