Four Common Birds of the Farm and Garden

FOUR COMMON BIRDS OF THE FARM AND GARDEN.

By SYLVESTER D. JUDD, Assistant Ornithologist^ U, S. Department of Agriculture. The present paper treats of the food habits of the catbird, mocking bird, brown thrasher, and honse wren—birds so closely related that ornithologists place them in the same family. A study of the food of these four birds shows that the percentage of animal matter, consisting mainly of insects with a small proportion of spiders and thousand- legs, is greatest in the wren and least in the catbird; the vegetable matter, chiefly fruits, stands, of course, in the reverse ratio. Conse- quently, of the four birds, the wren is the most beneficial, the whole of its food being insects and their allies; the catbird the least beneficial, because it takes more cultivated fruits than the others. The catbird and thrasher subsist largely on a vegetable diet, consisting mainly of fruits, though the thrasher, especially in spring, before berries and other small fruits ripen, has a decided taste for grain and acorns. For their supply of fruit both birds depend more on nature than on man. Thus the catbird takes twice as much wild fruit as cultivated; the thrasher three times as much. These different pro- portions of wild to cultivated fruit are probably not due so much to peculiarity of appetite as to dissimilarity in habits. Insects form the bulk of the animal food of the catbird, mocking bird, brown thrasher, and house wren. Notwithstanding the indi- vidual preferences of these birds, they all eat beetles, grasshoppers, ants, spiders, thousand-legs, caterpillars, and, to a less extent, bugs, wasps, and files. Of all the beetles, ground beetles are the most easily obtained, and consequently are picked up by birds in large quantities. The particular ground beetles eaten by the birds under consideration are only to a slight degree carnivorous; consequently the bird that eats them is not doing the harm that would have been done had beetles of more carnivorous habits been destroyed. Next in importance are the members of a family of beetles known as scar- abseids. Those eaten by the wren are the useful little scavenger beetles, while those eaten by the catbird and thrasher are May beetles and their relatives, all of which are injurious to agriculture. Another group of insects largely eaten comprises snout beetles or weevils, of which the plum curculio is a familiar example. These pests, on account of their small size and habit of developing inside the fruit, are very difíicult to cope with, because any means of reducing their 405 406 YEARBOOK OF THE U. S. DEPARTMENT OF AGRICULTURE.

numbers is liable to damage the fruit upon which they are feeding. Beetles of other families, such as leaf-eating beetles, click beetles, darlding beetles, longicorn beetles, blister beetles, and beetles of the firefly family, are occasionally eaten. The number destroyed belonging to any one of these families is insignificant, though the total talien from all is considerable. True bugs, which are bad-smelling insects with sucking mouth parts, are eaten in small quantities by many birds. The bugs eaten by the wren are stink bugs, which feed on plants, and are therefore injurious. On the other hand, many of the large bugs eaten by the thrasher and catbird have predaceous habits, and consequently are beneficial. More caterpillars, harvest spiders, and true spiders are destroyed by the wren than by any of the other three birds. All caterpillars are harmful. Harvest spiders, which prey on plant lice, are useful. True spiders, although carnivorous, may be considered as indifferent, because they destroy useful as well as noxious insects. The same may be said of the small centipedes, which are eaten by the catbird and thrasher. It is quite otherwise with thousand-legs, for they subsist on vegetable matter, and have consequently been regarded as detrimental. They w^ere frequently found in the stomachs of catbirds and thrashers. The knowledge obtained from the study of the food of the mocking- bird is very incomplete. The few stomachs available for examination showed that this bird is fond of grasshoppers; unfortunately, it also likes grapes and figs. The wren is exclusively insectivorous, and therefore highly beneficial to agriculture. The catbird and thrasher do much less good than the wren, because they live on a mixed diet of animal and vegetable food. The good they do depends in the main on the quantity of insects eaten. The proportion of animal matter in the thrasher's food for the entire season is 63 per cent, against 44 per cent in that of the catbird. The thrasher destroys twice as many caterpillars, beetles, and grasshoppers as the catbird, and hence is the more beneficial. CATBIRD. The catbird (fig. 106) breeds over a large part of Korth America, from British Columbia to the Atlantic Seaboard, and from the South- ern States northward to the British Provinces. It is most abundant in the Upper Austral and Transition zones of the eastern United States, and throughout most of its range it rears two broods in a season. Although often nesting in the lilacs that brush against the house, the catbird is in many instances an unwelcome tenant, and is often persecuted without mercy. The cause of this prejudice arises from the bird's fruit-stealing proclivity, and perhaps also from its rasping feline note. Nevertheless stomach examinations show that more than FOUR BIRDS OF THE FARM AND GARDEN. 407 lialf of the fruit eaten is wild, and that one-third of the catbird's food consists of insects, many of which cause annually heavy losses to our country. By killing the birds their services as insect destroyers would be lost, so the problem is to keep both the birds and the fruit. Experiments conducted by this division show that catbirds prefer mulberries to strawberries and cherries, hence it may be inferred that these two latter crops may be protected by planting the prolific Rus- sian mulberry, which, if planted in hen yards or pig runs, will afford excellent food for the hens and pigs, besides attracting the birds away from more valuable fruit. Wild cherry, buckthorn, dogwood, wild grape, and elder should be encouraged by the farmer who wishes to escape the depredations of birds and still receive their benefits. It has been shown by Mr. Forbush that by protecting and encouraging native birds in an orchard where heretofore caterpillars had stripped the trees a good crop of apples might be raised.

