22 Allen on Insectivorous Birds. 



INSECTIVOROUS BIRDS IN THEIR RELATION 

 TO MAN. 



BY J. A. ALLEN. 



Doubtless many ornithologists who have attentively exam- 

 ined the contents of birds' stomachs have suspected that were 

 the truth known it would be found that the insectivorous species 

 are not to so great an extent the ally of man in his contest with 

 voracious insect hordes as is generally believed. The commun- 

 ity at large fails to recognize in this connection two important 

 facts, namely : that there are beneficial insects as well as injurious 

 ones, and that birds are indiscriminate in their captures. Were 

 it an established fact that birds, in so fir as they are insectivorous, 

 are the friends of man. the notion that birds are useful in propor- 

 tion to the number of insects they destroy could hardly have a 

 firmer hold. On all sides the cry is raised " Protect the birds." 

 while their actual role in relation to the insect world has scarcely 

 received a serious thought. " Birds destroy insects, therefore 

 they are an invaluable aid to man in his unequal struggle with 

 these insidious foes.*" is a natural and general conclusion. That 

 there are rapacious and parasitic insects, that these are the great 

 natural check upon the undue increase of the plant-eating species, 

 and that birds are useful only in proportion to the number of the 

 latter they destroy as compared with the former, are facts that are 

 generally ignored. 



As above stated, it has not escaped the notice of those ornithol- 

 ogists who have a smattering of entomological knowledge that 

 insectivorous birds may do much harm as well as great good, and 

 that the popular and almost universal demand tor their protection, 

 while perhaps harmless, is at least based on ignorance of the real 

 state of the case. I well recall being pained years ago by finding, 

 with the cutworms and caterpillars, a conspicuous proportion of 

 •• lady bugs." rapacious ground beetles, and other predaceous 

 insects in the stomachs of Thrushes, and of ichneumons with the 

 soft aphides and caterpillars in those of Warblers. As an 

 enthusiastic lover of birds. I feared the results to which a 

 critical study of the food of insectivorous birds might lead ; and 



