80 STUDIES IN BIRD-MIGRATION 



migrants proceed towards the Orkney and Shetland 

 groups, whence they depart for the shores of Norway. 

 Others fly direct to the north for the Faroes, and thence 

 north-west to Iceland and Greenland, to reach which, 

 however, many of the birds also travel by the Orkneys 

 and Shetlands. 



These western routes boast of several most favour- 

 ably situated stations for observing these interesting 

 movements to and from the northern regions. These 

 include Skerryvore, situated out in the Atlantic, con- 

 siderably to the south of the Hebridean groups, being 

 II miles W.S.W. of the island of Tiree, and ^^ miles 

 S.S.E. of Barra Head, the southern extremity of 

 the outer islands. Many migrants pass this lonely 

 rock, and fortunately one of the head light-keepers, 

 the late Mr James Tomison, was a deeply interested 

 and most capable observer. As the result of nearly 

 four years' bird- watching there, he tells us ^ that 

 the birds (he is speaking of the autumn movements) 

 come direct from Barra Head, and that on reaching 

 Skerryvore they slightly alter their course to proceed 

 due south — a course which would carry them to the 

 north coast of Donegal. From Mr Tomison's experi- 

 ence it would seem, as we should expect, that the birds 

 travelling by the inner islands pass to the east of this 

 station, for, with the exception of Skylarks seen on 

 several occasions coming from Tiree, no migrants from 

 that direction came under his notice. 



The outermost fringe of the western stream passes, 

 as we have seen, along the Atlantic coast of Ireland, 

 and in its more northerly course touches St Kilda, 

 where the number of species occurring is quite remarkable 



' ?)tt. Afinals of Scottish Natural History^ icjo'] ;ip. 20-31. 



