EELATION TO AGRICULTURE 43 



only 114 per cent, of the total food consumed. 

 Let us therefore examine more closely into the 

 daily life of some of these so-caUed noxious crea- 

 tures. 



Every one has seen blackbirds descend upon 

 wheat-fields in flocks of thousands. The ques- 

 tign is : How much grain do they destroy? The 

 natural food of blackbirds, as has been proved by 

 investigation, is mainly insects. Naturally, upon 

 alighting in a field they will consume all they 

 can find before attacking the crop. For every 

 bushel of wheat they consume, the farmer can 

 feel assured that they have accounted for five 

 bushels of insects. If left alone to feed and 

 propagate, those insects within the next year 

 would have destroyed at least ten bushels of 

 grain. 



Among the several species of blackbirds, some 

 are more enamoured with grain than others. 

 The grackles fall in this latter class, whereas the 

 cowbird and red-winged blackbirds are almost 

 completely insectivorous. The scientific farmer 

 is now versed in the idiosyncrasies of the differ- 

 ent forms and, as a rule, confines Ms attention to 

 eradicating the grackles. Even with the 

 grackles, however, the greater part of their food 

 is insect. It is a historical fact that in 1749 in the 

 American colonies, after a wholesale destruction 

 of crows and grackles for a bounty of threepence 

 a dozen, the northernmost colonies had a season of 



