134 The Food of Birds. 



Economic A^alue. 



Compared with the robin for corresponding months, this 

 species seems to show very similar economic relations. 

 In both, the totals of beneficial elements eaten during this 

 period are to the injurious about as four to three ; but with 

 the brown thrush as with the catbird, its later arrival and 

 earlier departure are to its disadvantage. Balancing as 

 carefully as I can its seven i^arts of Lepidoptera, ten of 

 leaf-chafers, two of spring-beetles, two of snout-beetles, 

 one of chinch-bugs and four of Orthoptera on the one hand, 

 against its six parts of Carabidae, two of predaceous He- 

 miptera, one of spiders, one of predaceous thousand-legs and 

 twenty-one of small fruits on the other, I cannot see that, 

 so far as the immediate consequences of its food habits are 

 concerned, it does more good than harm. In short, its Or- 

 thoptera must pay for its garden fruits ; that is to say, 

 eliminating these two elements, I judge that the preda- 

 ceous insects eaten would destroy during the year about 

 as many injurious insects as the bird itself has taken. 

 However, I must repeat the suggestion that they could 

 hardly destroy the saine ki7ids as the bird, and that, if 

 allowed to live, they would probably decimate some spe- 

 cies already sufficiently restricted by existing checks, and 

 permit an unrestrained increase of others now kept down 

 by the thrush. That the disturbances thus set up w^ould 

 soon lead us to regret this bird if its numbers were greatly 

 lessened, is therefore very probable, and I believe the 

 species should be preserved. We must not overlook the 

 special services of the brown thrush in devouring a much 

 larger number of June-beetles than any other of the spe- 

 cies examined. 



