vi INTRODUCTION 



seek to devour them. Not only are the nests and eggs thus 

 concealed, but the sitting bird, in all cases where she hatches 

 in open nests, is dressed in the sombre colour of her sur- 

 roundings. The hen pheasant is not arrayed in the bright 

 plumage of the male, which would render her open to 

 observation as she sits on her nest. Her eggs accord with 

 the colour of the ground on which they are laid. White 

 eggs that would be conspicuous are usually placed in well- 

 concealed holes, such as are selected by the Kingfisher and 

 the Woodpecker, which themselves are brightly coloured, 

 and would be conspicuous on open nests. When the eggs 

 are white, they are either in concealed nests or, if in open 

 ones, are covered by the bird on leaving so as to be hidden 

 from observation. In many instances where the eggs are 

 placed in inaccessible positions they are brightly coloured. 

 The most remarkable English example of eggs of this 

 type is that of the Guillemot, whose eggs vary from the 

 dullest buff to the most resplendent blue, each bird, pro- 

 bably, always laying an egg of the same definite colour. The 

 difficulty of finding spotted eggs of many shore-nesting 

 birds, amidst the stones and shingle in which they are laid, 

 is well known, and is a remarkable example of the protective 

 influence of colour and marking. 



It is usually imagined that the nest of each species of bird 

 is built in precisely the same pattern as the others, owing to 

 an unreasoning and unvarying instinct. This, however, is not 

 the case. The Sparrow, originally a tree-building species, 

 has long since become a parasite on man, and its nests are 

 now usually built in holes in his buildings, or in any con- 

 tiguous place that will receive them. Many ground-building 

 birds of the Pacific Islands, whose nests were destroyed by 

 the pigs, rats, and other animals that were thoughtlessly 



