Fig. 14.—Red-winged blackbird. Length, about 9½ Inches.
Examination of 1,083 stomachs showed that vegetable matter forms 74 per cent of the food, while animal matter, mainly Insects, forms but 26 per cent A little more than 10 per cent consists of beetles, mostly harmful species. Weevils, or snout beetles, amount to 4 per cent of the year’s food, but in June reach 25 per cent. As weevils are among the most harmful insects known, their destruction should condone some, at least, of the sins of which the bird is accused. Grasshoppers constitute nearly 5 per cent of the food, while the rest of the animal matter is made up of various insects, a few snails, and crustaceans. The few dragon flies found were probably picked up dead, for they are too active to be taken alive, unless by a bird of the flycatcher family. So far as the insect food as a whole is concerned, the red-wing may be considered entirely beneficial.
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. Field investigation has shown, however, that, when local conditions are favorable, large flocks of red-wings may do considerable damage. Conspicuous among such cases are the losses suffered by farmers to sweet corn in some of the northeastern States and to milo in the South and West. In the rather limited grain-raising area of the Imperial Valley of California the annual damage to milo alone by enormous flocks of red-wings and yellow-headed blackbirds has been estimated to be fully $50,000. 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. It is apparent that where moderately abundant, the red-wing does more good than harm, but in sections where it becomes excessively abundant a reduction in its numbers is justifiable.
Fig. 15.—Bobolink, ricebird, or reed bird. Length, about 7 inches.
The bobolink, ricebird, or reedbird[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 reedbirds, and, becoming very fat, are treated as game.
[43] Dolichonyx oryzivorus.