VESPER SPARROW. 



57 



Dung-beetles, weevils, click-beetles, ground-beetles, and leaf -beetles 

 seem to be preferred to other kinds. The little dung-beetles of the 

 genera Apliodius and Atcenius, which are extremely abundant in the 

 pastures where the vesper sparrow nests, form 4 percent of the year's 

 food. As they are practically neutral, however, in their effect upon 

 agriculture, their destruction is of little interest. The destruction of 

 weevils is more serviceable, for these include many of our worst pests. 

 Weevils of the genus Sitones and several other members of the family 

 Curculionid?e are small, hard insects, apparently as inedible as gravel, 

 but they seem to be relished, as they form 4 percent of the year's food, 

 and in June amount to 20 percent of the food for that month. Click- 

 beetles, which are also pests, are taken to about half this extent. 

 Useful predaceous beetles amount to 2 percent of the year's food. 

 Remains of ground-beetles and their larvae were found in four of the 

 130 stomachs examined. In one of these was also found a tiger-beetle, 

 a most active fljang insect that seldom falls prey to birds. The remain- 

 ing 1 percent of the coleopterous food consists of small dark or green 

 leaf-beetles of practically no economic importance, which seem to be 

 eaten most freely in midsummer. 



From June to September grasshoppers and other Orthoptera pre- 

 dominate over all other forms of insect food. Those eaten are prin- 

 cipally short-horned grasshoppers of the genus Melanoplus and allied 

 genera. In July, when thej^ attain their maximum, thej^ constitute 

 41 percent of the month's food. Professor Aughey found that every 

 one of five vesper sparrows he collected and examined had fed on 

 these destructive insects, and that the stomachs averaged more than 

 13 each. 



Cutworms, arm}" worms, and other smooth caterpillars that infest 

 upland grass lands are less prominent in the food of the vesper spar- 

 row than grasshoppers and beetles, perhaps because they are less 

 readily obtainable. The}" are eaten freely, however, and, as far as is 

 shown b}' this investigation, form a larger proportion of the food of 

 this sparrow than of that of any other, with the exception of the 

 grasshopper sparrow and the dickcissel. In Ma}' they constitute 21 

 percent of the food. The remainder of the animal food is unimj)or- 

 tant, and includes ants and other Hymenoptera, true bugs, leaf- 

 hoppers, flies, spiders, snails, and according to Dr. Warren, earth- 

 worms.^ These various elements amount to about 3 percent of the 

 total animal food. 



Sparrows are primarily seed-eating birds, and it is usually the vege- 

 table element of their diet that is most conspicuous and most impor- 

 tant. While this is also true of the vesper sparrow, yet it is true to a 

 smaller degree than is common among sparrows. Its work as an insect 

 destroyer is very great, measured bj^the sparrow standard, and becomes 



'Birds of Pennsylvania, revised ed., p. 234, 1890. 



