Quolls are spotted, carnivorous marsupials native to the Australasian region, including mainland Australia, Tasmania, and New Guinea. These nocturnal, solitary hunters are native predators, helping to maintain balance by feeding on small animals and insects. Their historical range has dramatically shrunk, making the mapping of their current habitat an important effort for conservation.
Identifying the Quoll Species
The genus Dasyurus includes six recognized species that vary in size and habitat preferences. Four species are native to Australia, and two are restricted to New Guinea.
The largest Australian species is the Tiger Quoll (Dasyurus maculatus), also known as the Spotted-tailed Quoll, which can weigh up to seven kilograms. It is recognizable by spots extending all the way down its tail. The smallest is the Northern Quoll (Dasyurus hallucatus), which is the most arboreal of the Australian species.
The other Australian species are the Western Quoll (Dasyurus geoffroii) and the Eastern Quoll (Dasyurus viverrinus). The two species found only outside of Australia are the Bronze Quoll (Dasyurus spartacus) and the New Guinean Quoll (Dasyurus albopunctatus).
Mapping Their Geographical Distribution
The modern distribution of quolls is fragmented compared to their historical presence. The Tiger Quoll is found in two distinct populations: one along the eastern coast of mainland Australia from Queensland to Victoria, and the other across Tasmania. The Eastern Quoll once occupied southeastern Australia but became locally extinct on the mainland in the 1960s. It is now almost exclusively found in Tasmania, though reintroduction efforts are underway in protected mainland areas.
The Western Quoll previously occupied about 70% of Australia. It is now confined to a small area in the southwest of Western Australia, primarily within the Jarrah Forest and parts of the Wheatbelt region. The Northern Quoll has a discontinuous distribution across the top of Australia, with isolated populations scattered through northern Western Australia, the Northern Territory’s Top End, and Queensland’s Cape York Peninsula.
Outside of Australia, the New Guinean Quoll is widespread but patchy across much of New Guinea. The Bronze Quoll is restricted to the southern part of New Guinea, south of the Fly River.
Preferred Ecosystems and Habitat Needs
Quolls are adaptable and utilize a diverse range of environments, moving between vegetation types to meet their needs. Their habitats span from temperate and subtropical rainforests to wet and dry sclerophyll forests, woodlands, coastal heath, and rocky escarpments. The Spotted-tailed Quoll is typically found in areas with higher rainfall, while the Northern Quoll is associated with tropical, high-rainfall regions.
A consistent requirement across all species is the availability of secure den sites for resting during the day and raising their young. They do not excavate their own dens but rely on natural structures in the landscape. These shelters include:
- Hollow logs
- Rock crevices
- Underground burrows
- Tree hollows
- Abandoned termite mounds (used by the Northern Quoll)
Their dependence on these features means that areas with intact, mature vegetation are important for their long-term presence.
Conservation Status and Changing Habitats
The reduction in the quoll’s geographical distribution is linked to environmental pressures. Habitat fragmentation, caused by land clearing for agriculture and urban expansion, has reduced viable land and isolated populations. Introduced species represent a major threat to their survival across their range.
Feral cats and red foxes prey on quolls and compete for food resources, contributing to population decline on the mainland. For the Northern Quoll, the introduction and spread of the toxic Cane Toad has been harmful, as these marsupials often die after consuming the amphibians.
The Eastern Quoll and Northern Quoll are currently classified as Endangered. The Western Quoll and Tiger Quoll are listed as Near Threatened.