Response of medium-sized mammals in subtropical forests following Australian ‘Black Summer’ wildfires

Climate change is predicted to increase the frequency and severity of large-scale wildfires and threaten scores of wildlife species. However, the state of understanding of how medium-sized ground-dwelling mammals, of which many are threatened, respond to such wildfires remains limited. The Australian 'Black Summer' fires were unprecedented in their extent and severity, and burned large swathes of habitat for threatened species, providing an opportunity to address this information deficit. We used camera-trapping to investigate how populations of several small, threatened macropods and other medium-sized ground-dwelling mammals in five wildfire-affected subtropical study areas responded to the 'Black Summer' fires, two years on from the event. We examined whether occupancy was influenced by fire, habitat, or landscape variables to evaluate capacity to survive severe fire events and identify populations of conservation significance. Four species of small macropod (three threatened) were restricted to different subsets of the study areas but there was no evidence this was influenced by the wildfires. The red-legged pademelon showed a negative response to fire severity whereas occupancy of the other three was not influenced by fire. Two common species groups (bandicoots and brushtail possums), and the feral cat, were widespread and also showed no difference in occupancy in fire-affected areas. Vegetation cover positively influenced the occupancy of the northern long-nosed potoroo and the red-necked pademelon, and presumably offset any fire effect 2 years after the wildfires. Our study confirms that populations of threatened and non-threatened medium-sized mammals can recover following severe wildfires and suggests that conservation of most of the threatened macropods could be focused on threats other than wildfire in reserves where they appear to be most abundant.