ECONOMIC ORNITHOLOGY 269 



for the greater part of the year they feed almost exclusively on 

 wireworms, leather-jackets, chafer larvae, fever fly (Bibio spp.) 

 larvae, and other grubs in the soil, and also various cater- 

 pillars, such as winter moth and even the lackey moth, which 

 has so few natural enemies. 



It may be said that by banding the trees we can keep the 

 winter moth in check, and by spraying, the lackey moth ; but 

 one must remember that both occur in our woods and forests, 

 the former often in enormous numbers, and from thence spread 

 to fruit plantations near at hand. Moreover, the Rooks feed 

 on that destructive Green Tortrix {Tortrix viridanci) which too 

 frequently defoliates our oak-trees. 



That the Rooks do an enormous amount of good there is 

 no doubt ; at the same time every one acknowledges that they 

 do some harm. The farmer has to scare them off his seed- 

 corn and even young roots ; the fruit-grower rarely off his fruit. 

 Its attack on stacked corn in Fifeshire (16) seems to be local. 

 The cost of scaring off five thousand rooks is no more than 

 for fifty. Yet five thousand rooks will do an appreciable 

 amount of good ; fifty will do one hundred times less good. 

 Where, therefore, is the logic of recommending their reduction 

 in numbers? 



The Common Crow {Corvus corone) is not of any great 

 importance, but now and then is destructive to game eggs and 

 even sickly lambs. The Hooded Crow (C. comix) is said to be 

 "not abundant enough to affect agriculture to any appreciable 

 extent," and also " probably entirely beneficial from our present 

 point of view " by the Rev. Henry Slater (2, p. 248). This is 

 not correct, for this bird is very common in parts of Britain, 

 and is not only very harmful to game and poultry, but the 

 farmer suffers considerable loss by its attacking lambs and 

 pecking out their e3^es. The work of the Hooded Crow 

 in the poultry-yard is best expressed in the words of Mr. 

 W. Swaysland (7, p. 102, vol. ii.) : " Its powers of mischief in 

 respect to the poultry-yard during breeding time are so exceed- 

 ingly well developed that as late as the year 1835 the different 

 local authorities of Shetland and Orkney were in the habit of 

 paying 2d. for each crow killed in their districts." 



Although liking the littoral, the Royston Crow, as it is also 

 called, occurs far inland. In East Kent their ravages amongst 

 poultry and lambs are well known. A certain amount of insect 



