HOW BIRDS AFFECT THE ORCHARD.

By F. E. L. BEAL, B. S.,

Assistant Biologist, Biological Survey,

INTRODUCTION.

That birds sometimes inflict injuries upon orchard trees and their products is a fact with which every fruit grower is familiar; but it is not so well known that they are frequently of great service in destroying enemies of the orchard, and yet the aid they render in this subtler way far more than offsets the harm that is so apparent.

The enemies with which the fruit grower has to contend, aside from the elements and the birds themselves, may be divided into three cat- egories: Vegetable parasites, suchas fungi and bacteria; certain mam- mals, such as rabbits and mice; and insects of various kinds. Against vegetable foes birds afford little, if any, protection. Their efficiency is shown in the destruction of noxious mammals and insects. The value of their work in dollars and cents is difficult of determination, but careful study has brought out much of practical importance in ascertaining approximately to what degree each species is harmful or helpful in its relation to the orchard.

SOME BIRDS IMPORTANT TO THE FRUIT GROWER.

WOODPECKERS.

Among birds which most directly affect the interests of the fruit grower may be mentioned woodpeckers, of which about 45 species and subspecies are found within the limits of the United States, all of decided economic importance. Their subsistence is obtained for the most part upon trees, a mode of life for which they are specially adapted. The character of the feet and tail enables them to cling easily to upright trunks, and the structure of the bill and tongue gives them the power to cut into solid wood and withdraw the insects lodged inside. The toes are in pairs, one pair projecting forward and the other backward, and are furnished with very strong, sharp claws, an arrangement which insures a firm hold upon the bark. The tail ií^ composed of very stiff feathers pointed at the end, that can be pressed against the tree trunk, and thus made to support and steady the bird. The beak is rather long, but stout, and furnished with a chisel-shaped point, which is hardened and sharpened so as to render it a most effective wood-cutting instrument. The tongue, the most peculiar portion of the anatomy of these birds, is extended backward by two

291

292 YEARBOOK OF THE DEPARTMENT OP AGRICULTURE.

slender, flexible filaments of the hyoid bone, each incased in a muscular shfeath (fig. 34, a). These filaments, instead of ending at the back of the mouth, curve up over the back of the skull, across the top of the head, and down on the forehead, and in some species enter the opening of the right nostril, and extend forward to the end of the beak (fig. 35). In the last case the tongue is practically twice the length of the head. By means of its surrounding muscular sheath, the tongue can be pro- truded from the bird's mouth a considerable portion of its length, and can thus be inserted into the burrows of wood-boring larvae. In order to secure grubs or other insects, it is usually furnished with a sharp

point and is barbed on the sides (fig. 34, 5). It is evident that a bird possessing such an apparatus must be capable of doing work which less advantageously endowed species can not accomplish. Hence, while most birds content themselves with eating such insects as they find upon the surface, wood- peckers seek those larvae or grubs which are beneath the bark, or even in the very heart of the tree. To render more effective the mechanism here described, these birds are gifted with a remarkably acute sense of hearing by which to locate their prey within the wood. That they do so with great accu- racy, is disclosed by examination of their work, which shows that they cut small holes directly to the burrows of the grubs.

DOWNY WOODPECKER.—Of the various species of woodpeckers in the Eastern States, the two most important are the so- called downy and hairy woodpeckers. These birds are especially given to foraging in orchards, more particularly in winter; for,

unlike most species,they do not migrate, but remain on their range the year round.

A study of the contents of the stomachs of many specimens of the downy woodpecker {Dryobates pubescens) shows that nearly one-fourth of the yearly food consists of ants. A celebrated French writer upon popular natural history has spoken of the ant as "the little black milkmaid, who pastures her green cows in the meadow of a rose leaf." This is a graphic, if somewhat fanciful, picture of the relations of ants and plant lice (Aphidse); but unfortunately the black milkmaid does not limit her pastures to the rose-leaf meadows. There are compara- tively few plants which do not suffer to some extent by the ravages of plant lice, and fruit trees and ornamental shrubs seem to be more

FIG. 34.—Tongues of woodpeckers: a, hyoid of flicker {CoUiptes aura- tm); b, tip of tongue of downy woodpecker {Dryobates pvhescens).

