Allen on Insectivorous Birds. 25 



[predaceous beetles], while of 194 birds of other families in whose 

 stomachs insects were found, less than five per cent, had eaten 

 these Coleoptera. The worst sinner in this respect was the Her- 

 mit Thrush. . . . Curiously, the ratio of Carabidce continued un- 

 diminished during the fruit season, when the total of insect 

 food fell away very rapidly. For example, the Cat-birds ate in 

 May, June, and July eighty-seven per cent., sixtv-four per cent., 

 and eighteen per cent., respectively, of insect food, while the 

 Carabidce for those months averaged seven per cent., six per 

 cent., and ten per cent., the corresponding fruit record standing 

 nothing, thirty per cent., and seventy-one per cent. . . . The ab- 

 sence of all, or nearly all, the specially protected genera is notice- 

 able (unless the obscure color of many is reckoned a special pro- 

 tection)." * The full details of the observations made upon this 

 family f show certain specific differences of food ; that while the 

 different species of this group agree in many particulars as re- 

 gards food, that the differences are so marked that it is usually 

 possible to "determine the species by the contents of three or 

 four stomachs." 



During April, the eleven Robins examined were found to have 

 "apparently done very much more harm than good .... eating 

 predaceous beetles which would probably have destroyed many 

 more noxious insects than were found in their own stomachs." 

 In May the balance was found in favor of the four specimens ex- 

 amined ; in June, in respect to five specimens, the balance was in 

 the other direction, but probably turned favorably through the 

 large amount of insect food procured for their young. The July 

 record left " the scale trembling in the balance." The final con- 

 clusion respecting forty-one Robins is that they had, taken together, 

 " certainly done, just previous to their demise, fully as much harm 

 as good, as far as we can judge from the contents of their stom- 

 achs." With respect to the Catbird it was found that there was 

 " an unexpected balance of about seven per cent, of injurious 

 insects with which to pay for twenty-seven per cent, of fruit," 

 for the three months of May, June, and July. With regard to 

 the economic value of the Brown Thrush, Mr. Forbes thus sums 

 the evidence : "so far as it can be supposed to be indicated by 

 the stomachs of these twenty-eight individuals, I conclude that 



* Amer. Ent., 1. c. p. 13. 



f Trans. Illinois State Hort. Soc, . c. 



