Photo: Spotted-tailed quoll at Tarkine Wilderness Lodge - Maree Jenkins

This article featured in Wildlife Lands Issue 9

Four quoll species are native to and found only in Australia: the Eastern (Dasyurus viverrinus), Northern (D. hallucatus), Western (D. geoffroii) and spotted-tailed (or tiger) (D. maculatus) quolls, with two other species occurring in New Guinea.  Both the population size and distribution of all of the Australian species have drastically declined since European settlement, with the dire situation recognised through threatened listings under the Environment Protection and Biodiversity Conservation Act, 1999 (aside from the eastern quoll, which is quite abundant in Tasmania despite being driven to extinction on the Australian mainland).

Quolls are primarily nocturnal and carnivorous marsupials, with the smaller species most commonly eating birds, insects, frogs, lizards and fruit, while larger species such as the spotted-tailed quolls feed on larger birds, reptiles, and mammals such as possums and rabbits.  Quolls have adapted the ability to obtain all of their water requirements through food, a very useful trait during droughts and in areas where water is scarce!  Breeding typically occurs in the winter months, with the gestation period for all four species being 21 days.  Litters average around six pups, with the exception of the eastern quoll, which can give birth to up to 30 - however only six of these have the chance to live due to competition for teats.

The main threats to quoll survival are urban development, the expansion of agricultural lands, poisoning through cane toads or 1080 baits, and predators such as cats and foxes, which not only prey on quolls but compete with them for food.  Although 1080 (sodium fluoroacetate) - the contentious poison used to control feral species such as rabbits and foxes - does not affect quolls as severely as it does its target species, it is not uncommon for them to consume a lethal amount of the bait, resulting in an agonising death.  Ingesting a large cane toad can similarly kill quolls through poisoning, leaving very few with the opportunity to learn from experience.  Ecologists at the Universities of Sydney and Melbourne are combatting this issue by training "toad-smart" quolls - feeding them very small toads to make a negative association that stays with them for life.

Fortunately, a significant proportion of Wildlife Land Trust members have either spotted-tailed or eastern quolls on their property, demonstrating the important role conservation of private lands can play in alleviating the growing pressure on threatened species.  Humane Society International and the Wildlife Land Trust continue in our attempts to protect these species by nominating threatened habitats for legal protection, and pushing for species-specific and more humane control alternatives to 1080 baiting.