Larger trees may support larger Indiana bat maternity colonies in a dynamic landscape

Indiana bats (Myotis sodalis), federally listed as endangered, are of management concern in eastern North America. While researchers quantified the habitat affinities of the species throughout the range, few studies have occurred in regions where populations are at high risk for wind energy development and changing climes. Central Illinois, USA, is a dynamic landscape where forest area has been increasing in recent decades (on public and private land) because of changing farming practices and increased habitat protections. The increasing availability of large diameter trees, increasing forest biomass, and changing forest compositions have the potential to influence Indiana bat roost habitat preferences. We assessed Indiana bat maternity roost selection at the tree and forest plot scale to characterize patterns of use in this region from 2017–2018. We predicted that large trees on the landscape would support large colonies of Indiana bats. We located bats in multiple species of trees including elm (Ulmus spp.), cottonwood (Populus deltoides), and shagbark hickory (Carya ovata). We documented larger maternity colonies sharing roosts than in previous studies from the 1980s in the same region. We suggest managers and regulatory agencies monitor Indiana bats in dynamic landscapes such as those with changing forest composition and biomass.