The entire family of Flycatchers has been indicted as being harmful to honeybees but careful stomach examinations do not sustain this accusation. A few are eaten, of course, but these few are mostly drones or males so that the harm done in this direction is negligible. If the flycatchers do any harm at all it is in the destruction of parasitic and predaceous hymenoptera. So few predaceous hymenoptera are eaten, however, that their loss is of no practical importance. As for the parasitic species, it is true that some are taken by most flycatchers and that considerable numbers are eaten by the smaller species, the wood pewee being probably the worst sinner of the whole family in this respect. It has been estimated that about one-fourth of the ants, bees and wasps eaten by this bird are parasitic species. Theoretically this may seem to be inimical to the interests of the gardener or farmer but practically the amount of damage done may not be as great as is supposed, for it must be borne in mind that the parasitic species destroy useful insects, including other parasites, or are themselves destroyed by other insects. The end result would appear to involve a problem which is so complicated by a number of factors that an exact solution could probably never be arrived at.
Although there is no question but that the wood pewee does some harm in destroying useful parasitic insects, it must be remembered that the bird destroys many noxious species, such as plum curculios, corn weevils, clover-leaf weevils, rice weevils, horse-flies, robberflies, tree-hoppers, leaf-hoppers, squash bugs, moths and caterpillars. All in all I think we can condone the loss of a few useful bees and wasps in return for the help which the wood pewee renders in ridding the world of many annoying or harmful insects. In this respect the bird confers a real benefit upon us.
The wood pewee can be said to subsist almost entirely on animal food since 99 percent of his diet is of animal origin. Another bird that feeds almost entirely on animal food is the house wren. An examination of 52 stomachs showed that 98 percent of the contents was made up of insects or their allies, and only 2 per cent was vegetable matter, including bits of grass and similar material which apparently were taken quite by accident with the insects. Unlike the wood, pewee the house Wren does not feed, as far as is known, on any useful species and for this reason can be said to be entirely beneficial. Half of the bird's food consists of grasshoppers and beetles and "the remainder of caterpillars, bugs and spiders, all with the exception of the spiders being harmful species. These diminutive birds are industrious foragers and overlook no tree, shrub or vine for caterpillars; even posts and fence rails or other crannies or crevices are meticulously examined for insects and for this reason they should be encouraged to nest about our gardens and orchards except when they might unduly interfere with the nesting of other birds for they are pugnacious creatures and will often take to driving away the rightful occupants of birdhouses or other nesting sites.
There are many other birds that help to keep down the insect population, such as the brown thrasher, the chickadee, the catbird, the swallows, the towhee, the Baltimore oriole, the nighthawk, to name a few. The meadowlark also belongs in this list for this bird is highly useful in devouring ground caterpillars which are habitually overlooked by birds that frequent trees. Crickets and grasshoppers are the most important food item, constituting 26 per cent of the food of the year and 72 per cent of the food in August. Beetles come next and include such harmful species as the May beetles, the grubs of which are among the worst enemies to many cultivated crops, notably grasses and grains, and to a less extent strawberries and garden vegetables. In May cutworms constitute over 24 percent of the meadowlark's diet, and as this is the month when these insects begin their deadly careers the meadowlark at this time renders a distinct service.