Geographic hot spots of dingo genetic ancestry in southeastern Australia despite hybridisation with domestic dogs

Hybridisation resulting from human-driven shifts in species ranges is a global conservation concern. In Australia, hybridisation between dingoes (Canis dingo) and domestic dogs (Canis familiaris) has been identified as an extinction threat to the dingo, and is thought to be particularly widespread in south-eastern Australia. Here, we investigated the extent of hybridisation between dingoes and dogs in a sample of 783 wild-caught canids from eastern New South Wales, using an established 23-microsatellite test. We then mapped the distribution of these samples and identified three areas that are geographic hotspots of high dingo genetic ancestry using geospatial analysis. Between 9 and 23% of the wild canids that we sampled were classified as only having or likely to have only dingo ancestry. Only 0.6% of the wild canids we sampled were classified as having no dingo ancestry. Introgression from domestic dogs into the southeastern dingo gene pool has been extensive, with 76-88% of sampled dingoes carrying some dog ancestry. Spatial analyses revealed several geographic hotspots of high dingo genetic ancestry within north-eastern New South Wales (NSW) where there was a higher than expected prevalence of dingoes with no domestic dog ancestry. A key finding of our study is the observation of several regions where dingoes were largely free of admixture from dogs. There is an ongoing need for evidence-based strategies to reduce human-driven hybridisation by identifying and maintaining natural barriers to reproduction or limiting opportunities for wild-domesticate hybridisation. Globally, legislators and land managers may need to consider less restrictive species definitions to conserve endangered or ecologically significant taxa.