INTRODUCTION

Australia and Antarctica are the only continents without a native member of the cat family, Felidae. Felids are the most raptorial of mammals with body form, musculature, nervous coordination and senses highly specialised for stalking and capturing prey. Their nutrition and metabolism are such that they require large amounts of fresh animal protein, yet many felids can survive without drinking water. All species of wild cats prefer live prey and will rarely consume carrion except during droughts or when they are debilitated.

Cats (Felis catus) have a history of association with humankind dating back thousands of years. They have accompanied seafarers since the earliest times for vermin control, companionship and food (Jones 1989; Dickman 1996) and in this way the species has been distributed to virtually all inhabited parts of the globe as well as to many uninhabited islands. The species, which rarely exceeds eight kilograms in mass, is now the most widely distributed of all the world’s felids.

The first recorded instance of cats being brought to Australia is by English settlers in the 18th century. Cats may have arrived much earlier via trading routes from South-East Asia, shipwrecks or visits by European ships to the west coast (Baldwin 1980) but the available evidence for these origins is scant. Cats were deliberately released into the wild during the 19th century to control rabbits and mice (Rolls 1984) and feral cats are now found in all habitats, except some of the wettest rainforests, from the Torres Strait across the breadth of the mainland and Tasmania to sub-Antarctic Macquarie Island.

There is clear evidence that feral cats have caused the decline and extinction of native animals on islands through predation (Copley 1991; van Rensburg and Bester 1988). Dramatic recoveries of species on islands after the removal of feral cats is evidence of their impact (Dickman 1996). On the mainland, predation by feral cats is thought to threaten the continued survival of native species such as the eastern barred bandicoot in Victoria which currently persist in low numbers (Dickman 1996). Feral cats have been shown to thwart re-introduction programs for endangered species such as the numbat, golden bandicoot, burrowing bettong, mala and bilby in the arid and semi-arid zones of Western Australia and the Northern Territory (Johnson 1991; Gibson et al. 1994; Dickman 1996). For these reasons predation by feral cats is listed as a Key Threatening Process under Schedule 3 of the Commonwealth Endangered Species Protection Act 1992 (the Act).

For each of the processes listed in Schedule 3 of the Act, a nationally coordinated threat abatement plan must be prepared and implemented. The Act prescribes the content of a threat abatement plan and the mechanisms by which plans are to be prepared, approved and published. The relevant sections of the Act are reproduced in the Appendix. Where a threatening process occurs in more than one jurisdiction, the Commonwealth must seek the cooperation of the relevant States and Territories in the joint preparation and implementation of a threat abatement plan.

Categories of Cats

In recent years the impact of cat predation on native Australian wildlife has become a prominent public issue with strongly polarised opinions, especially where domestic cats are implicated. Cats can be grouped into categories according to how and where they live. The definitions and categories used vary widely in the published literature and the following terms are used for the purposes of this plan:

- Feral cats are those that live and reproduce in the wild, eg. forests, woodlands, grasslands and wetlands, and survive by hunting or scavenging. None of their needs are satisfied intentionally by people.

- Stray cats are those found in and around cities, towns and rural properties. They may depend on some resources provided by humans, but are not owned.

- Domestic cats are those owned by an individual, a household, a business or corporation. Most of their needs are supplied by their owners.

These categories of cats in effect reflect a continuum and there is evidence that individuals may move from one category to another (Moodie 1995; Newsome 1991). In a given situation, the category of cats that causes the most damage to wildlife needs to be identified. Management actions may differ according to the different categories of cats causing the damage. Where domestic cats are the primary cause, management is likely to concentrate on owners and consist of education and legislation to promote responsible ownership. For feral cats the requirement is to reduce numbers or inhibit predation using mechanical, chemical or biological methods. The management of stray cats often requires a combination of technical and social approaches.

