Optimization of Camera Trapping Methods for Surveying Mesopredators in the Appalachian Foothills

Indianapolis, IN

The global decline of apex predators has allowed mesopredator populations to increase, a phenomenon described by the mesopredator release hypothesis (MRH). Some mesopredator species, however, are of conservation concern, such as the eastern spotted skunk (Spilogale putorius), whose populations have noticeably declined in the past 40 years. Mesopredators generally prefer edges and corridors, landscape features that are increasingly common throughout the forests of eastern North America. To assess mesopredator habitat selection and camera deployment strategies in the Appalachian foothills, we conducted baited camera trap surveys in Kentucky, a state for which systematic methodological data is lacking. We surveyed 72 sites across 10 counties over more than 1,100 trap nights from May 2017 to February 2018, focusing on features associated with mesopredator presence. Cameras were deployed on tree trunks ca. 0.5 m off the ground facing a bait station 2-3 m away. We evaluated effects of bait type (sardines or sardines + fatty acid scent tablet) and deployment duration (2 weeks or 4 weeks) by comparing diversity indices and species accumulation curves. Habitat selection was assessed using ArcGIS data layers to determine preferred site characteristics. Additionally, bobcat presence data was used for preliminary occupancy modeling. To date, opossums (Didelphis virginiana) and raccoons (Procyon lotor) comprise over 90% of recorded mesopredator species. The results of this study will allow for targeted, more efficient camera trapping efforts throughout the Appalachian foothills region in the future.