Fig. 8.—Towhee. Length, about 8 inches.
Fig. 8.—Towhee. Length, about 8 inches.
The towhee, chewink, or ground robin[23](fig. 8), as it is variously known, inhabits nearly the whole of the United States east of the Great Plains. It breeds from the Middle States northward and winters in the southern half of the country. Naturally associated with the catbird and brown thrasher, it lives in much the same places, though it is more given to haunting hedgerows along roads and fences. After snow has disappeared in early spring an investigation of the rustling so often heard among the leaves near a fence or in a thicket will frequently disclose a towhee hard at work scratching for his dinner after the manner of a hen; and in these places and along the sunny border of woods old leaves will be found overturned where the bird has been searching for hibernating beetles and larvæ. The good which the towhee does in this way can hardly be overestimated, since the death of a single insect at this time, before it has had an opportunity to deposit its eggs, is equivalent to the destruction of a host later in the year. The towhee has also been credited with visiting potato fields and feeding upon the potato beetle. Its vegetable food consists of seeds and small wild fruits, but no complaint on this score is known to have been made. So far as observation goes, the bird never touches either cultivated fruit or grain; in fact, it is too shy and retiring even to stay about gardens for any length of time.
[23]Pipilo erythrophthalmus.
[23]Pipilo erythrophthalmus.
[24]The sparrows here mentioned are all native species. A full account of the English, or house, sparrow (Passer domesticus), including its introduction, habits, and depredations, was published in Bul. No. 1 of the Division of Ornithology in 1889. For information in regard to combating the English sparrow, see Farmers’ Bulletin 493, The English Sparrow as a Pest, by Ned Dearborn, 1912.
[24]The sparrows here mentioned are all native species. A full account of the English, or house, sparrow (Passer domesticus), including its introduction, habits, and depredations, was published in Bul. No. 1 of the Division of Ornithology in 1889. For information in regard to combating the English sparrow, see Farmers’ Bulletin 493, The English Sparrow as a Pest, by Ned Dearborn, 1912.
Sparrows are not obtrusive birds, either in plumage, song, or action. There are some 40 species, with nearly as many subspecies, in North America. Not more than half a dozen forms are generally known in any one locality. All the species are more or less migratory, but so widely are they distributed that there is probably no part of the country where some can not be found throughout the year.
While sparrows are noted seed eaters, they do not by any means confine themselves to a vegetable diet. During the summer, and especially in the breeding season, they eat many insects and feed their young largely upon the same food. Examination of stomachs of three species—the song sparrow[25](fig. 9), chipping sparrow,[26]and field sparrow[27](fig. 10)—shows that about one-third of the food consists of insects, comprising many injurious beetles, as snout beetles or weevils, and leaf beetles. Many grasshoppers are eaten. In the case of the chipping sparrow these insects form one-eighth of the food. Grasshoppers would seem to be rather large morsels, but the bird probably confines itself to the smaller species; indeed, the greatest amount (over 36 per cent) is eaten in June, when the larger species are still young and the smaller most numerous. Besides the insects already mentioned, many wasps and bugs are taken. Predacious and parasitic hymenopterous insects and predacious beetles, all useful, are eaten only to a slight extent, so that as a whole the insect diet of the native sparrows may be considered beneficial. There are several records of potato-bug larvæ eaten by chipping sparrow’s.
[25]Melospiza melodia.[26]Spizella passerina.[27]Spizella pusilla.
[25]Melospiza melodia.
[26]Spizella passerina.
[27]Spizella pusilla.
Fig. 9.—Song sparrow. Length, about 6½ inches.
Fig. 9.—Song sparrow. Length, about 6½ inches.
Their vegetable food is limited almost exclusively to hard seeds. This might seem to indicate that the birds feed to some extent upon grain, but the stomachs examined show only one kind, oats, and but little of that. The great bulk of the food is made up of grass and weed seed, which form almost the entire diet during winter, and the amount consumed is immense.
