Some Common Birds Useful to the Farmer (1926 edition)
Part 4
The blue jay[45] (fig. 17) is a conspicuous member of our bird population east of the Plains, especially in autumn when his brilliant plumage contrasts vividly with the brown> foliage. Even in winter he stays with us, though at this time he is less common along our northern border. In spring and summer, while by no means uncommon, the blue jay is not so often noticed, as the retiring disposition which he assumes during the breeding season assists in protecting him from enemies. This also allows him to carry on with considerable impunity that inglorious practice of nest robbing of which, in a measure, he has been rightfully accused.
[45] _Cyanocitta cristata_.
Examination of 530 stomachs collected at all times of the year in 30 of our Eastern States and Canada shows that insects comprise about 22 per cent of the yearly sustenance. About three-fourths of these are injurious, the remainder being neutral or beneficial. Of the injurious insects, grasshoppers form the largest portion; in August nearly a fifth of the food. Caterpillars are conspicuous in July and August and at this time average about a tenth of the stomach contents. Both laboratory investigations and field observations have established the fact that in winter the eggs of the tent caterpillar and the hibernating larvæ of the brown-tail moth in New England are eagerly sought Scarabæid beetles form about 4 per cent of the yearly food, and click beetles and wire-worms about 1 per cent. Of the beneficial forms, ground beetles (3 per cent) and hymenopterous insects, part of which are parasitic (2.5 per cent), are taken most frequently. A few other invertebrates, as spiders, millipedes, mollusks, and crustaceans, also are eaten throughout the year.
In the consideration of the vertebrate food of the blue jay we are confronted with the problem of the destruction of wild birds and their eggs. Special search was made for every possible trace of such material in the stomachs, and in 6 of the 530 were found the remains of wild birds or their eggs. In February two jays had killed a small bird apiece; in May one had robbed a nest of eggs; in June two had taken a small bird and a clutch of eggs, respectively; and in August another had robbed a nest As this trait of the jay appears to be most pronounced during its own breeding season, it is quite possible for many birds which have suffered from its boldness early in the season to raise another brood unmolested. Thirty-nine of the 530 jays examined had fed on hen's eggs. Much of this food, however, was picked up about rubbish heaps, to which the jay, like other members of the crow family, is partial. While the result of stomach analysis would appear to belittle this fault of the blue jay, it is doubtless quite characteristic of the bird under favorable conditions.
Complaint that the jay is the source of considerable damage to corn in the fall has been verified to a certain degree by stomach examination. This grain is taken in every month of the year, but in greater quantities during winter and early spring, when much of it is necessarily waste, and it forms about 18 per cent of the yearly food. Cultivated fruits of various kinds are eaten from June to the end of the year, and the 15 per cent taken in July apparently justifies complaints against the bird on this score. The favorite vegetable food of the blue jay is mast of various kinds, acorns predominating, but beechnuts, chestnuts, chinquaquins, and hazelnuts also are relished. This food is important in every month but July and August, the yearly average being over 43 per cent, and from October to March it constitutes about two-thirds of the diet. Occasionally harm is done by feeding also on cultivated nuts, as pecans. Wild fruits are eaten during the summer and fall and constitute about 7 per cent of the yearly sustenance.
The blue jay probably renders its best services to man in destroying grasshoppers late in the season and in feeding on hibernating insects and their eggs, as it does in the case of the tent caterpillar and brown-tail moth. Such forest insects as buprestid beetles and weevils of various kinds also fall as its prey.
The blue jay's vegetable food, with the exception of some cultivated fruit and corn in the fall, is largely neutral. The severest criticism against the species is the destruction of other birds and their eggs. Where we wish to attract birds in large numbers about our dooryards, in our parks, and in game preserves, it will be well not to allow the jays to become too abundant.
PACIFIC COAST JAYS.
In California and adjacent States two species of jays are much in evidence under several more or less well-marked forms.
