164 SPIIIKG. 



Rooks begin to build early when the weather is 

 favourable ; but should very severe weather come after- 

 wards, they will suspend their operations. The country 

 people say that having chosen a part of a tree which is 

 adapted for its purpose, the rook lays one stick by way of 

 taking possession ; and then begins the actual building 

 only when the weather is favourable; and to those who 

 do not remark that the weather is fine when the stick is 

 laid, and changes always when the labour of building is 

 suspended, there is perhaps as much foundation for 

 this as for any of the other functions of society with 

 which this bird has been endowed. 



It does not seem that the rook gives any preference 

 to one species of tree more than another ; but that its 

 choice is regulated by the height of the trees and their 

 vicinity to situations in which it may find an abundant 

 supply of food ; and when once a colony have settled on 

 any particular trees, they are very unwilling to leave 

 them. In the event of the trees being felled, they do 

 not always change to those that are in the immediate 

 neighbourhood. The great rookery to which so fre- 

 quent allusion has been made, was wholly in an ex- 

 tended wood of Scotch fir, (pinus sylvestris), though at 

 one part of the forest there were beeches of much 

 larger dimensions ; but the beeches, were, at least the 

 tallest ones, in a dell of considerable depth and very 

 narrow. It is very easy to see how a heavy bird like 

 the rook should select a situation as elevated as 

 that at which it generally flies, for the place of its 

 nest; because the air cells are thereby on the average 

 trimmed to its flight. In the situation alluded to, 

 there was, however, another inducement ; that part of 



