298 ANIMALS AT WORK AND PLAY 



necessary. A farmer drove away his neighbour's 

 rooks from a rookery by placing carrion in one or 

 two of the nests. Six years later their enemy's farm 

 was sold and occupied by a new owner, and in the 

 next spring the birds came to the house and built a 

 large rookery close to it. Some rooks taken out 

 lately to Australia met a curious fate. They had 

 completed their moult when shipped, but on arriving 

 in the splendid aviary built for them, were affected 

 by the hot weather, and moulted again. The exhaust- 

 ing effect of the double moult seems to have gradually 

 killed off the whole colony. 



But few birds besides the rook can resist one or 

 other of the attractions which we have described, and 

 some such provision is now needed ; for the tendency 

 of a growing population is to banish bird-life, not 

 in England, as in France, by killing the birds, but 

 by destroying their nesting-places. In the fruit- 

 growing part of Kent, for instance, the copsewood 

 which sheltered the warblers is giving place to currant 

 and gooseberry plantations, and the hedges are being 

 cut into formal lines. Yet a family of young white- 

 throats will do more to clear the bushes of insects 

 than the most skilful ' garden hand ' in the county. 



