Damage by the ferret
In its natural range the ferret is a minor pest of agriculture, causing damage to poultry production by preying on chickens and eggs.
Transmission of the disease bovine tuberculosis (Tb) to domestic stock is a serious threat to agriculture in New Zealand. The ferret is a Tb carrier and can infect stock through direct contact. The environment can also be contaminated with Tb-infected ferret faeces and urine that stock come into contact with while grazing.
The ferret is considered a moderate environmental pest, particularly in New Zealand, where vulnerable birds such as the weka, kiwi, kakapo, kea and laughing owl (now extinct) all declined in numbers after the ferret became established in the wild. Populations of black stilt and royal albatross (both endangered) were also adversely affected when their chicks were killed by the ferret.
The ferret can inflict painful bites on people and cause injury requiring medical treatment. Infants and small children are particularly at risk from facial bites.
Control programs are carried out in New Zealand to reduce populations of the ferret, and its destructive relatives the stoat and weasel. A variety of methods are used including trapping with a range of trap types, baits and detector dogs. Biological control methods are also being investigated for use in the future.
Potential to be a pest in Australia
The ferret is rated as being highly likely to establish wild populations in Australia and become a pest of agriculture, the environment and public amenity.
A scientific risk assessment conducted by the Department of Primary Industries and Regional Development, Western Australia and endorsed by the national Invasive Plants and Animals Committee indicates that the ferret poses an extreme threat (the highest of four categories) to Australia. Part of the assessment showed that the climates of the ferret’s overseas range and Australia are very similar.
It is therefore important that ferrets do not establish in the wild in Australia and that new genetic stock from overseas is not permitted to enter the country.
The ferret has the potential to establish small populations in the wild here that could go undetected for decades before increasing rapidly when favourable conditions occur. Successful populations could arise if any adaptation to current environmental conditions occurred, or as a result of the arrival of new genetic stock that allowed ferrets to thrive under a wider range of conditions in the wild.
The ferret is an aggressive predator that could threaten biodiversity in Australia, with a wide range of Australian native birds, mammals, marsupials, reptiles and frogs potentially at risk. Ground-nesting birds could be under threat from direct predation on their eggs and chicks, while small marsupials could be ideal prey. The ferret could also affect backyard and commercial poultry production by taking chickens and eggs.
Ferrets in the wild
Many ferrets are kept as pets in Australia and although many owners keep them leashed to avoid escape when the animals are outside their cages or on excursions, accidental release can occur. Some ferrets are still used to hunt rabbits, a practice that results in their escape into the wild. Unwanted ferrets are also intentionally released by irresponsible owners.
Ferrets make demanding pets. They must be kept indoors or in escape-proof enclosures, have a strong odour (particularly unsterilized males) and can give painful bites. They also have little monetary value because they are commonly available.
All these factors may contribute to ferrets escaping or being released into the wild, with some states and territories carrying out control programs to remove them. Some ferret societies in Australia offer a rescue service for unwanted or dumped ferrets and advocate responsible ownership.
Ferrets have occasionally been recorded in the wild in Western Australia and there are unconfirmed reports they are present on King Island in Bass Strait. In Tasmania some survey work has been carried out at South Arm (coastal, outer suburban Hobart). This is because authorities have received many reports of ferrets at large in that area, as well as from the south-east of the state generally. However, there are currently no confirmed, successfully established ferret populations in the wild in Australia.
Risk management
It is illegal to keep or import ferrets into the Northern Territory and Queensland, and a permit is required to keep ferrets in Victoria and the Australian Capital Territory. Ferrets are permitted in the other states, although in Tasmania and Western Australia it is an offence to release ferrets into the wild.
To help prevent ferrets from establishing in the wild and becoming pests in Australia, it is essential that captive animals are maintained in secure enclosures. Unwanted ferrets should be surrendered to a responsible organisation, not released. Any ferrets seen in the wild should be reported to the nearest relevant government department or wildlife authority so that appropriate action can be undertaken.
Declared pest category
The Western Australian Organism List (WAOL) contains information on the area(s) in which this pest is declared and the control and keeping categories to which it has been assigned in Western Australia (WA). Use the links on this page to reach ferrets in WAOL.