Room (Figure 1, Table 1) in clusters of up to 30 bats and lesser numbers of solitary individuals. 

 Between 8.3-9.2% occupied the Music Room, with the remainder in the Gnome Home Room 

 area, C Passage, and Big Room. This pattern of occupancy within Azure Cave has been 

 consistent for all previous surveys (Chester et al. 1979, Butts 1993, Hendricks and Genter 1997). 



Few bats were identified to species level during hibernation counts. During 1 8 April 

 1998, at least 3 of 6 bats in the Big Room were Eptesicus fuscus, and on 12 November 1998, 6 

 Corynorhinus townsendii were identified in this same room. By far, however, the vast majority 

 (>99%) of individuals were species of Myotis. Pelage color and size (although variable within 

 some species) indicated more than one species was present. Three skulls examined (two from 

 1997 and one from 1998) belonged to M. lucifugus (1) and M. volans (2). One M. volans was 

 found in the Lunch Room, the other beyond the Gnome Home Room. The single M. lucifugus 

 skull was found in a passage beyond the Gnome Home Room. Chester et al. (1979) collected 

 two M. lucifugus (1 male, 1 female) and two M. volans (1 male, 1 female) from within the cave 

 in April 1978. These specimens are now housed in the non-game collection of the Montana 

 Department of Fish, Wildlife & Parks in Bozeman (accession numbers NG-607 to NG-610). 

 Butts (1993) collected three M. lucifugus (1 male, 2 females), one M. volans (female), and one 

 Corynorhinus townsendii (female) from within the cave in March 1993. Location of these 

 specimens, purportedly deposited in the University of Montana Vertebrate Museum, is not 

 currently known. 



Mist-net Trapping — Four nights of netting at the mouth of Azure Cave (7-8 October 1997, 16- 

 17 September 1998) resulted in the capture of 165 individuals of six bat species. During the 

 October session, 15 individuals of 3 species were netted: 1 Corynorhinus townsendii, 13 

 Eptesicus fuscus, and 1 Myotis lucifugus. Mean ambient temperature during the two nights of 

 netting was 42°F (6.5°C) and 34.5°F (1.5°C), respectively. In September, 150 individuals of six 

 bat species were captured: 2 C. townsendii, 49 E. fuscus, 82 M. lucifugus, 10 M. volans, 4 M. 

 evotis, 3 M. ciliolabrum. The proportions of bat species in the samples varied significantly (G = 

 6.932, df = 2, P < 0.05) during the two nights in September. M. lucifugus and E. fuscus 

 comprised 42.3% and 38.8%, respectively, of the catch on the first night (n = 67 bats), and 63.9% 

 and 27.7%, respectively, of the catch on the second night (n = 83 bats). Mean ambient 

 temperature during the two nights of netting was 74°F (23.5°C) and 70.5°F (21.5°C), 

 respectively. 



A total of 218 individual bats of six species (all of the species netted during September 

 1998) have been captured at Azure Cave, of which 217 were identifiable to species (Table 2). All 

 six species have been documented at the cave on more than one occasion. The mouth of Azure 

 Cave has been netted in June, July, August, September, and October. Spring emergence and 

 autumn swarming periods provided the largest captures/net hour (Figure 3). Netting in July, 

 when maternity roosts typically are active, produced the fewest captures, supporting the pattern 

 of cave occupancy determined from internal counts. The internal counts and external trapping 

 indicate that Azure Cave is used primarily as a hibernaculum, less so as a summer night and day 

 roost, and probably not at all as a maternity roost. 



Sex ratio of captured bats favored males (80.3% of 218 individuals) in samples from 

 Azure Cave (Table 2), a pattern typical for caves and mines in this region (e.g., Schowalter 1980, 

 Bogan et al. 1996, Choate and Anderson 1997). Males were significantly more abundant (Table 

 2) in samples of the three most common bat species: Myotis lucifugus (86.9% of 107 

 individuals), Eptesicus fuscus (81.3% of 80 individuals), M. volans (78.6% of 14 individuals). 