HOW BIKDS AFFECT THE ORCHARD. 293

especially subject to their attacks. Ants protect these plant lice from harm, and, when the plant on which they are feeding is exhausted, carry them to fresh pastures, and in some cases actually build shelters over them. Besides destroying* the ants, the downy woodpecker eats many of the plant lice.

Again, when the woodpecker has, by its keen sense of hearing, located the larva of a wood-boring beetle in a tree, and dislodged it with the aid of the sharp-edged chisel and probe, there is much likeli- hood that the next time it visits the tree it will find a colony of ants snugly estab- lished in the burrow of the defupct grub, whose somewhat lim- ited quarters they are extending in every direction. It now brings to bear upon the ants the same ap- paratus it used in the case of the grub, and they are soon drawn out and devoured. From these two sources are obtained the ants that are found in the food of this bird, and that constitute 23 per cent of that food. In both cases the insects are harmful, and the woodpecker stops the injury and benefits the tree.

Of the food of the downy woodpecker, 13 per cent consists of wood- boring coleopterous larvae, insects that do an immense amount of dam- age to fruit and forest trees, and are, as stated, protected from the attacks of ordinary birds by their habit of burrowing in trees. Besides the grubs taken from within the wood, the woodpecker eats many of the parent insects from whose eggs these grubs are hatched. It also destroys numerous other species that live upon the foliage and bark. Caterpillars, both those that bore into the tree and those that live upon the leaves, constitute 16 per cent of its food, and bugs that live on berries and give to them such a disagreeable taste form a considerable portion of its diet. Bark lice or scale insects (Coccidae), pests of the worst description, are also eaten by this bird, and to an extent that is surprising when their minute size is considered.

HAIRY WOODPECKER.—The hairy woodpecker {Dryobates mllosus^ fig. 36) subsists on food that is similar in general to that of the downy; and although it does not eat quite so many ants, it destroys more

FIG, 35.—Special development of tongues of woodpeckers: a, skull of flicker {Colaptes auratus), showing root of tongue extending to tip of bill (after Lindahl); ö, head of hairy woodpecker {Dryobates villosus), showing root of tongue curving around eye (after Audu- bon).

294 YïlARBOOK OF THE DEPARTMENT OF AGRICULTURE.

-Hairy woodpecker {Dryo- bates villosus).

beetle larvae and more caterpillars, and thus renders quite as good service in the orchard. In winter, birds of both these species are more

pressed for food than in summer, and may be seen busily searching the crevices in the bark, where they find hibernating insects and insects' eggs. By devouring these they destroy many enemies that would have attacked the trees at the approach of warm weather.

FLICKER.—The flicker ( Colaptes auratus^ fig. 37), another member of the woodpecker family, is well known to most orchardists and farmers. It is larger than either the downy or the hairy woodpecker^, and differs somewhat from them in its food habits. It

eats fewer beetles and caterpillars, but devours an enormous number of ants. Two stomachs were examined, each of which contained more than 3,000 ants, and in a third were 5,000, of a very minute species. Not all of these ants, however, are obtained from trees; many are species that burrow in the earth, for the flicker is more terrestrial than most of the other woodpeckers, and takes much of its food from the ground.

YELLOW-BELLIED WOODPECKER. — On the other hand, some harm to fruit trees is to be charged against this family, though there is much popular misapprehension in this regard. The smaller species have been called sapsuckers, from the supposition that they puncture holes in the bark of trees in order

to get the sap and soft inner bark. The charge is well grounded, but only one species, so far as known, causes any appreciable harm through the practice. This is the yellow-bellied wood- pecker {Sphyrapicm varivs^ fig. 38), whose summer range is confined to Canada, the northern portions of the united States, and the Allegheny Mountains, and whose winter residence is in the Southern States. This bird is injurious to certain trees, at times removing the outer bark over a considerable area, and at others pecking numerous holes very close together, in each case practically girdling the

tree. As the sap collects in the pits thus formed, the bird drinks it, and also catches the insects that are attracted to the pits by the sweetness

JîTÎ FIG. 37.—Flicker {Colaptes auratus).

