34 UNIVERSITY OF COLORADO. 



probably jays and magpies as well, are at first fed principally on in- 

 sects (126). 



Icteridse. Blackbirds have been known to do much damage to crops 

 locally, where overabundant, and bounties have been paid for their destruc- 

 tion, but in most localities they do much more good than harm. That they 

 destroy millions of cutworms and other pests is well known (127). 



Red-wing, 1,083 stomachs, weed seeds 54.6%, grain 13.9%, grasshoppers 

 4.7% (17% in August), caterpillars 5.9% (20% in May), beetles 10% (128). 

 The food of western species and subspecies of red-wings differs from these 

 figures somewhat, as shown in detail by Beal (129). 



Yellow-headed blackbird, 138 stomachs, insects 33%, weed seeds 28%, 

 grain 38% (130). 



Bronzed grackle (crow blackbird), 2,346 stomachs, insects 27%, and 

 rusty grackle, 132 stomachs, insects about 42% (131). 



The nestlings of all these species are at first fed exclusively on insects 

 and spiders (132). 



Cowbirds, 544 stomachs, insects about 33% (133). 



Meadowlarks feed largely on grasshoppers, crickets and other ground 

 insects and are very useful. In 238 stomachs, insects averaged 71.7%, even 

 6 taken with snow on the ground averaging 47% ; grain 14%, weed seeds 

 11%. One contained 37 grasshoppers and another 54, which, of course, 

 represented only part of the daily food. It is estimated that in one square 

 mile meadowlarks destroy 30,000 grasshoppers in a month (134). This bird 

 is also numbered among the enemies of the cotton boll weevil (135). 

 Ninety-one stomachs of the western meadowlark, taken in California, con- 

 tained insects 70%, grain 27%, weed seeds 2% (136). Fifty-four stomachs 

 from Red Bluff, California, averaged 31% of cutworms, 66 from El Toro 

 averaged 73.23% of grasshoppers (137). 



Baltimore oriole, 113 stomachs, insects 83.4%, vegetation 16.6%, includ- 

 ing very little fruit (138). Three stomachs from a canker-infested orchard 

 contained beetles 60% (chiefly vine leaf chafers), canker worms 40% (139). 



Bullock's oriole, 162 stomachs, insects 79%, vegetation 21% (fruit 

 9%) (140). 



(126) Judd, The Food of Nestling Birds, U. S. Dept. Agric., Yearbook for 1900, pp. 

 424-426. 



(127) Sullivan, Kas. St. Agric. Coll., Agric. Educ., Vol. Ill, p. 34. 



(128) Beal, The Food of the Bobolink, Blackbirds and Crackles, U. S. Biol. Surv., 

 Bull. No. 13, pp. 33-44. See also Farmers' Bull. No. 54, pp. 19-21. 



(129) Beal, U. S. Biol. Surv., Bull. No. 34, pp. 36-59. 



(130) Beal, U. S. Biol. Surv., Bull. No. 13, pp. 30-33. 



(131) Beal, U. S. Biol. Surv., Bull. No. 13, pp. 13, 24-30, 45-49. This is, in part, 

 a revision of Crow Blackbirds and their Food, Yearbook for 1894, pp. 233-248. 



(132) Beal, Ibid., and Judd, Yearbook for 1900, pp. 422-423. 



(133) Beal, Ibid., Bull. 13, pp. 24-30. 



(134) Beal, The Meadowlark and Baltimore Oriole, Agric. Yearbook for 1895, pp. 

 419-430 ; Farmers' Bull. No. 54, pp. 21-23. Judd, Yearbook for 1898, p. 431. Dutcher, 

 The Meadowlark, Nat. Aud. Soc., Educ. Leaflet No. 3. 



(135) Bailey, U. S. Biol. Surv., Bull. No. 22, p. 16. Howell, U. S. Biol. Surv., 

 Bull. No. 25, p. 11; No. 29, p. 18. 



(136.) Beal, U. S. Biol. Surv., Bull. No. 34, pp. 65-68. 



(137) Bryant, The Numbers of Insects Destroyed by Western Meadowlarks 

 (Sturnella neglecta). Science, n. s., Vol. XXXVI, pp. 873-875. 



(138) Beal, Agric. Yearbook for 1896, pp. 426-429; Yearbook for 1900, p. 298. 

 Farmers' Bull. No. 54, p. 23. -Judd, U. S. Biol. Surv., Bull. No. 17, p. 96. 



(1395 Forbes. 111. St. Lab. Nat. Hist., Bull., Vol. I, No. 6, p. 14. 

 (140) Beal, U. S. Biol. Surv., Bull. No. 34, pp. 68-71. 



