INTRODUCTION 



Bats rank behind only rodents and carnivores in mammalian diversity over much of western 

 North America; this is also true for the Pacific Northwest. Ten species of insectivorous bat are 

 Icnown to occur in northwestern Montana, with the possibiUty that two additional species will be 

 found in the region following further survey effort. Bats often occur in forested landscapes like 

 those covering much of northwestern Montana, but the significance of forest structure for bats is 

 only now being clarified (e.g., Christy and West 1993, Gellman and Zielinski 1996, Mattson et 

 al. 1996, Perkins and Cross 1988, Thomas 1988, Thomas and West 1991, Wunder and Carey 

 1996). Because timber harvest practices alter the landscape mosaic, effective management of 

 bats requires knowledge of their habitat requirements. Thus, there exists a need for more 

 information on the distribution and abundance of bats in western Montana, especially in forested 

 landscapes. Forest managers must also direct attention to the bat fauna because Corynorhinus 

 (-Plecotus) townsendii, a species present in much of the region, is on the U. S. Forest Service 

 Sensitive Species list and, as such, has special legal status. 



In the summers of 1994 and 1995 a survey of bats occurring on the Kootenai National Forest 

 in Flathead, Lincoln, and Sanders counties, Montana was conducted by the Montana Natural 

 Heritage Program, expanding on preliminary efforts in 1993 (Roemer 1994) to determine species 

 presence and distribution on the different forest Districts. The field work in 1994-1995 differed 

 fi-om the 1993 study by emphasizing the use of ultrasoimd detectors. Their use permitted a more 

 rigorous sampling of bat activity in a variety of forested habitats. Of special interest was bat 

 presence in forest stands of different structure. The current report presents the results of the 1995 

 field season, with the 1994 results (Hendricks et al. 1995) subsumed herein. The survey includes 

 data published previously, and should form the basis for fiuther inventory and monitoring efforts. 



