Description
The fox (Vulpes vulpes) is a small to medium-sized animal with a burnished rusty-red coat colour and whitish/grey chin, chest and belly. They commonly have a white tip on their tail. Foxes are part of the Canidae family along with domestic dogs, wolves, and dingoes.
Adult foxes:
- weight from 3-14 kg with males generally heavier than females
- are 45 - 90 cm in length with a bushy tail length of 30 – 55 cm
- are athletic animals that can run and leap fences, and with partly retractable claws, climb fences and some trees.
The fox was introduced into Australia around 1845 with additional successful releases in southern Victoria in the 1870s. Within 20 years, the red fox had achieved pest status.
Distribution
Foxes have spread throughout most habitats of mainland Australia. The expansion was probably facilitated in some areas by the spread of the rabbit, a major food source. However, in those areas which have no rabbits, native species dominate their food preferences.
In NSW, the fox occurs throughout most habitat types although higher abundances and larger home ranges are recorded in primary production landscapes. Densities vary from:
- around 1 per km2 in the coastal forests
- 2–5 per km2 in the semi-arid and subalpine regions
- 6– 8 per km2 in the temperate grazing lands that cover most of NSW
- 16 per km2 in peri-urban and urban areas where food is abundant.
Diet
The fox is best described as an opportunistic predator and scavenger. Largely carnivorous, foxes eat a diet of 300–450 g per day of small prey in the weight range of 5– 15 kg, including native animals, birds, rabbits, house mice, and carrion. They readily eat and disperse fruits such as bitou bush and blackberry and eat insects such as scarab or ‘Christmas’ beetles when they are in abundance. Fox scats may be identified by the amount of invertebrate residue present at different times of the year. When food is abundant, foxes will often bury or ‘cache’ food to be consumed at some point in the future.
Reproduction
- Females come into oestrus once a year for 2– 3 days over 2–3 weeks in winter.
- Males are fertile throughout winter and early spring.
- Gestation lasts 51–53 days and a litter of generally 3–5, bluey grey cubs are born in a den early August to late September.
- Weaning occurs at 4 to 6 weeks after birth, by which time most of the grey colouring has gone. The young appear from the den in late spring, at about six weeks of age. During this time, daytime activity by adults feeding cubs is common.
- The cubs leave the den at about 10–12 weeks and are independent by six months of age.
- Both sexes reach sexual maturity in their first year. Where there is low mortality in the family group, a proportion of the female population may not breed. These helper vixens may assist to raise the cubs.
Social structure
Foxes form family groups comprising a male (sometimes called a ‘dog’) and vixen with helper vixens from the previous litter. They continuously mark their home range with urine, faeces and anal scent. Scent marking or olfactory communication is used to communicate with other foxes and co-existing species. Olfactory communication may leave information on the sex and breeding status of the fox or may act as a statement of territoriality.
Once foxes are independent, they begin to move or disperse out of the family group to find a breeding partner and /or establish new territories.
Dispersal can occur over long distances, e.g. over 300 km but is often within about 50 km. The inherent ability of the red fox to rapidly establish new territories over short or long distances ensures they are perfectly adapted to compensate for any population decline due to control programs.
Homerange and movement
Foxes are territorial, with home range sizes varying from 2 to > 5 km2 depending on the habitat type, availability of food, and population density of foxes. They usually move within their own territories but may travel more than 25 km at certain stages of their life history.
Foxes are mostly nocturnal animal although daytime activity is common, particularly after prolonged periods of rainfall and during the breeding season when hungry cubs require constant feeding.
Life span and mortality
Foxes can live up to 9 years although many don’t survive more than 6 years.
Litter survivorship and diseases such as distemper, parvo virus, and sarcoptic mange have an influence in regulating the fox population, along with shooting and road kills. Cubs can be vulnerable to other predators such as wild dogs and birds of prey.
However, the greatest single mortality occurs with targeted control programs using the toxin 1080.
Impacts
Agricultural impact
Fox predation has an economic impact on sheep, goat, poultry, and cattle enterprises. Estimates of more than $227 million/year in agricultural costs have been proposed. Foxes are also known to help spread weeds such as blackberries which may indirectly impact on agricultural production, and feed on dung beetles (important for controlling fly breeding and improving soil nutrients).
Environmental impact
Fox predation is recognised as having a serious impact on many native animals and is considered a major contributor to extinction of several species. Some of the species impacted include brush-tailed and yellow-footed rock wallabies, bettongs, numbats, mallee fowl, pied oyster catcher, little tern, plains wanderer, bush stone curlew, and the Murray River turtle. Foxes are also known to help spread environmental weeds such as bitou bush, blackberry and African boxthorne.
Fox predation is listed as a Key Threatening Process in NSW and a NSW Fox Threat Abatement Plan is in place to mitigate their impact.
Disease impact
The cost of disease spread by foxes has never been quantified despite their role in the epidemiology of many diseases such as Neospora caninum and Leptospirosis. Foxes would play an important role in the spread of rabies if it was introduced into Australia.
Social impact
Constant predation pressure by foxes can make it difficult to keep poultry and small pets such as guinea pigs and rabbits. This can cause stress and anxiety for many individuals.
Fox management
Reducing the impact of the red fox relies on a mixture of control techniques. No single control method will be successful on its own and when foxes are removed from an area, reinvasion or immigration from existing untreated areas generally occurs within 2 to 6 weeks.
The most efficient way to reduce the impact of foxes is to conduct coordinated, cooperative, broadscale control programs across multiple land holdings.
Control options
Baiting
1080 and PAPP are used to bait foxes with a variety of bait types available as either pre-prepared or fresh bait material.
Both poisons are available from a Local Land Services Authorised Control Officer. However, they are regulated and issuing of bait material is based on meeting legislative requirements.
Most fox control programs are coordinated in association with Local land Services staff and may involve local landholder groups, Landcare or other organisations.
Canid Pest Ejectors
Canid Pest Ejectors are a spring-loaded toxin delivery device buried in the ground with an attractant attached. They offer an alternative to ground baiting. An animal pulls up on the attractant triggering a spring-loaded plunger that punctures a capsule of toxin and propels it into the animal's mouth.
Both PAPP and 1080 can be used as the toxins in the Canid Pest Ejectors and, as for ground bait, access to the toxins is regulated. Contact Local Land Services to find out more about using Canid Pest Injectors and getting toxic capsules.
Fencing
Fencing can be used to keep foxes out of an area. Their construction can be expensive and time consuming, therefore the design and construction needs to be carefully determined. PestSmart provides more information on fence design for various purposes.
Shooting
Shooting is not an effective primary control technique to control foxes. Shooting can be integrated after using a primary control method like a coordinated, broadscale baiting program.
Trapping
The use of both cage traps and leg-hold traps for capture of the red fox can be used to manage foxes. Both leg-hold traps and cage traps are suitable for use around dwellings and built-up areas where poison baits cannot be used.
The use of leg-hold traps requires skill and training. Legislation governs what traps can be used and how and where they can be set.
Cage traps are most successful in towns and around houses where foxes are stealing pet food or poultry and where landholders object to poisons and shooting.
Guard animals
Although more research is required, there is some evidence that using 'guard' animals such as llamas, alpacas, donkeys and dogs can reduce fox predation on calves, lambs, goat kids, poultry and fairy penguins.
Habitat manipulation
Non-lethal strategies suggested to deter fox presence include the destruction of dens and harbour such as weed infestations, fallen timber and rubbish sites. The destruction of other food sources, particularly carcasses and management of food for domestic pets.
