24 THE AUKS 



suddenly startled by the report of a gun or otherwise, for each egg 

 rests between and partly, if not wholly, on the bird's webbed feet. 

 The sight of such sudden downfalls was, and possibly still is in certain 

 places, "one of the amusements of the gaping tourist," to quote 

 Alfred Newton. When not frightened off its egg, the bird is careful 

 to get its feet away from it before taking flight. When thus left, a 

 pear-shaped egg would, of course, if the rock where it stood were not 

 level, be much less likely to roll than a round one, but it would be 

 rash to assume that this explains the pear shape, for it is almost 

 certainly that of the guillemot's ground-laying ancestor. Indeed, 

 the similarity of the eggs of Auks and existing Plovers is regarded 

 as one of the proofs of their descent from a common stock. The 

 primary use of the pyriform shape may be seen by examining the 

 arrangement in the nest of the four eggs of the green plover or lap- 

 wing ( Vandlus milgaris). They lie with their points meeting, and so 

 occupy the minimum of space. 



Both guillemots and razorbills appear to sit with the egg not 

 across the webbed feet, but lengthwise between them. The guillemot 

 incubates either in an erect position or lying flat, the former, no 

 doubt, originating as a space-saving device on crowded ledges. It 

 usually sits with its breast facing the cliff. This is especially the 

 case on ledges sloping seaward. On less sloping cliffs its has been 

 seen to sit sideways, and on large roomy flat surfaces with the breast 

 to the sea. 1 The normal position of the incubating razorbill is the 

 recumbent. The nature of its nesting-place would in most cases 

 render any other impossible. Both sexes, in the case of both species, 

 share in incubation, and have brood-spots for the purpose. The males, 

 in addition, feed the hens when incubating. 2 Naumann denies this 

 in the case of the guillemot. 3 Personally I have watched incubating 



1 C. J. Patten, Aquatic Birds, p. 485. 



2 For the guillemot : Harvie-Brown and Buckley, Fauna of Outer Hebrides, p. 161 (Finlayson) ; 

 E. Selous, Bird Watching, p. 187. For the razorbill : Patten, A quatic Birds, p. 470 ; H. Saunders, 

 Manual of British Birds, p. 696. 



3 Vogel Mitteleuropas, xii. 212. 



