260 MOTACILLID^ MOTACILLA 



and in moist and humid situations, it frequents also dry and arid 

 localities at a distance from water, and is found equally in towns 

 and villages and in uninhabited districts. It is even a resident on 

 the barren and waterless guano islands off the west coast. Like 

 its congeners it appreciates the society of horses and cattle, and 

 follows these animals closely in order to catch the flies and other 

 insects which they disturb. It runs on the ground with activity 

 and frequently rises a few feet in the air in pursuit of a fly. When 

 prolonged its flight is undulating, in a series of curves. It has a 

 sharp call-note, " chis-sek," frequently uttered, almost invariably 

 as it takes flight, and in spring a somewhat feeble song. It feeds 

 almost entirely on insects, principally on flies and mosquitoes and 

 their larvae, occasionally on a few small seeds. The nest, usually 

 commenced in September, is a somewhat bulky cup-shaped struc- 

 ture, built of dry grass and dead leaves and lined with short hairs 

 and fur. It is often placed against the bank of a river or stream, 

 under a stone, or among the exposed roots of a tree or bush, some- 

 times in the hole of a wall or rock, at others on a heap of driftwood. 

 The eggs, three or four in number, are buff - coloured, thickly 

 spotted and mottled all over with brown. They average about 

 0-84 x 0-56. 



150. Motacilla campestris. Bay's Yellow Wagtail. 



Motacilla campestris, Pallas, Eeis. Buss. Beiclis. iii, Anhang, p. 697 

 (1776) ; Sharpe, Cat. B. M. x, p. 510, pi. 6, figs. 1 and 2 (1885) ; Shelley, 

 B. Afr. i, p. 11 (1896). 



Motacilla rayi, Dresser, B. Europe, iii, p. 277, pi. 131 (1875). 



Budytes campestris, Sharpe, ed. Layard's B. S. Afr. p. 551 (1884). 



Description. Adult male in breeding plumage. Above, back olive- 

 yellow merging into bright yellow on the rump, olive edged with 

 yellow on the upper tail-coverts ; lesser wing-coverts like the back ; 

 remaining coverts and quills dusky brown edged with yellowish 

 and pale brown, two outer tail-feathers white, the inner webs with 

 a brown streak, the next with the outer web and a patch on 

 the inner white, the rest dusky brown ; forehead bright yellow 

 becoming duller on the crown; eyebrow, eyelids, lores, centre of 

 ear-coverts and cheeks bright yellow ; rest of ear-coverts olive ; 

 below, bright yellow, the sides tinged with greenish ; axillaries 

 bright yellow; under wing-coverts white tinged with yellow and 

 mottled with dusky. 



