THE PRACTICAL VALUE OF BIRDS. 



1C 



Judd (23) reports the following percentages of grasshoppers in the sum- 

 mer stomachs of 7 members of the finch family, which are not generally 

 supposed to be especially insectivorous: Dickcissel 41%, grasshopper spar- 

 row 37%, lark sparrow 31%, vesper sparrow 23%, chipping sparrow 21%, 

 song sparrow 17%, field sparrow 13%. In a recent grasshopper outbreak in 

 California, Bryant examined 17 species of birds, and found grasshoppers in 

 the stomachs of all except 3, constituting from 2% to 100% of their food, as 

 follows (24) : Kilideer 100%, Anthony's green heron 15%, burrowing owl 

 90 % , western kingbird 67.5 % , black phoebe 50 % , California horned lark 7.5 % , 

 bicolored blackbird 81.2%, tricolored blackbird 97%, western meadowlark 

 96.2%, Bullock's oriole 92%, Brewer's blackbird 80%, English sparrow 

 2%, California shrike 47%. 



Four thousand stomachs of native sparrows and finches show that dur- 

 ing the colder half of the year their food consists almost entirely of weed 

 seeds (25). In a garden within 2 months they will sometimes destroy 90% 

 of such seeds as pigeon-grass and ragweed (26). Many birds besides finches 

 indulge largely in seed-eating. Judd (27) found that weed seeds constituted 

 18% of the total food of all birds collected on a Maryland farm, and th.-it 

 the seeds were taken by 20 of the species on the farm. 



(23) Judd, Sylvester D., The Relation of Sparrows to Agriculture, U. S. Dept. 

 Agric., Biol. Surv., Bull. No. 15, p. 62, 1901. 



(24) Bryant, Harold C., Birds in Relation to a Grasshopper Outbreak in California, 

 Univ. Call. Pub. in Zool., Vol. XI, No. 1, p. 9, 1912. 



(25) Judd, Sylvester D., Birds as Weed Destroyers, U. S. Dept. Agric., Yearbook 

 for 1898, p. 223. 



(26) Judd, Sylvester D., U. S. Biol. Surv., Bull. 15, p. 29. 



(27) Judd, Sylvester D., Birds of a Maryland Farm, U. S. Dept. Agric., Biol. 

 Surv., Bull. 17, pp. 70-71. 



