1920.] Birds of the Canary Islands. 547 



the view that the Canaries were ever joined to the continent, 

 tliat the only mammals wliich have foi;ncl their own Wiiy to 

 the Archipelago and have not been introduced, are those 

 which could fly there — members of the family Vespertilionidse 

 or Typical Bats, 



The birds which had already settled in the islands are then 

 the only species with which succeeding immigrants would 

 have to contend ; for it does not appear that mammalia in 

 any form inhabited the Archipelago in past epochs o£ its 

 history. 



" Enemies'" in the Canary Islands at the present day are 

 few in kind — small boys, '^ sportsmen "' — collectors of eggs 

 and of cage-birds being the most destructive. 



Of Kaptorial birds the Barbary Falcon, Buzzard, ? Kite, 

 and Sparrow- Hawk probably do the most harm, for the 

 Kestrels, wliicli swarm, pay iittle attention to the other birds 

 in the islands. The mongoose and snakes are unknown and 

 rats are confined to the towns, so that, on the whole, the 

 islands may be said to be singularly free from many of the 

 daggers which beset continental species. Of pugnacious 

 varieies which live in the islands the Spanish Sparrow 

 easily takes first place, and to this bird is probably due the 

 failure of the llirundinidcC to nest in the Archipelago. 

 Swallows or Martins Avould have little chance of using 

 the nests which they built. 



The fact that many of the birds of the same species in the 

 C^anaries are differently modified, although the islands are 

 all within sight of one another, requires more explanation 

 than is at first apparent. Undoubtedly the difference in the 

 ])hysical conditions, which I have shown to exist between 

 islands of the eastern group and those of the western 

 group, is sufHcient to explain the distinctive characters in 

 the birds inhabiting the two groups. The Brown Linnet, 

 Short-toed Lark, Blue Titmouse, Chifichaff', Barn Owl, 

 Kestrel, and Thick-knee are all subspecifically distinct in 

 the eastern group from the corresponding race in the western 

 islands ; those from the eastern group show in their 

 plumage or structure characters which have undoubtedly 