FIG. 38.—Yellow-bellied wood- pecker {Sphyrapicus varius).

HOW BIRDS AFFECT THE ORCHARD. 295

of their contents. The trees attacked, mostly birches, mountain ashes, maples, and apple trees, often die the first or second year after the girdling is done. Fruit trees, however, are not very frequently attacked by this bird, and the species is not numerous enough to cause any perceptible harm to the forest. Examination of the stomachs of yellow-bellied woodpeckers shows that alburnum, or the soft tissue lying between the inner layer of bark and the hard wood of the tree, constitutes quite an important item of the diet, 23 per cent of the food of the year. Other woodpeckers also eat sparingly of the same substance, but the little they take is of no practical importance.

RED-BELLIED WOODPECKER.—The red-bellied woodpecker {Melan- erpes carolinus)^ which is not common in the East north of Pennsyl- vania, has fallen into disrepute among the orange growers of Florida by its attacks on oranges. It does considerable damage by pecking holes in the ripe fruit, and sometimes causes serious loss. It is to be hoped that experience will show some way to prevent these ravages without destroying the bird, for its harmfulness is confined to the orange groves of Florida, and it is of much value elsewhere.

OTHER WOODPECKERS.—The other woodpeckers, both eastern and western, are all more or less useful to fruit raisers. In the West and South, besides several subspecies of the hairy and downy woodpeckers, are other members of the same genus {Dryohates)^ which have food habits, as shown by stomach examination, that closely approximate those of the hairj^ and downy. These include the red-cockaded {D, horealis)^ Texan {D, scalar is hairdi)^ St. Lucas {D, scalaris luca^aniis)^ Nuttall's {D. nuttalli)y and Arizona {D, arizonœ). Several woodpeck- ers belonging to the genus Picoides^ that inhabit the northern part of the country and beyond, are equally useful. The genus Melanerpes^ with its half dozen species, covers practically the whole United States, and, like the genus Dryobates^ is a group of useful insectivorous birds, with the possible exception noted above. In the West three species of nickers are found whose food is practically the same as that of the eastern species.

TITMICE.

BLACK-CAPPED CHICKADEE.—The w^ell-known titmice, or chickadees, though small in size and unobtrusive in habits, do much good in both orchard and forest. So far as known, the food habits of all are bene- ficial. The winter food of the familiar black-capped chickadee {Parus atricapillus)^ which has been investigated by Prof. Clarence M. Weed,^ of New Hampshire, and by the Biological Survey, consists of noxious insects, and more especially of insects' eggs. The eggs of plant lice (Aphidse) were found in a large proportion of the stomachs examined, and constituted an important percentage of the food. Besides these,

1 Bulletin 54, N. ÎL College Agr. Exp. Sta., June, 1898.

296 YEAEBOOK OF THE DEPARTMENT OF AGRICULTURE.

the eggs of such pests as the common tent caterpillar ( Clisiocampa arnericana)^ the forest tent caterpillar {C. disstria)^ and the fall canker- worm {Anisopteryxpometaria) are eaten. In winter chickadees spend most of the daylight hours in searching trunks and branches of trees, inspecting every crevice in the bark and examining every bud for the insects' eggs and hibernating insects, which constitute so large a part of their food.

Mr. E. H. Forbush, ornithologist to the Massachusetts State board of agriculture, has shown how these birds may be attracted to the orchard in winter by hanging up pieces of suet, or bones with a little meat still attached to them.^ In this way they are induced to leave the woods and live in the orchard during the winter, and finally to build their nests and rear their young there.