In the agricultural region of the upper Mississippi Valley, by roadsides, on borders of cultivated fields, or in abandoned fields, wherever they can obtain a foothold, masses of rank weeds spring up and often form almost impenetrable thickets which afford food and shelter for immense numbers of birds and enable them to withstand great cold and the most terrible blizzards. A person visiting one of these weed patches on a sunny morning in January, when the thermometer is 20° or more below zero, will be struck with the life and animation of the busy little inhabitants. Instead of sitting forlorn and half frozen, they may be seen flitting from branch to branch, twittering and fluttering, and showing every evidence of enjoyment and perfect comfort. If one of them is captured it will be found in excellent condition; in fact, a veritable ball of fat.
Fig. 10.—Field sparrow. Length, about 5½ inches.]
Fig. 10.—Field sparrow. Length, about 5½ inches.]
Fig. 10.—Field sparrow. Length, about 5½ inches.]
The snowbird[28]and tree sparrow[29]are perhaps the most numerous of all the sparrows. Examination of many stomachs shows that in winter the tree sparrow feeds entirely upon seeds of weeds. Probably each bird consumes about one-fourth of an ounce a day. In an article contributed in 1881 to the New York Tribune the writer estimated the amount of weed seed annually destroyed by these birds in Iowa. On the basis of one-fourth of an ounce of seed eaten daily by each bird, and an average of ten birds to each square mile, remaining in their winter range 200 days, there would be a total of 1,750,000 pounds, or 875 tons of weed seed consumed in a single season by this one species. Large as are these figures, they unquestionably fall far short of the reality. The estimate of 10 birds to a square mile is very conservative, for in Massachusetts, where the food supply is less than in the Western States, the tree sparrow is even more abundant than this in winter. The writer has known places in Iowa where several thousand tree sparrows could be seen within the space of a few acres. This estimate, moreover, is for a single species, while, as a matter of fact, there are at least half a dozen birds (not all sparrows) that habitually feed during winter on these seeds. Farther south the tree sparrow is replaced in winter by the white-throated sparrow,[30]the white-crowned sparrow,[31]the fox sparrow,[32]the song sparrow, the field sparrow, and several others; so that all over the land a vast number of these seed eaters are at work during the colder months reducing next year’s crop of worse than useless plants.
[28]Junco hyemails.[29]Spizella monticola.[30]Zonotrichia albicollis.[31]Zonotrichia leucophrys.[32]Passerella iliaca.
[28]Junco hyemails.
[29]Spizella monticola.
[30]Zonotrichia albicollis.
[31]Zonotrichia leucophrys.
[32]Passerella iliaca.
Of all the sparrow group, there is probably no member, unless it be the exotic form known as the English sparrow,[33]that has by reason of its food habits called down so many maledictions upon its head as the house finch,[34]red-head, or linnet, as it is variously called. This bird, like the other members of its family, is by nature a seed eater, and before the beginning of fruit raising in California probably subsisted upon the seeds of weeds, with an occasional taste of some wild berry. Now, however, when orchards have extended throughout the length and breadth of the State and every month from May to December sees some ripening fruit, the linnets take their share. As their name is legion, the sum total of the fruit that they destroy is more than the fruit raiser can well spare. As the bird has a stout beak, it has no difficulty in breaking the skin of the hardest fruit and feasting upon the pulp, thereby spoiling the fruit and giving weaker-billed birds a chance to sample and acquire a taste for what they might not otherwise have molested. Complaints against this bird have been many and loud, more especially in the years when fruit crops first came to be an important factor in the prosperity of the Pacific coast. At that time the various fruits afforded the linnets a new and easily obtained food, while cultivation had reduced their formerly abundant supply of weed seed. When the early fruit growers saw their expected golden harvest suddenly snatched away or at least much reduced in value by the little marauders, it is no wonder that they were exasperated and wished to destroy the authors of the mischief.
[33]Passer domesticus.[34]Carpodacus mexicanus frontalis.
[33]Passer domesticus.
[34]Carpodacus mexicanus frontalis.
In order to test the matter thoroughly and ascertain whether these birds ate any other kind of food that might to some extent offset the damage inflicted upon the fruit, the horticulturists and ornithologists of California were requested to secure a number of the stomachs of these birds and send them to the Biological Survey. An agent was also sent to the fruit-raising sections, who watched the birds in the orchards and collected a number of them. In this way 1,206 stomachs were obtained and carefully examined, and the result shows that animal food (insects) constituted 2.44 per cent and vegetable food 97.56 per cent of the stomach contents, not counting gravel.
