Fox action: step 3

Choosing your strategy

foxAs part of your fox management plan, you need to  decide which management strategies and control techniques will  best suit your situation and achieve your objectives. Some strategies  do not directly involve any fox control at all, and include considering changes to your current farm management practices, for example:

  • the type of enterprise (consider alternates such as moving to  cattle production)
  • improvements and changes to your current practices (eg the  timing and location of lambing, sheep breed and genetics)
  • other pest management activities (eg rabbits, weeds)

Fox control strategies can incorporate lethal and non-lethal  techniques. If you’ve decided on fox control you need to consider the:

  • requirements of the prey species or enterprise that is to be  protected
  • cost and effectiveness of the control technique
  • timing (fox biology vs other farm management activities)
  • your resources (financial and human)
  • potential risk for non-target damage (eg native wildlife, farm  dogs)
  • neighbours (their enterprises, level of fox and rabbit control, and  likelihood of cooperating in group activities)
  • ethical and welfare concerns.

Fox control techniques

In Australia poison baiting, using sodium monofluoroacetate (1080),  is considered to be the most effective broad-scale method of fox  control and is the most widespread technique used. Registration of  an alternate toxin (PAPP) is currently in progress. Shooting is also popular, but not considered as efficient as baiting over large areas.

Toxicants

Any toxins used against foxes in Australia must be registered with  the Australian Pesticides and Veterinary Medicines Authority  (APVMA, www.apvma.gov.au).

Sodium monofluoroacetate (1080): The most common toxicant used to control foxes is 1080, a restricted chemical product and a  schedule 7 poison. Foxes are among the most sensitive species to  this toxin, which occurs naturally in some Australian plant species. In  foxes this toxin affects the central nervous and respiratory  systems, and death occurs within 2 to 3 hours.
Para-aminopropiophenone (PAPP): PAPP is currently under  investigation as an alternate fox toxin in Australia, but is not yet  registered for general use. Foxes are highly susceptible to this toxin  with death occurring with 45 minutes. The effects of PAPP can be  reversed if the antidote is applied quickly.
Other toxins: Strychnine cannot be used as a bait toxin in Australia,  although it can still be used on traps in Queensland, if they cannot be checked daily. Cyanide is not a registered vertebrate pesticide in any  state in Australia, but limited-use permits may be obtained for research purposes.

Delivery of Toxicants

1080Baits can only be obtained through licensed officers or designated government agencies in each state and territory, and there are strict  guidelines relating to the use and placement of baits. Some states  require specific chemical training to have been completed, so it is advisable to check specific requirements with your local agency.

Toxins are mainly incorporated in some form of meat bait (either  fresh, dried or processed) for delivery to foxes. Baits can be distributed either from the air or by hand on the ground. Ground  baiting is the main technique used and involves regular monitoring of buried baits. Aerial baiting is used in remote, sparsely populated areas and requires a special permit.

Baiting programs have been shown to be most effective when done  twice a year. This causes maximum disruption to both the breeding  (late winter/spring) and migration (autumn) stages of the fox’s life cycle. For maximum success, baits should be available to foxes for at  least ten days. They should be checked at least every two days, and  replaced until no more are being taken.

Baits should be placed at strategic points along tracks and fence lines where foxes regularly  travel, or near carcasses or other attractants, allowing for distance  restrictions from residences and boundaries. Baits should be buried 5–10cm deep or tethered (in Queensland and Western Australia  only), at 200–500m intervals, with a total of about five baits laid for   each square kilometre. The positions of baits should be marked with tape or pegs so they can be easily checked later. Lures and scents  can be used to attract the foxes, although continuous scent trails  should be avoided. Removing all uneaten baits at the end of a program is important to  reduce the risk of bait aversion as well as to prevent poisoning of non-target species.

Following best practice baiting methods is important to maximise  the effectiveness of any baiting program and minimise the risk posed to non-target animals, regardless of which type of bait is used. Burying the baits helps eliminate the risk to most non-target  species, including birds.

Mechanical ejectors: The only emerging alternative to bait delivery is  the use of spring-loaded mechanical ejectors. These ejectors have been trialled in Australia using cyanide, 1080 and PAPP. They are  partly inserted into the ground with the exposed portion baited with  an attractant. When pulled, this exposed portion ejects a lethal dose of toxicant into the target animal’s mouth.

Mechanical ejectors  offer a number of benefits over traditional bait delivery of toxicants.  Since the toxicant is in a sealed capsule it does not breakdown as it  would if placed in a bait substrate. This allows ejectors to remain set  in the field for extended periods, enabling significant resource  savings as ejectors can be checked monthly. Mechanical ejectors cannot be cached or moved by foxes as an upward pull of sufficient  force results in activation of the device. This high level of bait  security provides land managers with the  confidence to implement fox and wild dog control programs with  minimal risk to both domestic and working dogs. Ejectors also provide high target selectivity due to the pull force and head  orientation required to activate and ingest a lethal toxicant dose from an ejector.

