INVESTIGATING HABITAT, TIES TO AQUATIC FOOD WEBS, AND ECOTOXICOLOGICAL THREATS TO COMMON AND DECLINING BAT SPECIES

Bats face many threats globally including habitat loss, emerging wildlife diseases and pollution. In North America (NA), insectivorous bat species are in decline due to white-nose syndrome (WNS). Herein, we investigate current and emerging threats to NA bats. First, we fill knowledge gaps in habitat requirements of the tricolored bat (Perimyotis subflavus), a once common but now declining bat species. We found that females forage in open areas (i.e., edges and grasslands), riparian zones and around the fingers of lakes, and over open water of rivers and lakes. Second, it investigates the role of ecotoxicological threats to insectivorous bats. To increase understanding of bat trophic ecology, we evaluated aquatic and terrestrial insect, and spider consumption using genetic analyses to identify prey items. Next, we conducted a literature review to investigate the role of contaminants in WNS-associated declines of northern long-eared bat (Myotis septentrionalis), little brown bat (M. lucifugus), tricolored bat, and Indiana bat (Myotis sodalis). The last two chapters investigated exposure to two contaminants with potential to adversely affect bat health. We found that mercury exposure was greater in a high-susceptibility to WNS group of species compared to a low susceptibility group and 14% of tricolored bats exhibited neurotoxic levels of exposure. We determined that NA insectivorous bats are exposed to microplastics, a contaminant of emerging concern, and that increased microplastic concentrations are significantly related to reduced bat mass. Maintenance of body mass is crucial for migratory, reproductive, hibernation, and disease-surviving processes. Overall, attention should be given to the issue of pollution as a threat to bats, understanding the aquatic-terrestrial linkages of contaminant exposure, and the species traits that contribute to increased exposure risk. Future research should address restoration and remediation practices to mitigate effects of environmental contaminant exposure and prey reduction to bats.