FIG. 106.—Catbird (Galeoscoptes carolinensis). Field reports received from voluntary observers show that catbirds pillage fruit crops in the central part of the United States, where wild fruits are scarce, much more than along the seaboard, where wild fruits grow in profusion. This accounts for such discrepancies as the following. Mr. R. P. Wilson, of Falls City, Nebr., says the catbird is a pest, because of its injury to raspberries, grapes, and apples, while Prof. F. E. L. Beal, of Lunenburg, Mass., says: On my farm in Massachusetts I have raised strawberries, blackberries, and raspberries by the acre, with grapes, pears, and apples in abundance, and although the farm was nearly surrounded by woods and was adjacent to a swamp where catbirds and thrashers abounded, I never knew one of them to touch a single fruit, though perhaps they have taken a few. I thought no more of accusing the catbirds or robins of fruit stealing than 1 would the swallows in the bam. 408' YEARBOOK OF THE U. S. DEPARTMENT OF AGRICULTURE.

In May, when the catbird arrives from the South, one-third of its food is gleaned from the previous summer's sumac, smilax, and other fruits that have been hanging all winter; but the greater part is derived from the animal kingdom, and consists of ants (15 per cent), thousand-legs (10 per cent), beetles belonging to or having the same habits as the May beetle family, predaceous ground beetles, and caterpillars (each 8 per cent). For the month of June as a whole, the May ratio of vegetable to animal matter is sustained, but during the latter part of June the proportion of vegetable food increases. As soon as the mulberries, raspberries, cherries, and strawberries ripen, the birds forsake the unsavory winter-cured berries. Early in the season the catbirds eat few grasshoppers and crickets, but during the second and third weeks in June they take so many as to cause a shrinkage in the other animal food. At the time when the birds eat most grasshoppers and crickets, 10 per cent of their food consists of these insects. Prof. S. Aughey examined five catbirds killed in June, and found that the stomach of each contained about 30 grasshoppers. During the last week of June the proportion dwindles, and throughout the remainder of the season it is insignificant. The number of May beetles eaten increases from the 1st of June until about the 20th, after which very few are taken. As July progresses, the vegetable constituent outstrips the animal by 4 to 1, and maintains this supremacy throughout August and Septem- ber. During the first twenty days of July the catbird takes the maximum amount of cultivated fruit. Raspberries and blackberries are the favorites, forming the most important element until the middle of August, when they give way somewhat to the black wild cherry, dogwood, and elder berry. Of the animal constituents, the ground beetles and caterpillars fall from their maximum of 6 per cent in June to 3 per cent in July, and then to 1 per cent in August, but rise again in September. During cold weather, when there is a scarcity of food, birds under stress of hunger eat what would in the time of plenty be disdained. In September the crop of wild fruits is apparently sufficient for ten times the number of birds and mammals inhabiting a particular area, but by the middle of October most of the wild berries have been picked. Although catbirds prefer to make a meal of insects and fruits, in their winter homes they often have to be contented with frozen berries. During the winter months it is probable that the catbird, impelled by hunger, searches out many hibernating insects that under the warming rays of next spring's sun would awaken to lay hundreds of eggs, which would soon hatch into voracious larvae capa- ble of consuming each day more than their own weight of garden plants. The testimony of 213 stomachs from points as far west as Kansas, FOUR BIRDS OF THE FARM AND GARDEN. 409 as far south as Florida, and as far north, as Massachusetts, collected from April to December, inclusive, shows that beetles and ants form the most important parts of the animal food of the catbird, though smooth caterpillars play no insignificant part. Crickets and grasshoppers are relished, and come next in importance. The less important though constant parts of the fare are thousand-legs, centipedes, spiders, and bugs. Blackberries and raspberries, with wild cherries, mulberries, elder berries, and buckthorn, form the bulk of the vegetable diet, which constitutes more than half of the catbird's food. The ñesh of a berry or fruit has a definite function, which is as important and necessary to the life of the plant as are its roots, for it is by means of the edible qualities of the pulp that the seeds of many plants are scattered. The most active agents in this process of dis- semination are birds, which greedily swallow the attractive fruits, the pulp of which is digested, while the seed or stone passes through the intestine and sprouts where it is dropped. In spring and autumn the catbirds plant dogwood, sour gum, smilax, black alder, sumac, and, unfortunately, some poison ivy and poison sumac. It is surpris- ing that birds can eat the fruit of plants which are so poisonous to the human system, and that they relish such highly flavored fruits as spice berries, or the berry of the black alder, which is bitter as quinine. To what extent cultivated fruit is damaged must be ascertained by observing the birds, because where the bulk of one cherry has been eaten a score may have been pecked, and because the injury of a single grape in a bunch detracts from the value of the whole bunch. Of the stomachs examined, 13 out of the 213 contained strawberry seeds; one bird, shot in a cherry tree, had eaten strawberries, but