BRITAIN^S BIRDS AND THEIR NESTS. 275 



The Martin, however, is not always allowed to cany 

 out its nesting operations in peace. Although the list of 

 its enemies is comparatively short, one of them — namely, 

 the House-Sparrow — is formidable in its numbers. The 

 Sparrow's particular crime in this case is that it takes 

 forcible possession of the Martin's newly built nest, and, 

 lining it to suit its own taste, uses it for its own eggs 

 and young. 



The Martin is but ill-adapted to fight the strong-billed 

 bully, and the result is nearly always the same ; the 

 useful insectivorous bird is ejected from its rightftil nest 

 by the bird which is now becoming more and more of a 

 plague to the farmer and the gardener. Repeated in- 

 stances of whole colonies of Martins having been thus 

 ousted by Sparrows are on record. But the House-Martin 

 seems to be at all times somewhat capricious in its choice 

 of nesting-sites, and given to abandoning chosen haunts 

 without obvious reason, and it remains to be shown to 

 what extent its persecution by the Sparrow has affected 

 the number nesting annually in our islands. 



THE SAND=MARTIN 



(Cotile riparia). 



Plate 93. 



For a number of reasons the Sand-Martin is the least 

 familiar of the three Swallows ; it is less numerous, 

 its haunts are usually remote from those of men, and 

 owing to its smaller size and its mouse-coloured plumage 

 it is altogether a less noticeable bird. The jerky 

 flight of this species may also be distinguished from the 

 graceful flight of the Swallow and the heavier flight of 



