Bare-nosed wombats are considered a widespread species of minimal conservation concern, despite having experienced significant range reductions and being impacted by widespread threats including: extreme range fragmentation, vehicle collisions, conflict with landholders, and sarcoptic mange disease. These threats can function individually or in combination, and anecdotal and empirical evidence strongly indicates they can be responsible for significant local declines. However, baseline information about the species’ genetic diversity is lacking, and subsequently, little is known about the species’ genetic resilience (or susceptibility) to deterministic and stochastic threats. The major aims of this research are, (1) to fill critical ecological, biological, and evolutionary knowledge gaps regarding the genetic structure and diversity of the bare-nosed wombat, (2) to resolve phylogenetic relationships among wombat populations from mainland Australia, across Bass Strait (Flinders Island), Tasmania, and Maria Island, to guide regional conservation priorities, and, (3) to reveal historical demographic changes and identify populations that are at-risk (i.e. populations that lack genetic diversity or have experienced a recent genetic bottleneck). These questions were addressed through genotyping by sequencing using diversity array technologies (Diversity Arrays Technology Pty Ltd, DArT), for 170 bare-nosed wombat samples from mainland Australia, Tasmania, and Tasmanian islands.
Results/Conclusions
Results reveal the presence of three genetically distinct populations, one from each of the geographically isolated sampling regions: mainland Australia, Flinder’s Island, and Tasmania. The Flinder’s island population was more genetically similar to the mainland population than to the Tasmanian population, reinforcing the theory that fauna migrated between Flinder’s Island and the southeast Australian mainland via the Bassian Plain, prior to being isolated by the formation of the Bass Strait around 14 kya. Low genetic diversity was observed in the Tasmanian population and may be indicative of a historical bottleneck; however, this requires further investigation. To maintain genetic diversity and promote preservation of this species, we suggest monitoring and managing each genetically important population, individually.