12 



Bird Notes and News 



Economic Ornithology. 



FOOD OF THE ROOK, STARLING AND CHAFFINCH. 



In 1908, it may be remembered, the British 

 Association appointed a committee to in- 

 vestigate the question of the food of birds, 

 with a view to ascertaining which are in- 

 jurious and which beneficial from the agri- 

 cultiuist's point of view. The birds selected 

 were the Rook, Starling and Chaffinch as 

 debatable species, and the work was carried 

 out in conjunction with the Board of Agri- 

 culture, who have now published the Report 

 on the subject. The work of examination 

 was first entrusted to Dr. Gordon Hewitt, and 

 after his appointment as Entomologist to 

 the Government of Canada, to Mr. H. S. 

 Leigh, M.Sc, of Manchester University, and 

 Mr. F. V. Theobald, F.E.S., of the South- 

 Eastem Agricultural College at Wye, assisted 

 by Mr. W. McGowan. The majority of birds 

 reported on by Mr. Leigh came from the 

 northern counties of England and from Wales, 

 and Mr. Theobald's from the southern 

 counties. It is interesting to note, says the 

 preface to the Report, " that the facts 

 ascertained from the two investigations are 

 in most respects very similar, but that in 

 the case of one bird the conclusions drawn 

 are very different." 



As Mr. Theobald observes, an investigation 

 can only show part of what birds eat, for 

 some things cannot be identified satisfactorily, 

 while the absence of records of the food of 

 nestlings is unfortimate, as this is a most 

 important point in deciding whether a bird 

 is harmful or beneficial. (Practically all 

 jnestlings are fed on animal food, and as 

 the bird population is infinitely greater at 

 the time the yoiing are in the nest than at 



any other period,!^they must account for the 

 destruction of immense quantities of insects.) 



The Rook. — The Manchester investigation 

 dealt with 332 Rooks from 63 localities, and 

 " has shown that the percentage of animal 

 matter taken from April to September is large, 

 and also that it is made up mainly of injuiious 

 insects. On the other hand, we have to 

 record a large quantity of grain in the Rook's 

 diet ; for nine months, from September to 

 May inclusive, the percentage of grain is very 

 highj and only falls to a really low level in 

 June, July and August." It is emphasized, 

 however, that the harm done is not in pro- 

 portion to the amoimt of grain eaten, since 

 in September and October it was frequently 

 observed that the birds were merely taking 

 up grain dropped during harvesting opera- 

 tions. The insects were mostly wireworms 

 and leather] ackets, one gizzard containing 

 as many as 95 whole leather jacket larvae, 

 and another 103 wireworms. Acorns, potato, 

 and a few weed-seeds occurred. 



The Wye investigators examined 277 

 Rooks from 53 localities, and come to the 

 conclusion that the bird is much more harmful 

 than beneficial, so far as the adult birds are 

 concerned. From February to April and 

 October to December the food chiefly con- 

 sisted of grain, which they appeared to take, 

 largely at all times except in May and July ; 

 but there are no records for August and 

 September. Nevertheless, it destroyed a 

 considerable number of harmful insects 

 (chiefly wireworms and leatherjackets) and 

 a few mollusca. A few strange articles were 

 found, including a bootlace, pieces of string 

 and cloth, and even a nail. 



The Starling. — The Manchester in- 

 vestigation dealt with 486 birds. Injurious 

 insects occurred in 365 cases, largely weevils 

 and leatherjackets ; one crop contained 197 

 leatherjackets, and at least four more than 

 150 each ; " it is plain therefore that these 

 birds were rendering valuable service to the 

 farmer." The percentage of animal food, 

 almost entirely insects, was very large. 



