I. MOUNTAIN LION 



1) Introduction 



Mountain lions probably utilized the majority of the impact 

 area prior to construction of Libby Dam and inundation of the pool 

 area. Large concentrations of big game animals present within the 

 area, particularly during winter, provided an abundant food supply 

 for this species. Many reports noted the presence of mountain lion 

 sign on the winter ranges; however, due to the lack of information, 

 no estimate of the mountain lion population inhabiting the impact 

 area prior to project construction was developed. Mountain lions 

 are currently ranked eleventh in the priority listing for management 

 within Region Oie (northwestern Montana) Montana Department of 

 Fish, Wildlife and Parks. 



2) Seasonal Habitat Preference 



Mountain lions are known to occur in a wide variety of bottom- 

 land and upland habitats in the North Fork of the Flathead River 

 drainage (Key 1979), approximately 45 miles east of the Kootenai 

 River valley. Hornocker (1983, pers. commun.) noted use of river- 

 bottom habitats in northwestern Montana, as well as upland mixed 

 coniferous forests in the South fork of the Flathead River drainage 

 (Hornocker and Hash 1981). Brown (1983, pers. commun.) has observed 

 relatively extensive use of the dense conifer bottoms (redcedar, 

 western hemlock ancVor spruce) by mountain lions in the Libby area. 

 Big game winter ranges were probably important winter habitat for 

 lions as well, since deer and elk are preferred prey (Hornocker 

 1970). Brown (1979) observed a mature bighorn ram that was killed 

 by a mountain lion on the Ural-Tweed winter range. Hoffman and 

 Pattie (1968) noted mountain lion distribution and abundance in 

 Montana is closely tied to deer populations. 



3) Population Status 



No population data were available for the mountain lion popu- 

 lation within the Kootenai River valley. It was assumed the lions 

 were distributed throughout the area of concern, and utilized the 

 abundant big game populations as a prey base. 



4) Assessment of Impacts 



Loss of habitat capable of sustaining a prey base (white- 

 tailed deer, mule deer, elk, and bighorn sheep) for mountain lions 

 is likely to have had a detrimental impact on the lion population 

 Ln the area of concern (M. Hornocker 1984, pers. commun.). It was 

 assumed a reduction in the prey base resulted in the loss and/or 

 redistribution of the mountain lion territories within the impact 

 area, resulting in the loss of a number of mountain lions. Loss of 

 the dense conifer bottomlands also negatively impacted the resident 

 mountain lion population. 



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