forests where snow depths are moderated. 

 Because of its body shape and energetic 

 demands, the fisher cannot easily cope with 

 deep snow conditions. Fishers will use a 

 variety of forest conditions, but often travel 

 and hunt near riparian zones and rest in snags, 

 down logs, witches-brooms, or other struc- 

 tures associated with older forests. They prey 

 on a variety of small mammals, including 

 voles, squirrels, snowshoe hares, and porcu- 

 pines. 



Fishers typically have large home ranges and 

 can be negatively affected at a population level 

 by excessive fragmentation of acceptable 

 habitat. Thus, assessing habitat features on a 

 small scale (e.g., stand level) is of limited use; 

 instead, landscape scale assessments are more 

 meaningful. This analysis will focus on the 

 project area. Mature forest with closed canopy, 

 a habitat feature usually associated with 

 fishers, is uncommon on the project area. 

 More specifically, we looked at 2 habitat 

 components that can be quantified at a land- 

 scape scale to assess current fisher habitat: 



canopy density (assumed to be a reason- 

 able surrogate for forest structure near the 

 ground) within buffers of 50 meters (ap- 

 proximately 164 feet) on either side of all 

 perennial streams within the project area, 

 as quantified by the SLI; and 

 connectivity among adjacent drainages, 

 defined again as a minimum acceptable 

 canopy density. 



The first analysis assumes that fishers prefer- 

 entially use riparian zones (and /or habitats 

 near them), and within these, prefer those with 

 substantial overstory structure. This structure 

 evidently provides for prey availability and 

 resting sites (Powell and Zielinski 1994). This 

 analysis also asks whether important riparian 

 buffers are so lacking in overhead cover that 

 they may act as barriers to fisher movement. 

 This analysis asks whether natural features 

 and /or timber harvesting have fragmented the 

 landscape to the point where the entire land- 

 scape no longer contains sufficient connectiv- 

 ity to allow for functional home ranges. 



We generated maps of buffers on all riparian 

 zones less than 6,000 feet in elevation (fishers 

 rarely hunt or rest in higher elevations), 

 excluding cover types that rarely contain 

 complex structures near the ground (Douglas- 

 fir and lodgepole pine-dominated sites). 

 Within these buffers, we identified those in 

 which stands were classified as "sawtimber" 

 (dominated by 9-inch+ dbh trees) and in 

 which stocking was characterized as "well- 

 stocked" overall, or at least "moderately 

 stocked" in the overstory component. The 

 project area consists of a number of lakes • ' 

 without outlets. Any streams that flow into 

 lakes are very short and originate from small 

 seeps. Therefore, these small, short riparian 

 areas are isolated from other fisher habitat. 

 Logging history in this landscape eliminated 

 most of the nonriparian habitats that might - 

 have served as connections. jj-jf. 



Streams in Sections 7 and 8 in the northern 

 part of the project area come closest to provid- 

 ing suitable habitat. This area is at the south- 

 ern end of Stillwater State Forest and is con- 

 nected by State land that, at one point, is only 

 one-fourth mile wide. Heavily logged private 

 and State lands and Boyle Lake isolate the 

 short segments of riparian habitat in Sections 7 

 and 8 from the rest of the main Stillwater State 

 Forest. Small stringers of timber on State land 

 are on both sides of Boyle Lake, but have open 

 canopies. The forest on the north side of the 

 lake is, generally, heavily logged. There is an 

 active railroad right-of-way between most of 

 the project area and the main Stillwater State 

 Forest. Even if a fisher managed to find its 

 way into these sections, it would find only 

 short segments of habitat that dead-ended. 

 Because of this lack of viable habitat, the fisher 

 will not be considered further. 



i ■-•/• 



LYNX (LYNX CANADENSIS) 



The lynx is currently a candidate species for 

 listing under the U.S. Endangered Species Act. 

 As of this writing (1998), it is widely expected 

 that lynx will be listed as either threatened or 

 endangered in Montana during 1999. 

 Throughout North America, lynx distribution 

 and numbers are strongly correlated with their 

 primary prey, snowshoe hares. At the lower 



Chapter III: Affected Environment 



^m-19 



