CHAPTER IV 



THE GEOGRAPHICAL ASPECTS OF BRITISH 

 BIRD-MIGRATION 



The geographical distribution of migratory birds in 

 the British Islands, at any season, obviously depends 

 upon the nature of the particular movement or move- 

 ments then occurring, or, in other words, upon whence 

 the migrants come and whither they are bound. 



In connection with the geographical aspect of 

 migration, it is impossible to over-estimate the value of 

 observations made at islands and rock stations, and 

 other places removed from the usual haunts resorted to 

 by the various species. At such stations to see certain 

 birds is to know at once that they are on migration, 

 for under no other conditions would these particular 

 species be observed there. 



The most unsatisfactory of all observations are 

 those made inland. Here individuals of many species 

 moving to other quarters in our islands are most 

 difficult, if not impossible, to distinguish from the native 

 representatives of the same species. In addition, the 

 area and, in many cases, the cover is so extensive that 

 few, very few, of the birds passing through any district 

 come under notice. One never knows what is in the 

 next field or the next bit of cover ; while woods are 



70 



