THE WORLD'S BIRDS. 3 



Auks (Alcidce). 



Diagnosis. — Diving sea-fowl, with simple nostrils and 

 three ivebbed 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. 



