92 STUDIES IN BIRD-MI&RATION 



traverse the Continental land-masses. That this should 

 be so is not at all surprising-. Our area is longitudinally 

 too circumscribed to render them necessary, for our coast- 

 lines are near at hand, and these birds keep to them 

 and their immediate neighbourhood with remarkable 

 pertinacity. As an indication of the coasting pro- 

 clivities of these migrants, it may be remarked that all 

 the species which are essentially birds of passage (such 

 as the Bluethroat, Curlew Sandpiper, etc., etc.), are of 

 rare or exceptional occurrence at inland localities in our 

 islands. The Scottish birds of passage include a 

 number of species which are breeding birds in England 

 and in Scandinavia, but not in Northern Britain (such 

 as the Lesser Whitethroat, Red-backed Shrike, Wry- 

 neck, Ruff, and others), and these are practically con- 

 fined to the Scottish coast-line and its neighbourhood 

 when passing northwards in the spring and southwards 

 in the autumn. The occurrence, inland, of any of the 

 species which visit us on passage only is more or less 

 rare, and certainly exceptional. 



There are, however, many highways of minor import- 

 ance which deserve some consideration, though our 

 knowledge of most of them is of a very imperfect 

 nature. These are the overland courses followed by the 

 summer and winter visitors when proceeding to and retir- 

 ing from their seasonal haunts on the mainland of Great 

 Britain and Ireland. 



After arrival on our shores in spring and autumn 

 many of these immigrants proceed to their accustomed 

 haunts along natural and convenient highways, and, the 

 summer or winter o'er, again seek the coast-line. In the 

 case of some species, to which reference will presently 

 be made, the routes followed are determined by the 