Domestic Cats

Concern about predation on wildlife by domestic cats developed in Victoria during investigations into the decline of the eastern barred bandicoot (Brown 1989). It has since become a national issue among cat owners, veterinarians, conservationists and wildlife managers. Results published in 1990 suggested that domestic cats in South Australia killed an average of 26 animals per year, many of them native birds (Paton 1990). Subsequent surveys have both supported (Trueman 1991) and contradicted (Reark 1994) Paton’s conclusions. In urban areas of Victoria, traumatised small mammals are reported as usually being victims of cat attack (Dowling et al. 1994).

The quality of data on predation by domestic cats is poor and does not provide information about the impact on populations of prey species (Barratt 1995). Data obtained by written or telephone questionnaire have a number of identified areas of potential bias (Manly 1992). Too much reliance is placed upon the memory of cat owners, their ability to identify prey animals and their willingness to participate fully in a survey. Also, it may not be justifiable to assume that any small animal brought home by a cat has been preyed upon by that cat. There are other possible causes of injury or debilitation to small animals in urban areas.

Management of cats in cities is primarily an issue of urban amenity or animal welfare rather than an issue of wildlife conservation. Animals which live in cities, whether native or introduced, are generally common, adaptable species. With few exceptions, rare or threatened species do not occur in or near cities and are not directly at risk from domestic cats. Nevertheless, domestic cats in cities occur in very high densities because their requirements are primarily met by their human owners. As a consequence, even if each individual cat is taking only a small number of prey, the sum of that predation may depress populations of desirable urban wildlife.

The responsibility for managing domestic cats ultimately rests with their owners. state, territory and local governments are supporting initiatives aimed at encouraging responsible pet ownership, including developing appropriate legislation, education and awareness programs, and management plans to address local problems with domestic and stray cats. Victoria has enacted the Domestic (Feral and Nuisance) Animals Act 1994 which requires cat owners to register their animals and gives councils the power to set fees and take remedial action when landowners experience problems with wandering cats. New South Wales has initiated the development of legislation to promote responsible ownership and improved welfare of companion animals.

Moves by some State and local governments to control cats present a range of opportunities to measure the conservation benefits to be derived from managing urban cats (Tidemann, 1994). Answers to questions surrounding domestic cat management are likely to be gained through rigorous monitoring and analysis of various management regimes that are currently being put in place. Suitably designed experiments could determine whether the enacting and enforcement of laws to control domestic cats leads to desirable outcomes for urban and peri-urban wildlife. However, because of the specific nature of the listing of predation by feral cats, the management of domestic cats will not be addressed in this plan.

Stray Cats

Irresponsible cat owners, and those who feed unowned cats, play a major role in maintaining populations of stray cats in urban and rural areas. Encouraging changes in the behaviour of these people has the potential to significantly reduce the numbers of free-ranging stray cats where these are causing damage. Control of unowned cats in these areas is primarily being promoted by groups such as the RSPCA, in order to address significant animal welfare concerns.

Capturing, sterilising and releasing is seen as an effective approach to managing colonies of stray cats in urban Europe (Hammond 1981) and has been used in parts of Adelaide (Pierson 1994). This approach has been promoted to achieve goals of cat welfare and enhanced urban amenity. No benefits to wildlife are derived from this approach, as the number of predators remains unchanged. Any programs to manage stray cats in urban and peri-urban areas should be subject to rigorous review to determine their effectiveness in achieving wildlife conservation goals.

Feral Cats

There is clear evidence that feral cats have caused the decline and extinction of native animals on islands through predation (Copley 1991; van Rensburg and Bester 1988). Sound evidence that feral cats exert a significant effect on native wildlife throughout the mainland is lacking (Dickman 1996; Jones 1989; Wilson et al. 1992). Feral cats have occupied tropical Australia, Tasmania and Kangaroo Island for at least a century and yet these areas have had virtually no extinctions, or none that could be attributed directly to feral cat predation. Yet there are a number of vulnerable and endangered species which are susceptible to feral cat predation in these areas.

