PASSERES (COEVIDiE). 391 



base, there being no white as seen in the rook. C. corone breeds 

 in trees, usually at a great height. The yoiuig, which are hatched 

 out very early — ^usually whilst other birds are laying — are most 

 voracious. It is especially at this time that the crow does so 

 much damage. They rob the nests of game-birds both of their 

 eggs and young; poultry, leverets, and lambs have even been 

 known to be attacked, whilst they are said to have killed ewes 

 detached from the flock. "With this food they feed the young, 

 often carrying the bones and debris away some distance, so that 

 their nests should not be detected. They apparently pair for 

 life. The crow flies either singly or in pairs, never in large 

 flocks as we see the rooks in England, although it is said to 

 do so abroad. The only good one can see that they do is to 

 destroy carrion on the seashore and on land, and to keep in 

 check the voles and field-mice, which they devour in numbers. 

 They must, however, be recorded amongst our harmful species. 

 Yet it is doubtful if it is wise to persecute them too far, for 

 then we get rabbits and small mammals increasing to excess. 



The Rook {O. frugilegus) is, on the other hand, partly bene- 

 ficial. The rook is larger than the crow, and can at once be 

 told by the white mark at the base of the bill. Moreover, 

 the rook is gregarious, flying about and nesting in large com- 

 panies. The main food of the rook consists of insect grubs, 

 especially the wireworm, leather -jackets, and cockchafer larvae. 

 Wherever we see rooks collected in the fields, there we have a 

 sure sign of insect infestation. Nevertheless they are often 

 ruthlessly destroyed, for it is said they do so much damage. 

 What damage do the rooks do ? They pull up roots and leave 

 them dying on the ground, they eat grain, and they carry off large 

 numbers of walnuts. Certainly in the last two instances they 

 are harmful, but not to any great extent, imless they are abnor- 

 mally abundant. The plants they pull up are not pulled up out 

 of pure mischief, but to get at the wireworm biting at the roots ; 

 this they devour : they thus destroy one turnip and one wire- 

 worm. How many turnips and other plants would the wire- 



