1906.] 



Food of Rooks. 



415 



further 166,650 plants in the third year, making a total of half 

 a million. The rooks also destroyed 2,264 white grubs, repre- 

 senting on the same basis a further 22,640 plants. Against all 

 this, which may be assumed to be saved by the death of the 

 chafer beetles, is to be placed the total of 39,077 cereal plants 

 (wheat, barley, oats) actually destroyed by the rooks. Similar 

 lessons are drawn by Dr. Hollrung from the destruction by the 

 rooks of other insect pests like wireworms. 



From these investigations Dr. Hollrung arrives at the follow- 

 ing conclusions : — (i) Rooks are omnivorous, taking seeds, 

 animals, insects, and all kinds of refuse ; (2) they are not 

 particular as to their feeding places, visiting alike freshly- 

 ploughed fields, orchards, dung heaps, open potato clamps, 

 corn ricks, &c. ; (3) they are harmful to game- preserving, 

 although they are frequently blamed for damage done by 

 other species of Cotvidce] (4) the cultivated crops chiefly 

 damaged are cereals (including maize), certain papilionaceous 

 plants, buckwheat, and potatoes ; (5) the chief insect pests 

 destroyed by them are cockchafers and their grubs, wireworms 

 and the click beetles, dung beetles, several species of weevils, 

 tortoise or helmet beetles, and many kinds of caterpillars ; 

 (6) in the neighbourhood of rookeries the harm done easily 

 outweighs the good ; where rooks occur in large flocks excess 

 of damage is to be feared, especially at times of the year 

 when insects are scarce ; when they are few in number or widely 

 dispersed, and where harmful insects abound rooks are un- 

 doubtedly useful ; (7) the extermination of rooks is under no 

 circumstances justifiable, for it is clearly proved that they 

 destroy insect pests harmful to crops, including those which 

 are with difficulty reached by artificial means ; (8) the reduc- 

 tion of the number of rooks to a given limit may be carried out 

 with certainty by shooting the young before they are fully 

 fledged, or by destroying a number of the nests by means of 

 explosive bullets ; (9) lastly, farmers who suffer much harm from 

 the attacks of rooks are advised to form a "Society for Insur- 

 ance against Damage by Rooks." 



As regards reducing the number of rooks in a given district 

 the harm done will only be transferred to another locality 

 unless all farmers take steps energetically and at the same 