The nature and extent of the threat posed to native wildlife by feral cats nevertheless remains poorly understood and the evidence relating to their impacts is largely inferred. Feral cats are mobile, especially during periods of food shortage (Newsome 1991) and can disperse widely. The feral cat population is self-sustaining and may breed at any time of the year under favourable conditions. Feral cats occupy virtually all Australian environments and the damage they cause to wildlife is likely to vary widely across this spectrum of habitats.

A review of recovery plans approved under the Act, and others in draft form, has identified feral cats as a confirmed threat or a perceived threat to a large number of listed endangered and vulnerable (threatened) species (Table 1).

This threat abatement plan focuses primarily on managing the impact of feral cats. In general, listed species which are susceptible to cat predation are found in remote parts of the country from which domestic and stray cats are absent. It is generally accepted that improvements in the management of domestic and stray cats are necessary to reduce recruitment to the feral cat population (Copley 1991), but there is little research demonstrating that populations of feral cats are significantly bolstered by such recruitment. Feral cats have self-sustaining populations and there is no evidence that they need recruitment from other categories to maintain their numbers over the long term.

Feral cats occur on Commonwealth land such as Department of Defence properties and in Commonwealth-managed national parks. On a national scale, however, management of feral cats on Commonwealth land is only a small part of the larger picture of conserving endangered or vulnerable species threatened by cat predation. State and Territory wildlife agencies have a long history of practical on-ground management of feral cats and it is largely through their efforts, often supported by Commonwealth programs, that major technical and strategic advances have been made. More recently, private sector and community initiatives have also contributed to feral cat control activities.

Table 1. Species listed on Schedule 1 of the Endangered Species Protection Act 1992 for which cats are a known or perceived threat

	Known Threat
Scientific Name	Common Name	Reference
Birds
Cyanoramphus novaezelandiae cookii	Norfolk Island Parrot	(Lane, B.A etal. 1998)
Sterna albifrons	Little Tern	(Lane, B.A., et al. 1998)
Mammals
Lagorchestes hirsutus	Rufous Hare-wallaby	(Lundie-Jenkins, G. and Moore, G. 1996)
Leporillus conditor	Greater Stick-nest Rat	(Copley, P.B. 1994)
Macrotis lagotis	Greater Bilby	(Southgate, R. 1997)
Myrmecobius fasciatus	Numbat	(Friend, J.A. 1994)
Perameles gunnii	Eastern Barred Bandicoot	(Driessen, M.M. & Hocking G.J. 1991)

