Declining, Native, Marsupial Predators… Quolls

By Keith Hutton on July 21, 2015 in Other

Quolls are lively, attractive predatory marsupials that superficially resemble small to medium size cats with pointed noses, long, hairy tails and brown to black coats distinctly spotted with white. There are four species that occur in Australia, and before white settlement most parts of the country were inhabited by at least one of these. Since then all four species have declined dramatically in numbers and distribution, and this decline is believed to have been linked largely to habitat change or loss, and the success of foxes and feral cats. The decline has been exacerbated by shooting, trapping, illegal poisoning and possibly by spread of disease.

Western Quolls were the most widely distributed, and used to inhabit suitable areas in all mainland states and territories except ACT. They are now rare and until recently limited to the southwest tip of WA. They are considered vulnerable, but have recently been reintroduced into SA where numbers are increasing so far, but it is probably too soon to conclude they will be successful long term, even in traditional habitat.

Northern Quolls used to be common in parts of north coastal WA, NT and into Queensland. They remain locally common, but are rapidly declining or extinct in much of their former range. Their recent accelerated decline in numbers appears to be strongly correlated with the relentless expansion of cane toads and they are now considered endangered.

Spotted-tailed Quolls are the largest native carnivores on the mainland. They can be distinguished from other quolls by their size, spotted tails and less pointed snouts. Their traditional distribution has decreased markedly since European settlement. The smaller isolated northern Queensland subspecies is nationally endangered, while the larger southeast subspecies is extinct in SA and vulnerable in Tasmania.

Eastern Sydney is a significant location in the sad history of quolls in Australia. An Eastern Quoll killed on the road in Nielsen Park, Vaucluse on 31 January 1963 is believed to be the last mainland specimen collected. They had previously been regarded as common, but are now considered extinct in the wild on the mainland, and declining in their remaining stronghold in Tasmania. It has been suggested that disease may have been a significant factor in the extinction of Eastern Quolls on the mainland and that the last animals were able to survive in the eastern suburbs only because of their isolation from other populations of quolls.

Recent media reports suggest there has been an increase in interest relating to reintroduction of quolls in mainland Australia. There are now several Eastern Quoll breeding programs on the mainland that have been successful. Furthermore, arrangements to release Eastern Quolls from Tasmania into the wild on the mainland have been reported more recently. At this stage these do not appear to have been confirmed, and at least one authority has suggested that the reintroduction of quolls needs to be considered very carefully to avoid unexpected consequences in fragile modified ecosystems.