Effects of white-nose syndrome on the bats of Acadia National Park: A comparison of mist-net capture results pre-WNS and post-WNS

Divoll, Timothy

From the executive summary: "White-nose syndrome (WNS) was detected at Acadia National Park (ANP) in the winter of 2011-12 in one bat species: the little brown bat (Myotis lucifugus). Several individuals were either found dead or observed exhibiting odd behaviors such as daytime flight. This is suggestive of a nearby hibernaculum infected with the fungus that has caused mass mortalities in this and other cave roosting bat species. To assess the potential impact of WNS on Acadia's bat population, we compared capture rates and ease of capture for each species using data before WNS was detected in the park compared to after detection. Based on summer capture results scaled for effort three seasons before and one season after apparent infection with WNS in one species, no major declines in the summer population were noticed. We did, however, notice an increase in abundance and ease of capture of red bats (Lasiurus borealis). This is consistent with patterns observed in other WNS impacted areas. The current explanation for this is that, because this species does not hibernate in caves, they are less susceptible to WNS, and thrive on increased available prey. Effectively, they fill the ecological void left by mass mortalities of Myotis species. We recommend continued mist-netting in an effort to recapture individuals banded before WNS at ANP and monitor population trends. Of most importance is locating maternity roosting sites and winter hibernacula sites of all Myotis species present: little brown (M. lucifugus), northern long-eared (M. septentrionalis), and eastern small-footed (M. leibii). Protection of critical habitat is essential in maintaining viable bat populations and a fully-functional ecosystem at ANP."