	Perceived Threat
Scientific Name	Common Name	Reference
Litoria aurea	Green and Golden Bell Frog	(Pyke, G. H. and Osborne, W.S. 1996)
Philoria frosti	Baw Baw Frog	(Hollis, G.J. 1997)
Birds
Geopsittacus occidentalis	Night Parrot	(Blyth, J. 1996)
DLathamus discolor	Swift Parrot	(Gaffney, R.F. and Brown, P.B. 1992)
Leipoa ocellata	Malleefowl	(Benshemesh, J. 1998)
Neophema chrysogaster	Orange-bellied Parrot	(Orange-bellied Parrot Recovery Team 1998)
Ninox novaeseelandiae undulata	Norfolk Island Boobook Owl	(Olsen, P. 1997)
Pezoporus wallicus flaviventris	Western Ground Parrot	(Burbidge, A.H., et al. 1996)
Stipiturus malachurus intermedius	Mount Lofty Southern Emu-wren	(Littely, T. and Cutten, J. 1994)
Turnix melanogaster	Black-breasted Button-quail	(Smyth, A. 1995)
Mammals
Bettongia lesueur	Burrowing Bettong	(Short, J. and Turner, B. 1993)
cDasyurus maculatus gracilis	Spotted-tailed Quoll or Yarri (North Queensland subspecies)	(Burnett, S. 1993)
Isoodon auratus	Golden Bandicoot	(Graham, G. 1996)
Petaurus gracilis	Mahogany Glider	(Queensland Department of Environment, 1995)
DBurramys parvus	Mountain Pygmy-possum	(Broome, L.S. 1996)
Crocidura tenuata var. trichura	Christmas Island Shrew	(Meek, P 1997)
F/DDasycercus cristicauda	Mulgara	(Masters, P. and Baker, L. 1996)
Dasyuroides byrnei	Kowari	(Lim, L. 1992)
Dasyurus geoffroii	Western Quoll	(Orell, P. and Morris, K., 1994)
^Lasiorhinus krefftii	Northern Hairy-nosed Wombat	(Horsup, A. 1998)
Onychogalea fraenata	Bridled Nailtail Wallaby	(Clancy, T.F. 1994)
Parantechinus apicalis	Dibbler	(Start, A.N. 1996)
Petrogale lateralis	Black-footed Rock-wallaby	Hall, G.P. and Kinnear, 1991)
Petrogale penicillata	Brush-tailed Rock-wallaby	(Hill, F.A.R. 1991)
^Petrogale persephone	Proserpine Rock-wallaby	(Rees, G., et al. 1997)
Potorous longipes	Long-footed Potoroo	(Nunan, D., et al., 1998)
Potorous tridactylus gilberti	Gilbert's Potoroo	Courtenay, J.,et al., 1998)
Pseudomys fieldi	Djoongari	(Morris, K. , et al. 1997)
Pseudomys oralis	Hastings River Mouse	(Smith, A.P. 1997)
Zyzomys pedunculatus	Central Rock-rat	(Burbidge, A. 1996)
Reptiles
Delma impar	Striped Legless Lizard	(Smith, W.J.S. and Robertson, P. 1997)

cCompetition for food by cats DDomestic cat predation

F/DDomestic and feral cat predation ^Predation and disease dispersal.

While key threatening processes are listed because of their impacts on listed threatened species, impacts from cat predation are not restricted to these species. Best practice management of feral cats must involve not only action to reduce the threat to targeted threatened species, but to all native species which may be threatened by feral cat predation.

Fundamental to the approach taken in this plan is the recognition that feral cats cannot be eradicated over most of their Australian range using current techniques and financial resources. However, it is feasible to restrict their distribution and abundance. Eradication of feral cats has been achieved on a number of Australian islands (Copley 1991; Burbidge 1989), in New Zealand (Veitch 1991; Burbidge 1989) and in the sub-Antarctic (Bester 1993). This usually requires a sustained effort using a range of conventional and biological techniques. For example, in 1977 Feline panleucopenia was introduced to sub-Antarctic Marion Island by South African wildlife authorities to control feral cats (van Rensburg et al. 1987). The disease caused a significant reduction in the island population, but feral cats were not eradicated until 1992 after a concerted effort combining trapping, baiting and shooting (Bester 1993).

Existing methods are not suitable for broadscale control of feral cats over most of Australia. However, it is possible to remove feral cats from small areas and to manage the effects of feral cats in localised areas with variable levels of success. Abatement of the threat that feral cats pose must initially be undertaken in discrete, manageable areas, selected according to national priorities. Feral cat control will have to continue for the foreseeable future and therefore must make the best use of available resources. The ongoing costs of feral cat control will, in most cases, be high. The construction and maintenance of exclusion fencing is expensive; for example, Coman and McCutchan (1994) report costs of $18 000 to $50 000 per kilometre have been incurred in constructing fox exclusion fences.

This plan delineates in broad terms the scope for national action and the apportionment of Commonwealth resources. It is intended that the plan will lead to changes in managing the impact of feral cats on endangered species, producing a more focused and strategic approach to reducing those impacts.

In accordance with the requirements of the Act this plan must be reviewed at intervals of no more than five years. At the end of the first five years, on-ground action will have increased protection for endangered species at high priority sites, and new techniques for controlling feral cat impacts will have been tested. The plan will also have assisted in documenting significant advances in knowledge, techniques and practice for abating the threat from feral cat predation. Towards the end of the period, the review required by the legislation will examine the plan, the supporting technical documents and the success or otherwise of management actions undertaken. Recommendations from the review will then be used to prepare another threat abatement plan for the next five-year phase.

