Desert Cottontai 1 . Results of the 1978 lagomorph survey are pre- 

 sented in Table 6 ; the number of cottontails observed does not differ 

 significantly from the 1977 data (p > .50). 



White-Tailed Jackrabbit . Results of the 1978 lagomorph survey are 

 presented in Table 6 ; the number of jackrabbits observed was signifi- 

 cantly lower (t-test, p < .05) in 1978 than in 1977. 



Black-Tailed Prairie Dog . The large prairie dog town within the 

 mine study area (WBS Figure 25) was completely poisoned out with strich- 

 nine-baited grain during the report period. 



Mule Deer . A summary of data collected on mule deer observed during 

 the study period is presented in Table 7. Fall production ratios of 96.8 

 fawns/100 females and 66.7 fawns/100 adults were obtained in 1978; this 

 is comparable to 1977 data and is rated as "good" by MDFWP standards. 



Aerial census data are presented in Table 8. It should be emphasized 

 that the low number of deer seen during summer reflect decreased obser- 

 vability, and do not necessarily indicate a corresponding decrease in 

 actual abundance. Based on these data, it can be assumed that at some time 

 during the study period the mine study area supported at least 0.7 deer/ 

 km'^ (1.9/mi^) (soring 1973) and the proposed mining area supported at 

 least 0.7 deer/km^ (1.8 mi^) (winter 1978-79). 



Distribution in the mine study area was generally similar to 

 that observed in 1977-78; use of both the mine study area and proposed 

 mining area was heaviest in winter and spring, and coulees and badlands 

 in the northwest and southwest portions of the mine study area received 

 the heaviest use at all seasons (Figures 1-4). 



White-Tailed Deer . Only seventeen observations of white-tailed 

 deer were recorded during the report period (Table 9). In the mine study 

 area, white-tailed deer were seen only near the silver sagebrush breed- 

 ing bird census plot in the southern portion of the proposed mining area. 



Pronghorn . A summary of data collected on pronghorn observed during 

 the study period is presented in Table 10. Summer-Fall production ratios 

 range from 63.8 - 80.6 fawns/100 females and 42.5 - 49.7 fawns/100 adults. 

 This is somewhat lower than 1977 production estimates. 



Aerial census data are presented in Table 8; it can be seen that 

 pronghorn do not use the study areas in winter, as was the case in 1977. 

 Based on these data, it can be assumed that at some time during the study 

 period, the mine study area supported at least 0.8 pronghorn/km^ (2.0/mi^) 

 (fall 1978), and that the proposed mining area supported at least 1.0 prong- 

 horn/km^ (2.6/mi^) (fall 1978). 



25 



