Part 3

Stomachs of nestlings, varying in age from 24 hours to some that were nearly fledged, were found to contain 89 per cent animal to 11 per cent vegetable matter. The largest items in the former were caterpillars, grasshoppers, and spiders. In the latter the largest items were fruit, probably cherries; grain, mostly oats; and rubbish.

BALTIMORE ORIOLE.

Brilliancy of plumage, sweetness of song, and food habits to which no exception can be taken are some of the striking characteristics of the Baltimore oriole[37] (fig. 12). In summer it is found throughout the northern half of the United States east of the Great Plains. Its nest commands hardly less admiration than the beauty of its plumage or the excellence of its song. Hanging from the tip of the outermost bough of a stately elm, it is almost inaccessible to depredators and so strongly fastened as to bid defiance to the elements.

[37] _Icterus galbula_.

Observation both in the field and laboratory shows that caterpillars constitute the largest item of the fare of the oriole. In 204 stomachs they formed 34 per cent of the food, and they are eaten in varying quantities during all the months in which the bird remains in this country. The fewest are eaten in July, when a little fruit also is taken. The other insects consist of beetles, bugs, ants, wasps, grasshoppers, and some spiders. The beetles are principally click beetles, the larvæ of which are among the most destructive insects known; and the bugs include plant and bark lice, both very harmful, but so small and obscure as to be passed over unnoticed by most birds. Ants are eaten mostly in spring, grasshoppers in July and August, and wasps and spiders with considerable regularity throughout the season.

During the stay of the oriole in the United States, vegetable matter amounts to only a little more than 16 per cent of its food, so that the possibility of its doing much damage to crops is very limited. The bird is accused of eating peas to a considerable extent, but remains of such were found in only two cases. One writer says that it damages grapes, but none were found in the stomachs.

BULLOCK ORIOLE.

The Bullock oriole[38] is practically a counterpart of the Baltimore oriole, taking the place of that species west of the Plains and throughout the Pacific coast region. It does not essentially differ in its habits of nesting or in its food from its eastern relative, but it is less beautiful in plumage. The examination of 162 stomachs shows that 79 per cent of its food consists of insects, with a few spiders, a lizard, a mollusk shell, and eggshells. Beetles amounted to 35 per cent, and all except a few ladybugs were harmful species. Ants were found in 19 stomachs, and in one there was nothing else. Bees, wasps, etc., were in 56 stomachs, and entirely filled 2 of them. Including the ants, they amount to nearly 15 per cent of the food of the season.

[38] _Icterus bullocki_.

One of the most interesting articles of food in the oriole's dietary was the black olive scale, found in 45 stomachs, and amounting to 5 per cent of the food. In several cases these scales formed 80 per cent or more of the contents, and in one, 30 individual scales could be counted. They were evidently a standard article of diet, and were eaten regularly in every month of the oriole's stay except April. Hemipterous insects other than scales, eaten quite regularly, make up a little more than 5 per cent of the food. They were mostly stinkbugs, leaf hoppers, and tree hoppers. Plant lice were found in one stomach.

Moths, pupæ, and caterpillars compose the largest item of the oriole's animal food; the average consumption during its summer stay Is a little more than 41 per cent. Of these, perhaps the most interesting were the pupæ and larvæ of the codling moth. These were found in 23 stomachs, showing that they are not an unusual article of diet. No less than 14 of the pupal cases were found in one stomach, and as they are very fragile many others may have been present, but broken beyond recognition.

Grasshoppers probably do not come much in the oriole's way. They were eaten, however; to the extent of a little more than 3 per cent. But in spite of the fact that grasshoppers are eaten so sparingly, 2 stomachs, both taken in June, contained nothing else, and another contained 97 per cent of them.

Various insects and spiders, with a few other items, make up the rest of the animal food, a little more than 5 per cent. Spiders are not important in the oriole's food, but are probably eaten whenever found. They were identified in 44 stomachs, but in small numbers. The scales of a lizard were found in one stomach and the shell of a snail in another.