CALIFORNIA BUSH-TIT.—Other species of titmice are quite as useful as the black-cap. Examination of the stomachs of a number of Cali- fornia bush-tits {Psaltriparvs minimus) revealed the presence in con- siderable number of the black scale (Lecanium oleœ)^ which infests the olive. This insect has been a serious pest to the olive trees on the Pacific coast, and any bird that will destroy it should certainly be encouraged by Western fruit growers. The usefulness of titmice de- pends largely upon the small size of the birds. In dealing with pests of any kind, the more minute they are the less the probability that man can by his own unaided efforts succeed in exterminating them. Plant lice and bark lice are, on this account, difficult of destruction by human agency, and are too small to attract the attention of many of our ordinary birds; but to the chickadees they must ^-ppear of considerable size, and so are easily found and eaten. The eggs of insects, especially those of such small species as plant lice, are often so minute as to escape the closest search by man; but the more microscopic eyes of these small birds detect them even in crevices of buds or bark.

NUTHATCHES AND CREEPEE.

Frequent associates of the chickadees, and doing practically the same work, are the nuthatches and the brown creeper. The nuthatches are of about the same size as the chickadees, but are more agile tree climbers, in this respect excelling all other North American birds. While woodpeckers and titmice usually run up the trunks, nuthatches run up or down, or along the underside of a horizontal branch, with equal facility, and do not depend upon the tail for support. The brown creeper, like the chickadee, is constantly engaged during the day in searching for insects' eggs and small insects in the crevices of the bark. It is an active, nervous little creature, which flits rapidly

,from one tree to another, generally alighting upon the trunk near the

^ Mass. Crop Reports, p. 349, 1895.

HOW BIRDS AFFECT THE ORCHARD. 297

base, then running spirally upward, and, after a hurried inspection, winging its way to the next tree. These three birds perform a service which it is difficult for man to do for himself, and they should be protected and encouraged.

CUCKOOS.

Probably no group of insects contains a greater number of orchard pests than the order Lepidoptera, which comprises butterflies and moths, with their larvae, or caterpillars. Tent caterpillars, cankerworms, fall webworms, tussock moths, codling moths, and a host of others are among the worst enemies of the fruit grower. It is, therefore, fortu- nate that there are in the United States two birds that subsist, to a great extent^ upon caterpillars, apparently preferring them to any other food. These are the cuckoos, the yellow-billed {Coccyzus americanus) and the black-billed {C, erythrophthalmus). For years it has been a matter of common observation that these birds feed largely on caterpillars, but, until a number of stomachs had been examined, it was not known how great a proportion of their food is made up of these harmful insects. The examinations indicated that caterpillars of various species, includ- ing some of the most destructive, constitute more than 48 per cent of their food. One stomach contained at least 250 tent caterpillars, probably a whole colony, in the young stage. In another 217 heads of the fall webworm {Ilyphantria cimea) w^ere counted, and this prob- ably fell far short of the real number, as these larvae are very small, and in many instances nothing but jaws remained undigested. In the stomachs of 155 cuckoos taken in various parts of the country were found 2,771 caterpillars of various species, or an average of 18 to each stomach. When we consider that a caterpillar is so soft and easily digested that soon after being swallowed it has entirely passed from the stomach, it is evident that in one day far more than this number (18) must have been eaten by the average bird. Many caterpillars are protected from the attacks of birds and parasitic insects by a covering of hair, and hairy caterpillars are only rarely eaten by most birds. Cuckoos, however, seem to prefer them to the smooth kind, and apparently eat them whenever they can be found. Caterpillar hairs are often stiff, bristl}^, and sharp at the end, like minute thorns, and it frequently happens that when a cuckoo's stomach is opened and emptied it is found to be completely furred on the inside by hairs which have pierced the inner lining and become fast. Cuckoos eat many noxious insects besides caterpillars, such as beetles, bugs, and grasshoppers. Unfortunately, they are naturally rather shy birds, preferring the edges of woodland and groves to the more open cul- tivated grounds and orchards. If, however, they are unmolested, they soon gain confidence, and in many cases frequent shade trees about houses and lawns, or even in the' very heart of the city.

1 A1900 20

2^8 YEAEBOOE: OF THE BEPASTMEIíT OF AGRICULTURE.

BALTIMORE OKIOLE.

