78 THE RELATION OE SPARROWS TO AGRICULTURE. 



was crammed full of the seeds of crab-grass. The much smaller con- 

 sumption of ragweed, amaranth, lamb's-quarters, and polj^gonum than 

 on the part of tree, white-throated, and song sparrows is probablj^due 

 to the smaller and less powerful digestive organs of the chipping 

 sparrow. 



No small service is rendered in destroying weed seed, but the utility 

 of the species is manifested most strikingly in its animal food, three- 

 fourths of which consists of noxious insects, principally caterpillars, 

 weevils, gTasshoppers, and leaf-beetles. Of the 38 percent of animal 

 matter, weevils constitute 6 percent; leaf -beetles, 2 percent; other 

 Coleoptera, including predaceous ground-beetles, dung beetles, click- 

 beetles, and May-beetles, collectively, 3 percent; caterpillars, 9 per- 

 cent; grasshoppers, 10 percent; and miscellaneous animal matter, 

 consisting of leaf-hoppers, true bugs, ants, spiders, and parasitic wasps, 

 8 percent. The maximum monthly average of weevils, 16 percent, 

 is attained in Maj^ In June, when 93 percent of the food is com- 

 posed of insects, grasshoppers form 36 percent, caterpillars 25 per- 

 cent, and leaf -beetles 6 percent. 



On the one side only 1 percent of the food consists of useful insects 

 (predaceous beetles and parasitic wasps), while more than 25 percent 

 is made up of insect pests; and on the other side, grain composes only 

 4 percent, in contrast to weed seed, which constitutes 40 percent. 

 These figures clearly show the good service rendered to agriculture. 



The food habits of this sparrow will receive further consideration 

 in connection with those of the next species — the field sparrow. 



FIELD SPARROW. 



{Spizella pusilla and Spizella p. arenacea.) 



The field sparrow (see fig. 16) summers in the northern half of the 

 United States east of the Rocky Mountains and in southern Canada, 

 and winters in the Southern States. 



It can perhaps best be distinguished from the many small species 

 of ground-colored birds by its reddish beak. It is thoroughly com- 

 monplace in appearance, and in habits is much shyer than the chip- 

 ping and song sparrows, which may be called dooryard birds. Often 

 seen in the same weed patch with these sparrows, it is nevertheless, 

 as its name indicates, a lover of open lands. Here it builds its nest, 

 generally among some small briers, and during the season rears two 

 to three broods of three or four each. Its food habits are very simi- 

 lar to those of the chipping sparrow, as would naturally be expected, 

 since both belong to the same genus. Forbush has found it preying 

 on plant lice, tent caterpillars, cankerworms, and the caterpillars of 

 the brown-tail moth.^ 



Mass. Crop Rept., Bull. 3, pp. 33-36, July, 1900. 



