southeastern corner of the Mine Study Area and contained 2 young on June 12. A 

 nest about 4 mi WSW of the Dreyer ranch house, which was active in 1979, was 

 unoccupied in 1980. 



Golden Eagle . The nest located in 1977 in the Proposed Mining Area fledged 

 2 young in 1980. A new nest site, located in the extreme northwestern corner of 

 the Mine Study Area, also fledged 2 young in 1980. 



Marsh Hawk . Although territorial pairs were observed in the Mine Study 

 Area, no nests were discovered. 



Prairie Falcon . The 1977 nest site contained 4 young on June 14, 1980. 



American Kestrel . No active Kestrel nests were found in 1980. 



Sharp-tailed Grouse . At least 22 male birds were displaying at lek No. 6 

 when visited in March 1980; 36 unclassified adults were seen nearby on another 

 day. Two birds were seen at lek No. 3 in April 1980, and 12 birds were seen at 

 lek No. 14 in March 1980. No activity was observed at leks No. 7 and No. 13, 

 although birds were seen on several occasions near these leks. 



Sage Grouse . Groups of 2-4 sage grouse were seen between March-May 1980 

 near: the old homestead site (area Y) ; section 9, area Z; the Waller ranch 

 house; and 2 mi NE of the Waller ranch house. No courtship activity was 

 observed, however, and no grouse were seen at lek No. 4 (DNRC 1978) when it was 

 visited in March. 



Ring-necked Pheasant . Figure 3 shows year-to-year changes in June sample 

 abundances of ring-necked pheasants as sampled in five roadside wildlife 

 surveys. Sample abundances did not differ significantly (t-test, p>.20) between 

 1979 and 1980. 



Great Horned Owl . Great horned owls seemed to be less common in 1980 than 

 in 1979. None of the previously used nest sites were active in 1980. 



Desert Cottontail . Results of the 1980 lagomorph survey are presented in 

 Table 4. As in 1979, no cottontails were observed during this survey (Figure 



White-tailed Jackrabbit . The number of jackrabbits observed during the 1980 

 lagomorph survey (Table 4) does not differ significantly from the number 

 observed in 1979 (t-test, p>,20) (Figure 4). 



Mule Deer . A summary of mule deer observations during the study period is 

 presented in Table 5. Production ratios obtained during the period 1977-1980 

 are shown in Figure 5. These were based on September-October data since summer 

 foliage limits pre-September observations of fawns and since hunting mortality 

 directly influences age structure in November populations. The 1980 production 

 ratio was 76 fawns/100 does, which is considerably lower than 1979 production. 



Aerial census data are presented in Table 6. It should be emphasized that 

 the low numbers of deer observed during the summer reflect decreased 

 observability at this season and do not necessarily indicate a corresponding 

 decrease in abundance. Since observability is highest in winter, both density 

 and distribution estimates are based on the winter aerial census. Figure 6 

 shows winter density indices obtained since 1976. Since the census data in 



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