632 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



numbers of the scourge may be due, in part at least, to the wholesale 

 destruction of summer grouse (both this species and the Pinnated), at 

 the period when their services are most valuable. I have of course, in 

 my proper official capacity, killed and opened great numbers of the 

 birds during the whole season; and I almost invariably found their 

 crops stuffed with grasshoppers, the only other contents being buds or 

 flowers or the tops or succulent leaves of various plants, and small num- 

 bers of beetles, spiders, or other insects. At the height of the grass- 

 hopper season, however, the birds appear to eat scarcely anything else, 

 and each crop will contain a large handful. If an army of grouse could 

 be mustered and properly officered, they would doubtless prove more 

 effectual in abating the pest than any means hitherto tried. 



In the winter, according to my observations made at Fort Eandall, 

 the food of the grouse consists chiefly of cedarberries and other hard 

 fruits that persist, and the sealed buds of various amentaceous trees. 



During the latter part of September or early in October, when old 

 and young have both finished the renewal of their plumage, and the 

 family arrangements are foreclosed, the habits of the birds are consider- 

 ably modified, — in nothing more than in the degree of shyness they ex- 

 hibit. During the summer, also, they are rarely seen on trees, or on the 

 open prairie, excejjt in the vicinity of wooded or brushy tracts to which 

 they may retreat. Now grown more confident, they scatter over the 

 high prairie to feed, following up the ravines that lead from the water- 

 courses, and in the afternoon returning to roost in the tops of the tallest 

 trees. These daily excursions and returns may be very plainly noted 

 along the Missouri, where the cottonwood bottoms are sharply divided 

 from the limitless prairie. During the winter, especially when the 

 ground is covered with snow, their arboreal habits are confirmed. The 

 birds then hug the timber, and sometimes, on lowering or stormy days, 

 remain motionless on their iierches for hours together. 



Along the Missouri, above the Yellowstone, the birds were seen in 

 considerable numbers during the second season ; but they were scarcely 

 so common as along the Eed and Mouse llivers. Small chicks were seen 

 the latter part of June. In the still more arid and forbidding region 

 through which the northern affluents of the Milk River flow, there were 

 fewer still ; days sometimes passed without my seeing any. In the bet- 

 ter country about the Sweetgrass Hills, they recurred in sufiicient num- 

 bers to afford fair sport; in the eastern foothills of the Rocky Mountains, 

 they were almost as numerous as anywhere else. They occur in the 

 mountains up to an altitude of at least 4,200 feet, where they meet, at 

 the bottom of the coniferous belt, the Spruce Partridge and Dusky 

 Grouse. All three of thcvse birds were common about our camp at Chief 

 Mountain Lake. 



