After the Megafires: Effects of Fire Severity on Reptile Species Richness and Occupancy in South-Eastern Australia

Abstract

The Australian megafires of 2019–2020 were considered catastrophic for flora and fauna, yet little is known about their impacts on reptiles. We investigated the impacts of the 2019–2020 megafires on reptiles in Morton National Park, New South Wales, in eastern Australia. To understand how fire severity affects reptile species richness and occupancy, we surveyed 28 replicate plots across unburnt areas and areas affected by high and low fire severity. We estimated reptile species richness and occupancy by performing systematic searches for reptiles during five sampling occasions in 2023, three years after the megafires. We measured vegetation structure and quantified the thermal environment in shelter sites used by reptiles. Vegetation structure varied significantly between burn severity groups. High-severity plots had the least canopy cover and the thinnest leaf litter depth but had a taller understorey with more stems. The thermal quality within reptile retreat sites did not differ between fire severity classes. Despite strong differences in post-fire vegetation structure, there was no evidence that fire severity affected reptile species richness or occupancy of the delicate skink, Lampropholis delicata. These results highlight the complexity of reptile responses to fires and contribute to increasing our understanding of the impacts of megafires on reptile communities.

Keywords

• megafire
• high severity
• community structure
• thermal regimes