Individual variation and seasonal shifts in the gut microbiome of a large burrowing herbivore (Lasiorhinus latifrons) across the rainfall range of its distribution

Southern hairy-nosed wombats (SHNW) are a semi-arid adapted species frequently found inhabitats of low productivity and are particularly reliant on their gut microbiome. In fact, theshort-chain fatty-acids produced by the gut microbiota of SHNW have been estimated toaccount for >60% of their daily energy requirements. Periods of drought have been associatedwith steep declines in SHNW body condition, breeding, and survival. Rainfall variability andthe frequency of drought events are predicted to increase due to climate change, likelyincreasing periods of low quality and low quantity of feed. We aimed to investigate seasonaldifferences and compare the gut microbiome of SHNW living under different rainfall zones(ranging from 178 to 395 mm annually) within their distribution. SHNW faecal samples(n=126) were collected from four different locations in South Australia across two timeperiods (summer-autumn and winter-spring). While both were significant, location (p <0.001) was found to have a larger effect on microbial composition than season (p < 0.001).The low rainfall location had significantly lower Alpha diversity than the high rainfalllocation in summer-autumn. Microbial diversity was higher in winter-spring than summer-autumn. With further research into the functions of Australian marsupial microbes, the resultsof this study will provide a basis for understanding the importance of the gut microbiome foranimals in a future under climate change.