THE NATURAL HISTORY OF AILSA CRAIG. 1 43 



This species is about the latest of the rock-birds frequenting the 

 Craig to begin laying. One year recently, on the 3rd of June, in 

 a number of nests but one egg was found. On a previous visit 

 on the same date a fair start had been made. Its eggs are more 

 varied in ground colour and markings than its congeners, and 

 many of the clutches are indeed very beautiful. It lingers at its 

 nesting haunts till the end of August, by which time some of its 

 neighbours are on their way to winter quarters. 



A group of oceanic birds which are rock-breeders now calls for 

 mention. The first is the razor-bill (A/ca tordd) which, like the 

 guillemot next to be referred to, swims and dives with great ease, 

 and offers capital sport as some ardent gunners in Clyde waters 

 very well know. In more northern localities the razor-bill is 

 migratory, but here it is found all the year round. The wings in 

 this group are used for propulsion under water, and as the 

 birds are somewhat confiding their evolutions under water can be 

 watched where the waters are clear. According to the light-keepers 

 they appear around their nesting haunts early in March in small 

 companies, gradually increasing in numbers until the middle or 

 end of May, when laying begins. The razor-bill lays a single large 

 egg, but neither in form nor colour does it equal the beauty of the 

 egg of the guillemot. The razor-bill further is sometimes found 

 on rocky places on the western slopes of the Craig. Mr. Seebohm, 

 in his posthumously published work on the Eggs of British Birds 

 (1896), says that " ledges are shunned. The razor-bill must have a 

 hole, if one can possibly be obtained." We find it, however, on the 

 Craig on the precipices, near their summits, literally "cheek-by- 

 jowl " with their congeners, the guillemots. This species suffers 

 greatly in time of storms in winter, and the shore is often strewn 

 with the dead, possibly, as the late Dr. Robertson of Millport 

 suggested, from emaciation and starvation, following on the 

 disappearance of the small fry and other fishes after heavy gales. 

 A great disparity in the relative numbers of the razor-bill and 

 guillemot has been noticed in Clyde waters in the present year 

 (1900), the latter greatly outnumbering the former. 



The guillemot ( Uria troile) occurs in great numbers and affects 

 the ledges on the cliffs. Its egg rests on the rock ledges with 

 no preparation whatever in the shape of a nest, and I have seen 

 eggs placed in situations at an angle from the horizontal which 



