Conservation Genomics of the Southern Emu-Wren in Mt Lofty Ranges

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RESEARCH AREA
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This week’s feature research article has just been published in Austral Ornithology by Flinders University, Conservation Council SA and SA Museum staff and examines the conservation genomics of an endangered subspecies of Southern Emu-Wren in the Mt Lofty Ranges. The endangered subspecies of Southern Emu-Wren (Stipiturus malachurus intermedius) in the Mount Lofty Ranges (MLR), South Australia has a fragmented distribution and poor dispersal capability. These factors make it susceptible to local population extinction, as evidenced by declining distribution and abundance since 1993. The researchers documented genetic diversity by genotyping thousands of nuclear markers from samples collected in the 1990s to inform genetic management. They found that Southern Emu-Wrens from south-eastern South Australia and the MLR, which are separate subspecies that share mitochondrial haplotypes, are genetically distinct based on nuclear DNA, albeit at a low level (FST = 0.21). Within the MLR, differentiation between southern and northern sites is consistent with the presence of two populations, with the boundary reflecting a disjunction in the distribution of historical records. Although Southern Emu-Wrens are now absent from our MLR sample sites, nearby occupied sites within each of the populations require continued management, and the results suggest these may warrant treatment as separate management units. At one site where birds had disappeared over an 8-year period, the retrospective genotyping found low levels of inbreeding, reinforcing the need to distinguish factors impacting on population viability to mitigate extinction likelihood. The researchers recommend the translocation of individuals from SESA for the continued survival of Southern Emu-Wrens in the MLR; however, it is prudent first to identify and manage the most important factors impacting on population growth which might otherwise affect survival of any introduced individuals. The paper can be downloaded here (or email jennie.fluin@sa.gov.au for a copy).