Abstract for presentation at Biodiversity Extinction Crisis Conference - A Pacific Response

The northern quoll (Dasyurus hallucatus) is the smallest of the Australian quoll species. It is a solitary, nocturnal and largely insectivorous carnivore, though as an opportunist, its diet may also include small mammals, amphibians, reptiles and plants. The geographical distribution of the northern quoll has been reduced to six isolated regions in northern Australia. Threats to its survival include habitat destruction, changed fire regimes and the invasion of the cane toad (Bufo marinus) into areas of its range. To this effect, the northern quoll is now listed as endangered under the current Commonwealth Environment Protection and Biodiversity Act. In 2003, as a form of insurance policy against extinction, northern quolls captured from mainland Northern Territory populations were translocated to two invasive animal-free offshore islands. These island populations are being monitored each year, with samples taken for genetic analysis. Genotypes at six polymorphic microsatellite loci revealed slightly lower genetic variation in the translocated populations (He 0.610-0.639; AR 3.33-3.37) compared to the mainland populations (He 0.623-0.646; AR 3.61-3.79), but higher than that found in other Northern Territory islands (He 0.129-0.396; AR 1.34-2.33) that may have gone through past bottlenecks and/or long-term isolation. There is also evidence of low, but highly significant (p = 0.001) genetic differentiation between the translocated populations and the source mainland population, possibly due to factors underlying local adaptation and genetic drift that may be common in closed island populations. To ensure that these populations remain viable and are able to successfully adapt to changing environmental conditions, they should continue to be monitored so that effects associated with genetic erosion may be readily detected over time, thus allowing rapid and well informed management decisions to be made accordingly.