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

Abstract

<p> Hybridisation resulting from human-driven shifts in species ranges is a global conservation concern. In Australia, hybridisation between dingoes (<i>Canis dingo</i>) and domestic dogs (<i>Canis familiaris</i>) 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. </p>