Translocations restore a population of a threatened rock-wallaby and bolster its genetic diversity

Black-flanked rock-wallabies ( Petrogale lateralis lateralis ) exist in small and isolated populations across Western Australia, making them highly susceptible to loss of genetic diversity and increased extinction risk. Conservation translocations are frequently implemented to improve threatened species population sizes with ongoing monitoring required to assess their short- to long-term demographic and genetic success. From 2016 to 2018, 72 wallabies from two widely-separated locations (WA Wheatbelt, Cape Range NP) were translocated to Kalbarri NP. Just prior to the translocation, an extant population of rock-wallabies was discovered in the Murchison River gorge within Kalbarri NP. We used 15 microsatellite markers to investigate genetic structure amongst populations and whether genetic diversity was bolstered by introducing multiple source populations as part of the translocation process. A population viability analysis was used to model admixture within translocated populations over a 10 year period post-translocation. Twenty-five new animals were trapped during post-translocation monitoring including three indigenous to Kalbarri and four sired by Kalbarri males. Merging Wheatbelt and Cape Range wallabies, with the addition of Kalbarri individuals in the breeding pool, resulted in translocated populations showing higher genetic diversity at the end of the monitoring period (H e = 0.578—0.663, A R = 2.7—3.1) and in the simulated populations 10 years post-translocation (H e = 0.572—0.613, A R = 2.6—2.8), relative to the two main Wheatbelt source populations. Whilst parentage analysis demonstrated successful breeding between Kalbarri and Wheatbelt individuals, it is important to monitor the survival of offspring to assess sustainability of the population and possible outbreeding depression effects.