Ornithology of Si. Kilda. 95 



deafening. The Shearwater is nocturnal in its habits and at 

 night-time becomes very garrulous. Donald imitated its note 

 to a nicety^ and it may be expressed on paper as kitty -coo-roo, 

 kitty -coo-r 00. This note is uttered when the bird is flying 

 and when sitting on its nest. Guided by the note, the men 

 are able to find the nests with little difficulty, so that they 

 always prefer to go in search of this species at night. I 

 obtained eggs of this bird in the cliffs on the south-west part 

 of St. Kilda. Much to the disgust of Donald I allowed one 

 of the Shearwaters to escape in order to observe its flight and 

 actions in the daytime. The St.-Kildans cannot understand 

 a man who having once caught a bird allows it to escape 

 again ; and in low whispers one asked the other in Gaelic if 

 the " Sassenach '' were not a madman ! The birds I dissected 

 had been feeding on sorrel^ and the stomach contained a dark 

 oily substance. 



Thalassidroma pelagica. "■ Assilag.^' 



I did not get a glimpse of the Stormy Petrel, but it is 

 very common, especially on Soay, where I was unable to land. 

 Sir William Milner obtained its eggs on Borreay on the 15th 

 of June; and it also breeds on Doon, where its eggs were 

 taken last year. Its date of arrival and departure is said by 

 the natives to be similar to that of the Shearwater. 



Thalassidroma leucorrhoa. '^Assilag." 



The natives do not distinguish by name the two species 

 of small Petrels that breed on St, Kilda, although Donald 

 seemed well aware of the difference between them. The first 

 British examples of the Fork-tailed Petrel were obtained on 

 St. Kilda in the summer of 1818 by Bullock, a year after 

 it was first described by Vieillot ; and at that time the 

 species was so rare that only three other examples were 

 known. I cannot find that Bullock ever published any 

 account of his discovery, but his specimen is described in 

 his sale-catalogue as '' an undescribed Petrel, with a forked 

 tail, taken at St. Kilda in 1818.'" It is pretty common on 

 Doon, and Sir "William Milner also obtained its eggs on 

 Borreay and Soay. It does not, so far as I could learn, breed 



