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 wireworms about 1 per cent. Of the beneficial forms
ground beetles (3 per cent) and hymenopterous insects, part of which
are parasitic (2.5 percent), 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 his 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 To 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, chinquapins, 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 they do 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 their 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 the latter 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. The 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 many
of 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 in
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.
[Illustration: _Fig. 18._—Phœbe. Length, about 6½ inches.]
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
flies—insects which prey largely upon other insects, especially
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.
[Illustration: Fig. 19.—Kingbird. Length, about 8½ inches.]
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 midair, 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 take 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
fly-catcher. 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.
The nighthawk, or bull-bat[54] breeds throughout most of the United
States and Canada, and winters in South America. It is strictly
insectivorous, and hence does no damage to crops. The only charge that
can be made against the bird is that it destroys some useful insects,
but these are greatly in the minority in its food.
[54] _Chordeiles virginianus._
Nighthawks are so expert in flight that no insects can escape them.
In their capacious mouths they sweep up everything from the largest
moths and dragon flies to the tiniest ants and gnats, and in this
way sometimes gather most remarkable collections of insects. Several
stomachs have contained 50 or more different kinds, and the number of
individuals ran into the thousands.
Nearly a fourth of the birds’ total food is composed of ants. These
insects are generally annoying and often very injurious, especially
on account of their damage to stored products and because of their
habit of fostering destructive plant lice. More than a fifth of the
nighthawk’s food consists of June bugs, dung beetles, and other beetles
of the leaf-chafer family. These are the adults of white grubs, noted
pests, and even as adults many members of the family are decidedly
harmful.
Numerous other injurious beetles, as click beetles, wood borers, and
weevils, are relished. True bugs, moths, flies, grasshoppers, and
crickets also are Important elements of the food. Several species of
mosquitoes, including the transmitter of malaria, are eaten. Other
well-known pests consumed by the nighthawk are Colorado potato beetles,
cucumber beetles, rice, clover-leaf, and cotton-boll weevils, bill
bugs, bark beetles, squash bugs, and moths of the cotton worm.