Red foxes in Australia

European red foxes were introduced to the British colonies of Van Diemen's Land as early as 1833, and to the Port Phillip District and Sydney Regions of New South Wales as early as 1845; introductions were, originally, intended to uphold the traditional English sport of fox hunting. Curiously, prior to 2010, a permanent fox population was not established on the island of Tasmania, and it is widely held that they were outcompeted by the Tasmanian devil (Dasyuridae).[3] Since 2010, however, red foxes have been accounted-for on Tasmania. On the mainland, the species was successful as an apex predator, with the absence of numerous large, mammalian carnivores (excepting dingoes, which occasionally hunt the foxes). The spread of the red fox across the southern regions of Victoria, South and Western Australia coincided with the spread of rabbits on the continent, another invasive species introduced in the 19th century with the intention of being hunted for sport.

An exotic fox in Mornington Peninsula National Park with mange

Established populations of red fox are found in all states, and are widespread throughout the country (with the exception of tropical areas of northern Queensland, the Kimberley and the Top End of the Northern Territory). Since 2010, confirmed evidence of foxes in Tasmania has been reported by the state's Department of Primary Industries, Parks, Water and Environment.[4] Foxes are also found in ever-higher concentrations in densely-populated suburban areas, as well as in large cities such as Melbourne.[5]

It is (generally) less common in areas where the dingo is more prevalent; however, it has, primarily through its burrowing behaviour, achieved niche differentiation with both the feral dog and the feral cat.

The West Australian conservation department, CALM, estimates introduced predators are responsible for the extinction of ten native species in that state. Red foxes have been directly implicated in the extinction and decline of populations of the family Potoroidae, including the extinction of the desert rat-kangaroo.[6]

The spread of the red fox population corresponds directly with the declining populations of several endemic terrestrial marsupials, including the brush-tailed, burrowing and rufous bettong, the bilby, numbat, bridled nailtail wallaby and the quokka.[7] Most of these species now only live in limited areas (such as islands) where red foxes are absent or rare. In 2016, researchers documented that some red foxes in Australia had learned to climb trees to look for baby koalas (and other unsuspecting creatures, such as sugar gliders), dispelling the long-held belief that arboreal creatures were safe from them.[8]

Alternatively, some researchers argue that there could be benefits with the presence of red foxes, primarily in suppressing the number of rodents, rabbits, and even feral cats in Australia, and eradication of foxes may harm native ecosystems inadvertently.[9][10]

Dead foxes displayed along a fence at Balliang, Victoria

Local eradication programs exist, although eradication has proven difficult due to the denning behaviour and nocturnal hunting, so the focus is on management with the introduction of state bounties.[11] Within smaller fenced reserves, eradicating feral cats and foxes can allow the reintroduction of extirpated mammal species.[12] However, eradication can be very time-consuming and labour-intensive. At the Australian Wildlife Conservancy's Pilliga reserve, a red fox nicknamed Rambo evaded all attempts to trap, poison, or shoot him for four and a half years, delaying planned mammal reintroductions until the fox's presumed death in 2022.[12]

The main form of control is baits, typically containing 1080 poison. Fox hunting is legal in all states and they are typically shot with the aid of spotlighting at night or attracted using fox whistles during the day. The eyeshine signature (from the tapetum lucidum in the eye) of foxes, and body shape and silhouette are used to identify them.

The reintroduction of competitive species has also been suggested as a method of control. Research by the CSIRO concluded that the presence of dingos not only decreases the presence of foxes but increases native fauna.[13] Chris Johnson of James Cook University and Euan Ritchie of Deakin University have advocated the reintroduction of Tasmanian devils to the mainland to perform a similar role, as evidenced by the past eradication of foxes from Tasmania, as well as to ensure the ongoing survival of that native species.[14][15][16][17]

• Invasive species in Australia