GEOGRAPHICAL ASPECTS 79 



Inner Hebrides, fly towards Barra Head and traverse 

 the outer group to their northern h'mit at the Butt of 

 Lewis. 



This deflection of the two streams of migration to 

 the west is probably due to the extreme irregularity, 

 ruggedness, and barren nature of the coast of the 

 western mainland of Scotland, with its numerous firths 

 ending in ciil de sacs — characteristics which render it 

 unsuitable as a migration route, inhospitable and unin- 

 viting for migrants, and almost impossible for the 

 observer. 



There is yet another western route, the westernmost of 

 all. This lies along the Atlantic coast of Ireland, which 

 is possibly reached direct from the north-west coast of 

 France, and not by way of the south-west coast of 

 England. The regular travellers by this Irish fly-line do 

 not, so far as is yet ascertained, belong to many species, 

 but they include the Whimbrel, White Wagtail, Snow 

 Bunting, Wheatear, White-fronted Goose, Barnacle 

 Goose, Golden Plover, Grey Phalarope, Great Northern 

 Diver.^ On quitting the Donegal coast, the migrants 

 proceed northwards by way of the Outer Hebrides, 

 including their outermost island, St Kilda. Having 

 reached the northern limit of the mainland and the Inner 

 and Outer Hebridean Islands, the majority of the 



^ The probability is that the west coast of Ireland is much more 

 resorted to as a migration route than is generally supposed. Certain islands 

 off the coast, Tearaght in particular, have produced some of the most 

 interesting migratory birds that have been obtained in Ireland, such as the 

 Yellow-browed Warbler, Red-breasted Flycatcher, Short-toed Lark, Golden 

 Oriole, Lapland Bunting, Greater Redpoll {A. rostrata), and others. In all, no 

 less than fifty-one species of migrants have, from time to time, been observed 

 there. If a trained observer were to spend a few weeks on one of these 

 islands during the autumn or spring, much light would be thrown on this 

 interesting far-western stream of migration. 



