48 FOOD OF BOBOLINK, BLACKBIRDS, AND GRACKLES, 
whole food, but from its distribution through the year does not 
appear to have been taken from the harvest fields. It is probable 
that some of it was gathered from newly sown fields, but the greater 
part was undoubtedly stolen from corncribs or picked up in roads and 
stock yards as waste grain. 
Weed seed is not so important an item of food with the rusty black- 
birds as it is with the redwings, since with the former it amounts to 
only 6 percent of the year’s food, and contrary to observations on 
most seed-eating birds, the greater portion of it is apparently eater 
in the insect season. Only 1 percent was found in the stomach taken 
in January, but the amount increases irregularly up to a maximum 
of 23.3 percent in May. Of June and July we know nothing, but 
in August, the month in which the redwing begins to increase its 
seed diet, there is not a single trace of weed seed in the food of the 
rusty blackbirds. It constitutes 6.6 percent in September, a trifle in 
October, and 15 percent in. November and is entirely absent in the 3 
stomachs taken in December. This erratic distribution evidently indi- 
cates that weed seed is not sought after, but is simply taken when 
nothing better is at hand. Miscellaneous items of vegetable food 
amount to 16.6 percent of the food of the year. Fruit was found ina 
few stomachs, but does not appear to any important extent. Only 
three kinds were determined, but several stomachs contained pulp or 
skin that could not be identified. Several buffalo berries (Shepherdia 
argentea) were found in one stomach, hackberries (Celé/s oce/dentalis) 
in another, and seeds of blackberries or raspberries (udus) in two or 
three others. Mast was found in a few stomachs, but the greater part 
of the miscellaneous food was indeterminable. The birds are evi- 
dently great scavengers, and so gather much food that is scarcely sus- 
ceptible of classification. 
SUMMARY. 
N 
While this record of the food of the rusty blackbird is somewhat 
fragmentary it still gives a very good idea of the bird’s general diet. 
One important conclusion that can be drawn is that animal food is 
preferred, vegetable food serving as a makeshift. It is nearly certain 
that in June and July, when the birds are engaged in the exhausting 
function of reproduction, the diet must be almost exclusively animal. 
If those months were represented in this investigation, the relative 
proportion of the two classes of food would be much changed, and 
animal food would take a higher rank. The vegetable food is of little 
consequence, as the birds show no decided predilection for any partic- 
ular kind, but eat whatever is at hand when animal food can not be 
obtained. Grain is not eaten to any great extent at harvest time, and 
the other items do not seem to have any special relation to the season 
in which they are eaten. While considerable animal food beside 
insects is eaten, on the other hand a considerable quantity of harmful 
