using US Geological Service (USGS) topographic maps and ground 

 searches. Caves and mines were located using USGS maps and 

 "Caves of Montana" (Cambell, 1978). Bats were captured at water 

 sources and caves using one or more 1 1/2 " mesh mist nets 5.5 or 

 9 m long. Since bats may become more effective in avoiding nets 

 on subsequent nights of trapping (Kunz, 1973; Laval, 1970; Kunz 

 and Kurta, 1988) , net configurations and positions were altered 

 from night to night, and an attempt was made to avoid netting at 

 the same site on two or more successive nights. Mist nets were 

 deployed shortly after sunset when bat activity commenced, and 

 were either dismantled three to four hours later or left deployed 

 through the night until dawn. 



All captured bats were identified to species, and sex and 

 reproductive condition was assessed via visual examination and 

 manual palpation (Racey, 1988) . Age was determined via visual 

 examination of epiphyseal-diaphyseal fusion of wing bones. Body 

 mass was determined by placing bats in a small plastic bag and 

 weighing them using a 50 gm Pesola scale. Forearm length was 

 measured using dial calipers. Capture time and weather 

 conditions were recorded. Except for those bats captured during 

 the first three weeks of the study, bats were marked using color 

 and number coded split-plastic wingbands (Barclay and Bell, 1988) 

 to facilitate identification upon recapture. 



RESULTS 



Seven caves and ten water sources were investigated for bat 

 activity. Bats were captured on 40 nights at 10 of 13 locations 

 that were netted, between 15 June and 10 September 1989. A total 

 of 316 bats were captured representing eight species (Table 3) . 

 Only one marked bat was recaptured. 



TABLE 3. — All Bat Captures, 1989 



Species 



Males Females Unknown Total 



Myotis lucifugus 91 



Myotis ciliolabrum 23 



Myotis volans 54 



Myotis evotis 37 



Lasiurus cinereus 11 



Eptesicus fuscus 26 

 Lasionycteris noctivaqans 2 



Antrozous pallidus 2 



Total 



246 



9 

 18 



1 



21 



7 



7 



69 



100 

 41 

 55 

 58 

 19 

 33 



8 



316 



Few bats were caught in nets at water sources. The greatest 

 number of bats taken in any one night of netting at a water 



