THE WORLD'S BIRDS. 133 



usually nearly self-coloured, or in large masses ; 

 no difference between the sexes or according to 

 season. Young usually like adults. 



YOUNG. Downy, but helpless and fed by parents, 

 who disgorge food into the young one's bill in- 

 serted into their own. The down is self-coloured, 

 sooty or white. 



NEST. Usually a burrow ; in Albatrosses a raised 

 structure in the open, of earth and turf. 



EGGS. One ; white, in some cases with red spots. 



INCUBATION. From one to two months. 



COURTSHIP. In the case of the Albatross the birds 

 stand face to face, point their bills skyward, and 

 utter a groaning sound. 



FOOD. Marine animals, ships' refuse, and carrion; 

 some large species eat the smaller ones. 



GAIT. An awkward walk ; many assume a crouching 

 attitude when walking. They swim welV as a 

 rule, and some are also good divers. 



FLIGHT. Remarkably powerful in most, though they 

 often have a difficulty in rising off a level surface 

 either on land or water ; they are adepts at 

 sailing, especially the large species, and usually 

 fly low. The small Petrels fly much like swallows. 

 The neck is drawn in, and the feet stretched out 

 behind, in flight. 



NOTE. Various, and rather discordant ; groaning and 

 cooing sounds are common. 



DISPOSITION AND GENERAL HABITS. Many of these 

 birds are largely nocturnal, and few come inland 

 voluntarily, so little is often known about them. 

 Many, however, follow ships. They seem ravenous 

 and not very intelligent. 



ECONOMIC QUALITIES. The young of some species 

 are used as food locally, while all are of aesthetic 

 value as enlivening vast stretches of ocean. 



DISTRIBUTION AND IMPORTANT SPECIES. They are 