During each five-year phase, knowledge will grow and efficiency and effectiveness of threat abatement actions should improve through information from well-monitored programs. The success of the plan will be dependent on the long-term commitment of resources by Commonwealth, State and Territory Governments, private landholders and community groups. The activities and priorities under the threat abatement plan will need to evolve with, and adapt to, changes as they occur.

By taking this measured approach, recognising the limitations and opportunities that exist, and ensuring that field experience and research are applied to further improve management of cats, the threat abatement plan process will ensure a responsible use of public resources and give the best outcome for wildlife threatened by cat predation.

The success of this threat abatement plan will depend on a high level of cooperation between all key stakeholders, including landholders, community groups, local government, State and Territory conservation and pest management agencies, and the Commonwealth Government and its agencies. The programs of the Natural Heritage Trust, particularly the National Feral Animal Control Program and the Endangered Species Program, will make significant contributions to implementing the plan. Success will only be achieved if all participants are prepared to allocate adequate resources to achieving effective on-ground control of feral cats at critical sites, improving the effectiveness of control programs and measuring and assessing outcomes.

Measures to address the key threatening process

Eradication of feral cats is often suggested as an attractive option because, once achieved, it requires no further commitment of resources other than for monitoring. Bomford and O’Brien (1995) argue that the following conditions must apply to achieve eradication:

The rate of removal exceeds the rate of increase at all densities;
There is no immigration; and
All reproductive animals are at risk.

They further state that it is the preferred option only when:

all animals can be detected at low densities;
discounted benefit-cost analysis favours eradication; and
there is a suitable socio-political environment.

These conditions cannot be met for feral cats on mainland Australia or in Tasmania at present. Eradication of feral cats is well beyond the capacity of available techniques and resources because the species is so well established across such a vast area. In contrast, eradication of a population of feral cats from an island may be feasible provided a persistent campaign can be mounted (Veitch 1985).

Historically, a range of techniques has been used in attempts to control feral cats, including shooting, trapping, poison baiting, fumigation and hunting. Control techniques, both those currently available and those being developed, are briefly reviewed below. Available methods are generally expensive, labour intensive, require continuing management effort and can be effective only in limited areas.

Commercial Harvesting

Feral cats have been hunted for their fur, which was mostly exported, but no skins or furs have been exported since 1988-89 (Ramsay, 1994). This export was low volume and subject to fluctuations according to the value of skins (Ramsay, 1994). Commercial hunting will only harvest a target species as long as it is commercially viable to do so. Social considerations also strongly influence such activities, even when commercially viable. Where the desired benefit of commercial harvesting is the protection of threatened species from predation, market variability is unlikely to result in controls being applied in a consistent manner.

Shooting

Newsome et al. (1989) found that rabbit numbers increased significantly in areas where feral cats and foxes were systematically removed by spotlight shooting, and demonstrated that systematic spotlight shooting of predators is a method for managing some endangered species in appropriate habitats. As a control technique its value lies in being applied for an extended period, or being timed to take advantage of opportunities that expose feral cats to such control actions, eg. wet season flooding.

Feral cats are killed by recreational shooters but the magnitude of the impact on feral cat or prey populations is unknown. The South Australian Department of Environment and Natural Resources uses recreational hunters for controlling feral goats and to complement other methods of fox and feral cat control in some areas (T. Naismith pers. comm.). Their use is regulated by a code of conduct and collectively by the hunters as a club.

In identifying shooting, when carried out humanely, as an acceptable control technique, it should be noted that it is labour intensive and currently there is no code of practice for the humane destruction of feral cats. Development of a code is identified as an action for this plan.

