structural diversity of habitat and the greatest amount of cover locally avail- 

 able, and therefore often supported a fairly high diversity and abundance of 

 wildlife. These groves are favored nesting sites for raptors (especially red- 

 tailed hawks), and the more open groves are favored hunting perches. Character- 

 istic species include: 



Yearlong Residents : sharp-tailed grouse, ring-necked pheasant, great horned 

 owl, black-capped chickadee, desert cottontail, white-tailed deer. 



Winter Residents : tree sparrow. 



Summer Residents : red-tailed hawk, Swainson's hawk, American kestrel, 

 mourning dove, eastern kingbird, western kingbird, house wren, warbling vireo, 

 yellow warbler, northern oriole, and common grackle. 



Tall Coulee Shrubbery 



Deeply-eroded coulees containing tall shrubs were a unique and highly impor- 

 tant habitat for many wildlife species. In treeless, non-sagebrush areas, these 

 coulees provided the only cover for many large and medium-sized birds and mammals, 

 and the only nesting habitat for shrub-nesting birds. Breeding bird census plots 

 located in this habitat supported the greatest species diversity and total biomass 

 of all plots studied, and a small mammal trapline located in a typical coulee also 

 showed by far the greatest biomass of all habitats similarly sampled. Many 

 species in the mine study area were clearly limited by the availavility of this 

 habitat. Characteristic species include: 



Yearlong Residents : sharp-tailed grouse, ring-necked pheasant, black-billed 

 magpie, least chipmunk*, deer mouse*, desert cottontail, mule deer. 



Winter Residents : northern shrike, tree sparrow. 



Summer Residents : mourning dove, eastern kingbird, brown thrasher*, logger- 

 head shrike*, yellow warbler, yellow-breasted chat, brewer's blackbird, rufous- 

 sided towhee. 



Snowberry-Rose 



This habitat category was of limited occurrence in the mine study area. 

 While bird diversity and abundance were fairly low, small mammal 

 biomass was fairly high, as indicated by snap-trapping results (table 37); 

 the dense, low shrub cover afforded by this type appears to be quite favored 

 by rodents. Similar results were obtained by Swenson (1978) for this habitat 

 in Dawson County. Characteristic species include: 



Yearlong Residents : deer mouse, prairie vole. 



Summer Residents : marsh hawk, eastern kingbird, common yellowthroat*, 

 clay-colored sparrow*. Where this type occurs as low coulee shrub, species 

 composition is similar. 



187 



