DIVERS 225 



Allied Species. 



The Black-Headed Gull (L. ridibundus) is most frequently met with 

 on inland waters. It is only about the size of a crow, and in the colour 

 of its plumage resembles the herring gull, with the exception of the 

 head, which is dark brown in summer, but white in winter. 



The Albatross (Diomedea exulans) belongs to this order. Its body 

 measures over 3 feet in length. It breeds on the solitary islands of 

 the Southern Atlantic and Indian Oceans. It is the true monarch of 

 the ocean, being able to fly for days long without even once taking rest 

 upon the waves. It allows itself, in fact, to be driven along by the wind, 

 using its wings as sails (soaring flight). 



ORDER XIV. : DIVERS (IMPENNES). 



Beak laterally compressed. "Wings very short ; legs also very short, 

 articulated to the body very far back. The webs of the feet often deeply 

 incised (cleft-webbed feet). Aquatic in habit. Young either helpless 

 or "precocious." 



Great Crested Grebe {Podiceps cristatus). 



(Length 26 inches.) 



This curious bird is even more typically a denizen of the waters than 

 the species described above. It is met with on all the larger lakes of 

 Germany, and in England breeds on the Norfolk Broads and certain 

 other lakes in the Northern counties. It never leaves the water unless 

 actually compelled, and even sleeps on the surface. The eggs, too, are 

 hatched in a nest which floats on the water attached to rushes. On 

 leaving it, the bird covers over the eggs, which are white (devoid of 

 protective colouring), with some of the materials of which the nest is 

 cpmposed, so that the latter now assumes a striking likeness to a heap 

 of water-plants drifted together. The food of the bird consists of aquatic 

 insects, amphibians and their larvae, but especially fish, which it catches 

 by swimming and diving. For these actions the bird is excellently 

 adapted by the following features : the heavy, elongated body, which is 

 richly supplied with fat ; the close, well-oiled plumage ; the short legs, 

 which are placed almost at the extremity of the body, and in which the 

 tarsus is strongly compressed from side to side, whilst the three front 

 toes are united by deeply-incised webs. (Compare with duck.) This 

 bird can accomplish a distance of about 130 yards per minute when 

 diving under water. Its straight, sharp-edged beak is excellently adapted 



