Keywords:Corynorhinus townsendii, Little Brown Myotis, Long-eared Myotis, Minnetonka Cave, Myotis ciliolabrum, Myotis evotis, Myotis lucifugus, Myotis sp, Townsend’s big-eared bat, Western Small-footed Myotis
Idaho Department of Fish and Game biologists and U. S. Forest Service biologists surveyed Minnetonka Cave for hibernating bats on 2 February 2016. We counted a total of 888 bats within the cave system: Townsend's big-eared bat (84), western small-footed myotis (1), long-eared myotis (2), little brown myotis (1), and an estimated 800 were Myotis sp. There has been an increasing trend in the number of Townsend's big-eared bats counted in the cave [76 (2014), 60 (2012), 58 (2010), 49 (2007), 44 (2004), and 25 (1996)] since consistent mid-winter surveys began. When possible, every attempt was made to identify Myotis to species; however, the distance from which the bats were observable made such identification extremely difficult. We did note that in certain clusters of Myotis species, some of the bats had a distinct difference in color of the pelage: some were a rich chocolate brown, potentially indicating the presence of long-legged myotis (Myotis volans), which are known to have richer coloration when compared to little brown myotis (Myotis lucifugus) and Yuma myotis (Myotis yumanensis). No bats were observed to exhibit signs of white-nose syndrome (WNS). We observed decomposed bat carcasses. Decomposition was so advanced that bones were visible and species identification was impossible. There did not appear to be any fungus visible that would indicate WNS infection; fungus was bright green and globular, not fuzzy. We measured air temperature and humidity where bats were present (Table 2) and deployed 3 HOBO temperature and humidity dataloggers. Invertebrate samples and 3 bat carcasses were collected for identification. We took precautions to prevent possible contamination and spread of white nose syndrome by following U.S. Fish and Wildlife Service WNS protocols.