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56 THE EELATIOK OF SPARROWS TO AGRICULTURE. 



VESPER SPARROW. 



(Pooecetes gramineus and Pooecetes g. confinis.) 



The vesper sparrow is a bird of the upper Austral and Transition 

 zones. Its breeding range covers such portions of the United States 

 and Canada as are included in these zones, though it rarely or cas- 

 ually occurs in the Great Basin and California. In winter it is found 

 from the southern part of this range as far south as Vera Cruz, Mexico. 

 It is a bird of the dr}^, open upland, where its attractive song may 

 be heard throughout the summer, particularly in the evening. It 

 is found most frequently along roadsides or in grassy fields. When 

 disturbed while feeding it flits up from the ground, spreading its 

 white-splashed tail, and alights but a short distance away to resume 

 its work. It is not as gregarious as the snowflake and Lapland long- 

 spur; for although several families may usually be seen in one com- 

 pany during the summer, and loose flocks of 20 to 50 may be noted 

 during the southern migration, yet no such immense concourses are 

 to be encountered as are frequently seen in the cases of those birds. 



One hundred and thirty stomachs of vesper sparrows, collected from 

 a dozen States, but mostly from Massachusetts, New York, Iowa, and 

 Kansas, have been examined. The food for the year, exclusive of 

 March, as indicated by these stomach examinations, consists of 69 

 percent of vegetable matter and 31 percent of animal matter. 



The diet of a bird varies with the season. Thus, during the winter, 

 practically the entire food of this sparrow is vegetable matter, while 

 in summer its food is mainl}^ animal matter. The animal food, at 

 zero in winter when the snow covers the ground, rises with the tem- 

 perature of the advancing season, and attains its maximum of 90 per- 

 cent with the full heat of summer. It then gradually falls as sum- 

 mer declines and autumn progresses, until the return of winter again 

 marks its minimum. The animal matter consumed comprises one- 

 third of the total food of the year, and is made up of insects. The 

 vegetable food consists of seeds. The insect portion of the diet is 

 divided as follows: Beetles, 12 percent; grasshoppers and other 

 Orthoptera, 11 percent; smooth, hairless caterpillars, 5 percent, and 

 bugs (Heteroptera and Jassidse), ants, and other Hymenoptera, taken 

 together, 2 percent. Beetles and grasshoppers form the bulk of the 

 animal food, as they do with manj^ other species of birds. As soon 

 as the beetles begin to crawl and take wing the bird is on the alert 

 to capture them, and by May they have increased to one-third of the 

 total food; but as grasshoppers become more and more abundant with 

 the further j^rogress of the season, these increase proportionately in the 

 food until they become its chief constituent. The bird, however, is 

 evidently very partial to beetles, and does not abandon them when the 

 grasshopper diet is at its maximum, and even in winter an occasional 

 hibernating beetle is plucked from its winter quarters and eaten. 