Trapping

Historically, a number of trap types have been used to capture feral cats including steel-jawed traps and neck snares. These trapping methods are widely recognised as being inhumane and of little use in broad scale control programs. Soft-jawed traps, such as the Victor Soft Catch™ traps, are humane, are often used for the live capture of feral cats and represent a viable option for control. Soft catch traps have an adjustable pan that tensions the trap to prevent lighter non-target species from being caught.

Cage traps are also widely used, but are generally ineffective for trapping feral cats. Cage traps have, however, been effective in trapping stray and domestic cats around rubbish dumps and in nature reserves close to urban development (Edwards pers. comm.). To successfully trap feral cats, the lure or attractant chosen is most important. Research on a number of lure types is currently being undertaken (see below). Trapping as a control method is labour intensive and is only recommended where eradication is the objective, such as on islands or small areas.

Trained dogs have been used in the management of endangered species for tracking individual members of the species for capture and relocation (Best and Powlesland, 1985), as experimental predators to condition native captive-bred animals (J. Short pers. comm.) and to track, but not to ‘course’ or hunt, problem predators.

Aboriginal Expertise

Indigenous Australians are able to offer unique skills in the management of natural areas, particularly in central and northern Australia where traditional skills are still taught and Aboriginal culture is less affected than in southern and eastern Australia. Aboriginal people are able to interpret the landscape and give insights into the natural history of certain species. In particular, some people are able to track individual animals. By employing such skilled people, problem predators can be tracked, resulting in the animals’ capture or destruction.

Tracking is a labour intensive technique but the time and expense may be offset by the benefit in being able to remove particular problem animals from the predator population. By selectively removing a few individual cats, such as large, experienced males specialising in hunting particular rare species, the primary agents of damage may be eliminated allowing wildlife colonies to survive even though there are other feral cats around (Gibson et al. 1994).

Financial Incentives

Reviews of the history of pest management conclude that, in general, subsidies and bounties have rarely been effective in reducing damage by pest animals (Braysher 1993, Saunders et al. 1995). As a general policy it is not cost-effective to seek to raise the level of recreational or professional hunting or trapping of feral cats on a broad scale by payment of bounties, subsidies or other similar artificial market incentives. Where private land adjoins or contains important wildlife habitat, assistance or encouragement to landowners and the development of incentives to promote feral cat control on private land may be appropriate, especially if the property forms part of a buffer zone to protect threatened species populations.

Baiting

Baiting is usually the cheapest and most effective broad scale technique for controlling the numbers of inconspicuous small and medium-sized pest animals. Baiting techniques for feral cats currently appear much less effective than techniques for baiting dogs and foxes. This may reflect the fact that, until recently, little research had been conducted on control strategies for feral cats.

Baiting feral cats is difficult as they are often found in low densities, can have large home ranges, are disinclined to feed on carrion except during drought or during food shortages, and are naturally wary. A successful feral cat bait must be able to be detected by, and be attractive to, feral cats particularly where they occur at low densities. The timing of a baiting program is a critical element in the successful baiting of feral cats (Short et. al. 1997, D. Algar pers. comm.).

Applied Biotechnologies in an unpublished 1996 report to the New Zealand Department of Conservation, reported that a range of baits tested did not appear to be significantly more effective than commercial cat food as attractants. Shea (1996) announced the development by the Western Australian Department of Conservation and Land Management of a bait which is attractive to cats, but this bait has yet to be widely evaluated.

Development of an effective baiting technique, and the incorporation of a suitable toxin for feral cats, is a high priority as it is most likely to yield an operational and cost-effective method to reduce cat numbers in strategic areas.

Toxins

The use of cyanide in Australia for pest control is currently illegal except under permit for research. Algar and Kinnear (1992) developed the use of cyanide as a research tool for studies of fox ecology. The technique has also been used to assess bait preferences of feral cats (Friend and Algar 1995; Algar and Sinagra 1996). The use of cyanide as a control technique was also evaluated by Marks and Gigliotti (1996) who found that there was some benefit in using it as a means of taking foxes to measure population parameters, develop indices of abundance, verify target/non-target impact and monitor rates of re-invasion. This was a consequence of the speed with which the poison acted and was seen as being humane. An ejector system to deliver the poison was also developed, but this remains a tool for research and has not been licensed for general use. The capacity to use this technique on feral cats has not been evaluated.

