122 



C 



of traditional winter concentration areas impossible. Antelope 

 were able to range widely during the entire season. 



Cover type usage : The preponderance of antelope observations in 

 sagebrush and grassland habitats Illustrates the dependence of 

 this species upon these habitats (Table 56). Use of the sage- 

 brush sub-category peaked during winter. Mesic creek bottom 

 habitats received significant use during spring, summer and fall 

 of 1980. But as in the case of mule deer, use of this habitat 

 category was much less the following year. Agricultural types 

 received significant use during the winter season. 



Activity ; Antelope activity at time of observation is presented 

 in Table 57. The largest proportion of animals were standing 

 alert or running when first observed. Feeding activity was most 

 prevalent during spring. 



Use of topography : Use of dissected mid-slopes remained high and 

 relatively constant during spring, summer and fall seasons 

 (Table 58). A shift to alluvium/terrace areas was evident in 

 winter. Flood plain features were used more during I98O than 

 1981 



Use of exposure: The greatest proportion of antelope observations 

 were made on flat terrain during all seasons (Table 59). Antelope ( 

 were observed using all exposures during every season except winter, 

 when northeast, northwest and southeast aspects appeared to be 

 favored. 



Use of slope : Most antelope sightings occurred in habitats 

 characterized by gentle slopes or flat terrain all seasons (Table 

 60). This trend was particularly evident in winter. 



Birds 



One hundred and twenty-seven species of birds were observed on 

 the Foster Creek study area during the study period (Table 6I). 

 Resident breeding was documented for 52 species. The goshawk. 

 Cooper's hawk, ferruginous hawk, golden eagle, bald eagle, 

 prairie falcon, peregrine falcon, merlin, long-billed curlew, 

 upland sandpiper, burrowing owl, long-eared owl and field sparrow 

 are all listed by Flath (198I) as species of special concern in 

 Montana. The ferruginous hawk, bald eagle, golden eagle, 

 burrowing owl, peregrine falcon, prairie falcon and long-billed 

 curlew are also listed as migratory birds of high federal interest 

 in the Powder River coal region (U.S. D.I. 1979). 



Sharp-tailed grouse : Sharp-tailed grouse were abundant in the Foster 

 Creek vicinity. Twenty-five sharp-tailed grouse arenas were 

 located within the study area (Figure 67). Attendance by (" 



displaying males on the 12 arenas located in spring of I98I 

 averaged 9.^ (Table 62). Attendance averaged 22.1 in 198O and 

 11.7 in 1981 on the 13 arenas for which two years of data were 

 obtained. The 50$ drop in attendance between years is consistent 

 with poor sharptail oroduction documented throughout southeastern 

 Montana for I98O (Knapp et al. I98I). 