Ejectors can be used in NSW with 1080 under the Pesticide Control  (1080 Ejector Capsules) Order 2011. Their use is permitted on all  NSW National Parks estate, all other lands covered by an approved  site plan under the NSW Fox Threat Abatement Plan, lands administered by ACT Parks, Conservation and Lands, and Scotia Sanctuary managed by Australian Wildlife Conservancy in Western NSW. An ejector registration package will need to be provided to the Australian Pesticides and Veterinary Medicines Authority  (APVMA) if ejectors are to be permitted for use across Australia as  an additional tool for wild dog and fox control.

Shooting is a humane method of destroying foxes if carried out  correctly. It is considered too labour intensive for broad-scale fox  control but is useful for targeting small areas or problem animals. Shooting is mainly done at night with the aid of a spotlight when  foxes are most active. Fox drives or battues which involve scaring  foxes towards shooters are occasionally used in rural areas.

Trapped_fox_LapidgeTrapping is considered too labour intensive for broad-scale fox  control but is useful in urban areas or for targeting problem animals  and protecting specific assets such as poultry houses and wildlife refuges. Some states allow modified and padded (soft-jaw) leg-hold  traps, but the use of steel jaw leg-hold traps (toothed and/or without  padding) are prohibited across Australia. Cage traps are  preferred in urban areas as they are perceived to cause fewer  injuries than leg-hold traps and non-target animals can be easily released.

Den Fumigation: Fumigation of breeding, or natal dens is sometimes  used to destroy young fox cubs. The only registered  fumigant for foxes in Australia is carbon monoxide (CO), which is a  colourless, odourless gas that causes oxygen depletion leading to unconsciousness and rapid death without pain or discernible  discomfort. The gas is generated by the incomplete combustion of  carbon using sodium nitrate within a fumigant cartridge. Although  den fumigation may locally reduce the number of foxes or problem animals, it is not effective as a broad-scale fox control method.

Guard animals have been used to protect domestic stock from wild  predators since ancient Roman times. Guard animals used in Australia to protect from fox predation include dogs and alpacas,  and to a lesser extent llamas and donkeys. Four breeds of guard dogs  are available in Australia; Maremma, Great Pyrenean,  Anatolian Shepherd/Karabash, and Central Asian Ovcharka. Overseas research suggests that guard animals have potential, however there has been little research conducted in Australia, with  supporters mainly relying on testimonial accounts. Factors that need to be addressed before the use of guard animals can be  considered a viable technique include the collection of more  evidence of their efficacy and cost effectiveness; the availability of  guard animals and the costs of training; the change in industry  perceptions (and likely acceptance) of the technique as anything other than a novel measure; and security against theft.

Exclusion fencing is a non-lethal method commonly used to prevent  fox predation on domestic livestock and threatened wildlife species.  It can be an effective method, however the barrier is not absolute, so  here needs to be a monitoring system and a management plan in  place to rapidly detect and control breaches. The control of foxes in a buffer zone outside the enclosure can greatly enhance its  effectiveness. There are a range of fence designs developed to  exclude foxes. Choosing the best design is dependent on: the species to be protected, the area to be covered, if other pests are also to be excluded (eg rabbits), presence of other non-target animals, budget,  resources for regular maintenance, and features of the local  environment such as topography, substrate, vegetation density,  climatic conditions and geographical location.

JakeRelf_FoxHabitat modification can work in two ways: either to improve the  survival chances of the animal being protected, or to reduce fox  abundance. This method can only work if the habitat resource is a  limiting factor and can be modified economically. The fragmentation  of habitat across Australia has been suggested to increase the  vulnerability of native wildlife to fox predation. One idea to counter  this is to increase the structural complexity of habitat to protect native species. Research has shown, however, that this is not such a simple solution. Other outcomes need to be considered such as the  cover provided for other unwanted animals, disease transmission  and other complex population interactions that maybe occurring.

Den destruction, particularly at breeding time, is one habitat  modification that might reduce fox abundance. Even though there is  no evidence that the general fox population is limited by den sites,  urban foxes have been shown to prefer den sites associated with  exotic weed infestations such as blackberries. It has been suggested that controlling these weeds may influence the fox numbers living in  a particular area.

Improving general hygiene practices and removing  other food sources from around a farm or suburb is another  modification that has been suggested to deter foxes and reduce their numbers. Wild rabbits and mice should be controlled. Poultry and pets such as  rabbits and guinea pigs should be locked up in a secure, fox-proof enclosure at night. Household garbage, pet food, compost heaps,  fruit dropped from trees and carrion should be cleaned away or placed in covered bins.

Step 4: Control and monitor

 

 


More information:

Guides to help develop a fox management plan:

  • Glovebox Guide for Managing Foxes - This glovebox guide is part of the PestSmart Toolkit for Foxes, produced by the Invasive Animals CRC. It is designed to provide current information on best practice fox management for […]
Last updated: December 2, 2014