INVESTIGATING THE ECOLOGY AND BEHAVIOR OF THE INDIANA BAT AND TRI-COLORED BAT DURING FALL SWARMING AND SPRING STAGING

White-nose syndrome has devastated bat populations across North America since 2005. Due to declines in Indiana bat (Myotis sodalis) and tri-colored bat (Perimyotis subflavus) populations across the eastern United States, management prescriptions need to consider all seasons of these species annual cycles. However, data is severely lacking on the two seasons surrounding winter hibernation. These include fall swarming, a time period when bats are mating and preparing for hibernation, and spring staging, when bats are emerging from hibernation and preparing for spring migration. Both periods are critical for successful reproduction and survival following white-nose syndrome infection.

To investigate the timing of these two periods, I used Passive Integrated Transponders to detect bat activity at the entrances of caves from 2016–2019. We detected peak Indiana bat activity during fall swarming from September 10–October 2 and during spring staging from March 26–May 13^th. For tri-colored bats, we detected increased activity from August 20– September 30 and February 19–April 22.

To understand roosting behavior and ecology of both species, we tracked bats to their diurnal roosts during fall swarming. We tracked 15 Indiana bats and 18 tri-colored bats from 2016–2019. For tri-colored bats, we were able to assess roost selection using AIC_c. Tri-colored bats selected roosts with less clutter and high solar exposure that were closer to caves. Due to small sample size, we were unable to assess selection for Indiana bat roosts. Indiana bats roosted in caves more often than in trees, and roosts were snags that were 108 ± 64.80 m (from caves.

The results from this thesis can be used to determine more efficient and timely management prescriptions and restrictions near caves during fall swarming and spring staging. Further monitoring and research should investigate roosting ecology and behavior during spring staging, foraging ecology during both time periods, and the true sensitivity of bats to management activities during these critical times.