SPECIAL CONCERNS 



HABITATS OF SPECIAL CONCERN 

 Coulees 



Coulee habitats include tall coulee shrub and low coulee shrub habitats. 

 Habitats associated with deeply eroded coulees and gullies, especially near 

 coulee heads, were the most mesic and diverse of all upland habitats encountered 

 in this study. Of special importance were coulees containing clumps of tall 

 coulee shrubbery, (silver buffaloberry, chokecherry, western service berry and 

 red osier dogwood) which were most frequently found in rolling uplands above 

 792 m (2600 feet) elevation along an axis extending roughly from Flowing Well to 

 Weldon Junction and including the northern half of the proposed mining area. 

 Although such tall coulee shrubbery comprises approximately one percent of the 

 available habitat (table 5), it accounted for over five percent of all recorded 

 mule and white-tailed deer observations as well as nearly ten percent of all 

 sharp-tailed grouse observations (figures 5, 27 and 30) in spite of decreased 

 detectability of animals in this habitat. Coulee topography, including both 

 shrub and non-shrub habitats, was even more important for mule deer, and in fact 

 accounted for nearly 40% of all mule deer observations (figure 27). Coulees were 

 also found to support highly diverse and productive bird communities. Of the 

 five breeding bird census grids, those two including coulee shrubbery had the 

 highest total biomass, and the silver buffaloberry-red osier dogwood coulee had 

 the highest species diversity (table 33). The highest biomass of all small mam- 

 mal communities sampled by snap-trap lines was also found in this latter community. 

 Coulee shrub habitats, therefore, although of limited representation, may be con- 

 sidered critical habitats and should be preserved or restored. 



Silver Sagebrush Flats 



Dense stands of silver sagebrush having a canopy cover greater than 25% are 

 of limited occurrence in the mine study area (table 5). However, they are of 

 high importance to many species of wildlife. Silver sagebrush provides cover 

 for sharp-tailed grouse, white-tailed jackrabbits, and desert cottontails, 

 all of which were found in abundance in the silver sagebrush flat near 

 the southern end of the proposed mining area. It is also essential habitat 

 for sage grouse and wintering pronghorn antelope. The breeding bird census 

 plot located in silver sagebrush had both the greatest number of species 

 and highest total density of all plots studied (table 33). It also harbored 

 small mammal densities much higher than those of grassland habitats sampled 

 (figure 50) . 



Stockponds 



While a few stockponds are located in the mine study area, they provide 

 essential habitat for waterfowl, shorebirds, large water birds, semi-aquatic 

 mammals, and several species of reptiles and amphibians. In some areas they are 

 the only late-summer source of water available to wildlife. Of special importance 

 are stockponds bordered by marsh, shrubs or trees. 



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