46 FOOD OF BOBOLINK, BLACKBIRDS, AND GRACKLES. 
The great majority of these birds nest so far north that they 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 toassemble and move southward, and it 
is evident that such vast flocks as they form might prove a serious 
menace to any crop on which they chose to prey. 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 
inroadsand stock yards. That they have a decided taste for foraging 
in wet ground or about water is shown by the contents of their 
stomachs, which included aquatic beetles of many species, with larve 
of ephemeride, caddice-fly cases, a few dragon-flies, small snails and 
other mollusks, salamanders, and small fishes. 
The food of rusty blackbirds 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 the various forms of 
insect life, snails, ete., that abound in the aquatic grasses; but during the winter 
months, when forced to feed largely upon grains and seeds, they frequent the cattle 
yards and corn fields, and further south forage off the rice plantations.’ 
Dr. Warren says: 
The food of this species 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 menu; the scattered 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 perch on the shocks and pick from the ears 
a few grains, the damage, however, which they do in this way is of but little 
importance.’ 
The investigation of the food of the rusty blackbird made by the 
Biological Survey is based on 132 stomachs, obtained from 16 States, 
the District of Columbia, and Canada (see p. 74). These stomachs 
represent every month of the year except June and July, when the 
birds are on their breeding range away from well-settled portions of 
the country. It ix 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 but one 
to its credit. 
The stomachs contained a larger proportion of animal matter (53 
percent) than those of any other species of American blackbirds except 
the hobolink. This is the more remarkable in view of the fact that 
none were taken in the two breeding months of June and July, when 
in all probability the food consists almost exclusively of animal matter. 
'Birds Eastern N. A., p. 147, 1881. 
* Hist. Birds of Kansas, p. 408, 1891. 
* Birds of Pa., revised ed., p. 219, 1890. 
