RESULTS 



Species composition and relative abundance 



A total of 123 bats representing eight species were captured in 

 the study area during 1993 (Table 2) . Two species - Plecotus 

 townsendii and Lasiurus cinereus - are represented by only one 

 capture during the study, at Flat Creek on the Superior Ranger 

 District. Myotis lucifugus comprised 48 percent (n=59) of all 

 captures. Most captures of M. lucifugus occurred at Lower Fortine 

 Creek (n=3 5) and Sunday Creek (n=9) . At the remainder of the 

 capture sites, M. lucifugus comprised only 20 percent of bats 

 captured. Bats of the genus Myotis were captured most frequently, 

 conprising 91 percent (n=112) of total captures. After M. 

 lucifugus, other species of the genus Myotis captured include M. 

 californicus (15%), M. evotis (13%), M. volans (8%), and W. 

 ciliolahrum (7%) . Lasionyctereris noctivigans comprised 7 percent 

 (n=9) of all captures, being the most common non-Myotis bat 

 encountered. Plecotus townsendii and Lasiurus cinereus each 

 comprised less than one percent of the total capture. 



Relative bat abundance as expressed by bat passes per hour varied 

 greatly between sites monitored during the study (Table 3). High 

 levels of bat activity were found at Caxvtp 32 (74 passes/hr.). 

 Upper Fortine Creek (72 passes/hr.), and Trout Creek (60 

 passes/hr.). Sites demonstrating the most foraging activity as 

 measured by feeding buzzes per hour were Camp 32 (n=29). Big Creek 

 (n=14) and Bull Lake (n=13) . The mean index of bat activity at 

 the 24 transect locations was 33.5 ± 8.9 passes per hour and 6.3 ± 

 2.7 feeding buzzes per hour (a=0.025). 



Capture success 



Bats were captured at 24 of 3 3 locations visited during the study 

 (73%) . Attempts to capture bats were made on 54 nights, of which 

 33 attempts resulted in one capture or more (61%) . Bats were not 

 captured on 21 sanpling nights at 18 locations (Table 4) . A 

 higher number of species were captured at Flat Creek and Bear 

 Creek (n=4) than at other sites, although sampling effort was 

 greater at Bear Creek. Ten sites yielded three species or more - 

 Flat Creek (4), Bear Creek (4), Rock Creek (3), Ross Creek Cedars 

 (3), Timber lane Campground (3), Lower Fortine Creek (3), Sylvan 

 Lake (3), Weigle Creek (3), Big Creek (3), and Young Creek (3). 

 Other sites yielded two species (n=7), one species (n=7), or none 

 (n=9) . See Table 2 for summary figures. 