The vegetable contingent of the oriole's food is mostly fruit, especially in June and July, when it takes kindly to cherries and apricots, and sometimes eats more than the fruit grower considers a fair share. However, no great complaint is made against the bird, and it is probable that as a rule it does not do serious harm. With such a good record as an insect eater it can well be spared a few cherries.

THE MEADOWLARKS.

The eastern meadowlark[39] (fig. 13) is a common and well-known bird occurring from the Atlantic coast to the Great Plains, where it gives way to the closely related western species,[40] which extends thence westward to the Pacific. It winters from our southern border as far north as the District of Columbia, southern Illinois, and occasionally Iowa. The western, form winters somewhat farther north. Although it is a bird of the plains, and finds its most congenial haunts in the prairies of the West, it is at home wherever there is level or undulating land covered with grass or weeds, with plenty of water at hand.

[39] _Sturnella magna_.

[40] _Sturnella neglecta_.

In the 1,514 stomachs examined, animal food (practically all insects) constituted 74 per cent of the contents and vegetable matter 26 per cent. As would naturally be supposed, the insects were ground species, as beetles, bugs, grasshoppers, and caterpillars, with a few flies, wasps, and spiders. A number of the stomachs were collected when the ground was covered with snow, but even these contained a large percentage of insects, showing the bird's skill in finding proper food under adverse circumstances.

Of the various insects eaten, crickets and grasshoppers are the most important, constituting 26 per cent of the food of the year and 72 per cent of the food in August. It is scarcely necessary to mention the beneficial effect of a number of these birds on a field of grass in the height of the grasshopper season. Of the 1,514 stomachs collected at all seasons of the year, 778, or more than half, contained remains of grasshoppers, and one was filled with fragments of 37 of these insects. This seems to show conclusively that grasshoppers are preferred, and are eaten whenever they can be found. Especially notable is the great number taken in August, the month when grasshoppers reach their maximum abundance; stomach examination shows that large numbers of birds resort at this time to this diet, no matter what may be the food during the rest of the year.

Next to grasshoppers, beetles make up the most important item of the meadowlark's food, amounting to 25 per cent, about one-half of which are predacious ground beetles. The others are all harmful species.

Forty-two individuals of different kinds of May beetles were found in the stomachs of meadowlarks, and there were probably many more which were past recognition. To this form and several closely allied ones belong the numerous white grubs, which are among the worst enemies to many cultivated crops, notably grasses and grains, and to a less extent strawberries and garden vegetables. In the larval stage they eat the roots of these plants, and being large, one individual may destroy several plants. In the adult stage they feed upon the foliage of trees and other plants, and in this way add to the damage which they began in the earlier form. As these enemies of husbandry are not easily destroyed by man, it is obviously wise to encourage their natural foes.

Among the weevils found in the stomachs the most important economically are the cotton-boll weevil and the recently introduced alfalfa weevil of Utah. Several hundred meadowlarks were taken in the cotton-growing region, and the boll weevil was found in 25 stomachs of the eastern meadowlark and in 16 of the western species. Of the former, one stomach contained 27 individuals. Of 25 stomachs of western meadowlarks taken in alfalfa fields of Utah, 15 contained the alfalfa weevil. In one stomach 23 adults were found, in another 32 adults and 70 larvæ, still another had 10 adults and 40 larvæ, and a fourth had 4 adults and 100 larvæ.

Caterpillars form a very constant element of the food, and in May constitute over 24 per cent of the whole. May is the month when the dreaded cutworm begins Its deadly career, and then the lark does some of its best work. Most of these caterpillars are ground feeders, and are overlooked by birds which habitually frequent trees, but the meadowlark finds and devours them by thousands. The remainder of the insect food is made up of ants, wasps, and spiders, with some bugs, including chinch bugs, and a few scales.

