Summary 



We surveyed ten workings at six abandoned mine sites (Swamp Frog, Marie, Dandy, Roberts 

 Incline, CM & M, Lisbon) on the southern slope of Big Pryor Mountain in the Pryor Mountains, 

 Carbon County, Montana, for evidence of use by bats in the summer of 2001 . This aggregation 

 of mines, spread along two linear miles between 5380-6800' elevation, was "reclaimed" in 1989, 

 but reclamation involved primarily the posting of warning signs at portals and construction of 

 fence barriers around open shafts and pits. Thus, several mine workings were still accessible to 

 bats. 



We inspected and trapped at mines during three visits: 17-18 July, 24-29 July, and 4-6 

 September, 2001 . We made complete or partial internal inspections of eight workings and found 

 scattered bat droppings in seven of these. During eight nights of trapping at six portals of four 

 mines we captured 48 bats of three species: 21 Western Small-footed Myotis {Myotis 

 ciliolahnim), 15 Western Long-eared Myotis (Myotis evotis), and 12 Big Brown Bats (Eptesicus 

 fusciis). The two Myotis species are U.S. Fish and Wildlife Service species of special concern. 

 No Townsend's Big-eared Bats (Corynorhimis townsendii), another special concern species, 

 were captured or detected, although this species has been documented in winter at two of these 

 mine workings. We heard the audible calls of Spotted Bats [Euderma maculatiim), another 

 special concern species, early in the morning of 18 July, 25 July, and 29 July over the Swamp 

 Frog, Dandy, and Roberts hicline mines, respectively, but found no evidence of mine use by this 

 species. 



We recommend that the Dandy Upper West Adit #4 and the Marie, two workings with extensive 

 underground passage, be considered for bat-accessible gating. Summer bat activity was 

 significant at the Dandy working (83% of our total captures), a documented Townsend's Big- 

 eared Bat hibemaculum. The Marie site, although currently experiencing relatively little summer 

 use by bats (4% of our total captures), has the potential to become a significant site for bats if 

 protected from human intrusion. 



Ill 



