14 



BIRD-LIFE OF THE BORDERS 



winter to C, while those at the latter point would move 

 southwards to D — the two latter being- the most southerly 

 points in the two areas. In the overlapping - zone (the 

 doubly-crossed portion) there will obviously be found birds 

 of the species in question permanently at all seasons. But 



■O MILCS 



1000 



Zooo 



3000 



7? 



they are clearly not the same individual birds. Those 

 individuals which occupied this area in summer will be 

 wintering — say iooo miles south- — at E ; while the places 

 they have vacated are reoccupied by others which have 

 passed the summer iooo miles north at F. 



Now, birds of such distribution as above are clearly 

 quite as much migrants as are the swallow or the 

 cuckoo. If one happened to live in Siberia or in Africa, 

 there would be no difficulty in recognising- the fact ; 

 but to those who live, as we do, within that central area 

 where their summer and winter rang-es overlap, the 

 movements of such birds are not patent, and are easily 

 overlooked. It is a prevalent mistake to regard birds 

 of this class as resident [i.e., non-migratory), and this is a 

 point I wish to elucidate. 



Take the curlew as an example. Probably nine 

 people out of ten — shore-shooters and others accustomed 

 to seeing them daily — will tell you that the curlews are 

 on the moors all the spring, and on the coast all the 

 winter. This, in a sense, is perfectly correct ; but 



