The Bird Study Book

by T. Gilbert Pearson

Destructiveness of Insects.—If we go back a few years and examine certain widely read publications issued by the United States Department of Agriculture, we can understand more fully why our legislative bodies have regarded so seriously the subject of bird protection. In one of the Year Books of the Department we read that the annual loss to the cotton crop of the United States by insects amounts to sixty million dollars. We learn, too, that grasshoppers and other insects annually destroy fifty-three million dollars' worth of hay and that two million dollars' worth of cereals are each year eaten by our insect population. In fact, we are told that one-tenth of all the cereals, hay, cotton, tobacco, forests, and general farm products is the yearly tax which insects levy and collect. In some parts of the country market-gardening and fruit-growing are the chief industries of the people. Now, when a vegetable raiser or fruit grower starts to count up the cost of his crops, one of the items which he must take into consideration is the 25 per cent. of his products which goes to feed the insects of the surrounding country.

Not all insects are detrimental to man's interests, but as we have just seen the Government officially states that many of them are tremendously destructive. Any one who has attempted to raise apples, for example, has made the unpleasant acquaintance of the codling moth and the curculio. Every season the apple raisers of the United States expend eight and one-quarter million dollars in spraying, to discourage the activities of these pests. In considering the troubles of the apple growers we may go even farther and count the twelve million dollars' worth of fruit spoiled by the insects despite all the spraying which has taken place. Chinch bugs destroy wheat to the value of twenty million dollars a year, and the cotton-boll weevil costs the Southern planters an equal amount.

Plagues of Insects.—Every now and then we read of great plagues of insects which literally lay waste a whole section of country. History tells of these calamities which have troubled the civilized world from the days of Pharaoh to the present time. During the summer of 1912 there was a great outbreak of army worms in South Carolina. In innumerable millions they marched across the country, destroying vegetation like a consuming fire. In the year 1900 Hessian flies appeared in great numbers in Ohio and Indiana, and before they subsided they had destroyed absolutely two and one-half million acres of the finest wheat to be found in the Middle West, and wheat land dropped 40 per cent. in value.

Closing this Year Book, with its long tables of discouraging statements, we may find more cheerful reading if we turn to another Agricultural Department publication entitled, "Some Common Birds and Their Relation to Agriculture; Farmers Bulletin number Fifty-four." We need peruse only a few pages to become impressed with the fact that our Government Biological Survey has made an exhaustive and exceedingly thorough investigation of the feeding habits of the wild birds that frequent the fields and forests. The reports of the economic ornithologists herein given are almost as surprising as the sad records given by the entomologists in the Year Book. We learn that birds, as a class, constitute a great natural check on the undue increase of harmful insects, and furthermore that the capacity for food of the average bird is decidedly greater in proportion than that of any other vertebrate.

Some Useful Birds.—Most people who have made the acquaintance of our common birds know the friendly little Chickadee, which winter and summer is a constant resident in groves of deciduous trees. It feeds, among other things, on borers living in the bark of trees, on plant lice which suck the sap, on caterpillars which consume the leaves, and on codling worms which destroy fruit. One naturalist found that four Chickadees had eaten one hundred and five female cankerworm moths. With scalpel, tweezers, and microscope these moths were examined, and each was found to contain on an average one hundred and eighty-five eggs. This gives a total of nearly twenty thousand cankerworm moth eggs destroyed by four birds in a few minutes. The Chickadee is very fond of the eggs of this moth and hunts them assiduously during the four weeks of the summer when the moths are laying them.

The Nighthawk, which feeds mainly in the evening, and which is equally at home in the pine barrens of Florida, the prairies of Dakota, or the upper air of New York City, is a slaughterer of insects of many kinds. A Government agent collected one, in the stomach of which were the remains of thirty-four May beetles, the larvae of which are the white grubs well known to farmers on account of their destruction of potatoes and other vegetables. Several stomachs have been found to contain fifty or more different kinds of insects, and the number of individuals in some cases run into the thousands. Nighthawks also eat grasshoppers, potato-beetles, cucumber-beetles, boll-weevils, leaf-hoppers, and numerous gnats and mosquitoes. Surely this splendid representative of the Goatsucker family deserves the gratitude of all American citizens.

Among the branches of certain of our fruit trees we sometimes see large webs which have been made by the tent caterpillars. An invading host seems to have pitched its tents among the boughs on all sides. If undisturbed these caterpillars strip the foliage from the trees. Fortunately there is a bird which is very fond of these hairy intruders. This is the Cuckoo, and he eats so many that his stomach actually becomes lined with a thick coating of hairs from their woolly bodies. The Baltimore Oriole also is fond of rifling these webs.

Another well-known bird that helps to make this part of the world habitable is the Flicker. It is popular in every neighbourhood where it is found and is known by a wide variety of local names, over one hundred and twenty-five of which have been recorded. Golden-winged Woodpecker some people call it. Other names are High-holder, Wake-up, Walk-up, Yellowhammer, and Pigeon Woodpecker. The people of Cape Hatteras know it as Wilkrissen, and in some parts of Florida it is the Yucker-bird. Naturalists call it Colaptes auratus, but name it as you may, this bird of many aliases is well worthy of the esteem in which it is held. It gathers its food almost entirely from the ground, being different in this respect from other Woodpeckers. One may flush it in the grove, the forest, the peanut field, or the untilled prairie, and everywhere it is found engaged in the most highly satisfactory occupation of destroying insect life. More than half of its food consists of ants. In this country, taken as a whole, Flickers are very numerous, and the millions of individual birds which have yet escaped the guns of degenerate pot hunters constitute a mighty army of destruction to the Formicidae.

Let us not forget that any creature which eats ants is a decided boon to humanity. Ants, besides being wood borers, invaders of pantries, killers of young birds, nuisances to campers and barefoot boys, care for and perpetuate plant lice which infest vegetation in all parts of the country to our very serious loss. Professor Forbes, in his study of the corn plant louse, found that in spring ants mine along the principal roots of the corn. Then they collect the plant lice, or aphids, and convey them into these burrows and there watch and protect them. Without the assistance of ants, it appears that the plant lice would be unable to reach the roots of the corn. In return for these attentions the ants feast upon the honey-like substances secreted by these aphids. The ants, which have the reputation of being no sluggards, take good care of their diminutive milch cattle, and will tenderly pick them up and transport them to new pastures when the old ones fail. Late in the summer they carefully collect all the aphid eggs that are obtainable, and taking them into their nests keep them safe during the winter. When spring comes and the eggs hatch, the ants gather the young plant lice and place them on plants. It may be seen, therefore, that the Flicker by digging up ants' nests and feeding on the inhabitants has its value in an agricultural community.

The Question of the Weed Seeds.—The work of the Chickadee, the Nighthawk, the Cuckoo, and the Flicker is only an example of the good being done by at least two-thirds of birds in the United States, and most of the remainder are not without their beneficial qualities. When the coming of winter brings a cessation of insect life, many birds turn to the weed patches for food. Especially is this the case with the various varieties of native Sparrows.