The vegetable food consists of grain and weed and other hard seeds. Grain in general amounts to 11 per cent and weed and other seeds to 7 per cent. Grain, principally corn, is eaten mostly in winter and early spring and consists, therefore, of waste kernels; only a trifle is consumed in summer and autumn, when it is most plentiful. No trace of sprouting grain was discovered. Glover seed was found in only six stomachs, and but little in each. Seeds of weeds, principally ragweed, barnyard grass, and smartweed, are eaten from November to April, inclusive, but during the rest of the year are replaced by insects.

Briefly stated, more than half of the meadowlark's food consists of harmful insects; its vegetable food is composed either of noxious weeds or waste grain; and the remainder is made up of useful beetles or neutral insects and spiders. A strong point in the bird's favor is that, although naturally an insect eater, it is able to subsist on vegetable food, and consequently is not forced to migrate in cold weather farther than is necessary to find ground free from snow.

THE RED-WINGED BLACKBIRDS.

The red-winged or swamp blackbird[41] in its various forms (fig. 14) is found all over the United States and the region immediately to the north. While common in most of its range, its distribution is more or less local, mainly on account of its partiality for marshes. It builds its nest over or near standing water, in tall grass, rushes, or bushes. Owing to this peculiarity the bird may be absent from large tracts of country which afford no swamps or marshes suitable for nesting. It usually breeds in large colonies, though single families, consisting of a male and several females, may sometimes be found in a small slough, where each female builds her nest and rears her own little brood. While her liege lord displays his brilliant colors and struts in the sunshine. In the upper Mississippi Valley the species finds most favorable conditions, for the countless prairie sloughs and the margins of the numerous shallow lakes afford nesting sites for thousands of red-wings; and here are bred the immense flocks which sometimes do so much damage to the grain fields of the West. After the breeding season the birds congregate preparatory to migration, and remain thus associated throughout the winter.

[41] _Agelaius phœniceus_.

Three species and several subspecies of red-wings are recognized,[42] but practically no difference exists in the habits of these forms either in nesting or feeding, except such as may result from local conditions. Most of the forms are found on the Pacific side of the continent, and may be considered as included in the following statements as to food and economic status.

[42] Agelaius phœniceus (8 forms), Agelaius gubernator, and Agelaius tricolor.

Many complaints have been made against the red-wing, and several States have at times placed a bounty upon its head. It is said to cause great damage to grain in the West, especially in the upper Mississippi Valley, but few complaints come from the northeastern section, where the bird is much less abundant than in the West and South.

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.

BOBOLINK.

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_.

Formerly, when the low marshy shores of the Carolinas and some of the more southern States were devoted to rice culture the bobolinks made great havoc both upon the sprouting rice in spring and upon the ripening grain on their return migration in the fall. While the damage is not so great as when this region was the center of rice production, still it amounts to many thousands of dollars annually. As a remedy, an open season on ricebirds was provided in the Coast States from New Jersey to Florida.

CROW.

In one or another of its geographic races the common crow[44] (fig. 16) breeds in great numbers throughout the States east of the Plains and from the Gulf well up into Canada, while in less abundance it is found in California and in the Northwestern States. During the colder months a southern migratory movement brings most of these birds within the borders of the United States, and at about the latitude of Philadelphia and southern Illinois we find them congregating nightly in roosts. Farmers dwelling in the vicinity of such roosts frequently suffer losses to shocked corn.

[44] _Corvus brachyrhynchos_.

In fact, none of our native birds so much concerns the average farmer of the Eastern States as the common crow. Many of our present criticisms of this bird, as its pulling sprouting corn, feeding on ripening ears, damaging fruits of various kinds, destroying poultry and wild birds, and disseminating diseases of live-stock, were common complaints in the days of the early colonists. Many of the virtues of the crow, now quite generally recognized, also have been matters of record for many years. In recent times, however, scientific study of these problems, including the examination of the stomachs of hundreds of crows secured in every month of the year and under a variety of conditions, has enabled us to render a much fairer verdict than was formerly possible.

The crow is practically omnivorous. During spring and early summer any form of insect life seems to make a desirable item in its diet, and in winter when hard pressed nothing in the animal or vegetable kingdoms which contains a morsel of nutriment is overlooked.

