SPECIES. 



95 



Marshall Hall, is frequently shot, and its valuable work as a destroyer 

 of weed seed and insects is thus often cut off. 



When the bobolink {Dolichonyx oryzivorus^ fig. 35) tarries on the 

 farm in its southward migration it lives wholly on the wild rice of the 

 calamus swamp, but on its return journej' in May it eats injurious 

 insects and weed seed of the wheat and clo\'er fields. Six stomachs 

 were collected in May. 



The cowbird {Molothrus ater), as has been shown ?)y Prof. F. E. L. 

 Beal," takes three times the volume of seeds that it takes of insects. 

 Both of the 2 stomachs examined contained grasshoppers {Xiphidium 

 and Melanoplus) and 1 of them leaf -hoppers, two elements charactcr- 



FiG. SB.— Bobolink. 



istic of the insect food of the species. The bird does little damage 

 to grain fields, and renders much service with other birds in reducing 

 the weed-seed harvest of the farm. 



BLACKBIRDS AND ORIOLES. 



The red-winged blackbird {Agelams phoiniceus, fig. 36), however 

 destructive to grain it may be elsewhere, does no damage in the grain- 

 fields at Marshall Hall. Its insect food, which is to its vegetable food 

 as one to three, is composed largely of weevils, caterpillars, and grass- 



aBobolink, Blackbirds, and Grackles. Bull. No. 13, Biological Survey, Dept. of 

 Agriculture, p. 29, 1900. 



