Invasive Predator Management Can Mitigate the Impacts of Fire and Low Rainfall for Some Herpetofauna

Effective wildlife conservation relies on understanding how threats and associated management actions can interact to affect biodiversity. However, the impacts of concurrent disturbances on wildlife can be complex and difficult to predict. Altered fire regimes, invasive predators, and reduced rainfall are major threats to herpetofauna, but no research has investigated their interactive effects on any reptile or amphibian species to date. We undertook a natural experiment employing a control-impact design in southern Australia to examine the combined and independent effects of prescribed fire, invasive red fox (Vulpes vulpes) management and low rainfall on reptile and amphibian richness and abundance. We found negative effects of prescribed fire on reptile species richness and the capture rates of four (out of five) herpetofauna species. Fox management had a positive effect on three skink species and a negative effect on the fourth. Our results demonstrate important interactions for some species. For example, low rainfall exacerbated the negative effects of prescribed fire for two species, while fox management mitigated the negative effects of prescribed fire and low rainfall for two species. This is the first study investigating the interactive effects of these three key threats on herpetofauna. Our discoveries demonstrate that investigating interactive effects can help explain why species have spatially and temporally variable responses to disturbances. Our results suggest that it may be beneficial to avoid prescribed fires and increase invasive predator management during climatically stressful periods.