82 STUDIES IN BIRD-MIGRATION 



and our islands lie in the course of their migrations, 

 when they are proceeding from, and returning to, their 

 European or African winter quarters. It is probable 

 that the majority of them make their passages along our 

 western shores, for important movements of Red- 

 wings, Wheatears, White Wagtails, and Whimbrels are 

 observed on the west coast of Great Britain and the 

 Irish coasts (both east and west) when they are not 

 observed elsewhere with us. That many of them visit 

 the Orkneys and Shetlands, and some of them the east 

 coast of Britain on their journeys is manifest from the 

 abundance of the large form of Wheatear (S. leucoi'rhoa), 

 which in summer is confined to Greenland and Iceland. 

 This bird occurs at Fair Isle, and in a lesser degree 

 on the mainland shores of the North Sea, in both 

 spring and autumn. No doubt many other migrants 

 to and from the north-west also proceed along our 

 eastern sea-board, but being of the same species as the 

 travellers from the northern portions of the Continent, it 

 is impossible to distinguish them. 



In instituting a comparison between the east and 

 west coast routes, we find that the birds of passage 

 travelling to and from Northern Europe are more 

 numerous in kinds, and very much more so in individuals, 

 on the east side than on the west. Many species that 

 traverse our eastern coast-line in vast numbers, and 

 others that do so less abundantly, but yet regularly, 

 occur on the western coasts, either in much smaller 

 numbers or only as occasional or rare visitors. The 

 following are among the migrants which are less frequent 

 or actually rare on the west coast : — the Redstart, Tree- 

 Pipit, Hedge Accentor, Red-backed Shrike, Pied Fly- 