Development of a felid-specific toxin has been identified as a priority for feral cat control. The development of such a toxin must have due regard for humaneness, species specificity and a suite of other issues. An appropriate delivery system needs to be developed that is capable of minimising non-target exposure; meets the needs of agencies in applying the baiting system over chosen areas; and is cheap, safe and easy to deploy. Application of such a system will need to be complemented by an education and awareness program.

Preliminary studies by the Victorian Institute of Animal Science (Department of Natural Resources and Environment) have identified a possible felid-specific toxin. Trial results demonstrate that the toxin is effective and observations made by a veterinary surgeon on the clinical signs of the toxicosis suggest that the toxin is humane. With Commonwealth support, the Victorian Institute of Animal Science and the WA Wildlife Research Centre (Department of Conservation and Land Management), are undertaking complementary laboratory and field studies to investigate the feasibility of using this toxin. Future development of such a toxin will have due regard to the assessment of pain and the humaneness of the toxin in its application as a control technique.

Lures

Feral cats’ hunting skills rely on audio and visual stimuli rather than an acute sense of smell. Researchers within Australia are currently examining audio and visual attractants that will lure feral cats to baits. Bait additives that enhance smell and taste are also being evaluated. Certain lures being examined may also be used to trap cats and monitor cat abundance.

Fumigants

Feral cats and foxes are known to use rabbit warrens as dens or shelter. They are therefore vulnerable to techniques such as fumigation. Native wildlife such as goannas, other reptiles and small native mammals also use rabbit warrens and may be at risk of exposure to the fumigants. Any use of fumigants would have to take account of the risk to native species.

Aside from the risk to native species there are serious concerns about the animal welfare implications of using certain fumigants. Williams et al. (1995) regard chloropicrin as inhumane. The risk to operators using fumigants such as chloropicrin is also recognised in terms of stringent handling requirements under occupational health and safety guidelines.

Biological control

In 1977 the viral disease Feline panleucopenia, also known as feline parvovirus and feline enteritis, was introduced to sub-Antarctic Marion Island by South African wildlife authorities to control feral cats (van Rensburg et al. 1987). The disease caused a significant reduction in the island's cat population, but feral cats were not eradicated until 1992 after a concerted effort combining trapping, baiting and shooting (Bester 1993). The reason for the initial success of biological control is that the cats had no immunity to the disease.

Feline panleucopenia occurs in feral cat populations on all large land masses including mainland Australia and Tasmania. This disease causes high mortality in non-immune populations, but confers immunity on survivors. Screening of blood samples in Australian feral cats indicates that there is widespread immunity to the disease (Moodie 1995). This suggests that the disease is already circulating through feral cat populations and any control effect is already operating. For mainland situations this disease has little tactical value and its deliberate introduction to susceptible populations may be questioned as inhumane (Copley 1991, Moodie 1995) as well as being of concern to the legitimate pet trade.

For Australia, it seems unlikely that there are any felid-specific pathogens that may be suitable as biological control agents, that is, any that are sufficiently virulent, humane and from which domestic cats can be protected (Moodie 1995).

Fertility Control

Substantial efforts are being made at the Vertebrate Biocontrol Co-operative Research Centre to develop immunocontraceptive vaccines for several vertebrate pests, particularly foxes, rabbits and mice. This is a high cost/high risk venture and it would be inappropriate to expand the program to include work on cats at this time. If this venture is successful, it may be possible to apply the techniques to develop such a vaccine for feral cats. Currently there are no effective chemical sterilants which produce permanent sterility in cats (Moodie 1995).

