SRA

Kangaroo Island experienced extensive bushfires in December 2019 and January 2020, affecting almost half of the island. This has impacted several threatened species including the Kangaroo Island echidnas (Tachyglossus aculeatus multiaculeatus). Echidnas can often survive fires and were amongst the first animals observed foraging in the burnt areas once the fires on Kangaroo Island had subsided. However, changes in soil chemistry and food availability in the burnt areas raises questions about the impact on the gut health and foraging behaviours of echidnas. Here, we assessed the gut microbiome of Kangaroo Island echidnas before and after the fires. Metabarcoding of scat microbiota revealed substantial changes in diversity and composition of bacteria in echidna faeces post-bushfire when compared to samples collected prior to the bushfires. Before the fires, echidna gut microbiomes were more variable and contained mostly soil-associated bacteria, whereas post-fire samples shifted to more uniform bacterial communities consisting of lactic acid and gut commensal bacteria. Interestingly, changes were observed in scats collected in both burnt and unburnt areas of the island, suggesting echidnas are foraging between these areas, depending on their home ranges. This is the first study to document changes in gut microbiome of any mammal following bushfires. More work is needed to investigate if the gut bacterial communities continue to change as the areas recover from the fires and to understand the effects on animal health.