56 The Food of Some British Wild Birds. 



Newstead (92) only examined fourteen specimens, nine of 

 which were shot on one day in May. 



Florence (47) examined one hundred and sixty-two, and Ham- 

 mond (60) gives the results of the examination of a dozen 

 specimens. 



Thring (31) in 1908 made post-mortems of one hundred and 

 forty-one, and in 1907 and '08 I examined 58, and six hundred and 

 thirty -one in 1909, and since then a further 32, so that we now have 

 the records of 1,393 stomach contents. 



As I have elsewhere mentioned (31) it has generally been 

 supposed that the food of the rook consists very largely of beetles, 

 insect larvae, and earthworms. A well-known ornithologist, the 

 Rev. F. O. Morris, presented the following calculation before the 

 "Wild Birds' Protection Committee of the House of Commons of 

 1873 " : "A rook," he states, " requires at least one pound of food 

 in a week, and of this nine-tenths is insect and worms. A rookery 

 of 10,000 rooks will consume in one year 209 tons of worms, insects, 

 and their larvae." Other writers have made similar statements, 

 but without any convincing evidence, so far as I am aware. 



Of the 631 specimens I opened, 70 per cent, of their food 

 consisted of grain, 15 per cent, of seed, fruits, roots, and miscel- 

 laneous vegetable matter; 4 per cent, of wireworms, 4 per cent. 

 of other insects (mostly injurious), 1 per cent, millipedes, 2 per 

 cent, earthworms, 4 per cent, miscellaneous food. Adding these 

 to the 141 rooks recorded by Mr. Douglas T. Thring, and the fifty- 

 eight specimens previously dissected by myself, the results may be 

 tabulated as follows : 



No. of Rooks 



Grain 



Seeds, fruits, roots, and 



miscellaneous vegetable 



matter 

 Wireworms 

 Other insects 

 Millipedes 

 Earthworms ... 

 Miscellaneous Food (eggs, 



young game, field mice, 



etc.) 



The following diagram illustrates at a glance, the monthly 

 consumption of food, animal and vegetable. 