The Steller jay[46] much resembles the eastern bird, but it is more shy and retiring and seldom visits the orchard or vicinity of the ranch buildings. Stomach examination shows that its food does not radically differ from that of the eastern blue jay. As is the case with that bird, a very considerable part of the food consists of mast, together with a little fruit and some insects. The insects are largely wasps, with some beetles and grasshoppers. This jay also eats some grain, which is probably waste or volunteer. No complaints, so far as known, are made against this bird. Until it shall become less wary it is not likely to trespass to a serious extent upon the farmer's preserve.
[46] _Cyanocitta stelleri_.
The California jay,[47] although of a different genus, more nearly resembles its eastern relative in food habits and actions. It freely visits the stockyards near ranch buildings, and orchards and gardens. As a fruit stealer it is notorious. One instance is recorded where seven jays were shot from a prune tree, one after the other, the dead bodies being left under the tree until all were killed. So eager were the birds to get the fruit that the report of the gun and the sight of their dead did not deter them from coming to the tree. In orchards in canyons or on hillsides adjacent to chaparral or other cover great mischief is done by this bird. In one such case an orchard was under observation at a time when the prune crop was ripening, and jays in a continuous stream were seen to come down a small ravine to the orchard, prey upon the fruit, and return.
[47] _Aphelocoma californica_.
Fruit stealing, however, is only one of the sins of the California jay. That it robs hens' nests is universal testimony. A case is reported of a hen having a nest under a clump of bushes; every day a jay came to a tree a few rods away, and when it heard the cackle of the hen announcing a new egg it flew at once to the nest. At the same time the mistress of the house hastened to the spot to secure the prize, but in most cases the jay won the race. This is only one of many similar cases recounted. The jays have learned just what the cackle of the hen means. Another case more serious is that related by a man engaged in raising white leghorn fowls on a ranch several miles up a canyon. He stated that when the chicks were very young the jays attacked and killed them by a few blows of the beak and then pecked open the skull and ate out the brains. In spite of all efforts to protect the chicks and kill the jays the losses in this way were serious.
Examination of the stomachs of 326 California jays shows that 27 per cent of the contents for the year consists of animal matter and 73 per cent of vegetable. Although the great bulk of the animal food is made up of insects, the remains of eggshells and birds' bones appear much too often. The insect food is fairly well distributed among the more common orders, but grasshoppers are slightly the most numerous and constitute 4.5 per cent of the year's food. In July, August, and September, however, the amount is 14, 18, and 19 per cent, respectively. Four per cent of the food consists of wasps, bees, etc., but in the three months named they constitute 15, 7, and 9 per cent, respectively. A worker honeybee found in each of two stomachs is rather surprising, for it is unusual to find a bird like the jay eating these active and elusive insects, which enter into the diet of the flycatchers. The remainder of the insect food is pretty evenly distributed among beetles, bugs, flies, and caterpillars. Eggshells were found in 21 stomachs and birds' bones in 5. Six stomachs contained the bones of mammals and two those of a lizard. No bird has a worse reputation for nest robbing than has the eastern jay, and yet of 530 stomachs of the eastern species only 6 contained eggshells or the bones of birds. This comparison serves to show what a marauder and nest thief the California jay really is.
In its vegetable diet this bird much resembles its eastern relative, the most remarkable difference being in the matter of fruit eating. With greater opportunities the California bird has developed a greater appetite for fruit and indulges it to the fullest extent. Remains of fruit were found in 220 of the 326 stomachs. The percentage for the year is only 16, but for the four months of June, July, August, and September it is 44, 33, 53, and 25, respectively. Cherries, apricots, and prunes are the favorites among cultivated fruits, and elderberries are relished to some extent. Grain, which was found in 48 stomachs, amounts to 6 per cent of the food of the year. Practically all of it was taken in the four months above mentioned, but it is not probable that much damage is done by the jay in this respect. The major portion of the grain was oats. What was not wild was probably simply scattered grain gleaned after the harvest. Mast is eaten by the California jay from September to March, inclusive, and constitutes during most of that period one of the principal elements of its food. In this respect the bird shows a remarkable similarity to the eastern species. A few weed seeds and other miscellaneous items make up the balance of the vegetable food.
