LETTER OF TRANSMITTAL. U. S. DEPARTMENT OF AGRICULTURE, Washington, D. C., May 22, 1900. SIR: I have the honor to transmit herewith for publication as Bulletin No. 13 a report on 'The Food of the Bobolink, Blackbirds, and Grackles,' by Prof. F. E. L. Beal, assistant biologist. This report is based on a careful examination of the contents of more than 4,800 stomachs, representing nine species and several subspecies of American blackbirds. The family of orioles and blackbirds, to which the bobolink, cowbird, blackbirds, and grackles belong, is one of much economic importance. The ravages of the bobolink in the rice fields of the South, and of some of the blackbirds in the grainfields of the Upper Mississippi Valley at planting and harvesting time, are matters of common knowledge, but the other food of these and other species is not so well known. The present bulletin is devoted mainly to the food of the various blackbirds during the summer months; several of the species consume insects in such quantities at this time as to compensate in great measure for the grain they destroy. Respectfully, Hon. JAMES WILSON, C. HART MERRIAM, Chief, Biological Survey. Secretary of Agriculture. 3 CONTENTS. Yellow-headed blackbird (Xanthocephalus xanthocephalus). Red-winged blackbird (Agelaius phœniceus). California red-winged blackbird (Agelaius gubernator californicus). ILLUSTRATIONS. Page. PLATE. PLATE I. Map showing breeding range of the bobolink (Dolichonyx oryzivorus) . Frontispiece. TEXT FIGURES. FIG. 1. Bobolink 2. Diagram illustrating proportions of food elements of bobolink... 5. Diagram illustrating proportions of food elements of redwing 6. Crow blackbird..... 6 |