45 



ducing the present conditions in portions of the region now covered 

 by the locust plague. 



At Caspar, W3'o. , August 20, conditions while rather bad were not 

 nearly so alarming as they were in some portions of Nebraska, and 

 farther east in Wyoming. In driving out among the ranches and 

 over the range some new light on the probable cause of the recent 

 increase among grasshoppers in this and other regions of the country 

 was secured. 



Upon driving up to the buildings on a ranch on Goose Creek, about 

 10 or 12 miles southeast from Caspar, a very nice flock of sage gi'ouse 

 (30 or more) was observed walking about the premises and picking up 

 grasshoppers. These grouse were so tame that they reminded one of 

 domestic fowls as they worked about among the vegetation in search 

 of grasshoppers. During the da}' several additional coveys of these 

 grouse were seen and the remnants of several dead birds that had been 

 shot and drawn by hunters offered opportunities for examining the 

 stomach contents. Such examinations invarialdy resulted in the flnd- 

 ing of large quantities of grasshopper fragments. By inquiring 

 around among ranchmen it was also ascertained that a great slaughter 

 of these l)irds had been going on for the past few years in the sections 

 of WA'oming now most overrun by locusts. A careful survey of the 

 field brought out the fact that a similar destruction of these birds, as 

 well as of the sharp-tailed grouse, has been progressing over con- 

 siderable country. It was learned that such slaughter had occurred at 

 Chadron, Crawford, Harrison, McCook, Culbertson, Trenton, Haigler, 

 North Platte, and Sidney, in Nebraska; and at Lusk, Douglas, Orin 

 Junction, Guernsey, and elsewhere in Wyoming. At each of these 

 localities the grasshoppers were more numerous during the past sum- 

 mer than formerly. 



When this idea first came up in connection with other probable rea- 

 sons for the increase of the various species of locusts found it did not 

 seem at all probable, but the more I consider it, the more I am inclined 

 to accept it as an important factor in the problem. When we take 

 into consideration the fact that when man occupies a new area he 

 finds the forces of nature nearly or quite in a state of equilibrium, 

 no one form of life having much the advantage over others, then does 

 this explanation of the matter appear quite possible. The country 

 imdisturbed by man affords food for a certain number of mammals, 

 birds, reptiles, and insects, all of which are more or less interdependent. 

 If, for instance, man removes a few hundreds of the individuals of any 

 one species, he soon finds a change taking place in the numbers of indi- 

 viduals of some other form. The birds feed on both vegetation and 

 insects. If grasshoppers are included in their food a smaller number 

 of birds will require a less number of 'hoppers, and the latter will 

 thus be given the opportunity to increase beyond the normal. This 