In summing up from an economic point of view the character of the food of the California jay, it must be conceded that it is not all that could be wished. Its taste for birds' eggs and fruit is entirely too pronounced, and at present the species is superabundant in California. While the natural food supply of the bird has been lessened by bringing the woods and brushy canyons under cultivation, the same areas have been planted to fruit, and naturally the jay takes the fruit as an acceptable substitute. A considerable reduction of the bird's numbers would appear to be the only effective remedy.
THE PHŒBES.
Among the early spring arrivals to their northern homes none is more welcome than the phœbe (fig. 18). The common phœbe[48] breeds throughout the United States east of the Great Plains, and winters from the South Atlantic and Gulf States southward. Its western relative, the black phœbe,[49] is found from Texas west to the Pacific coast, which it occupies as far north as Washington, replacing through most of this region the common or eastern form.
[48] _Sayornis phœbe_.
[49] _Sayornis Nigricans_.
Though naturally building its nest under an overhanging cliff of rock or earth, or in the mouth of a cave, the preference of the eastern species for the vicinity of farm buildings is so marked that in the more thickly settled parts of the country the bird is seldom seen at any great distance from a farmhouse, except where a bridge spanning a stream affords a secure spot for a nest. Its confiding disposition renders it a great favorite, and consequently it is seldom disturbed.
The phœbe subsists almost exclusively upon insects, most of which are caught upon the wing. An examination of 370 stomachs showed that over 89 per cent of the year's food consists of insects and spiders, while wild fruit constitutes the remainder. The insects belong chiefly to noxious species, and include many click beetles. May beetles, and weevils. Other beetles, belonging to 21 families that were identified, make up 10.65 per cent. They appear to be eaten very regularly in every month, but the most are taken in spring and early summer. May is the month of maximum consumption, with 20.43 per cent. Beetles altogether amount to 15.3 per cent, which places them second in rank of the items of animal food. The notorious cotton-boll weevil was found in six stomachs taken in the cotton fields of Texas and Louisiana, and five individuals of the strawberry weevil were taken from one collected in Texas. Many other beetles contained In the stomachs are equally harmful, but are not so widely known. Such are the corn leaf-beetle, which feeds upon corn; the 12-spotted cucumber beetle, and the striped cucumber beetle, both of which seriously injure and sometimes destroy cucumber and squash vines; and the locust leaf miner, which is sometimes so numerous that all the locust trees over large areas are blasted as by fire.
In the phœbe's diet hymenopterous insects stand at the head, as is the case with most of the flycatchers. They are eaten with great regularity and are the largest item in nearly every month. A few are useful parasitic species, but these are offset by a number of sawfly larvæ, which are very harmful insects. Ants were found in 24 stomachs. No honeybees were identified. In their season grasshoppers are much relished, while wasps of various forms, many flies of species that annoy cattle, and a few bugs and spiders are also eaten regularly. It is evident that a pair of phœbes must materially reduce the number of insects near a garden or field, as the birds often, if not always, raise two broods a year, and each brood numbers from four to six young.
There is hardly a more useful species about the farm than the phœbe, and it should receive every encouragement. To furnish nesting boxes is helpful, but not necessary, as it usually prefers a more open situation, like a shed or a nook under the eaves, but it should be protected from cats and other marauders.
The black phœbe has the same habits as its eastern relative, both as to selection of food and nesting sites, preferring for the latter purpose some structure of man, as a shed or, better still, a bridge over a stream of water, and the preference of the black phœbe for the vicinity of water is very pronounced. One may always be found at a stream' or pool and often at a watering trough by the roadside.
