The author was surprised by the lack of movement of bats between 

 caves. While Mystery Cave and Little Ice Cave are approximately 

 3 km apart, no bats were found to move between these two roosting 

 sites, either during 1990 or between 1989 and 1990. It therefore 

 appears that in this study, bats maintain seasonally distinct 

 roosts. It is not certain that this separation is maintained 

 year round. However, since bats captured at one cave in 1989 

 were not found at the other in 1990, it is possible that the 

 populations at each of these caves may be reproductively 

 isolated. Further investigation with banded individuals is 

 necessary to address this possibility. Species composition 

 varied from cave to cave. At both Mystery Cave and Little-ice 

 Cave, the little-brown bat was the most common species 

 encountered, accounting for over 50% of captured bats. At Royce 

 Cave, the little-brown bat accounted for only 2% of captured 

 bats, while the long-eared myotis accounted for nearly 80%. At 

 both Royce Cave and Four-eared Bat Cave, numbers of bats captured 

 were low compared to Mystery Cave and Little Ice Cave, but these 

 were the two sites where the Townsend's big-eared bat was most 

 frequently encountered. The differences in species composition 

 could be due to differences between the caves (e.g. size, 

 structure, temperature, or humidity) , by the habitat in which a 

 cave occurs, or by a combination of these factors. Thus while 

 Mystery cave was most productive in terms of numbers of bats 

 captured, followed by Little Ice Cave, the conservation of bats 

 in all of the caves investigated in this study may be important 

 in maintaining a diversity of bat species in the Pryor Mountains. 



The caves investigated in this study do not represent all of 

 those in the Pryor Mountain area. Frogg ' s Fault Cave, for 

 example, is very extensive, but is vertical in nature and 

 requires technical equipment to enter. Several caves in the 

 western portion of the area were not investigated, and may 

 represent important bat habitat. 



While not entirely complete in its inventory of potential cave 

 habitat in the Pryor Mountains, this study does indicate that the 

 area is inhabited by a bat fauna of significant diversity (10 of 

 the 14 species known to occur in Montana are represented) and 

 suggests that cave management in the Pryor Mountains could have a 

 significant impact on these species. Conservation of these caves 

 is likely to be extremely important in maintaining both the 

 numbers and species diversity of bats in the Pryor Mountains. 



20 



