14 THE AUKS 



the breeding season from the clear-cut thin white lines round the beak, 

 and from the beak to the eye. Its figure, if a trifle stout, is compact 

 and well defined. The guillemot lacks finish, especially about the 

 head and beak, owing to the unrelieved uniformity of the coloration of 

 its upper parts. The ringed, bridled, or spectacled variety, which has 

 a white ring round the eye and a white streak behind it, makes a 

 better appearance, but these additions do not compensate for the 

 want of a clear dividing-line between the head and the beak. The 

 bridle marking has yet to be explained. The individuals which have 

 it mix and breed freely with the ordinary type, but remain in a minority, 

 which appears to vary, however, in different localities. The propor- 

 tion of the variant to the typical form is given as one to fifty in 

 Ireland, and one to five in the Western Isles. 1 At the Flamborough 

 Cliffs (Bempton, May 1911) I saw scarcely any of the former, not 

 more than three among some hundreds of birds. 



Between the breeding seasons both species are to be found, 

 usually in comparatively small parties, off our coasts or far out to sea. 2 

 They pass their days and nights on the water. Towards the beginning 

 of February, or sometimes later, they draw near their breeding-haunts, 

 which they appear to frequent somewhat irregularly till April, when 

 they begin to occupy their nesting-sites in considerable numbers; 3 

 but laying does not begin till May. 



Razorbills and guillemots are generally to be found on the same 

 cliffs, but their relative numbers vary to a greater or less degree 

 according to the nature of the nesting-sites provided. As is well 

 known, guillemots prefer open ledges, or the tops of stacks, 

 though they may also be seen in crevices or holes in the face of 

 the cliff. Razorbills prefer the crevices, or a ledge which is over- 

 hung. On the Flamborough cliffs (Bempton) I have seen both 



1 Ussher, Birds of Ireland, p. 361 ; Harvie-Brown, Outer Hebrides, p. 161. 



1 The extent of their gregariousness between the breeding season is not very clear from the 

 evidence. The same applies to the movements of the two species previous to their occupation 

 of their breeding-haunts in April. 



' Usaher, Birds of Ireland, pp. 356, 361 ; Nelson, Birds of Torks., ii. 711 ; Annals of Scottish 

 Natural History, 1904, p. 22. 



