Reduction in native biodiversity: The damage to Australian wildlife since European settlement has been catastrophic (e.g. Salo et al. 2007). At least 20 species of Australian mammals have become extinct (Saunders et al. 1995). This represents about one half of the world’s mammal extinctions in the last 200 years; a further 43 species are judged to be either endangered or vulnerable (Commonwealth Endangered Species Advisory Committee Report 1992, in Saunders et al. 1995). The causes are complex and the impact of foxes on wildlife have probably been exacerbated by habitat modification and fragmentation (Saunders et al. 1995).
In Austrialia the fox has eliminated remnant populations of some native rodent and marsupial species. The best known Australian example of impact on a native species as reported by Saunders and colleagues (1995) is that of the 'Near Threatened (NT)' black-footed rock-wallaby (Petrogale lateralis), living in small, relict colonies in the wheatbelt of Western Australia. Management of local fox populations using poisoned baits resulted in a substantial increase in wallaby numbers. Another threatening process which has recently come to light is the impact of predation by foxes on native marsupials and on the 'Vulnerable (VU)' malleefowl Leipoa ocellata) (Saunders et al. 1995). For more examples of Australian fox removal studies please see Saunders et al. 1995.
In North America, introduced foxes have negative impacts on many ground-nesting birds, such as ducks and grouse. In California, European red foxes have to be controlled on an annual basis to protect the nesting grounds of several endangered species of birds. European red foxes also negatively impact smaller native canids, such as the endangered San Joaquin kit foxes and subspecies of native red foxes.
Competition: The impact of competition by foxes appears to be secondary to that of predation. Morris (1992) suggests foxes may compete with the chuditch or western quoll (Dasyurus geoffroii) for food in jarrah forest in Western Australia. Foxes also prey on young chuditch.
Agricultural: European red foxes are also a threat to livestock as they prey on poultry, lambs and kids.
Disease Transmission: In its introduced range in Australia the fox carries no diseases of serious economic or public health significance, although recently foxes have been found to harbour the hydatid parasite (Saunders et al. 2007). Controversy still surrounds its possible role as a wild reservoir host for the rabies virus (Saunders et al. 2007). In many parts of the northern hemisphere, the fox is the main reservoir of this disease and, given the widespread distribution of foxes in Australia, the possibility of rabies developing as an established disease in fox populations cannot be dismissed (Saunders et al. 2007).
Many other infectious diseases occur in foxes, although little is known of their incidence in Australia, or their impact on population regulation. These include mange, canine distemper, parvovirus, toxoplasmosis, canine hepatitis, tularaemia, leptospirosis, staphylococcal infections and encephalitis (Saunders et al. 1995). Like most carnivores that feed on a wide range of prey, foxes also carry a variety of endoparasites (Saunders et al. 1995). The incidence of helminth parasites, in foxes in particular, has been intensively surveyed in southeastern Australia because of their potential transmission to domestic animals (Saunders et al. 1995).
Location Specific Impacts:
Disease transmission: The disease most commonly associated with the red fox in Europe and North America is rabies. The potential of foxes to act as a wild reservoir for the virus in Australia is uncertain (Saunders et al. 2007). The possibility of rabies developing as an established disease in fox populations cannot be dismissed (Saunders et al. 1995). Many other infectious diseases occur in foxes, although little is known of their incidence in Australia. These include mange, canine distemper, parvovirus, toxoplasmosis, canine hepatitis, tularaemia, leptospirosis, staphylococcal infections and encephalitis (Saunders et al. 1995). Like most carnivores that feed on a wide range of prey, foxes also carry a variety of endoparasites (Saunders et al. 1995). The incidence of helminth parasites in foxes has been intensively surveyed in southeastern Australia because of their potential transmission to domestic animals (Saunders et al. 1995).
Economic/Livelihoods: Foxes kill around 10% of lambs Australia-wide and research has shown kill rates may be as high as 30%. In 2004 red foxes were estimated to cost the Australian environment and agricultural industries more than $227 million (McLeod 2004, in DEWHA 2008a). This estimate was based on a total of 7.2 million foxes in Australia (DEWHA 2008a).
Human health: In Australia the red fox carries no disease of serious economic or public health significance. However, recently foxes have been found to harbour the hydatid parasite (Saunders et al. 1995).