no cherries; another, from a strawberry patch, contained, besides strawberries, several currants; and 20 of the 213 catbirds had eaten cherries. Unfortunately, the stomachs available for examination were not accompanied by data as to what fruits the birds had the opportu- nity of eating, or what plentiful injurious insects had been passed by with indifference. To obtain such data. Prof. F. E. L. Beal and the writer visited, on July 30, 1895, one of the many ravines that in- tersect one of the bluffs overlooking the Potomac. Here we took note of the insects and berries that were accessible to the birds, in order to learn their preferences when the time came to examine the stomachs. The particular ravine chosen was about 80 yards wide by twice as long, and extended back at right angles to the river, until it rose to the level of the bluff. On the slanting sides of this depression a belt of catbriers afforded excellent cover for catbirds. Just above the catbriers was a belt of locust trees. The part of the ravine next the 2 A 95 15* 410 YEARBOOK OF THE U. S, DEPARTMENT OF AGRICULTURE. river was swampy, and supported a forest of willows, while the upper part was drier, and afforded an abundance of ripe elderberries and blackberries, upon which catbirds were seen feeding. The birds seemed to devote most of their time to berrying. They were also seen far up in the tops of the locusts, which had been browned as by fire by the locust leaf-miners (larvae of Odontota dor salís), the beetles of which were swarming in myriads over the leaves. Several male catbirds sang sweetly in the sassafras trees which were spar- ingly intermixed with the locusts, while others were seen hopping on the ground, where they had a chance to pick up grasshoppers, millers, or ants. Thirteen of the 15 catbirds seen were shot, and their whole digest- ive tracts examined; 9 contained the destructive orange and black locust beetle, 18 of which were taken from one bird. This is surpris- ing, because beetles of this family {Ohrysomelidœ) secrete a sub- stance which is supposed to be distasteful to birds. Every one of the catbirds had eaten elderberries, and all but two blackberries. The countless numbers of leaf-mining beetles on the trees where the catbirds were feeding, and the consequent ease of obtaining them, are the only tangible facts to account for the rejection of such favor- ite food as ants and. grasshoppers. Not one of the thousands of smooth caterpillars that were stripping the bushes under the willows was to be found in the catbirds, thus showing that these birds prefer beetles to caterpillars. It is important to know whether a bird prefers wild fruits or cultivated, noxious insects or beneficial. In order to ascertain these preferences a series of experiments was made by the writer. Four catbirds which had been recently trapped were confined in a large cage and yielded many interesting results, a few of which will be cited here. It was demonstrated that smooth caterpillars are preferred to hairy ones, and that butterflies are not relished, though a mourning- cloak butterfly and a hawk moth were -eaten after having been chased and battered about the cage for some time. After several unsuccess- ful attempts one catbird was induced to eat a honeybee. Beetles of the firefly family were eaten under stress of hunger. Small slugs {Gastropods), though eaten by one bird, seemed to be regarded as unsavory. Weevils and bad-smelling bugs were eaten with relish, as were also sow bugs. Plant lice were refused, though the ants which tended them were greedily devoured. Maggots were eaten, and a hideous black spider was torn to pieces by all four catbirds, and then eaten with relish. The conclusion suggested by this last experiment w^as borne out by stomach examination, which showed that 7 per cent of the birds had eaten spiders. About the same number had selected thousand-legs, which subsist on plants and of ten attack garden vege- tables. Owing to their habits of living under stones and other objects on the ground they are not so often picked up as one would expect FOUR BrRD§-OF THE FARM AND GARDEN. 411 from seeing how they were relished by caged catbirds, as were also small harmless centipedes, which have similar haunts but carnivorous habits. These little centipedes were found in several stomachs, as were also small snails which were eaten by the captive birds. Earthworms are not eaten by birds, the robin included, to nearly such an extent as is commonly supposed. Only one out of the 213 catbirds contained an earthworm. More than half of the stomachs examined contained ants, conspicuous among which were two black species, one of which was half an inch long. Ants often make nui- sances of themselves by entering houses and getting into the sweets. Many ants tend plant lice, which they pasture and milk at the expense of the farmer. One little brown ant, which raises plant lice among the cherry leaves, was found in many stomachs. The economic status of the catbird may be summed up as follows: The food consists of 3 per cent of carnivorous wasps and wild bees that carry pollen from flower to flower, but this is counterbalanced by the destruction of weevils, thousand-legs, and plant-feeding bugs. Catbirds have a partiality for the easily obtainable predaceous ground beetles, which are supposed to be beneficial to the farmer, but the loss of these insects is made up for by the destruction of beetles related to the May beetle. The catbird subsists largely on fruit, of which one-third is taken from cultivated crops. It eats caterpillars, grasshoppers, and crickets, with a small percentage of leaf-eating and click beetles. The volume of these insects destroyed is equal to only one- half of that of the cultivated fruit eaten.

