[Illustration: Fig. 2.--Robin. Length, about 10 inches.]
The robin[5] (fig. 2), in many parts of the country one of the most
cherished of our birds, is found throughout the States east of the Great
Plains, and is represented farther west and south by slightly different
subspecies.[6], [7] It breeds far north through Canada, and is found even
in Alaska. Although the great bulk of the species leaves the Northern
States in winter, a few individuals remain in sheltered swamps, where
wild berries furnish abundant food. The robin is an omnivorous feeder
and its food habits have sometimes caused apprehension to the fruit
grower, for it is fond of cherries and other small fruits, particularly
the earlier varieties. For this reason many complaints have been lodged
against robins, and it has been necessary to permit the killing of the
birds in some fruit-growing regions.
[5] _Planesticus migratorius_.
[6] _Planesticus migratorius propinquus_.
[7] _Planesticus migratorius achrusterus_.
Examinations of 1,236 stomachs show that 42 per cent of its food is
animal matter, principally insects, while the remainder is made up
largely of small fruits or berries. Over 16 per cent consists of beetles,
about one-third of which are useful ground beetles, taken mostly in
spring and fall when other insects are scarce. Grasshoppers make up about
5 per cent of the whole food, but in August they comprise 17 per cent.
Caterpillars form about 9 per cent, while the rest of the animal food,
about 11 per cent, is made up of various insects, with a few spiders,
snails, and angleworms. All the grasshoppers, caterpillars, and bugs,
with a large portion of the beetles, are injurious, and it is safe to say
that noxious insects comprise more than one-third of the robin's food.
Vegetable food forms 58 per cent of the stomach contents, over 42 per
cent being wild fruits and only a little more than 8 per cent being
possibly cultivated varieties. Cultivated fruit amounting to about 25 per
cent was found in the stomachs in June and July, but only a trifle in
August. Wild fruit, on the contrary, is eaten every month and constitutes
a staple food during half the year. No less than 65 species of fruit were
identified in the stomachs; of these, the most important were 4 species
of dogwood, 3 of wild cherries, 3 of wild grapes, 4 of greenbrier, 2
of holly, 2 of elder; and cranberries, huckleberries, blueberries,
barberries, service berries, hackberries, and persimmons; together with 4
species of sumac and various other seeds not strictly fruit.
The depredations of the robin seem to be confined to the smaller and
earlier fruits, few, if any, complaints being made that it eats apples,
peaches, pears, grapes, or even late cherries. By the time these are
ripe the forests and hedges are teeming with wild fruits which the bird
evidently finds more to its taste. The cherry, unfortunately for man,
ripens so early that it is almost the only fruit accessible at a time
when the bird's appetite has been sharpened by a long-continued diet of
insects, earthworms, and dried berries, and it is no wonder that at first
the rich juicy morsels are greedily eaten.
While the robin takes some cultivated fruits, it must be remembered that,
being a natural enemy of the insect world, it has been working during the
whole season to make that crop a possibility, and when the fruit ripens
the robin already has a standing account with the farmer for services
rendered, with the credits up to this time entirely on his side.
Much has been written about the delicate discrimination of birds for
choice fruit and their selection of only the finest and costliest
varieties. This is contrary to observed facts. Birds, unlike human
beings, seem to prefer fruit that, like the mulberry, is sweetly insipid,
or that, like the chokecherry or holly, has some astringent or bitter
quality. The so-called black alder, a species of holly, has bright
scarlet berries tasting as bitter as quinine, that ripen late in October
and remain on the bushes through November. Though frost grapes, the fruit
of the Virginia creeper, and several species of dogwood are abundant at
the same time, the birds have been found to eat the berries of the holly
to a considerable extent. It is, moreover, a remarkable fact that the
wild fruits upon which birds largely feed are those which man neither
gathers for his own use nor adopts for cultivation.
Where wild fruit is not abundant, a few fruit-bearing shrubs and vines
judiciously planted will serve for ornament and provide food for the
birds. The Russian mulberry is a vigorous grower and a profuse bearer,
ripening at the same time as the cherry. So far as observation has gone,
most birds seem to prefer its fruit to any other. It is believed that a
number of mulberry trees planted around the garden or orchard would fully
protect the more valuable fruits.