The insect food of the crow, which comprises about a fifth of its yearly sustenance, does much to atone for its misdemeanors. Grasshoppers, May beetles and their larvæ (white grubs), caterpillars, weevils, and wireworms stand out prominently. In 1,340 stomachs of adults examined these highly Injurious forms comprised over 80 per cent of the insect food. Grasshoppers are naturally taken in greatest abundance late in the season. September being the month of largest consumption, when they form about a fifth of the total food. May beetles and white grubs are eaten in every month, but occur most prominently in May. In June caterpillars are a favorite food, and weevils of various kinds are taken in varying quantities throughout summer and fall. About half of the remaining 20 per cent of insect food is composed of beneficial ground beetles, ladybirds, predacious bugs, and parasitic wasps, and related forms, the rest consisting of neutral or injurious forms. Numerous instances are on record where fields badly infested with white grubs or grasshoppers have been favorite resorts of crows, whose voracity has resulted in a material suppression of the pest. When the amount of food required to sustain the individual crow is considered, the work of these birds appears all the more important Single stomachs containing upward of 50 grasshoppers are not uncommon. Thus in its choice of insect food the crow is rendering an important service to the farmer.

In the other animal food of the crow are several items of the utmost economic importance. Spiders are taken in considerable numbers in May and June, but the yearly total is a little over 1 per cent of the food. In early spring crawfish are eagerly sought, and other aquatic food, as fish and mollusks, lend variety to the crow's bill of fare the year round. In the consumption of toads, salamanders, frogs, and some snakes, which together compose a little over 2 per cent of the yearly food, the crow is doubtless doing harm. Small rodents occurred in the stomachs collected nearly every month, but it Is often difficult to determine whether small mammals found in birds' stomachs were taken alive or found dead.

From its carrion-eating habits the crow has been unfairly criticized as a disseminator of live-stock diseases. While this may be to some extent just, the fact that there are many other important carriers which lie largely beyond our control, shows that we must seek final relief only through the strictest methods of sanitation.

The nest-robbing habit of the crow, long a serious criticism, is verified by stomach analysis. Of the 1,103 crows examined, 47 had fed on wild birds or their eggs, and the eggs of domestic fowls were found somewhat more frequently. The crow's habit of rummaging about garbage piles may explain much of this latter material.

Of the vegetable food, corn, which is eaten every month, is the most important item and forms about 38 per cent of the diet. Much of this, however, must be considered waste, since over 60 per cent of it is consumed from the first of November to the end of March. During the periods when corn is sprouting and when in the "roasting-ear" stage the crow is eating this grain at a rate considerably less than the yearly average, and the months of smallest consumption are July and August. At times, however, the damage to corn becomes a serious problem, and were it not possible to make use of such deterrents as coal tar upon seed corn there would be little friendship for the crow in some sections of the East. The "pulling" of corn is a trait most prevalent in small-field areas. Wheat and oats suffer similar damage at times, especially in the Northwestern States, where these grains predominate. About the only safeguard to ripening grain is the constant use of powder and shot or the scarecrow.

Various kinds of cultivated fruits are also eaten, and local damage to such crops as apples, melons, peas, beans, peanuts, and almonds is occasionally reported. In long, rigorous winters, the crow, like other birds, resorts to the fruit of numerous wild plants, as dogwood, sour gum, hackberry, smilax, and the several species of sumac and poison ivy.

Damage to the eggs of poultry may be reduced to a minimum by careful housing of lasting hens, and the farmer can protect his sprouting grain to a large extent by the use of tar-coated seed. It will be well also to keep the crow within reasonable numbers on game preserves and public parks where it is desired to encourage the nesting of smaller birds. While legal protection is not needed for so wary an individual as the crow, it seems well, where local conditions have not aggravated some particular shortcomings of the bird, to allow it to continue the good services gendered to man in the destruction of noxious insects.

BLUE JAY.