BROWN THRASHER. The brown thrasher (fig. 107) breeds from Dakota to îTew England, and thence south to Florida. It is most common in the Carolinian zone, where it rears two broods a season. Besides having a more lim- *ited range than the catbird, the thrasher is not so abundant, and is less confiding in man, never pouring forth its rich and varied medley from the lilacs under the window, but pteferring to serenade from the swaying top of a small tree at the foot of the garden, where a thicket is convenient in case of intrusion. The feet of this shy bird are large and well adapted to a life of scratching for a living among thickets. It prefers to build its nest of coarse rootlets, in old brush piles, but when these can not be found it nests among brambles. The haunts* of the thrasher, unlike those of the catbird, may be remote from water courses, though often both birds may be heard singing in the same brier patch. , Reports from field observers state that the thrasher commits depredations on fruit crops, but to a much less extent than the catbird or robin. These reports speak of attacks on black and red raspberries, cherries, strawberries, grapes, plums, peaches, pears, and apples. The fruit grower who sees the birds flocking into his cherry tree not only 412 YEARBOOK OF THE U. S. DEPARTMENT OF AGRICULTURE. neglects to observe the birds sandwiching in with the luscious fruit dainty morsels of insects, but also overlooks the fact that when the cherry season is over they raise havoc among his worst enemies. Field work, which requires the unprejudiced efforts of a botanist and entomologist, conducted under the most favorable conditions, must be regarded not as a final solution of the problem, but only as an incomplete contribution to our knowledge. In determining the diet of a bird, the examination of the contents of the stomach is, as Pro- fessor Beal aptly says, ''the court of final appeal." The execution of this method is not only laborious, but difQcult, because birds' stomachs may contain anything from a minute fungus cup up to a rabbit. Sur- passing the difficulty of investigation, owing to the diversity of bird food, is the difficulty of identifying fruits by Little pieces of skin, which

