36 FOOD HABITS OF THE GROSBEAKS. 



Henry Nehrling va writes: 



It is said to eat green peas, and for this reason it is often killed, though the 

 damage done in this way does not compare \yith the many benefits it bestows. 



The question is, Do stomach examinations support this view? 

 Years ago Prof. F. E. tu. Beal observed the rosebreast in the act of 

 eating peas and found the pods cut open and the peas gone ; the con- 

 tents of a stomach were examined, and two or three peas, several 

 potato beetles, and a tomato worm were found; whence it is evident 

 that this particular grosbeak, at least, was paying well for its peas. 



In this connection the record of 6 birds from Iowa gardens is of 

 interest. Fifteen percent of their food was peas, and to that extent, 

 of course, they were detrimental; but as an offset more than IT per- 

 cent consisted of bronzy wood-borers and 12.5 percent of weevils, in- 

 cluding the injurious pine bark- weevil and 2 nut weevils. While 

 these insects are very injurious to timber, it may be claimed that they 

 are not of direct consequence to the gardener. But insects especially 

 injurious to garden crops also were consumed, 14.8 percent of the 

 food consisting of white grubs, which are enemies of strawberries, 

 and a flower beetle, which injures young corn and many fruits, besides 

 the notorious Colorado potato beetle. Caterpillars and ants also 

 were preyed upon by these 6 birds, and scale insects (Eulecanium 

 sp.), the very worst pest of fruit trees, formed 4.5 percent of their 

 food. The gardener is vitally concerned in reducing the numbers of 

 these insects, and it is evident that the 15 percent of peas consumed 

 is paid for many times over b}^ the destruction of more than three 

 times that amount of garden and forest enemies. Moreover, to de- 

 termine the true significance of the damage done, not only the birds 

 which had eaten peas, but the species collectively must be considered. 

 The present investigation shows that 3 birds out of 176 had stolen 

 peas, while scores had literally feasted upon the worst enemies of 

 agriculture. Peas constitute 1.36 percent of the total food of the 

 grosbeaks examined, while noxious insects certainly compose thirty 

 times as much. Viewed in the light of these facts, the loss sustained 

 would be nothing compared to the benefits received were it not for 

 the fact that the birds' depredations are often local in character, as 

 in the case cited above, one cultivator, perhaps, furnishing the supply 

 of peas for all the grosbeaks in the neighborhood. 



However, even under such circumstances a remedy is available 

 without the necessity of sacrificing the birds. Wire guards or bird 

 netting afford protection, and in the case cited above Professor Beal 

 at once stopped the grosbeaks' visits to his pea patch by means of an 

 old coat on a pole. 



a Our Native Birds of Song and Beauty, II, 1896, p. 206. 



