Frogs, fires, floods and fungi

Presented by Eli Bieri

PhD Candidate, University of NSW

Supervisors: Dr Jodi Rowley (AM, UNSW)

Extreme weather events, including droughts, fires, storms, and floods, are intensifying and impacting ecosystems with unknown effects. The main drivers of population decline in Australian frogs have been identified as climate change and disease. The broad impacts of these extreme events on disease-affected frog species remain unclear, however. Using a Before-After-Control-Impact (BACI) design and citizen science data from the FrogID platform, we assessed the effects of severe wildfires and floods in New South Wales on species richness and distribution changes. We found a significant decline in species richness in flood-affected areas but not in fire-affected areas.

Additionally, to evaluate wildfire effects on amphibian chytrid fungus prevalence and infection intensity, we conducted capture-mark-recapture and disease surveys of Northern Stuttering Frogs (Mixophyes balbus) at burnt and unburnt sites. Our results support a thermal refuge hypothesis, suggesting that warmer microhabitats created by fire may provide disease refugia for frogs impacted by a fungal pathogen.