FIG. 107.—Brown thrasher {Harporhynchus ruf us), • must be subjected to most critical microscopic examination. The pro- portions of the different elements of the food of the brown thrasher, as determined by an examination of 121 stomachs collected from Maine to Florida and as far west as Kansas, is as follows : Animal matter, 63 percent; vegetable, 35 ; mineral, 2. Beetles form one-half of the animal food, Orthoptera (grasshoppers ♦and crickets) one-fifth, caterpillars somewhat less than one-fifth, bugs, spiders, and thousand-legs about one-tenth. The percentage of food taken from cultivated crops by the thrasher amounts to only 11; of this, 8 per cent is fruit and the rest grain. The farmer is more than compensated for this loss by the destruction of an equal bulk of May beetles, which, if allowed to live, would have done much more harm than the thrashers, and left a multitudinous progeny for next year. The thrasher eats 8 per cent of ground beetles, supposed to be beneficial to the interests of the husbandman. To offset this he destroys FOUR BIRDS OF THE FARM AND GARDEN. 413 an equal volume of caterpillars, to say nothing of grasshoppers, crickets, weevils, click and leaf beetles. The economic relation of the brown thrasher to agriculture maybe summed up as follows: Two- thirds of the bird's food is animal; the vegetable food is mostly fruit, but the quantity taken from cultivated crops is offset by three times that volume of insect pests. In destroying insects, the thrasher is helping to keep in check organisms the undue increase of which disturbs the balance of nature and threatens our welfare. A good example of the result of such irregular increase is to be had in the fluctuations of the Rocky Mountain locust. The diet of a bird changes with the food supply. Thus when the thrasher returns in April from its sojourn in the Southern States, it takes three times as much animal food as vegetable. Later in the season, but before much fruit is ripe, insects become more abundant. Consequently during May the animal food attains its maximum, out- stripping the vegetable by 7 to 1. When the fruits ripen in abundance, however, the proportion of animal food decreases until in Sep- tember it stands in the inverse ratio of 1 to 2. Although the thrasher takes its maximum of 17 per cent of cultivated fruit, mainly red and black raspberries, with a few currants, in July, the horticulturist at this time does not mind the loss, because there is plenty; on the contrary, when cherries and berries first com- mence to ripen they bring good prices and the loss is keenly felt. During the first half of July, mulberries form an important element of the vegetable food, but soon buckthorn comes in and continues to play an important part in August until the black wild cherry, elder, dogwood, and other fruits become plentiful. Ants attain their maximum during the month of July, and, with equal volumes of May beetles and caterpillars, compose one-fourth of the food for the month. Caterpillars, which reach their maximum in June, are almost forsaken in July for the ripening fruits, thus falling to 4 per cent, a proportion which is maintained throughout September. During August the animal matter continues to fall off; nevertheless a great many bees and wasps are eaten, while more ground beetles are taken at this time than at any other. For the month of September two-thirds of the food of the thrasher is fruit. Of the insects, grasshoppers and crickets have been steadily decreasing since June, and the May beetle has also been decreasing until in September it is no longer found. Bugs which crawl over clusters of fruit, often getting into one's mouth to leave a disgusting taste, rise in September to a maximum of 5 per cent. In October only two stomachs were collected; one was packed with dogwood berries, while the other contained a number of elder berries and the grinder of a grasshopper's jaw. A bird killed on the 22d of November had eaten a grasshopper, several seeds of sumac and poison ivy, and some mast. It is much regretted that no winter birds were examined. The 414 YEARBOOK OF THE U. S. DEPARTMENT OF AGRICULTURE. thrasher and catbird when they migrate to the South in autumn become very shy, preferring thickets remote from dwellings; and it is probable that in the South these birds not only do no harm, but on the contrary do much good in searching out hibernating insects, which if allowed to live might lay countless eggs, to hatch and threaten next year's crops. If a series of experiments similar to those carried out with the catbird could have been performed, the economic value of the thrasher w^ould have been determined with greater accuracy, for only by experiment is it possible to ascertain a bird's preferences in the matter of food and the quantity eaten in a given time. Thus, caged catbirds refused bristly caterpillars, were specially fond of ants, and preferred mulberries to cherries. Birds selected for experiment should be adults recently trapped, because those that have been long in confinement usually develop unnatural tastes. A tame thrasher, which was raised from the nest and had been in captivity four years, was equally fond of roast beef and broiled chicken, and ate bread three times a day. Members of the family frequently caught for him nies, grasshoppers, meal worms (beetle larvae), and millers, which he appreciated to the utmost. In order to prove Or disprove the statement that leaf-eating beetles are distasteful to birds, he was offered a spotted squash beetle, which he immediately swallowed. On three occasions potato beetles were put in the cage. These after having been thrashed about on the floor for several minutes were swallowed and then disgorged, but in two instances parts of the beetles were again swallowed. When offered a squash bug, he tore it to pieces and devoured it, but kept shutting and opening his eyes as though disturbed by the nauseating odor. When a ground beetle {Harpalus caliginosus) was placed in the cage, he acted in the same way. Two hairy caterpillars were offered him; the first, a fall webworm, was refused; the second, a bristly brown caterpillar, was seized and rubbed on the floor of the cage until devoid of bristles, then swallowed, to be immediately disgorged. Several green caterpillars of the cabbage butterfly were eaten with relish, showing, as with the catbird, that smooth caterpillars were preferred to hairy ones. This thrasher relished blackberries, raspberries, strawberries, grapes, apples, pears, and peaches. In the woods the writer has seen thrashers feasting on the bitter sour gum berries with the flickers and robins; the thrashers were also eating frost grapes and pokeberries. Some pokeberries and sour gum were picked and offered to the caged thrasher; he seized the stem attached to a sour gum berry, swung it around his head, and let it go across the cage like a hammer thrower. After repeating this athletic feat several times, he ate the berries. When fed exclusively on mocking-bird food for seven days, the average quantity consumed in a day w^eighed, dry, half an ounce. The biown thrasher in its present numbers is a useful bird, and should be strenuously protected from gunners and nest-plundering FOUR BIRDS OE THE FARM AND GARDEN. 415 boys. It is to be regretted that a bird of siicli harmonious coloring, coupled with a sweet, ringing voice, is so shy and distrustful.

