The Summer Birds of the Summer Islands. 49 



saw a Raven, no doubt one of the owners of the nest, 

 examining the ground systematically in quest of food. I 

 found on Priest Island a dead Eaven at the foot of the 

 cliff which is tenanted by the Peregrine Falcon. 



9. CoRVUs coRXix, Linn. 



(Hooded Crow.) 



Several seen on Horse Island, Carn-nan-Sgeir, Eilean 

 Dubh, and Tanera More ; and it probably breeds on nearly 

 all the islands. 



10. AL-\rDA ARVEXSIS, Linu. 



(Skylark.) 



Observed only on Horse Island, where it nests. 



11. Falco peregeixus, Tunstall. 

 (Peregrine Falcon.) 



A pair nest on Priest Island. After some little trouble 

 Mr Bonar discovered the eyrie, which contained four young 

 birds about a week old. Their larder was very well stocked, 

 and contained the head of a Pied shank, a bird which was not 

 observed on any of the Summer Islands. 



Upon landing at Glasleacbeg we found that the island 

 had been visited by some large raptorial bird. A very 

 powerful freebooter it must have been, as was proved by the 

 numbers of skulls and wings of Black-backed Gulls which we 

 found lying about. The depredations were probably caused 

 by the Peregrines from Priest Island. Indeed it is difficult 

 to lay them to the charge of any other bird. On the other 

 hand, the castings were large for those of a Peregrine — at all 

 events they were much larger than any which had previously 

 come under my observation. Moreover, it does seem strange 

 that the Peregrines should prey upon such large and 

 powerful birds as the Black-backed Gulls, when they could, 

 by attacking incomparatively weaker quarry, obtain an 

 abundant food-supply. 



VOL. XIV. D 



