The Food of Some British Wild Birds. 



CHAPTER I. 



INTRODUCTION. 



" Economic Ornithology, or the study of the inter-relation of 

 birds and agriculture, and an investigation of the foods, habits and 

 plants, is an untrodden and promising field that lies open for investi- 

 gation by the English agricultural scientist. " 



EARL CATHCART, The Times, May 16th, 1891. 



The nature of the food of many of our wild birds has hitherto 

 been largely guesswork, for, with the exception of a very few 

 species, no detailed investigations have been carried out, and 

 without these details, obtained in both the field and the laboratory, 

 it is impossible to arrive at any sound conclusions respecting their 

 economic status. 



In the present investigation upwards of three thousand post- 

 mortems have been made of adult birds, and three hundred and 

 twelve of nestlings ; and the conclusions arrived at have only been 

 obtained after a considerable amount of work extending over many 

 years, during which period numerous observations have been made 

 in the field. 



It is now universally recognised that birds play a most 

 important part in checking the ravages of various animal pests of 

 our crops, particularly so in the case of insects. Prejudice, ignor- 

 ance and faulty observation have undoubtedly had much to do with 

 our lack of information in the past, whilst many writers have been, 

 and still are, content, when writing upon the subject, to simply 

 reiterate the statements of earlier authors. 



Casual observations made in the field, which are frequently 

 put forward in newspaper discussions, are of little value, indeed, 

 they are generally most misleading, as they take no note of what 

 the particular species of bird feeds upon at other seasons of the 

 year, or in other districts, or during 1 the period they are looking 

 after their young. 



Many birds which are injurious at one season of the year are 

 distinctly beneficial for the remainder. Again, many birds that are 

 beneficial, may, if allowed to unduly increase, become equally 

 injurious. In other cases the partial failure of their natural food 

 supply, or other causes, may lead to a change in their food habits, 

 in a like manner the alteration or removal of their natural environ- 

 ment may lead to equally disastrous results. 



