BIRDS OF ARRAN. 311 



common. It breeds, though not in great numbers, in some 

 of the lochs of Arran. Mr. Mackenzie informs me that he 

 has caught the young ones among the heather as late as the 

 middle of August. 



Obs. I have frequently, in some of the sheltered bays 

 which are fringed with wood, seen flocks of gulls of 

 various species engaged in catching flies and other insects, 

 while at a considerable height in the air. Sometimes the 

 birds were near enough for me to see the gulls snapping 

 with open mandibles at the insects, like accomplished fly- 

 catchers. In September, 1867, when on the west side of 

 the island of North Uist, in the outer Hebrides, I saw 

 nearly a thousand sea gulls of all kinds hovering over the 

 heads of a large congregation of persons asembled for worship 

 in the open air. The weather was extremely hot; and, as 

 the service was entirely in Gaelic, my attention was wholly 

 drawn to the gulls, whose instincts had brought them where 

 they would find an ample supply of insect food. They flew 

 to and fro, snapping up the flies with amusing dexterity ; and 

 though I did not remain longer than an hour at the place, 

 I was afterwards informed they had continued their soaring 

 flight until the assemblage dispersed. 



POMERINE SKUA (Lestris pomerinus). I have recognized 

 this bird off Brodick, and also in Kilbrannan Sound. 



RICHARDSON'S SKUA (Lestris Ricliardsonii). This pirate 

 bird has also been recognized in passing during the autumn 

 months. 



MANX SHEARWATER (Puffinus anglorum). Recognized by 

 myself off Brodick, on more than one occasion. 



FORK-TAILED PETREL (Thalassidroma Leachii). Occurs in 

 the Firth of Clyde every winter, and is occasionally blown on 

 shore during a storm of unusual severity. 



STORM PETREL (Thalassidroma pelagica). I have seen 

 small parties of this interesting little bird on dull days while 

 boating in the firth. A few pairs breed on Ailsa Craig, where 

 I have seen them quitting their holes at mid-day. 



