Time and landscape context shape insular bat responses to wildfire

Abstract

Abstract Background Wildfires are increasing in frequency and severity, yet their longer-term effects on island bats remain poorly understood. We assessed temporal and landscape-dependent patterns in bat activity following the 2016 wildfires on Madeira by resurveying 58 acoustic sampling sites (33 burned, 25 unburned) approximately one month after the fires and five years later. We quantified total and species-specific activity for Pipistrellus maderensis , Nyctalus leisleri verrucosus , and Plecotus austriacus and analysed assemblage-level feeding-buzz activity in 2021. Results Fire-status effects changed between survey years for total activity, P. maderensis , and N. l. verrucosus , but not for P. austriacus . Activity declined at unburned sites for all three species. At burned sites, total activity and the activity of P. maderensis and N. l. verrucosus showed no statistically supported temporal change, whereas P. austriacus declined significantly. Consequently, total activity was approximately 6.5 times higher at burned than at unburned sites in 2021. Landscape associations were species- and fire-status-specific: agricultural area was negatively associated with activity at burned sites for total activity, P. maderensis , and N. l. verrucosus , whereas no landscape predictor was retained for P. austriacus . Feeding-buzz activity was approximately three times higher at burned sites and increased with forest and woodland area. Conclusions Bat responses to wildfire were dynamic, species-specific, and dependent on landscape context. High activity at burned sites in 2021 generally reflected persistence at burned sites alongside declines at unburned sites rather than increasing activity following fire. Post-fire management should therefore retain heterogeneous landscapes containing unburned refugia and complementary woody, edge, and open habitats.