Remnant wild kenngoor (Marsupialia: Dasyuridae: Phascogale calura) populations retain genetic connectivity and genetic diversity in a highly fragmented landscape

Abstract

Kenngoor (Phascogale calura) persist in < 1% of their original distribution, occupying highly fragmented remnant habitat in south-west Western Australia, with very little known of the genetic health of remaining wild populations. Recently, the species has been translocated to managed reserves to improve its conservation. Understanding genetic structure and patterns of genetic diversity is crucial to inform conservation translocations for species recovery. This study aims to 1) assess genetic structure and genetic diversity across remaining wild populations, 2) assess long-term genetic outcomes of a mixed-source wild-to-wild translocation, and 3) estimate global effective population size. We sequenced 209 samples from 13 fragmented wild populations were sequenced using reduced representation sequencing. An isolation by distance model best explained genetic structure across the wild populations, with evidence of fine scale divergence of two northern populations. Allelic richness and autosomal heterozygosity measures indicated that diversity is spread uniformly across populations, and no populations showed signs of inbreeding or strong genetic drift. The mixed-source translocation has retained the diversity of the wider species ten years post-translocation. Overall, our results suggest that connectivity between wild populations has largely been maintained and that no population is in poorer genetic health, despite the highly fragmented nature of remnant kenngoor habitat. Future translocations should aim to represent a mixture of genetically divergent populations to maintain the diversity present at the species level. Ongoing conservation management will be required to ensure the long-term viability of the species in this fragmented landscape.