The Baltimore oriole or golden robín {IcUrus gálbula) also feeds larg^ely on caterpillars, which amount to B4 per cent of its summer food. When nesting, the oriole may be seen searching among the outer twigs of trees, examining every leaf in quest of its favorite food. In addition to caterpillars, it destroys many noxious beetles and plant and bark lice. But its reputation is not unblemished. Some complaint has been umde against it by fruit growers, and John Burroughs accuses it of destroying gmpes- However, its peculations of this character are protmbiy not very gi^eat, for in an examination of more than 100 stoîïmcho very little fruit was found, and that chiefly of wild varieties, while there was an entire absence of any remains indicating grapes.

WARBLERS.

The family of warblers is of wide distribution and comprises species that are usually siiaall and brilliantly colored. These differ greatly among themselves in habits, some remaining in the deepest shades of the forest, while others frequent groves, orchards, shrubbery, and gardens. Some seek their food by running over the bark of trees like woodpeckers or chickadees; others are terrestrial; but the great naalority live on the insects which they find upon the leaves of trees. While definite data are wanting as to the food of these birds, field observation indicates that it consists largely of small caterpillars and other insects that feed on the leaves of fruit and forest trees. Although warblers are, individually, small, their numbers are great, and the qimntity of insects they destroy in the aggregate must be large. A single observation will illustrate the character of their work. In the moßÜi of May, 1900, when the apple trees had just expanded rosettes of small leaves and flower buds, a multiüide of warblers of several sp^ies were seen going through an orchard examining these rosettes, and apparently pecking something from each. An investigation of the trees not yet reached by the warblers showed that each rosette contained from one to a dozen large plant lice^ while a similar investi- gation of the trees explored by the birds revealed few of these insects.

The víreos are similar to the warblers in habits. Several species commonly nest in the orchards and about the buildings, obtain their food from foliage, and so destroy many insects harmful to fruit trees.

FOOD OF THE YOUNG BIRDS.

All these species do good service to the orchard when rearing their young. Our small birds, even those that, when adult, feed on fruit or seeds, rear their young on insects. Nestlings can not digest hard sub- stances, such as beetles or hard seeds, so their parents select for them

HOW BIEDS AFFECT THE OECHAED. 299

soft-bodied insects like caterpillars and other larvas, ^^oung grassho^^- pers, and spiders. Stomach examination shaws that they are fed on caterpillars or spiders almost exclusively during the first week of their existence, after which the diet is gradually changed and becomes more varied.

BIRDS OF PREY.

When fruit trees are young, and more especially when they are in the nursery rows, they are subject in winter to attacks from various species of mice and rabbits, which gnaw the bark from the trunks, completely girdling the trees, and thus ruining them. As a case in point, may be mentioned a single small nursery a few acres in extent in Iowa, in which more than 3,000 trees had been girdled by rabbits in a single v/inter—one of several instances of equal damage that occurred in the same town. In a nursery of less than 5 acres, situated in Mary- land, only a few miles from Washington, 2,000 out of about 4,000 apple trees were girdled and ruined by rabbits within two months. It is very significant that the nursery was near farm buildings where the wild enemies of the rabbits did not dare to come, while a newly set orchard at a distant part of the farm, and close b}^ woods and tnickets, was hardly touched.

Field mice and other small rodents are represented in the United States by numerous species, all of which ma}^ do mischief to young trees in winter, and most of which are doing some mischief at all sea- sons. Rabbits, as a rule, are not so numerous, but their larger size and fondness for young fruit trees makes their destructiveness fully as great as that of the smaller rodents, and, in fact, much greater in some sections where they are particularly abundant. But there is a group of birds which seems to be especially adapted to pre}^ on these harmful rodents and hold their numbers within reasonable bounds; although it often happens that through the shortsightedness of man this wâse arrangement is disturbed.

This group comprises the hawks and owls, of which about 73 important species and subspecies are found in the United States. Dr. A. K. Fisher has investigated^ the diet of these birds, and has shown that the great bulk of their food consists of injurious rodents. After an examination of some 2,700 stomachs, only 6 of the 73 species and subspecies are classed as in the main hamiful; the testimony of stom- ach examination is overwhelmingly in favor of the majority of the species. Mice, rats, rabbits, gophers, and ground squirrels constitute the chief food of most of the larger species, while many harmful insects are destro3^ed by the smaller ones. These birds at times feed on smaller insectivorous birds and poultry, but mice and other rodents are by far the commonest food of most species.