MOCKING BIRD.

The mocking bird (fig. 108), famous in both hemispheres, is a South- ern bird, breeding from Virginia, southern Illinois, and Kansas south- ward. It is found also in Arizona, Utah, Nevada, and southern Cali- fornia, and is particularly abundant along the seaboard of the South- ern States, where it often raises three broods a year. The mocker is seldom seen remote from plantations, since, like the robin, it loves the habitation of man. It often chooses as a building site an orange tree in the planter's dooryard, where it constructs its inartistic nest of sticks lined with soft materials, in which to lay its clutch of brown- blotched, greenish eggs. During the period of incubation the song of the mocker is at its best, and is heard at night from the male perched

FIG. 108.—Mocking bird (Mimus polyglottos). on the gable. Despite this token of its confidence in man, a planter in Florida killed over a thousand mockers and buried them under his grapevines because they had taken some fruit. In southern Texas the mocker is so abundant that it is always in sight. Here the bird does some damage to cultivated fruit. Dr. E. P. Stiles, writing from Austin, Tex., states that it damages fruit, chieñy peaches and grapes, and that to prevent its ravages it is a common practice to tie up the vines in mosquito netting. In southern Cali- fornia Mr. F. Stephens reports that mockers eat figs, and from Florida Mr. S. Powers writes, " Mockers eat strawberries to some extent, but it is only when the patch is a small one, or very early in the season, when th^ berries are few and worth $3 a quart, that anybody feels the loss from them." On the other hand, the mockin'g bird is known to destroy many insects. Dr. E. P. Stiles states that in Texas it eats 416 YEARBOOK OF THE U. S. DEPARTMENT OF AGRICULTURE. large spiders and grasshoppers, and the late Prof. C. V. Riley, in the Fourth Annual Report of the United States Entomological Commis- sion, enumerated it among the enemies of the destructive cotton worm. Only 15 stomachs of the mocking bird were examined, and most of these were taken in autumn and winter, the seasons when the greatest proportion of vegetable food is eaten. In these stomachs the quantity of vegetable matter was decidedly in excess of the animal matter. The former consisted for the most part of the skin and pulp of some large fruit, together with seeds or berries of sumac, smilax, black alder, poison ivy, Virginia creeper, red cedar, pokeberry, mulberry, and bayberry. The animal food consisted wholly of spiders and insects. Among the latter were ants, caterpillars, beetles, and grasshoppers. While the available data are far too imperfect to form the basis of any generalization with regard to the mocking bird's food, there is nothing in the facts at hand to indicate that it differs materially from that of its relatives, the catbird and thrasher.

