Few birds are altogether good, still fewer are altogether bad; most species are of great benefit, even if at the same time they do some harm. Some birds do serious damage at one season, and much good at another. The most notable example of this is the bobolink, which in northern wheat fields is loved no less for his merry song than for the thousands of weed seeds and insects he destroys; while in the South he is known as the reed-bird or rice-bird, the most dreaded of all foes to the rice crop. Flying down on the fields by hundreds of thousands these birds often take almost the entire crop of a district. The yearly loss to rice-growers from bobolinks has been estimated at two million dollars. If crows or blackbirds are seen in large numbers about fields of grain they are generally accused of robbing the farmer, but more often they are busily engaged in hunting the insects that without their help would soon have destroyed his crop; and even if they do considerable damage at one season they often pay for it many times over. Whether a bird is helpful or the reverse, in fact, depends entirely on the food it eats and often even farmers who have been familiar with birds all their lives do not know what food a bird really eats. As an example of the misunderstanding that is often found in regard to birds, when hawks are seen searching the fields and meadows, or owls flying about the orchards in the evening, the farmer always supposes that his poultry is in danger, when in reality the birds are quite as likely to be hunting for the animals which destroy grain, produce, young trees, and eggs of birds. In order to correct such mistaken ideas the Department of Agriculture has made a most careful and accurate study of the habits of birds, and it is the results of these observations that are recorded here. Field workers from this Department who have observed the habits of the principal birds that live among men, have watched them all day and from one day to another as they fed their little ones, and, to be more certain of their facts, they have examined the stomachs of hundreds of birds, both old and young, to learn exactly what each bird had eaten. In this way they have proved absolutely that many species that are supposed to eat chickens, or fruit or grain, in reality never touch them, but are among the farmer's best friends.