THE WOBLD'S BIRDS. 3 



AUKS (Alcidce). 



DIAGNOSIS. Diving sea-fowl, with simple nostrils and 

 three webbed toes ; no hind-toe. 



SIZE. From that of a small goose to that of a 

 lark. 



FORM. Bill variously formed, corner of mouth ex- 

 tending to below eye ; feet with short shanks and 

 three fully webbed front toes ; wings short and 

 narrow ; tail short. Neck of medium length, body 

 stout and heavy. 



PLUMAGE AND COLOURATION. Dark above, white 

 below, or nearly all dark ; no sexual difference, but 

 usually a seasonal change. The Puffins shed the 

 outer sheath of the bill after breeding. 



YOUNG. Downy and active, but fed by the parents ; 

 down not streaked or spotted ; first plumage like 

 the winter dress of adults. 



NEST. None, the eggs being laid on a rock-ledge or 

 in a hole. 



EGGS. One or two only ; large, more or less conical, 

 spotted. 



INCUBATION. About a month, or even longer. 



COURTSHIP. In the Guillemot the male rises in the 

 water and swells his throat. 



FOOD. Marine animals, fish, Crustacea, etc. 



GAIT. On land an awkward waddle ; they sit erect, 

 and hobble on the hocks in some cases (Common 

 Guillemot), but not usually. They are fine 

 swimmers, especially below the surface, where 

 they use the half-closed wings for propulsion, not 

 the feet. 



FLIGHT. Heavy and straight, performed by constant 

 rapid beats of the wings. 



NOTE. A croak or whistle. 



DISPOSITION AND HABITS. They seem to be stupid 

 and quarrelsome. They are, however, sociable. 



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