124 BRITAIN^S BIRDS AND THEIR NESTS. 



a good average height. The nest may also be in 

 bushes, hedgerows, or thick ivy on crags or ruins ; and 

 old nests of other species may even be used. 



The two glossy, white, oval eggs of the first clutch 

 are laid in March or April. Both parents take part in 

 incubation, which lasts for two and a half weeks. The 

 chicks are nidicolous, being blind, naked but for a few 

 down - feathers, and helpless at first. They are fed with 

 ' pigeon''s milk,"" a curdy secretion from the crops of 

 both adults, and later with more solid food from the 

 same sovu'ce. 



This brings us to consider the food of the adults 

 themselves. This consists almost entirely of vegetable 

 substances, although snails, and so on, are occasionally 

 taken. The following are the most important items in the 

 bill of fare : grain and seeds of various sorts, turnip- 

 tops and the like, beans and peas, berries, acorns, and 

 beech-mast. The quantity of food that one bird is 

 capable of stowing away is enormous. Records such as 

 that of a thousand grains of corn from the crop of a 

 single bird are common. In summer certain moth- 

 caterpillars that are injurious to forest trees are sometimes 

 eaten. The balance of the evidence, however, seems to 

 be markedly against the Wood-Pigeon, the harm it does 

 to agriculture outweighing all other considerations. 



The great decrease of our birds of prey has removed 

 an important natural check on the undue increase of the 

 Wood-Pigeon. Similarly, it has been found in some places 

 that the forester's destiniction of Squirrels has reacted 

 harmfully on the agriculture of the neighbourhood, through 

 the medium of this bird, whose eggs and young were thus 

 rid of a serious enemy. Other checks, however, are by no 

 means wanting. Of two we may make brief mention. 

 In winter the Wood-Pigeon becomes an object of sport, 



