no THE BIRDS OF THE BRITISH ISLES. 



males may have wide or narrow eye-stripes, and may be 

 almost without green on the cheeks ; the green crown and 

 yellow eye-stripe, however, always distinguishes them from the 

 blue crowned and white streaked Blue-headed Wagtail. The 

 colour of the back varies in shade and intensity, and this is 

 more marked in the females. The streaks and chins of hens 

 are often nearly white, making it practically impossible to 

 separate them from the other species, whose whites are some- 

 times slightly tinged with buff. I have examined birds which 

 might be of either species. In a flock of Yellows, where there 

 was one white-streaked bird which I could not place, another 

 female had a perfectly grey head and no visible streak above 

 the eye. Length, 6-5 ins. Wing, 3*25 ins. Tarsus, -9 in. 



Blue-headed Wagtail. Moiadlla flava Linn. 



That the Blue-headed Wagtail (Plate 45), the European 

 representative of our insular Yellow Wagtail, not only visits 

 Britain regularly, but also breeds in certain localities is proved, 

 but how many of its various allies and sub-specific races have 

 visited us on migration or as wanderers is still uncertain. The 

 typical M. f. flava breeds from Scandinavia and Russia to 

 southern central Europe and winters in Africa, and with us is 

 a regular bird of passage along both coasts. 



Any observer who has opportunity or luck and a keen eye 

 for colour may come across the Blue-headed Wagtail travelling 

 with Yellows, and it has nested in various English and Welsh 

 counties even as far north as Durham as well as in Kent and 

 Sussex, its best known haunts. Its nesting and other habits, 

 its voice and flight, and in the main its plumage, closely 

 resemble those of the Yellow, and hard and fast distinctions 

 cannot be safely stated. The eggs (Plate 41) so nearly corre- 

 spond that their identification is only safe when the male bird 

 has been seen at the nest (Plate 48). 



