I So THE MIGRATION OF BRITISH BIRDS 



exceptions all these resident birds range much higher in 

 continental Europe than they do with us. The exceptions 

 arc the Nuthatch and the Bullfinch, represented however 

 in more northern latitudes by closely allied climatic races. 

 This fact, as applicable to the Summer Migrants as to 

 the Residents, shows very clearly that it is only the 

 indigenous or British individuals of the species that are 

 endeavouring to expand, and in some cases to regain, 

 their northern range, the dominant line of Emigration 

 of the indigenous continental individuals being in the 

 majority of cases entirely outside our limits, and, in the 

 remaining few cases, principally so. We may also here 

 remark that species in which the habit of Migration is 

 dominant (although individuals may be sedentary with 

 us or partly so) appear to extend their range more 

 rapidly than strictl}- sedentary species — the migratory 

 Ring Dove, for instance, advances quicker and more 

 dominantly than the much more sedentary Stock Dove. 

 There is one very important fact connected with all 

 this current emigration, and that is its invariable north- 

 ward tendency. It may be in an easterly or westerly 

 direction, but the trend is always north, never south. I 

 find that in the majority of cases this emigratory move- 

 ment has been attributed to the spread of cultivation, to 

 the planting of trees and the making of shrubberies ; 

 but are we justified in accepting such an explanation, 

 when we invariably find that this movement has been 

 ever northerly, and of course in accordance with a 

 known Law } Has cultivation and tree planting always 

 been in a northerly direction .' surely much of it has 

 taken place in southerly areas as well ; but with no 

 accompanying signs of Avian Emigration from north to 