Predation: Predation by the red fox is listed as a key threatening process under the Environmental Protection and Biodiversity Conservation Act 1999. The red fox endangers a large number of threatened species (see Appendix A of DEWHA 2008b). Anecdotal, circumstantial and experimental evidence shows that fox predation is a major threat to the survival of native Australian fauna (Saunders et al. In Press 2008, in DEWHA 2008a). Terrestrial mammals at greatest risk of falling prey to the red fox are those that weigh between 35 and 5500 grams (sometimes referred to as the critical-weight-range species), many of which are endangered or vulnerable (DEWHA 2008a). Ground-nesting birds are also at high risk of predation by the red fox.
Predation: Native to Australia, the Night Parrot (Pezoporus occidentalis) is listed as Critically Endangered (CR) in the IUCN Red List of Threatened Species. Predation by foxes (Vulpes vulpes) and feral cats (Felis catus); competition for food and habitat degradation by introduced rabbits (Oryctolagus cuniculus) and reduced availability of water due to over-use by introduced camels (Camelus dromedarius) are some of the potential threats to the survival of this species. Decline in populations have been recorded in some areas coinciding with the arrival of feral cats (BirdLife International 2009).
Predation: The Australian native Princess parrot (Polytelis alexandrae) is listed as Near Threatened (NT) in the IUCN Red List of Threatened Species. Habitat degradation due to altered fire regimes; herbivory and competition by introduced herbivores, rabbits (Oryctolagus cuniculus); sheep (Ovis aries) and camels (Camelus dromedarius); and predation by cats (Felis catus) and red foxes are some of the threats to this species (BirdLife International 2008)
Predation: The Baw Baw frog (Philoria frosti) is listed as 'Critically Endangered (CR) in the IUCN Red List of Threatened Species. Native to Australia it is restricted to the Baw Baw plateau east of Melbourne. There is a deficiency of information in relation to demography and population dynamics of this species. Climate change impacts, pathogens such as the chytrid fungus (Batrachochytrium dendrobatidis); Willow (Salix cinerea), cattle (Bos taurus), rabbits (Oryctolagus cuniculus), Sambar deer (Rusa unicolor), foxes (Vulpes vulpes), dogs (Canis lupus) and cats (Felis catus) have been identified as invasive species that might be impacting the species (Hero et al 2004).
Threat to endangered species: European foxes are considered a threat to 14 birds, 48 mammals, 12 reptiles and 2 amphibians listed under the Environmental Protection and Biodiversity Conservation Act 1999. This includes three critically endangered birds, one critically endangered mammal and one critically endangered reptile.
Foxes in Australia are a real or perceived threat to the following critically endangered birds: Spotted quail-thrush (Mt Lofty Ranges) (Cinclosoma punctatum anachoreta); Orange bellied parrot (Neophema chrysogaster); and Herald petrel (Pterodroma heraldica).
In Australia red foxes are a threat to the following endangered birds: Eastern bristlebird (Dasyornis brachypterus); Night parrot (Pezoporus occidentalis); Western ground parrot (Pezoporus wallicus flaviventris); Gould’s petrel (Pterodroma leucoptera leucoptera); and Southern emu-wren (Fleurieu Peninsula) (Stipiturus malachurus).
In Australia red foxes are a threat to the following critically endangered mammal:
- Gilbert’s potoroo (Potorous gilbertii) and the following endangered mammals: Northern bettong (Bettongia tropica); Mountain pygmy-possum (Burramys parvus); Ampurta (Dasycercus hillieri); Spotted-tailed quoll, or yarri (north Queensland subspecies) (Dasyurus maculatus gracilis); Spot-tailed quoll, spotted-tail quoll, tiger quoll (southeastern mainland population) (Dasyurus maculatus maculates); Southern brown bandicoot (Isoodon obesulus obesulus); Mala, rufous hare-wallaby (central mainland form) (Lagorchestes hirsutus unnamed subsp.); Karkarratul, northern marsupial mole (Notoryctes caurinus); Yitjarritjarri, southern marsupial mole (Notoryctes typhlops); Bridled nail-tail wallaby (Onychogalea fraenata); Dibbler (Parantechinus apicalis); Western barred bandicoot (Shark Bay) (Perameles bougainville bougainville); Eastern barred bandicoot (mainland) (Perameles gunnii unnamed subsp.); Red-tailed phascogale (Phascogale calura); Long-footed potoroo (Potorous longipes); Konoom, smoky mouse (Pseudomys fumeus); Hastings river mouse (Pseudomys oralis); Julia Creek dunnart (Sminthopsis douglasi); Sandhill dunnart (Sminthopsis psammophila); and Central rock-rat (Zyzomys pedunculatus).