1 Bulletin 3, Div. Ornith. and Mamm., Dept. Agr., 1893.

300 YEARBOOK OF THE DEPAETMEKT OF AGEICULTURE.

Hawks and owls hold the same relation to rabbits and mice that the smaller birds hold to the insect enemies of the orchard. For j^ears they have been looked upon as harmful, but investigation has dissipated much of this error. While, as is the case with most birds, nearly all of them do some hai'm, the great majority are preeminently useful. Mice, rabbits, and other rodents are a constant menace to the interests of the fruit gfrower, and sometimes when through some combination of circumstances their numbers become superabundant, as has frequently happened in the case of field mice in Europe, their ravages are enor- mous. Indiscriminate slaughter of hawks and owls has often been followed by great ravages by voles and other mice. This should be sufficient to demonstrate the great utility of these birds as a check upon the undue increase of such pests.

. GREAT HORNED OW^L.—The great horned owl {Bubo virginiamis)^ a bird well known in most parts of the country—though not often seen, owing to its retiring habits—is probably one of the most potent factors in holding in check that troublesome pest of the orchard and nursery, the common cottontail rabbit. Several j^ears ago in a locality in eastern Massachusetts, through some unknown cause, rabbits became wonderfully abundant, and the following winter woodchoppers and others who visited the woods were surprised to see many great horned owls where in former years not more than two or three were annually observed. The pi^esence of these birds so soon after the increase of the rabbits shows how quickly they avail themselves of an unusual sup- ^\j of food, and thus restore the disturbed equilibrium, unfortunately, it happened that at this time stuffed owls were fashionable as parlor ornaments, and taxidermists were therefore willing to pay a good price for them; so when it became known that the woods were full of owls, the natives did their best to reduce the number, and so perpetu- ated the rabbit scourge.

In a number of the Eastern States the rabbit is protected by law, and can be killed only during a small part of the year; but the animal is as much of a nuisance as are the various species of field mice, and the accident of its larger size only renders it capable of more mischief. To offer bounties for the destruction of hawks and owls and simulta- neously protect rabbits is an anomaly of legislation which will probably puzzle and amuse future and wiser generations. The food value of the rabbit is insignificant compared with its capacit^^ for mischief when it becomes overabundant. In the West the larger species, or jack rabbits, have many times become excessive in numbers, and ''rabbit drives,^' in which the animals are surrounded and driven into a small inclosure, where they are killed, have grown to be of frequent occurrence. In Australia the European rabbit some years ago became so abundant as to threaten the very existence of the sheep industry over a wide expanse of territory. The common cottontail rabbit is already much

HOW BIEDS AFFECT THE ORCHARD. 301

too numerous for the best economic results in many States of the Mississippi Valley, and is likely to become so in the East if the protection of the law is not removed.

MARSH HAWK.—An idea of the good work done by hawks and owls in the destruction of smaller mammals may be obtained by watching a marsh hawk ( Circus hudsonius) foraging for its dinner. This hawk preys extensively on the mice and other small mammals that live on the ground near fences and hedgerows. It may be seen skimming along close to the surface, following a fence up one side and down the other, stopping now and then to circle around a particularly prom- ising spot, and examining every rubbish heap or stone pile, till a chance movement in the grass catches its eye, when, in an instant, it throws up its wings, suddenly checking its flight in mid-air, and drops with outstretched talons upon its unfortunate prey. Mouse after mouse will be taken in this way, each of which is capable of doing much mischief to trees or grain.

The extent of the benefit of this work and full corroboration of its character is shown by stomach examination. Thus, in the stomachs of 45 rough-legged hawks {Archibuteo lag opus sancti-johannis)^ taken in several different States, were found 128 harmful rodents, 1 weasel, 1 shrew, 1 lizard, and YO insects. The rodents, besides 19 which could not be determined specifically from the remains, consisted of 1 gopher, 2 rabbits, 4 house mice, 4 white-footed mice, and 98 meadow mice. No traces of birds or poultry were found in any one of the 45 stomachs.

