62 of 120 adults captured in mist nets (52%) . Lactating M. 

 lucifugns, M. californicus, M. ciliolabrum, and M. evotis were 

 captured during the study between 15 July and 1 September. 

 Lactating females represented 7 percent of the total bats captured, 

 and 13 percent of adult female bats captured. During the study, 24 

 percent of adult female bats captured were classified as either 

 lactating (n=8), gravid (n=6), or postpartum (n=l) . The observed 

 low fecundity is likely due to the cold and wet weather experienced 

 during the study. 



Information needs for the effective management of bat populations 

 include knowledge of distribution, population status, and habitat 

 requirements. Echolocation monitoring and mist-netting can 

 provide much-needed information that is the first step towards 

 protecting bat habitat . 



INTRODUCTION 



Little is known regarding the distribution and abundance of bats 

 in the forests of northwestern Montana. Nine species have been 

 recorded in northwestern Montana (northwest of 47° latitude and 

 114° longitude) (Thortpson 1982 )i including the western big-eared 

 bat (Plecotus townsendii) which is listed as a species of special 

 concern by the Montana Natural Heritage Program (Center 1993) and 

 Montana Department of Fish, Wildlife, and Parks (Flath 1984) . 

 P. townsendii is also pending candidate status (C2) for possible 

 protection under the Endangered Species Act, and a sensitive 

 species for Regions 1, 3, and 4 of the USDA Forest Service (Finch 

 1992) . 



Bats may be sensitive to environmental modifications such as even 

 age stand management, changes in the age-structure of forests, and 

 changes in snag abundance (Thomas and West 1989). In order to 

 assess the potential adverse effects of current and future land 

 management practices on bat populations, a general survey of bat 

 populations is needed. The scope of this study is to collect 

 information on species composition, relative abundance, and 

 activity patterns found in the forests of northwestern Montana. 

 It is hoped that this study will provide land managers with 

 reliable information with which to conduct future bat monitoring, 

 and better assess the effects of land management activities. 



^ Myotzis californicus, M. ciliolabrum. M. lucifugus, M. yumamensis , M. volans, 

 M. evotis, Plecocus townsendii, Lasionycteris noctivigans, and Eptesicus 

 fuscus . 



