The well-known eastern kingbird[51] (fig. 19) is essentially a lover of
the orchard, though groves and the edge of forests were probably its
original habitat. It breeds in the States east of the Rocky Mountains,
and less commonly in the Great Basin and on the Pacific coast. Its
hostility to hawks and crows is proverbial, and for this reason a family
of kingbirds is a desirable adjunct to a poultry yard. On one occasion
in the knowledge of the writer a hawk which attacked a brood of young
turkeys was pounced upon and so severely buffeted by a pair of kingbirds
whose nest was near by that the would-be robber was glad to escape
without his prey. Song birds that nest near the kingbird are similarly
protected.
[51] _Tyrannus tyrannus_.
The kingbird is largely insectivorous. It is a true flycatcher and takes
on the wing a large part of its food. It does not, however, confine
itself to this method of hunting, but picks up some insects from trees
and weeds, and even descends to the ground in search of myriapods
or thousand legs. The chief complaint against the species by both
professional bee keepers and others has been that it preys largely upon
honeybees. One bee raiser in Iowa, suspecting the kingbirds of feeding
upon his bees, shot a number near his hives; but when the stomachs of the
birds were examined by an expert entomologist, not a trace of honeybees
could be found.
An examination of 665 stomachs collected in various parts of the
country, was made by the Biological Survey, but only 22 were found to
contain remains of honeybees. In these 22 stomachs there were in all 61
honeybees, of which 51 were drones, 8 were certainly workers, and the
remaining 2 were too badly broken to be further identified.
The insects that constitute the great bulk of the food of the bird
are noxious species, largely beetles--May beetles, click beetles (the
larvæ of which are known as wire-worms), weevils, which prey upon
fruit and grain, and a host of others. Wasps, wild bees, and ants are
conspicuous elements of the food, far outnumbering the hive bees.
During summer many grasshoppers and crickets, as well as leaf hoppers
and other bugs, also are eaten. In the stomachs examined were a number
of robber files--insects which prey largely upon other insects,
including honeybees, and which are known to commit in this way extensive
depredations. It is thus evident that the kingbird by destroying these
flies actually does good work for the apiarist. The 26 robber flies found
in the stomachs may be considered more than an equivalent for the 8
worker honeybees already mentioned. A few caterpillars are eaten, mostly
belonging to the group commonly known as cutworms, all the species of
which are harmful.
About 11 per cent of the food consists of small native fruits, comprising
some 30 common species of the roadsides and thickets, as dogwood berries,
elderberries, and wild grapes. The kingbird is not reported as eating
cultivated fruit to an injurious extent, and it is very doubtful if this
is ever the case.
In the Western States the Arkansas kingbird[52] is not so domestic in
its habits as its eastern relative, preferring to live among scattering
oaks on lonely hillsides, rather than in orchards about ranch buildings.
The work it does, however, in the destruction of noxious insects fully
equals that of any member of its family. Like other flycatchers, it
subsists mostly upon insects taken in mid-air, though it eats a number
of grasshoppers, probably taken from the ground. The bulk of its food
consists of beetles, bugs, wasps, and wild bees. Like its eastern
representative, it has been accused of feeding to an injurious extent
upon honeybees. In an examination of 62 stomachs of this species,
great care was taken to identify every insect or fragment that had any
resemblance to a honeybee; as a result, 30 honeybees were identified, of
which 29 were males or drones and 1 a worker. These were contained in
four stomachs, and were the sole contents of three; in the fourth they
constituted 99 per cent of the food. It is evident that the bee-eating
habit is only occasional and accidental, rather than habitual; and it is
also evident that if this ratio of drones to workers were maintained, the
bird would be of more benefit than harm to the apiary.
[52] _Tyrannus verticalis_.
[Illustration: Fig. 19.--Kingbird. Length, about 8½ inches.]
The Cassin kingbird[53] has a more southerly range than the Arkansas
flycatcher. Examination of a number of stomachs shows that its food
habits are similar to those of others of the group.
[53] _Tyrannus vociferans_.
Three points seem to be clearly established in regard to the food of
the kingbirds--(1) that about 90 per cent consists of insects, mostly
injurious species; (2) that the alleged habit of preying upon honeybees
is much less prevalent than has been supposed, and probably does not
result in any great damage; and (3) that the vegetable food consists
almost entirely of wild fruits which have no economic value.
All of the kingbirds are of the greatest importance to the farmer and
fruit grower, as they destroy vast numbers of harmful insects, and do no
appreciable damage to any product of cultivation.