So small a proportion of animal food can not, of course, mean a great destruction of insects. As these stomachs were collected in every month, with the greater number taken during the summer, it is evident that whatever good one may expect from the linnet must not be looked for in this direction. Unlike most of the sparrow family, the linnet does not feed its young upon insects to any great extent. The contents of the stomachs of a number of nestlings were carefully examined, and the only animal food was found to consist of woolly plant lice. These also constituted the great bulk of the animal food eaten by adults.
The vegetable food of the species consists of three principal items—grain, fruit, and weed seeds. Grain amounts to less than 1½ per cent in August, which is the month of greatest consumption, and the average for the year is a trifle more than one-fourth of 1 per cent. Fruit attains its maximum in September, when it amounts to 27 per cent of the whole food, but the average for the year is only 10 per cent. The seeds of weeds constitute the bulk of the diet of the linnet, and in August, the month of least consumption, amount to about 64 per cent of the food. The average for the year is 86 per cent.
From the foregoing it is evident that whatever the linnet’s sins may be, grain eating is not one of them. In view of the great complaint made against its fruit-eating habit, the small quantity found in the stomachs taken is somewhat of a surprise. But it must be remembered that the stomach contents do not tell the whole story. When a bird takes a single peck from a cherry or an apricot, it spoils the whole fruit, and in this way may ruin half a dozen in taking a single meal. It is safe to say that the fruit pulp found in the stomach does not represent more than one-fifth of what is actually destroyed. That the linnets are persistent and voracious eaters of early fruits, especially cherries and apricots, every fruit raiser in California will bear testimony. That the damage is often serious no one will deny. It is noticeable, however, thatthe earliest varieties are the ones most affected; also, that in large orchards the damage is not perceptible, while in small plantations the whole crop is frequently destroyed.
The crow blackbird or grackle[35](fig. 11) in one or more of its subspecies is a familiar object in all the States east of the Rocky Mountains. Throughout the year it is resident as far north as southern Illinois, and in summer extends its range into the Canadian Provinces. In the Mississippi Valley it is one of the most abundant of birds, preferring to nest in the artificial groves and windbreaks near farms instead of in the natural “timber” which it formerly used. It breeds also in parks and near buildings, often in considerable colonies. Farther east, in New England, it is only locally abundant, though frequently seen in migration. In the latter days of August and throughout September it is found in immense numbers before moving southward.
[35]Quiscalus quiscula.
[35]Quiscalus quiscula.
The grackle is accused of many sins, such as stealing grain and fruit and robbing the nests of other birds. An examination of 2,346 stomachs shows that nearly one-third of its food consists of insects, most of which are injurious. The bird also eats a few snails, crawfishes, salamanders, small fish, and occasionally a mouse. The stomach contents do not indicate that it robs other birds’ nests to any great extent, as remains of birds and birds’ eggs amount to less than half of 1 per cent.
It is on account of its vegetable food that the grackle most deserves condemnation. Grain is eaten during the whole year, and only for a short time in summer is other food attractive enough to induce the bird to alter its diet. The grain taken in winter and spring probably consists of waste kernels from the stubble. The stomachs do not indicate that the bird pulls sprouting grain; but the wheat eaten in July and August and the corn eaten in fall are probably from fields of standing grain. The total amount of grain consumed during the year constitutes 45 per cent of the food, but it is safe to say that at least half is waste grain and consequently of no value. Although the crow blackbird eats a few cherries and blackberries in their season, and in the fall some wild fruit, it apparently does no damage in this way.
Fig. 11.—Purple grackle. Length, about 12 inches.
Fig. 11.—Purple grackle. Length, about 12 inches.
Large flocks of grackles no doubt do considerable injury to grain crops, and there seems to be no remedy, except the destruction of the birds, which is in itself expensive. During the breeding season, however, the species does much good by eating insects and by feeding them to its young, which are reared almost entirely upon this food. The bird does the greatest amount of good in spring, when it follows the plow in search of large grubworms, of which it is so fond that it sometimes literally crams its stomach full of them.
