B ighorn Sheep 



Eastern Segment 



A small bighorn sheep herd is found in the eastern end of 

 the study area and completely within the Charles M. Russell Wild- 

 life Range. This small bighorn population has remained rela- 

 tively stable during the study period, as the ewe population has 

 varied between 8 and 11 and the rams have dropped from 2 to 1 

 (1 winter-killed in the 1977-78 winter) . Reproduction rates are 

 high, as numerous lambs have been observed each summer; however, 

 few lambs survive their first year. Only one lamb was recruited 

 in 1977, one or two lambs in 1978 and two lambs in 1979. All 

 lambs recruited were ewes. This bighorn population has not 

 changed much since the major die-off during the winter of 

 1971-72 when the population dropped from at least 90 to 23. It 

 is apparent that this sheep herd is barely holding on, and addi- 

 tional research should be done to pin-point the causes preventing 

 a population increase. 



Observations during the 4-year study (Constan 1976, 77, 78 

 and Appendix Table 4) show that these bighorns spend most of the 

 year within approximately 3 square miles, N^ S 30, NJj S 29, N's 

 S 28, S 20, SJj S 19, T22N, R23E. During a severe winter, these 

 bighorns use only about 1 square mile of range, Figure 18, and 

 not much more during an average winter. This bighorn habitat is 

 being affected by several factors: (1) the rough breaks that 

 comprise the bighorns' range appears to have a minimum quantity 

 of vegetation, (2) the area used by the bighorns is quite small 

 in size, (3) there is substantial competition between livestock 

 and bighorns, and (4) elk are beginning to winter on the bighorn 

 winter range, and elk will compete directly with bighorns (Con- 

 stan 1972) . 



The Charles M. Russell National Wildlife Range is responsible 

 for the management of these bighorns. Their management plans 

 should include directives that will eliminate livestock grazing 

 on bighorn range and closely monitor elk use on the bighorn 

 winter range to protect the bighorns from excessive elk-bighorn 

 competition . 



Elk 



Eastern Segment 



Throughout the 4-year study, only a few elk have been ob- 

 served within the study area. These observations have been re- 

 stricted to the extreme eastern end of the study area, and all 

 observations were made within the Charles M. Russell National 

 Wildlife Range (Constan 1976, 77, 78 and Appendix Table 5). 



39 



