46 FOOD OF BOBOLIISTK, BLACKBIRDS, AND GKACKLES. 



The great majority of these birds nest so far north that thej are 

 beyond the limits of cultivation, and consequently have no economic 

 interest during the breeding months. But as soon as the season of re- 

 production is over they begin to assemble and move southward, and it 

 is evident that such vast flocks as they form might prove a serious 

 menace to any crop on which thej chose to prej^ Reports, how- 

 ever, have not implicated them to any great degree in the devastation 

 of grainfields, and it seems to be their habit to feed about swamps and 

 inroads and stock j^ards. That they have a decided taste for foraging 

 in wet ground or about water is shown bj" the contents of their 

 stomachs, which included aquatic beetles of many species, with larvae 

 of ephemeridiB, caddice-fly cases, a few dragon-flies, small snails and 

 other mollusks, salamanders, and small fishes. 



The food of rusty black! )irds does not seem to have received much 

 attention, but a few ornithologists have given it brief consideration. 



Mr. C. J. Maynard reports that he has never found anything in 

 their stomachs except insects and small mollusks.^ 



Col. N. S. Goss says: 



They are largely omnivorous in their food habits, preferring tlie various forms of 

 insci-t life, snails, etc., that alujund in tlie aquatic grasses; but during the winter 

 niontlis, when forced to feed largely upon grains and seeds, they frequent the cattle 

 yards and com fields, and further south forage off the rice plantations.'^ 



Dr. Warren says: 



The food of this sjiecies consists largely of beetles, grasshoppers, snails and earth- 

 worms. They feed to a considerable extent on the seeds of various plants; different 

 kinds of small berries are added to their lucim; the scatt€re<l grains of wheat, rye 

 or other cereals, which are to be found in the fields and meadows, are likewise eaten. 

 When in cornfields they sometimes i)erch on the shocks and pick from the ears 

 a few grains, the damage, however, which they do in this way is of 1>ut little 

 importance.' 



The investigation of the food of the rusty hhickbird made by the 

 Biological Survey is based on 132 stomachs, obtained from 16 States, 

 the District of Cokmibia, and Canada (see p. 74). These stomachs 

 represent every month of the j-ear except June and July, when the 

 birds are on their breeding range away from well-settled portions of 

 the coimtry. It is to be regretted that none of the months except 

 March, April, October, and November are fairly represented. Few 

 stomachs were obtained in the other months, January having ]>ut one 

 to its credit. 



The stomachs contained a larger proportion of animal matter (53 

 percent) than those of any other species of American black) )irds except 

 the bobolink. This is the more remarkable in view of the fact that 

 none wore taken in the two bi-eeding months of June and July, when 

 in all prolmbility the food consists almost exclusively of animal matter. 



' Birds Eastern N. A., p. 147, 1S81. 

 * Hist. Birds of Kansas, p. 408, 1891. 

 •''Birds of Pa., revised ed.. p. 219, 1890. 