BARN OWL.—When hawks or owls devour their prey they usually bolt it whole or in large fragments, with the bones, hair, and many of the unremoved feathers. B}^ the action of the stomach the indiges- tible portions, such as bones and hair, are soon separated from the flesh and rolled up in a neat pellet, which is then disgorged. In the vicinity of their nests many such pellets are to be found; and when these are dissected the bones, and still more the teeth, show what animals the bird has been eating. In a tower of the Smithsonian Institution in Washington a pair of barn owls {Strix pratíncola) have had their nest for several years. Dr. Fisher visited this eyrie on several occa- sions, and collected 675 pellets, of which he made a careful study, with the result that he identified the remains of 1,787 small mammals, mostly rodents, 36 birds, and 2 frogs. Of the mammals, there were 1,119 common meadow mice, one of the worst enemies to young fruit trees as well as to farm crops in general.

BUTCHER BIRD.—Besides hawks and owls, certain other native birds demand passing notice on account of the services they render by destroy- ing mice. These are the shrikes, birds with many peculiar character- istics, whose food habits have been investigated by Dr. Sylvester D.

302 YEAEBOOK OF THE DEPAKTMENT OF AGEICULTURE.

Judd/ One species, commonly known as the butcher bird {Laniios iorealis)^ nests far to the north, but winters in the United States. It is a frequenter of orchards and open lands, where it constantly watches for its prey—mice, an occasional small bird, and what few insects it can obtain in winter. It is an inveterate enemy of the English sparrow, which it finds in parks and suburbs of cities and towns. A peculiar habit largely increases its usefulness. Its instinct for hunting is so keen that it can not refrain from taking its game whenever and wherever it can find it, and as the bird frequently is not hungry at the time of capture, it spits the prey on a convenient thorn, sharp twig, .or barb of a wire fence. It was formerly supposed that the provisions thus saved were for future use; but although some may be subsequently eaten, most of them are left to dry up or decay.

LOGGERHEAD SHRIKE.—The loggerhead shrike {Zaniiis ludovicianus) is more southern in distribution. Its habits are similar to those of the butcher bird, but as it is with us during the summer, it captures more insects and fewer birds and mice. As it rears its young here, however, and so has occasion to use more food, it is probably fully as beneficial as the other species. Shrikes kill small birds, and to that extent do harm, but they seem to prefer mice when these can be obtained.

BIRDS HARMFUL. TO ORCHARDS.

The other side of the subject under consideration remains to be shown. The injurious habits of a few birds have already been men- tioned. In the case of the shrikes, the destruction of small birds is likely to be detrimental, as small birds are generally valuable aids to the cultivator; but the injury done in this indirect way is more than counterlmlanced by the destruction of mice and insects, which form the great bulk of the shrike's food. Sometimes the damage is more direct. A few birds feed in winter and spring on buds of trees, both in forest and orchard. Birds of this habit will be briefly considered.

PUEPLE FIKCH AND HOUSE FINCH.

The so-called purple finch ( Carjpodaciis piirpureivs) breeds in the northern tier of States and to the northward, west to the Dakotas, and south in the Allegheny Mountains as far as North Carolina, and win- ters from the southern part of its breeding range south to the Gulf States. When migrating in spring it subsists somewhat on buds of fruit and other trees, and later occasionally destroys the blossoms. The actual damage done by the Eastern purple finch seems trifling, but in the case of its Western relative, the house finch, or linnet {G, mexi- canica frontalis)^ the matter is much more serious. This closel}^ related bird does much harm, especially in California, by destroying the flower buds of peach, apricot, almond, and other trees. In many cases serioua

^BnUetin 9, Biol. Surv., Bept. Agr., 1898.

HOW BIRDS AFFECT THE ORCHAED. 303

injur}^ has been done in this way, and much expense entailed, as the birds are wonderfully abundant in that section of the country.

EOBIX.

