THE RAZORBILL AND GUILLEMOT 15 



species on the same ledge, the guillemots on the half which was 

 open, and the razorbills on the other half, which was overhung in 

 such a way as to permit the birds to occupy it only in a sitting 

 position. On these cliffs the former species is in a large majority. 

 The opposite is the case at the Scilly Isles, " where precipitous rock 

 faces are few in number, whilst rocks covered with huge boulders and 

 intersected in all directions with nooks and crannies abound. Here, 

 in the latter, razorbills are swarming, and are indeed often quite as 

 numerous as the puffins. There are many low islets which only rise a 

 few feet above the sea, and are scattered all over with boulders of 

 various sizes, amongst which razorbills and puffins are about equally 

 distributed, but where not one guillemot will be found." 1 On the 

 Fames, on the other hand, the guillemots are much the more numerous, 

 for here they have not only suitable ledges but the flat top of the 

 stacks known as the Pinnacles. The photograph of these on PL xxxix. 

 and Mr. Seaby's drawing (PI. 94) will give a good idea of the pressure 

 upon the available space. To realise, however, the enormous numbers 

 in which these birds, together with puffins and other cliff-frequenting 

 species, congregate in the breeding season, one must go to larger 

 colonies, like those in the Western Isles, where the birds crowd the 

 sea and the cliffs, and blacken the air in their passage from one to the 

 other. At N. Ronay, in the Outer Hebrides, the huge number of 

 breeding guillemots is said to be augmented by the visitations of 

 hundreds of thousands of non-breeding birds. 2 These include, no 

 doubt, a certain proportion of immature individuals. In the case of 

 razorbills, Mr. Ussher states that a certain number of the birds of the 

 previous year make their appearance at the Irish breeding-haunts, 

 but only in small numbers. 3 According to Naumann, the non-breeding 

 birds may be seen in pairs, either sitting among the others, or in groups 

 apart, the groups being mostly composed of the young of the previous 

 year. He adds that these pairs perform just the same love actions, 



1 C. J. King in litt. 



* Harvie-Brown and Buckley, Fauna of the Outer Hebrides, p. 161. 



3 Birds of Ireland, p. 356. 



