151 



Use of topography : Deer appeared to use steep slopes to a greater 

 extent In 19«0 than in 1981 (Table 75). Use of dissected mid-slopes 

 peaked in winter when deer heavily used ponderosa pine ridges. 

 Dissected mid-slope and alluvium/terrace features were used to a 

 greater extend during spring and summer of 198I than 198O. A 

 corresponding lesser use of flood plain areas was noted the 

 second year. 



Use of exposure ; The percentage of deer observations on flat 

 terrain was highest during summer of 198O and least in winter 

 (Table 76). South exposures received disproportionately higher 

 use than other aspects during summer of both years. 



Use of slope ; The majority of mule deer observations were made on 

 areas characterized by flat terrain or gentle slopes in all 

 seasons except winter (Table 77). A shift to terrain of medium 

 and steep slope was evident during winter. Heavy use of medium 

 slopes was also evident during the 198I spring season. 



White-tailed Deer 



Twenty-five individual white-tailed deer were observed on the study 

 area during the study period (Figure 77). These observations were 

 made primarily at the southwest boundary of the study area, in 

 deciduous and ponderosa pine habitats. 



Pronghorn Antelope 



Population characteristics ; During the study period 266 antelope 

 were observed on the Sand Creek study area (Table 78). Mean group 

 size ranged from 2.6 (summer 1980) to 17 (winter 198O-8I). Mean 

 number of observations per hour of aerial survey was substantially 

 higher during summer 1981 than in any previous season (Table 71). 

 No antelope were observed on the study area during 1980 fall surveys. 



Summer population structure is presented in Table 79. Small sample 

 size limits the use of these figures for comparative purposes. 

 Population trend surveys covering all of hunting district 7^^ between 

 1971 and 197^ indicated fawn/doe ratios between 21; 100 and 112:100 

 for this area (Wentland I98I). The 1979 survey revealed a fawn/doe 

 ratio of 55:100, following a decline during the severe winters of 

 1977-78 and 1978-79. 



Distribution: Antelope distribution during soring, summer and 

 fall of 19«0 and winter of 198O-8I is illustrated' in Figure 78. 

 Most observations occurred in sagebrush habitats of the 

 northeast portion of the study area. Sightings in the southern 

 half of the study area occurred on agricultural areas. Observations 

 during 198I were clustered in sagebrush habitats of the northern 

 half of the study area (Figure 79). 



Cover type usage ; The preponderance of antelope observations in 

 sagebrush and grassland habitats illustrates the dependence of 

 this species upon these habitats (Table 80). Agricultural types 

 (grain fields) received substantial use during the summer season. 



