The interest in the vegetable food of this bird centers around grain. Only three kinds, corn, wheat, and oats, were found in the stomachs in appreciable quantities. They aggregate but little more than 13 per cent of the whole food, oats forming nearly half of this amount. In view of the many complaints that the red-wing eats grain, this record is surprisingly small. The purple grackle has been found to eat more than three times as much. In the case of the crow, corn forms one-third of the food, so that the red-winged blackbird, whose diet is made up of only a trifle more than one-eighth of grain, is really one of the least destructive species. The most important item of the bird’s food, however, is weed seed, which forms practically all of its food in winter and about 57 per cent of the fare of the whole year. The principal weed seeds eaten are those of ragweed, barnyard grass, and smartweed. That these seeds are preferred is shown by the fact that the birds begin to eat them in August, when grain is still readily obtainable, and continue feeding on them even after insects become plentiful in April. The red-wing eats very little fruit and does practically no harm to garden or orchard. Nearly seven-eighths of its food is made up of weed seed or of insects injurious to agriculture, indicating unmistakably that the bird should be protected, except, perhaps, in a few places where it is overabundant.
[Illustration: Fig. 15.—Bobolink, rice bird, or reed bird. Length, about 7 inches.]
The bobolink, rice bird, or reed bird[43] (fig. 15) is a common summer resident of the United States, north of about latitude 40°, and from New England westward to the Great Plains, wintering beyond our southern border. In New England there are few birds about which so much romance clusters as this rollicking songster, naturally associated with sunny June meadows; but in the South there are none on whose head so many maledictions have been heaped on account of its fondness for rice. During its sojourn in the Northern States it feeds mainly upon insects and seeds of useless plants; but while rearing its young, insects constitute its chief food, and almost the exclusive diet of its brood. After the young are able to fly, the whole family gathers into a small flock and begins to live almost entirely upon vegetable food. This consists for the most part of weed seeds, since in the North these birds do not appear to attack grain to any great extent. They eat a few oats, but their stomachs do not reveal a great quantity of this or any other grain. As the season advances they gather into larger flocks and move southward, until by the end of August nearly all have left their breeding grounds. On their way they frequent the reedy marshes about the mouths of rivers and on the inland waters of the coast region and subsist largely upon wild rice. In the Middle States, during their southward migration, they are commonly known as reed birds, and becoming very fat are treated as game.