Careful study of the habits of the bird shows that it obtains a large portion of Its food about wet places. While camping beside a stream in California the writer took some pains to observe the habits of the black phœbe. The nesting season was over, and the birds had nothing to do but eat. This they appeared to be doing all the time. When first observed in the morning, at the first glimmer of daylight, a phœbe was always found flitting from rock to rock, although it was so dusky that the bird could hardly be seen. This activity was kept up all day. Even in the evening, when it was so dark that notes were written by the aid of the camp fire, the phœbe was still engaged in its work of collecting, though it was difficult to understand how it could catch insects when there was scarcely light enough to see the bird. Exploration of the stream showed that every portion of it was patrolled by a phœbe, that each one apparently did not range over more than 12 or 13 rods of water, and that sometimes two or three were in close proximity.
The number of insects destroyed in a year by the black phœbe is enormous. Fortunately, the examination of stomachs has supplemented observation in the field, and we are enabled to give precise details. Of the 333 stomachs examined, every one contained insects as the great bulk of the food. Only 15 contained any vegetable food at all, and in no case was it a considerable part of the contents of the stomach. The insects eaten were mostly wasps, bugs, and flies, but many beetles also were destroyed.
Useful beetles belonging to three families amount to 2.8 per cent of the food. Other beetles of harmful or neutral species reach 10.5 per cent. Wasps, the largest item of the food, were found in 252 stomachs and were the whole contents of 15. The average for the year is 35 per cent. Parasitic species were noted, but they were very few. Ants were found in 48 stomachs, and for a short time in midsummer they constitute a notable part of the food. Various wild bees and wasps make up the bulk of this item. No honeybees were found.
Bugs in various forms constitute 10.56 per cent and are eaten in every month but May. Stinkbugs appear to be the favorites, as they were contained in 10 stomachs. Plant lice were found in one stomach. Flies, forming the second largest item, were found in 97 stomachs and completely filled 3. They constitute the most regular article in the black phœbe's diet. The maximum consumption occurs in April, 64.3 per cent. The black phœbe well merits its title of flycatcher.
Moths and caterpillars amount to 8.2 per cent of the food. They were found in 72 stomachs, of which 51 contained the adult moths and 28 the larvæ or caterpillars. One stomach was entirely filled with adults. This is one of the few birds studied by the writer that eats more moths than caterpillars, for as a rule the caterpillars are largely in excess. Flycatchers, taking their food upon the wing, would naturally prove exceptions to the rule. Crickets are evidently not a favorite food of the black phœbe, as they amount to only 2.45 per cent. They were found in 39 stomachs, but usually the amount in each was small, though one stomach was entirely filled with them. Grasshoppers did not appear. Dragon flies were eaten to some extent, and these illustrate the fondness of the species for the neighborhood of water.
The vegetable matter eaten consisted chiefly of small wild fruits of no economic importance.
Another phœbe inhabiting the Western States and breeding as far north as Alaska is the Say phœbe.[50] Investigation of its food was based on the examination of 86 stomachs, and while none were available for the months when insects are most numerous, the bird proved to be one of the most exclusively insectivorous of the family. That it takes a few useful insects can not be denied, but these are far outnumbered by the harmful ones it destroys, and the balance is clearly in favor of the bird. Its vegetable food amounts to only 2 per cent and is made up of a little wild fruit, seeds, and rubbish.
[50] _Sayornis sayus_.
THE KINGBIRDS.
The well-known eastern kingbird[51] (fig. 19) is essentially a lover of the orchard, though groves and the edge of forests were probably its original habitat. It breeds in the States east of the Rocky Mountains, and less commonly in the Great Basin and on the Pacific coast. Its hostility to hawks and crows is proverbial, and for this reason a family of kingbirds is a desirable adjunct to a poultry yard. On one occasion in the knowledge of the writer a hawk which attacked a brood of young turkeys was pounced upon and so severely buffeted by a pair of kingbirds whose nest was near by that the would-be robber was glad to escape without his prey. Song birds that nest near the kingbird are similarly protected.
