F. E. L. Beal

“ Earthworms themselves are rather rarely found in stomachs, although some birds, as the robin, eat them freely. It is well known that the food of earthworms consists largely of partially decayed vegetable matter found in the soil. Hence it is probable that decayed vegetation found in the stomachs of thrushes is the food contained in the earthworms when they were swallowed. ”

“ Summary.—The animal food of the wood thrush includes remarkably few useful insects and contains some very harmful ones, as the Colorado potato beetle and many of the Scarabæidæ, the larval forms of which are the well-known white grubs which are a pest to agriculture in preying upon roots of plants. ”

“ Thrushes of the genus Hylocichla show a very pronounced taste for ants, and the average consumption of these insects by the five species is 12.65 per cent. Few birds other than woodpeckers show so strong a liking for this highly flavored food. Hymenoptera in general, including ants, bees, and wasps, are the second largest item of insect food. Lepidoptera (caterpillars) stand next as an article of thrush diet, while Orthoptera (grasshoppers) , which are a favorite food with most birds, do not seem to appeal much to the thrushes. ”

“ The habits of birds of this species resemble those of others of the genus in living in swamps and woodlands rather than in gardens and orchards. The russet-back on the Pacific coast, however, seems to have become quite domestic, and wherever a stream runs through or past an orchard or garden, or the orchard is near thick chaparral, this bird is sure to be found taking its toll of the fruit and rearing its young in the thicket beside the stream. During the cherry season it takes a liberal share of the fruit, but its young, then in the nest, are fed almost entirely on insects. ”

“ The vegetable portion of their diet consists mostly of berries and other small fruits. As a family thrushes can not be called clean feeders, for the food eaten often contains a considerable proportion of such matter as dead leaves, stems, and other parts of more or less decayed vegetation. It might be supposed that this was gathered from the ground with insects and other food, but investigation shows that much of it has a different origin. It was noticed that the setæ or spines of earthworms were a very common accompaniment of this decayed vegetation. ”

“ Spiders are freely eaten by the gray-cheeked thrush in spring, and sparingly in fall. For the season they constitute 5.77 per cent of the food. A few other animals, as crawfish, sowbugs, and angleworms (0.41 per cent) , complete the animal food.
Following is a list of the insects identified and the number of stomachs in which found:
Vegetable food.—A few Rubus seeds were recorded as cultivated fruit, but they were found in only two stomachs and probably were wild, as the gray-cheeked thrush does not live where it is likely to come in contact with cultivated blackberries or raspberries. ”

“ The ants destroyed—12.46 per cent of the food—keep up the reputation of thrushes as ant eaters. They were taken constantly every month, with the greatest number from May to September; a falling off in July is partly accounted for by the fact that more fruit is taken in that month. Other Hymenoptera (bees and wasps) were eaten to the extent of 5.41 per cent, a surprising amount for a bird that feeds so largely upon the ground, as these insects are usually of fleet wing and live in sunshine and open air. ”

“ Next to Rhus the fruit most eaten was the dogwood berry, found in 34 stomachs, yet from a human estimate these berries are distasteful and contain such large seeds that they afford but very little actual food.
Summary.—The hermit thrush, as it name indicates, is of solitary habits and neither seeks human companionship nor molests cultivated products. It destroys nothing indirectly helpful to man, as beneficial insects, but aids in the destruction of the myriad hosts of insect life which at all times threaten vegetation. ”

“ From this percentage of domestic fruit one might infer that the veery was, or might be, a serious menace to fruit growing, but no such complaints have been heard, and it is probable that the species is not numerous enough to damage cultivated crops. ”

“ The bird lives among men, but not with them. The western form, the russet-back, comes more into relations with the cultivated products because it visits orchards and partakes freely of the fruit. Even then the damage is slight, as much of the fruit eaten is that fallen to the ground. Moreover, while the adult bird is feeding upon fruit a nestful of young are being reared upon insects which must be largely taken from the orchard, thus not only squaring the account but probably overbalancing it in favor of the farmer.
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HERMIT THRUSHES.
(Hylocichla guttata subspp.) ”

“ Vegetable food.—The vegetable food of the olive-backed thrush consists of small fruit. The bird has a weak bill and can not break through the tough skin of the larger kinds. In the cherry orchards of California the writer many times observed the western subspecies of this bird, the russet-back, on the ground pecking at cherries that had been bitten open and dropped by linnets and grosbeaks. ”

“ As a group thrushes are plainly colored and seem to be especially adapted to thickly settled rural districts, as the shyest of them, with the exception of the solitaire, do not require any greater seclusion than that afforded by an acre or two of woodland or swamp. ”

“ They have been known, however, to visit orchards and sometimes gardens which are not kept too trim. It is thus evident that the food has little direct economic interest, as this bird does not come in contact with the farmer's crops. ”

“ It is partial to running streams and often builds its nest just above a rushing mountain torrent. It ranges from Alaska through the Sierras south to San Bernardino, Cal., and through the Rockies to Arizona and New Mexico, and occasionally farther east. ”