The Brewer blackbird[36]takes the place in the Western States of the grackle, or crow blackbird, which lives in the Mississippi Valley and farther east and is very similar in appearance and habits. It breeds east to the Great Plains and north into Canada, and winters over most of its breeding range in the United States and south to Guatemala. At home in fields, meadows, and orchards, and about ranch buildings and cultivated lands generally, it nests in bushes and weeds, sometimes in trees, and is very gregarious, especially about barnyards and corrals. The bird feeds freely in stockyards and in cultivated fields, and when fruit is ripe does not hesitate to take a share. During the cherry season in California the birds are much in the orchards. In one case they wereobserved feeding on cherries, but when a neighboring fruit grower began to plow his orchard almost every blackbird in the vicinity was upon the newly opened ground close after the plowman’s heels in its eagerness to secure the insects turned up.
[36]Euphagus cyanocephalus.
[36]Euphagus cyanocephalus.
The laboratory investigation of this bird’s food covered 312 stomachs, collected in every month and representing especially the fruit and grain sections of southern California. The animal portion of the food was 32 per cent and the vegetable 68 per cent.
Caterpillars and their pupæ amounted to 12 per cent of the whole food and were eaten every month. They include many of those pests known as cutworms. The cotton-boll worm, or corn-ear worm, was identified in at least 10 stomachs, and in 11 were found pupæ of the codling moth. The animal food also included other insects, and spiders, sow bugs, snails, and eggshells.
The vegetable food may be divided into fruit, grain, and weed seeds. Fruit was eaten in May, June, and July, not a trace appearing in any other month, and was composed of cherries, or what was thought to be such, strawberries, blackberries or raspberries, and fruit pulp or skins not further identified. However, the amount, a little more than 4 per cent for the year, was too small to make a bad showing, and if the bird does no greater harm than is involved in its fruit eating it is well worth protecting. Grain amounts to 54 per cent of the yearly food and forms a considerable percentage in each month; oats are the favorite and were the sole contents of 14 stomachs, and wheat of 2, but no stomach was completely filled with any other grain. Weed seeds, eaten in every month to the extent of 9 per cent of the food, were found in rather small quantities and irregularly, and appear to have been merely a makeshift.
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.
Fig. 12.—Baltimore oriole. Length, about 7½ inches.
Fig. 12.—Baltimore oriole. Length, about 7½ inches.
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.
[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.
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.
[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 pupa 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 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.
[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 morethan 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.
Fig. 13.—Meadowlark. Length, about 10 inches.
Fig. 13.—Meadowlark. Length, about 10 inches.
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, while 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. Clover 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 or swamp blackbird[41]in its various forms (fig. 14) is found all over the United States and the region immediately to the north. Whilecommon 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.
[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, andAgelaius tricolor.
[42]Agelaius phœniceus(8 forms),Agelaius gubernator, andAgelaius 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 no complaints come from the northeastern section, where the bird is much less abundant than in the West and South.
Fig. 14.—Red-winged blackbird. Length, about 9½ inches.
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 20 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. In view of the many complaints that the red-wing eats grain, this record is surprisingly small. The purple grackle has been found to eat more than three times as much. In the case of the crow, corn forms one-third of the food, so that the red-winged blackbird, whose diet is made up of only a trifle more than one-eighth of grain, is really one of the least destructive species. 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. Nearly seven-eighths of its food is made up of weed seed or of insects injurious to agriculture, indicating unmistakably thatthe bird should be protected, except, perhaps, in a few places where it is overabundant.
Fig. 15.—Bobolink, rice bird, or reed bird. Length, about 7 inches.
Fig. 15.—Bobolink, rice bird, or reed bird. Length, about 7 inches.
The bobolink, rice bird, or reed bird[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 reed birds, and becoming very fat are treated as game.
[43]Dolichonyx oryzivorus.
[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. With a change in the rice-raising districts, however, this damage is no longer done.
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.
[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 1,103 stomachs 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 except January, 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.