The robin {Iferula migratoria) has often brought itself into unenvi- able notoriety by its depredations upon small fruits. Many complaints have been received from growers of fruit, especially those who raise but a small amount. Sometimes people who grow a few choice cher- ries do not get even a sample of the fruit, and those who raise fine strawberries for family use sometimes secure only a few boxes, while the robins take most of the crop. On the other hand, thousands of fruit raisers in various parts of the country are never troubled by robins, although these birds may be just as abundant in their vicinity as elsewhere. The probable explanation of this is not far to seek. An examination of the stomachs of 500 robins, collected in various parts of the country, shows that cultivated fruit forms but a moderate percentage (less than 8 per cent) of their diet; and that practically all of this is eaten in June and July; while wild fruits, of which 42 vari- eties have been identified, constitute more than 43 per cent of the year's food. Investigation shows that complaints have come chiefly from two principal sources, the suburbs of large towns in the East and the prairie region of the West. Such localities lack those wild fruits which robins evid.ently prefer. Near cities such fruits have been destroyed, and in the prairie region they rarely grow. As soon as the prairies were settled many small fi-uits were planted, thus affording a supply of food to the birds, while the larger fruit trees furnished sites for their nests. As none or but few of the wild fruits were accessible, it follows naturally that the birds resorted to the available supply, that is, to the cultivated varieties. Much the same condition has been created about large cities by the substitution of cultivated for wild fruit.

CATBIßD.

In parts of the Mississippi Valley the catbird ( Galeoscoj>tes caroU' nensid) also has become one of the pests of the small-fruit orchard. East of the Appalachian range there are so many varieties of wild fruits in forests and swamps that, as a rule, the bird confines itself to these localities and does not distui'b orchard products. In the prairie region, however, it is different. Before that part of the country w^as settled the bird was confined to the narrow belts of woods and shrubs along streams, where it found agi'eeable nesting sites and suitable food. V/hen civilization transformed the prairies into farms, gardens, orchards, and vineyards, a new field was opened to the catbird as well as to other species. The fruit trees and vines not only furnished secure nesting places, but also afforded a new and abundant source of food. It is probable that this resulted in a decided increase in the numbers of the birds, which, depending largely on domestic fruit for their food.

304 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE.

soon became a nuisance. These conclusions, as has been suggested in several recent considerations of this subject, point to the planting of wild fruit about gardens and lawns as a protection to the cultivated varieties. Many of the wild fruit shrubs are ornamental, either in flower, as the shadbush {Amelanchier), or in fruit, as the mountain ash {Sorbus).

CEDAR WAXWING.

The cherry bird or cedar wax wing {Ampelis cedrorwn) occurs over the greater part of the United States and is known everj^where by its fondness for cherries and other small fruits. Like the robin and cat- bird, however, it eats far more wild than cultivated fruit. Complaints against it have been chiefly on account of cherry eating, but its depre- dations are mostly confined to the early ripening varieties of cherries. By the time the later kinds ripen other fruits have also become abun- dant, and the bird's attention is probably diverted.

Besides eating fruit, the robin, catbird, and waxwing destroy many harmful insects, and, where not too numerous, probably do much more good than harm. All three species are very abundant in New England, but are seldom molested. The cherry bird is the only one of which serious complaint is made, and that simply on the score of stealing early cherries, while the robin is regarded almost as sacred.

CAUSE OF HARM BY BIRDS.

A careful examination of the circumstances in which birds have done harm leads to the belief that the damage is usually caused by an abnor- mal abundance of a species within a limited territory. In such cases so great is the demand for food that the natural supply is exhausted and the birds attack some of the products of garden or orchard.

Economically considered, birds are simply natural forces, and it should be our purpose to ascertain how they may be turned to our greatest advantage. The best economic conditions are probably ful- filled when birds are numerous as species and moderately abundant as individuals. Under such conditions there will be a demand for food of many kinds, without excessive demand for an}^ one kind. The most desirable status would seem to be such a relation of numbers and spe- cies between birds and insects that the birds would find plenty of food without preying on useful products, while^ the insects would be held in such check that they would neither increase to a harmful extent nor be completely exterminated. The proper course to pursue, apparentl^^, is to study the food habits of both birds and insects, to favor the increase of species which seem best adapted to preserve the proper balance, and to reduce the numbers of those that prey too greatly on the products of orchard or farm.