INDEX TO PAPERS RELATING TO FOOD OF BIRDS. 13 



Bulletin 27. The North American eagles and their economic rela- 

 tions. By Harry C. Oberholser. 31 pp. 2 pis. 2 figs. (maps). 

 1906. 

 This report is a compilation of information on the habits and distribution of 

 3 species of eagles — the bald, the golden, and the gray sea eagles. Their 

 relations to fish, wild birds, poultry, and wild and domestic mammals are dis- 

 cussed and opinions given as to their economic status. Maps showing the 

 breeding ranges of the bald eagle and the golden eagle are included in the 

 bulletin. 



Bulletin 29. The relation of birds to the cotton-boll weevil. By 

 Arthur H. Howell. 31 pp. 1 colored pi. 6 figs. Oct. 10, 1907. 

 Bulletin 29 is a resume of the study of birds in relation to the boll weevil. 

 Forty -three species are listed (on page 6) as enemies of the insect, adding 15 

 to the list in Bulletin 25. Recommendations of measures designed to increase 

 the efficiency of bird enemies of the pest include proposals for legislation in 

 favor of the upland and killdeer plovers and the blackbirds, and suggestions 

 for the special protection of swallows, meadow larks, and painted buntings. 

 Nesting boxes for purple martins are described and illustrated. The relations 

 of the various groups of birds to the boll weevil are described separately, the 

 results of the field work of 1906 and 1907 are given, and the paper ends with 

 tabulated records of birds examined which had and which had not eaten boll 

 weevils. The field work was carried on by the author and the stomachs were 

 examined by W. L. McAfee. 



Bulletin 30. Birds of California in relation to the fruit industry. 



Part I. By F. E. L. Beal. 100 pp. 5 pis. (1 colored). Nov. 



11, 1907. 

 The introductory paragraphs in this bulletin state the general problem of the 

 relations of birds to cultivated fruit in California. They serve as an introduc- 

 tion to both Part I, the present bulletin, and Part II, issued as Bulletin 34. 

 The status of birds in newly settled regions, the effect of migration on the 

 economic relations, the causes of depredations, conditions in California com- 

 pared with those in the Eastern States, and protective measures, such as the 

 planting of decoy plants and provision of water supplies, are some of the 

 subjects discussed in the introduction. It is shown that, while birds are 

 usually destructive to crops in newly planted regions, "experience everywhere 

 shows that after a time there is a partial readjustment of conditions, so that 

 inroads by birds become much less common or wholly cease." The usual 

 causes of damage by birds wherever or whenever occurring are defined; the 

 principal bird enemies of fruit in California are named in order of importance, 

 following which are the separate accounts of the species. The food habits of 

 35 species are fully discussed, including the most important species from the 

 tanagers to the thrushes, in systematic order, together with the linnet, or 

 house finch, the worst fruit pest among the birds in the State. The account of 

 this species is based upon the examination of 1,206 stomachs. The food of the 

 nestlings or young of several species is described, the most extended account 

 dealing with those of the russet-backed thrush. 



Bulletin 31. An economic study of field mice (genus Microtus). 

 By David E. Lantz. G4 pp. 8 pis. 3 figs. Oct. 28, 1907. 

 In treating the natural enemies of field mice the author mentions some 50 

 species of birds, including shrikes, cuckoos, crows, herons, bitterns, storks, 



