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UNITED STATES DEPARTMENT OF AGRICULTURE

BULLETIN No. 280

Contribution from the Bureau of Biological Survey

HENRY W. HENSHAW, Chief

----------------------------------------------------------------- Washington, D. C. PROFESSIONAL PAPER September 27, 1915 -----------------------------------------------------------------

FOOD HABITS OF THE THRUSHES OF THE UNITED STATES

By F. E. L. Beal, Assistant Biologist.

CONTENTS.

Page.

Introduction 1

Townsend's solitaire 3

Wood thrush 5

Veery and willow thrush 9

Gray-cheeked and Bicknell's thrushes 11

Olive-backed and russet-backed thrushes 13

Hermit thrushes 18

WASHINGTON GOVERNMENT PRINTING OFFICE 1915

UNITED STATES DEPARTMENT OF AGRICULTURE

Contribution from the Bureau of Biological Survey

HENRY W. HENSHAW, Chief

------------------------------------------------------------------ Washington, D. C. PROFESSIONAL PAPER September 27, 1915 ------------------------------------------------------------------

FOOD HABITS OF THE THRUSHES OF THE UNITED STATES.

By F. E. L. Beal, Assistant Biologist.

INTRODUCTION.

North American thrushes (Turdidæ) constitute a small but interesting group of birds, most of which are of retiring habits but noted as songsters. They consist of the birds commonly known as thrushes, robins, bluebirds, Townsend's solitaire, and the wheatears. The red-winged thrush of Europe (Turdus musicus) is accidental in Greenland, and the wheatears (Saxicola œnanthe subspp.) are rarely found in the Western Hemisphere except in Arctic America. Within the limits of the United States are 11 species of thrushes, of which the following 6 are discussed in this bulletin: Townsend's solitaire (Myadestes townsendi), the wood thrush (Hylocichla mustelina), the veery and willow thrush (Hylocichla fuscescens subspp.), the gray-cheeked and Bicknell's thrushes (Hylocichla aliciæ subspp.), the olive-backed and russet-backed thrushes (Hylocichla ustulata subspp.), and the hermit thrushes (Hylocichla guttata subspp.). An account of the food habits of the 5 species of robins and bluebirds appeared in Department Bulletin No. 171.

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.

The thrushes are largely insectivorous, and also are fond of spiders, myriapods, sowbugs, snails, and angleworms. 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. 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. The tissues of worms are quickly digested, leaving the contents of their alimentary canals mixed with the hard indigestible setæ or spines.