32 BLACK-AND-WHITE BIRDS. 



the dark markings ; others are plain green, and oc- 

 casionally of a rich reddish-brown=; 3-25 x 2-0 inches 

 (plate 123). 



Nest. — None, the egg being placed' on open cliff- 

 ledges or on the flat tops of rock-stacks. 



Distribution. — Around the coasts of the British 

 Isles wherever suitable cliffs or rock-stacks occur. 



Common Guillemots breed in colonies on cliif- 

 ledges or rock-stacks, the single egg being deposited 

 on the bare rock. During the breeding season many- 

 birds, closely packed, line the ledges, their dusky 

 backs turned landwards and their white breasts 

 towards the sea. In this they resemble their asso- 

 ciates the Puffins and Razorbills, also birds with dark 

 upper plumage, and with the lower parts white. The 

 long, sharp bill of the Guillemot, however, at once 

 distinguishes it from both. In flight the Guillemot's 

 short wings beat violently, and the bird shoots 

 rapidly along, in form like a small torpedo, unable 

 to indulge in any graces of flight beyond the long, 

 gradual curve with which it sweeps in from the 

 sea or hurries out to sea again. When it alights 

 either on the rock or on the water, it plumps down 

 abruptly. Large companies of Guillemots generally 

 cover the water at the foot of the cliffs, drifting 

 irregularly with the currents. The bird is an expert 

 diver, using its wings as fins under water. The 

 Guillemot's principal cries are an almost human 

 moan and a barking sound as of a pup. This bird 

 is more numerous than the Razorbill, with which it 

 associates freely, generally sharing the same nesting- 

 site, the Guillemots depositing their eggs on the more 



