The release of the highly toxic South American cane toad (Bufo marinus) to the toad-free Australian continent in 1935, and their subsequent rapid spread over large areas of tropical Australia, has resulted in a massive decline of predators such as yellow-spotted goannas (Varanus panoptes) and northern quolls (Dasyurus hallucatus). In spite of dramatic declines of northern quoll populations in the Northern Territory, a few populations still persist in areas of Queensland where northern quolls have co-existed with toads for several decades