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THE FOOD OF SOME WILD BIRDS 



By James Ritchie. 



Every honest endeavour to settle the vexed question of 

 the standing of particular birds in the economy of a man- 

 ridden world is deserving of the closest attention and 

 encouragement, and at no time has the necessity for such 

 endeavours been more apparent than in these days of 

 special agricultural effort. Farmers and all concerned with 

 the raising of crops are willing and ready to take action ; 

 the difficulty has always been to decide what action ought 

 to be taken for the ultimate benefit of the human occupants 

 of the land. Many efforts have been made by laborious 

 examination of the food of birds, as represented in their 

 dead bodies, to reach a basis from which a definite conclusion 

 as to their usefulness or harmfulness might be drawn. Most 

 of these tabulations have failed to gain the confidence of the 

 ordinary naturalist, mainly because, while claiming statistical 

 infallibility in results, they have neglected the first rule of 

 statistics, that the data shall be gathered without prejudice. 

 The value of the newer methods of recording the food of 

 birds will depend no less on the soundness of the statistical 

 method than on the technical skill of the worker concerned. 



In recounting " Some Recent Investigations on the Food 

 of certain Wild Birds" in the September number of the 

 Journal of the Board of Agriculture^ Dr W. E. Collinge has 

 added another to his many contributions on this subject. 

 The nine birds selected for consideration Missel-thrush, 

 House-sparrow, Rook, Skylark, Green Woodpecker, Sparrow- 

 hawk, Kestrel, Wood-pigeon and Lapwing possess very 

 different feeding habits, so that the detailed results of an 

 examination covering 3670 adult and 595 nestling birds are 

 unusually interesting. One important change is to be noted 

 in the statistical method adopted in this latest contribution. 

 Dr Collinge, in accordance with his views recently published 

 in the Scottish Naturalist, has rejected the numerical method 

 of estimating crop contents for a method based on relative 

 volumes of food-stuffs, and his faith in the new method is 

 only equalled by his distrust of that which stood him 