HOUSE V^REN. The sprightly little house wren (fig. 109), that carols from the fence post while its mate sits snugly on her clutch of reddish-brown eggs in the box on the veranda, is distributed throughout the United States, except in the mountainous districts. After wintering in the Southern States it returns to the Northern States about the first of May, and, like the bluebird, nests in holes. It is nothing daunted by the size of the cavity, and often takes quarters large enough for an owl. In one instance a pair of wrens chose a watering pot hanging on the back porch. To this they carried twigs until the cavity was filled. Then the nest proper, of soft materials lined with feathers from the barnyard, was placed in the midst of the sticks. Six to eight eggs are laid, and two broods are raised in a season. The parent birds hunt through orchards and along fences, peering into every nook and cranny for insects to feed their clamorous youngsters. When the nestlings are fledged, the parents conduct them with the greatest care about the vicinity of the nest and teach them to catch insects. A whole family may often be seen scurrying about in a brush heap. In case of danger they do not fly, but bury themselves in the bottom of the heap for a few moments, and then poke their heads out like mice. The house wren is beloved by everyone, and recognized by the husbandman as a destroyer of insect pests. None of the field reports sent to the division contain complaints against the wren, while all speak of it as one of the most useful birds of the farm. In the labora- tory these reports have been substantiated; 98 per cent of insects and their allies was found in 52 stomachs collected from Connecticut to Georgia, and as far west as California. The 2 per cent of material as yet unaccounted for consisted of such rubbish as bits of grass or wood and sand, which in all probability was taken accidentally. FOUß BIRDS OF THE FARM AND GARDEN. 417 Half of the food of the wren consists of grasshoppers and beetles; the other half is made up of approximately equal quantities of caterpillars, bugs, and spiders. Several of the most important families of beetles were represented. Among them the omnipresent little ground beetle formed 6 per cent; weevils, which amounted to 11 per cent of the food in June, ranked next in importance. Wrens eat about half as many little dung beetles as weevils. The former amount to 10 per cent of the food in May, but are not eaten later in the season. Beetles belonging to other families amount to 8 per cent. One bird had eaten a beetle of the firefly family, another a leaf beetle, and three birds had eaten click beetles. Rove beetles were found in two stomachs. One wren had eaten a longicorn beetle.

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FIG. 109.—House wren (Troglodytes aëdon).

Common grasshoppers, green grasshoppers, and crickets form the most important part of the house wren's food, reaching a maximum of about 60 per cent in August, and practically excluding many here-' tofore conspicuous elements. The catbird and thrasher stop eating grasshoppers when fruit ripens, but the wren keeps right on with the good work. The bugs eaten by wrens include many plant-feeding stink-bugs {Fentatomidœ), leaf-hoppers, and in one instance plant lice, but this good was more than counterbalanced by the destruction of daddy longlegs, which subsist largely on aphids. The scales of butterflies or moths were found in two stomachs. Flies, though relished by birds, 418 YEARBOOK OF THE U. S. DEPARTMENT OF AGRICULTURE. are too wary to be caught in large numbers. Only five of the wrens examined contained flies. Wasps Avere detected in three instances. From the foregoing detailed account of the wren's food, it is obvious that the bird is very beneñcial to agriculture. Such insectivorous birds should be encouraged. It is a pity that the quarrelsome English sparrow can not be exterminated, for if in place of every dozen spar- rows there was one house wren, our churches and statues would present a more sightly appearance, while in the country the yield of crops would be greatly increased. At Cambridge, Mass., the sparrow has driven the wren away by occupying its nesting places. This is true to a certain degree wherever the two birds have met. To secure the services of the wren, the farmer must put up nesting boxes and declare war against the sparrow.

Table shoicing numher of stomachs examined and percentages of food constituents.

Brown House Catbird. thrasher. wren.

Number of stomachs. 213 121 Percentages of animal foods : Ants _ 4 Caterpillars {Lepidoptera) 16 Beetles {Coleóptera) 22 Grasshoppers, etc. {Orthoptera) 25 Bugs (Hemiplera) 12 Spiders and thousand-legs, etc. (Arachnida and Myriapoda). It Miscellaneous animal food. Total animal- 44 63 98 Percentages of vegetable foods : Cultivated fruits Wild fruits Grain Miscellaneous vegetable food. Total vegetable 55 35