APRIL. 



BIRD NESTING. 



By Aubyn Trevor- Battye. 



III.— TREE NESTING BIRDS. 



The best way in which to treat this subject will probably be first to 

 take those birds that nest in the tops or branches of trees and 

 shrubs, and then those which nest in holes, or against the trunks. 

 It is obviously quite impossible within the limits of a short article 

 to attempt to exhaust either group. All we can do is to point to a 

 few of the best known instances. 



The Rooks, which begin nesting early in the spring, may serve us 

 for a start, the more particularly as they go to illustrate very well 

 a constant general law of nature. It is this : wherever you have 

 a class of creatures of either a predatory or semi-predatory 

 character, whose habits are colonial or semi-colonial, there you will 

 find a considerable proportion which never breed at all, and of 

 these a predominating proportion of males. This opens up a very 

 wide and most interesting subject ; but here we can only point to 

 it as a fact. Rooks are exceedingly capricious in their choice of 

 a nesting site ; but, examined carefully, their ways will be 

 generally found to be backed by common sense. For example, 

 they will continue nesting in a pine tree long after the tree is dead, 



