Conservation concerns associated with low genetic diversity for K’gari–Fraser Island dingoes

Abstract

The dingo population on world heritage-listed K’gari-Fraser Island (K’gari) is amongst the most well-known in Australia. However, an absence of population genetic data limits capacity for informed conservation management. We used 9 microsatellite loci to compare the levels of genetic diversity and genetic structure of 175 K’gari dingo tissue samples with 264 samples from adjacent mainland regions. Our results demonstrated that the K'gari population has significantly lower genetic diversity than mainland dingoes (AR, HE, PAR; p < 0.05) with a fourfold reduction in effective population size (Ne = 25.7 vs 103.8). There is also strong evidence of genetic differentiation between the island and mainland populations. These results are in accordance with genetic theory for small, isolated, island populations, and most likely the result of low initial diversity and founder effects such as bottlenecks leading to decreased diversity and drift. As the first study to incorporate a large sample set of K’gari dingoes, this provides invaluable baseline data for future research, which should incorporate genetic and demographic monitoring to ensure long-term persistence. Given that human-associated activities will continue to result in dingo mortality, it is critical that genetic factors are considered in conservation management decisions to avoid deleterious consequences for this iconic dingo population.

An isolated population reveals greater genetic structuring of the Australian dingo

“…The WV population of free-ranging dogs shows measures of genetic diversity close to those found in the dingo population on K'gari 36 . Allelic richness, observed heterozygosity and effective population size values were similar (Allelic richness = 3.61 in K'gari and 2.61 in WV, observed heterozygosity = 0.27 in K'gari and 0.26 in WV, effective population size 25.7 in K'gari and 22.0 in WV), with the K'gari study using a reduced version of the same microsatellite marker set employed in this study.…”

“…Biogeographic barriers to human and animal movements possibly affected colonisation by dingoes and subsequently impeded gene flow through biogeographic semi-isolation. Previous analyses of genetic subdivision in dingoes focussed on either a broad geographic range with few samples 4 , 11 or a more limited area with more intensive sampling 16 , 36 . The Australia-wide studies identified a split between the lineages of dingoes in the south east and north west.…”

“…Although the south east/north west split and the K’gari subdivision have previously been combined under ‘ESUs’ 4 , subsequent analyses suggest the processes that caused them differed. The K’gari (and WV) populations appear to have arisen from isolation after the colonisation of the continent by dingoes 36 , while the mitochondrial south east/north west lineages are more likely to have occurred during their initial or early migration into Australia, with unknown contemporary ecological significance. We should therefore consider more subtle effects across the landscape given complex but temporally shallow demographic history of dingoes, to then relay this information to local managers to enable more precise recommendations in the context of regional conditions and pressures.…”

Before Azaria: A Historical Perspective on Dingo Attacks

“…In one sense it is a moot point, however, given that almost any dingo encountered after European settlement (except in the most remote areas) could potentially have derived from a lineage that had undergone genetic admixture with European domestic dogs [ 36 ]. Even the K’gari dingoes—supposedly among Australia’s ‘purest’ from a genetic perspective—may have at least some dog DNA [ 37 ], as domestic canines were only banned from the island in 1981 [ 38 ]. There might also have been introgression between dingoes and dogs in the vicinity of Uluru prior to Azaria Chamberlain’s disappearance (see, e.g., [ 39 ]), raising the possibility that the dingo that took her was not a ‘pure’ dingo.…”

Ecological and Cultural Understanding as a Basis for Management of a Globally Significant Island Landscape

“…Contemporary taxonomic arguments exist for both Canis dingo and C. familiaris and although considerable debate also remains regarding the timing of their arrival to Australia, we adopt C. dingo in this paper due to the unique evolutionary history of the dingo [90][91][92][93]. The fact that this island-bound population of a highly politicised and contested taxon is relatively small (~70-200 individuals) [94,95], is low in genetic diversity, and has become genetically distinct from their mainland counterparts, represents a conservation concern and also adds to their intrigue [95]. The island offers a rare opportunity for people to observe and encounter wildlife, including dingoes.…”