234 Foundations of the Rook's Nest. 



nients. The latter are not large or thick : they are 

 clearl}' the work of one, or at most two, seasons only ; 

 for it is noticeable that when rooks build at a distance 

 from the centre of population the}' are some time 

 before they finally decide on a site, abandoning one 

 place after another. But the nests forming the prin- 

 cipal streets are piled up to a considerable height — 

 fresh twigs being added e\evy 3'ear — and are also 

 thick and bulky. The weight of the whole must be 

 a heavy burden to the trees. 



Much skill is shown in the selection of the branches 

 upon which the foundations are laid. In the first 

 place, the branch must fork sufflcientlj^ to hold the 

 bottom twigs firmly and to give some side-support. 

 Then it must be a branch more or less vertical, or it 

 would swing with the wind too much up and down as 

 well as to and fro. Thirdly, there should be a clear 

 or nearly clear space above the nest to give easy 

 access, and to aiford room for it to increase in size 

 annuall3^ For this reason, perhaps, nests are gen- 

 erally placed near the top or outer sides of the tree, 

 where the boughs are smaller, and every upward ex- 

 tension reaches a clearer place. Fourthly, the bough 

 ought not "to be too stitf and firm ; it should yield a 

 little, and sway easily, though onl}- in a small degree, 

 to the breeze. If too stiff, in strong gales' the nest 

 runs the risk of being blown clean out of the tree. 

 Fifthl}^, no other branch must rub against the one 

 bearing the principal weight of the nest, for that 

 would loosen the twigs in time, and dislocate the en- 

 tire structure. Finall}', rooks hke an adjacent bough 

 on which the bird not actually engaged in incubation 

 can perch and ' caw ' to his mate, and which is also 



