GREY WAGTAIL. I07 



at this season many move southward, and some emigrate. 

 The call is a soft tzissi, and in spring it has a low plaintive 

 love-note ; but it is not much of a songster, though its short 

 twittering melody occasionally mingles with the music of the 

 stream. The flight is decidedly undulating, and as the bird 

 alights it almost invariably spreads and raises its tail. 



The nesting site is usually in some crevice in a rock, wall or 

 bank, sheltered above, and close to running water. Rootlets 

 and a" little grass are the outer materials, and hair forms the 

 lining ; Seebohm noticed a decided preference for white cow- 

 hair. Four to six eggs, speckled or marbled with grey and 

 brown and often with one or two hair-hnes (Plate 41), are laid 

 late in April, and a second brood is reared. 



The title Grey Wagtail is apt to mislead, and frequently 

 birds seen in winter are mistaken for Yellows ; Slate-backed 

 Yellow Wagtail would be more descriptive, for the distinguish- 

 ing coloration is a slate-blue head and back, with greenish- 

 yellow rump and tail-coverts and sulphur-yellow under parts. 

 In breeding dress the grey cheeks of the male are set off by 

 white streaks above and below, and the chin and throat are 

 black ; this black is assumed during the spring moult, and at 

 first many of the feathers are margined with white. In addition 

 to the white feathers of the tail, pale margins to the inner 

 secondaries are distinct on the brown-black wings. The 

 female has little or no black on the throat, and her head and 

 back are tinged with green. The bill, legs and eyes are brown. 

 The black on the throat is lost after the autumn moult and is 

 replaced by white ; the slate is tinged with olive. Young birds 

 resemble the adult in winter, but are browner, and the whites 

 are suffused with buff. Length, 7*5 ins. Wing, 3*25 ins. 

 Tarsus, '85 in. 