[51] _Tyrannus tyrannus_.
The kingbird is largely insectivorous. It is a true flycatcher and takes on the wing a large part of its food. It does not, however, confine itself to this method of hunting, but picks up some insects from trees and weeds, and even descends to the ground in search of myriapods or thousand legs. The chief complaint against the species by both professional bee keepers and others has been that it preys largely upon honeybees. One bee raiser in Iowa, suspecting the kingbirds of feeding upon his bees, shot a number near his hives; but when the stomachs of the birds were examined by an expert entomologist, not a trace of honeybees could be found.
An examination of 665 stomachs collected in various parts of the country, was made by the Biological Survey, but only 22 were found to contain remains of honeybees. In these 22 stomachs there were in all 61 honeybees, of which 51 were drones, 8 were certainly workers, and the remaining 2 were too badly broken to be further identified.
The insects that constitute the great bulk of the food of the bird are noxious species, largely beetles--May beetles, click beetles (the larvæ of which are known as wire-worms), weevils, which prey upon fruit and grain, and a host of others. Wasps, wild bees, and ants are conspicuous elements of the food, far outnumbering the hive bees. During summer many grasshoppers and crickets, as well as leaf hoppers and other bugs, also are eaten. In the stomachs examined were a number of robber files--insects which prey largely upon other insects, including honeybees, and which are known to commit in this way extensive depredations. It is thus evident that the kingbird by destroying these flies actually does good work for the apiarist. The 26 robber flies found in the stomachs may be considered more than an equivalent for the 8 worker honeybees already mentioned. A few caterpillars are eaten, mostly belonging to the group commonly known as cutworms, all the species of which are harmful.
About 11 per cent of the food consists of small native fruits, comprising some 30 common species of the roadsides and thickets, as dogwood berries, elderberries, and wild grapes. The kingbird is not reported as eating cultivated fruit to an injurious extent, and it is very doubtful if this is ever the case.
In the Western States the Arkansas kingbird[52] is not so domestic in its habits as its eastern relative, preferring to live among scattering oaks on lonely hillsides, rather than in orchards about ranch buildings. The work it does, however, in the destruction of noxious insects fully equals that of any member of its family. Like other flycatchers, it subsists mostly upon insects taken in mid-air, though it eats a number of grasshoppers, probably taken from the ground. The bulk of its food consists of beetles, bugs, wasps, and wild bees. Like its eastern representative, it has been accused of feeding to an injurious extent upon honeybees. In an examination of 62 stomachs of this species, great care was taken to identify every insect or fragment that had any resemblance to a honeybee; as a result, 30 honeybees were identified, of which 29 were males or drones and 1 a worker. These were contained in four stomachs, and were the sole contents of three; in the fourth they constituted 99 per cent of the food. It is evident that the bee-eating habit is only occasional and accidental, rather than habitual; and it is also evident that if this ratio of drones to workers were maintained, the bird would be of more benefit than harm to the apiary.
[52] _Tyrannus verticalis_.
The Cassin kingbird[53] has a more southerly range than the Arkansas flycatcher. Examination of a number of stomachs shows that its food habits are similar to those of others of the group.
[53] _Tyrannus vociferans_.
Three points seem to be clearly established in regard to the food of the kingbirds--(1) that about 90 per cent consists of insects, mostly injurious species; (2) that the alleged habit of preying upon honeybees is much less prevalent than has been supposed, and probably does not result in any great damage; and (3) that the vegetable food consists almost entirely of wild fruits which have no economic value.
All of the kingbirds are of the greatest importance to the farmer and fruit grower, as they destroy vast numbers of harmful insects, and do no appreciable damage to any product of cultivation.
NIGHTHAWK.