In Australia red foxes are a threat to the following globally threatened mammals: the 'Critically Endangered (CR) Brush-tailed bettong (Bettongia penicillata); the 'Endangered (EN)' Numbat (Myrmecobius fasciatus); the 'Vulnerable (VU)' Bilby (Macrotis lagotis); the 'Near Threatened (NT)' Burrowing bettong ( Bettongia lesueur); and Brush-tailed rock-wallaby (Petrogale penicillata).
In Australia red foxes are a threat to the following reptiles: the 'Critically Endangered (CR)' Western swamp tortoise (Pseudemydura umbrina) and the 'Endangered (EN)' Loggerhead turtle (Caretta caretta); and the Mary River tortoise (Elusor macrurus).
New South Wales (Australia)
Interaction with other invasive species: The red fox has been identified as a vector of weed species such as bitou bush (Chrysanthemoides monilifera rotundata).
Predation: Foxes suppress animal populations, particularly medium sized ground-dwelling and semi-arboreal mammals, ground-nesting birds and freshwater turtles. Foxes have also caused the failure of numerous attempts to reintroduce native fauna into areas of their former range. Red foxes have been implicated as partially responsible for the disappearance of medium-sized, ground-dwelling mammals from the arid and semi-arid regions of New South Wales. See the New South Wales National Parks and Wildlife Service website on Foxes for more details.
Threat to endangered species: Species threatened by the red fox in New South Wales include the 'Critically Endangered (CR)' mountain pygmy-possum (Burramys parvus); the 'Endangered (EN)' long-footed potoroo (Potorous longipes); the 'Vulnerable (VU)' malleefowl (Leipoa ocellata), Hastings river mouse (Pseudomys oralis); the 'Near Threatened (NT)' broad-toothed rat ((Mastacomys fuscus), yellow-footed rock-wallaby (Petrogale xanthopus), and the brush-tailed rock-wallaby (Petrogale penicillata); the 'Least Concern (LC)' Little tern (Sterna albifrons), and
Southern brown bandicoot (Isoodon obesulus).
Northern Territory (Australia)
Disease transmission: Please see "Disease Transmission" under Australia distribution record.
Predation: The European red fox preys on many native mammals, birds, reptiles and invertebrates.
Threat to endangered species: Engandered species are at risk of predation by the European red fox.
Southeastern Australia (Australia)
Ecosystem change: Mammals play a number of important roles in the forest ecosystem, as pollinators, seed-dispersers and dispersers of fungal species important for plant growth. They are also important for soil aeration and the breakdown of leaf litter. In this way predation by the red fox on native mammals may lead to forest ecosystem changes.
Predation: The European red fox is believed to have contributed to the extinction of at least twenty native Australian mammals. An examples in East Gippsland includes the 'Near Threatened (NT)' eastern quoll Dasyurus viverrinus).
Agricultural: Red foxes consume fruit such as grapes and damage bunches. Foxes also have a habit of chewing on irrigation emitters such as plastic drippers, destroying thousands of dollars of irrigation infrastructure. Foxes will prey on lambs, kids, fawns and poultry. Foxes kill around 10% of lambs Australia-wide and research has shown kill rates may be as high as 30%.
Disease transmission: Please see "Disease Transmission" under Australia distribution record.
Economic/Livelihoods: Losses to Tasmania's lamb and wool industries from fox predation may reach several million dollars per annum. Foxes also threaten Tasmania's image as an unspoiled tourist destination and its burgeoning nature-based tourism.
Predation: Tasmania's wildlife has not evolved in the presence of foxes and therefore lacks adequate adaptations to cope with fox predation. It is estimated that at least 78 native Tasmanian vertebrate species would be at risk if foxes became established. Of these 34 species have locally restricted ranges, 16 are suspected to be already declining in distribution and 12 are threatened according to Commonwealth or State threatened species legislation. Threatened and high conservation significance species at risk would include: the globally 'Near Threatened (NT)' Eastern barred bandicoot (Perameles gunnii gunnii); the globally 'Vulnerable (VU)' New Holland mouse (Pseudomys novaehollandiae); Little tern (Sterna albifrons sinensis ); Fairy tern (Sterna nereis nereis); Great crested grebe (Podiceps cristatus); the globally 'Endangered (EN)' Green and gold frog (Litoria raniformis); Tussock skink (Pseudemoia pagenstecheri ); and the Glossy grass skink (Pseudemoia rawlinsoni).
