833. Motacilla borealis *.
The Grey-headed Wagtail.
Motacilla flava borealis, Sundev. Aefv. K. Vet.-Acad. Fork. Stockh. 1840, p. 53. Budytes viridis (Gmel.), apud Blyth, Cat. p. 138; Horsf. & M. Cat. i, p. 350; Jerd. B. I. ii, p. 222; Anders. Yunnan Exped., Aves, p. 608; Legge, Birds Ceyl. p. 617 ; Oates, B. B. i, p. 161. Budytes cinereocapilla (Savi), apud Hume, Cat. no. 593; Brooks, J. A. S. B. xliii, pt. ii, p. 248 ; Barnes, Birds Bom. p. 238. Motacilla borealis, Sundev. Sharpe, Cat. B. M. x, p. 522, pl. vii, figs. 1.3.
The Indian Field- Wagtail, Jerd.; Pilkya, Hind.
Coloration. Male. In normal winter plumage, on first arrival in India, the forehead, crow, nape, and hind neck are bluish grey, a few of the feathers with greenish tips; the back, scapulars, and rump dull olive-green; upper tail-coverts dark brown edged with olive-green; the four middle pairs of tail-feathers black, narrowly edged with olivaceous; the two outer pairs almost wholly white ; coverts and quills dark brown or black, margined with pale fulvous, sometimes with a greenish tinge; lores, cheeks, and ear-coverts dark slaty black, the ear-coverts paling to bluish grey posteriorly; the whole lower plumage yellow, tinged with ochraceous across the breast, and the feathers of that part with dark bases showing through, and giving the breast a mottled appearance; traces of a white interrupted supercilium are frequently visible over the lores and ear-coverts, but these traces are quite absent in most birds.
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,
* I agree with Sharpe that Brown's figure of the Green Wagtail is quite unrecognizable, and that consequently Gmelin's name of viridis, founded on this figure, must be rejected.