Acoustic monitoring for bats at Indiana Dunes National Park: Data summary report for 2016–2019

Abstract

The Great Lakes Inventory and Monitoring Network initiated an acoustic monitoring program for bats in 2015. At Indiana Dunes National Park, monitoring began in 2016. This report presents results for the 2016–2019 surveys. Acoustic recordings were analyzed using the software program Kaleidoscope Pro and a subset of files were manually reviewed to confirm species identifications. Seven of the eight bat species previously documented at the park were reconfirmed. These include big brown bat, eastern red bat, hoary bat, silver-haired bat, evening bat, little brown bat, and tricolored bat. In addition, the Kaleidoscope software classified some acoustic files to northern long-eared bat and Indiana bat, however none of these recordings were verified through manual vetting. Activity levels for six of the nine species (big brown bat, hoary bat, silver-haired bat, evening bat, northern long-eared bat, and Indiana bat) appeared to be stable or slightly increasing. For northern long-eared and Indiana bats, observed activity levels were very low in all four years, so we may not have adequate data to assess trends for those species. The remaining three species (eastern red bat, little brown bat, and tricolored bat) showed slightly decreasing trends.