The Tasmanian pademelon and Tasmanian bettong, both of which thrive in Tasmania, are now extinct on the mainland because of the fox. The mainland eastern barred bandicoot has been reduced to a mere 200 surviving individuals due to fox predation. The young of unique species such as the Tasmanian devil, spotted tail quoll that are left unattended in dens are highly vulnerable to fox predation. More widespread species like ducks, shorebirds, ground nesting birds, blue tongue lizards, mountain dragons, skinks and frogs are all highly at risk. Even animals such as the little penguin and platypus are at risk. See the Department of Primary Industries, Water and Environment website on Foxes in Tasmania - A Grave Threat to Our Wildlife for more details.
Agricultural: Pest status of the red fox in Victoria was based initially on livestock predation, particularly on newborn lambs (Saunders et al. 2007).
Disease transmission: Please see "Disease Transmission" under Australia distribution record.
Economic/Livelihoods: The importance of red fox predation on lambs as a cause of economic loss varies spatially and temporally. Foxes kill around 10% of lambs Australia-wide and research has shown kill rates may be as high as 30%. Fox predation may have a large impact in areas where foxes are common and where lambing occurs early in the season. Extensive lamb loss can occur when lambing is out of step with, or isolated from, neighbouring flocks.
Human nuisance: The red fox can be a major nuisance to landholders especially hobby farmers through loss of household or hobby stock. Urban foxes have become a significant nuisance problem in a number of Australian cities. In parts of Melbourne the estimated fox density is up to 16 km-2 . Urban areas that support high densities of foxes also provide reservoirs that can replenish rural populations.
Predation: The red fox has been implicated in the extinction of six mammal species in the Victorian Mallee.
Western Australia (Australia)
Predation: Small threatened native mammals in Western Australia which are impacted by the red fox have benefited from the baiting programme including the tammer wallaby (Macropus eugeii). On Dolphin Island a population of Rothschild’s rock-wallaby (Petrogale rothschildi) was near extinction by the 1970s but remained abundant on nearby Enderby and Rosemary Islands (which lack foxes).
Threat to endangered species: Small threatened native mammals in Western Australia which are impacted by the European red fox and have benefited from the baiting programme include the 'Critically Endangered (CR) woylie (Bettongia penicillata); the 'Endangered (EN)' numbat (Myrmecobius fasciatus), the 'Vulnerable (VU)' western ringtail possum (Pseudocheirus occidentalis).
Hybridisation: It is possible that the red fox may hybridise with native subspecies.
Predation: The red fox has a major impact on small bird and mammal populations, especially the California quail and mountain quail (Mosquin & Theodore 1997).
Isle of Man
Predation: The red fox preys on terns and ground-nesting raptors among other animals (MacDonald & Halliwell 1994, in Varnham 2006).
Competition: European red foxes likely replaced native red foxes throughout all northern boreal regions and may threaten remaining native populations at higher elevations in the western United States.
Predation: European red foxes have negative impacts in many ecosystems due to the fact that they are generalist predators which attain relatively high densities.
Alaska Maritime National Wildlife Refuge (United States (USA))
Habitat alteration: Guano (bird droppings) are a strong fertiliser for vegetation. The impact of the European red fox on bird colonies could impact local vegetation by reducing the amount of fertiliser.
Predation: Foxes severely reduce populations of nesting birds by eating eggs, nestlings and adult birds in summer and caching birds and eggs for later consumption. In the Alaska Maritime National Wildlife Refuge waterfowl, shorebirds, seabirds and ptarmigan were particularly impacted (Bailey 1993, in Ebbert & Byrd 2002). Most of Alaska’s breeding seabirds are not adapted to co-exist with terrestrial mammals. Almost all islands where introduced foxes persisted are tree-less and most species nest on the surface of the ground or in earthen burrows making them particularly vulnerable to predation. For instance foxes eliminated populations of the threatened Aleutian Canada geese (Branta canadensis leucopareia) on many islands (Jones 1963; Byrd 1998, in Ebbert & Byrd 2002).
Threat to endangered species: Foxes have eliminated populations of the threatened Aleutian Canada geese (Branta canadensis leucopareia) on many islands endangering this species.