A major benefit of the development of immunocontraceptive techniques is that they are humane. Broad scale control of cats using an immunocontraceptive vaccine, if one were developed, would be dependent upon the development of a suitable delivery mechanism for the vaccine and appropriate approvals to release the vaccine into the wild.

Barriers

At present the most effective management technique for wildlife vulnerable to terrestrial predators, such as feral cats, relies on barriers. In many cases these are natural barriers–stretches of water surrounding islands–but a number of small reserves have been enclosed with predator-proof fencing (Coman and McCutchan, 1994, Aviss and Roberts, 1994).

Translocations of threatened species and eradication of introduced predators on islands have been important strategies for wildlife conservation (Burbidge 1989). Eradication of feral cats has been achieved on a number of Australian islands (Copley 1991, Burbidge 1989), in New Zealand (Veitch 1991, Burbidge 1989) and in the sub-Antarctic (Bester 1993). Where there are no suitable islands, fenced exclosures have been used to separate vulnerable species from introduced predators.

A review of predator-proof fencing in Australia (Coman and McCutchan 1994) has found that, although most fences are a significant barrier to foxes and feral cats, even the most elaborate can be breached. If breached, fences increase the vulnerability of endangered species by preventing their escape from the predator(s). To minimise this risk, fencing should be combined with an integrated baiting and trapping program to reduce the frequency of challenge to the fence by incoming predators. The combination of fencing with a baiting and trapping program is an expensive option which is likely to be useful only for small areas or areas with specific characteristics, such as peninsulas. It may also affect movements of other wildlife, preventing their dispersal and interbreeding with other populations. Recent projects in Shark Bay, WA, have sought to use a combination of conventional control methods, natural water barriers and fencing to create large predator-free reserves on peninsulas (Department of Conservation and Land Management 1994).

Habitat Management

Although it is recognised that habitat fragmentation has the potential to deplete species richness (Bennett 1990) and to increase the incursions of invasive species, the magnitude of the impact of this invasion is not well quantified (May and Norton 1996). Observations have been made that feral predators such as foxes and dingoes use roads and other easements to travel through or gain access to areas where they hunt (Catling & Burt 1995 & 1997 Mahon et.al.1998) but that cats tend to move directly across roads or travel only short distances along roads (Edwards pers. comm.). This behavioural difference has direct implications for the study and control of cats. Weed incursions and human activities, such as tree removal, alter the floristics and complexity of the vegetation (Bennett 1990). Claridge et al. (1991) suggested that as a consequence of social interactions, female and juvenile bandicoots were affected by logging activities and subsequent incursions by foxes and wild dogs. It has also been recognised that roads, in particular, affect small forest mammals, depending on the traffic volume, road surface, and activity and foraging patterns of the mammals (Oxley et al. 1973).

Components of the environment may be manipulated or managed in order to reduce the damage done by feral cats. Therefore, habitat management in itself represents a critical factor in feral cat control. Native animals may be more secure in structurally complex habitats (Dickman 1996) so management of habitat to reduce fragmentation (rehabilitation of fire trails, roads and clearings) and to increase the density of vegetation (perhaps by better managing fire and grazing) may be effective in reducing the level of feral cat predation. This issue may need clarification to quantify the impacts of feral cats on native animals and make recommendations for future work in this area. In addition, the rabbit calicivirus disease (RCD) monitoring program may provide some answers on the response of predators to reduced rabbit densities.

FACTORS INFLUENCING FERAL CAT CONTROL

In developing an agreed approach to the management of the impacts of feral cats on threatened species or other native wildlife, a range of issues and constraints need to be considered.

Understanding the Extent and Nature of the Threat

Convincing evidence that feral cats exert a significant effect on native wildlife on the mainland is scarce (Dickman 1996; Jones 1989; Wilson et al. 1992). Feral cats have occupied tropical Australia, Tasmania and Kangaroo Island for at least a century. Although there are a number of vulnerable and endangered species which are susceptible to feral cat predation in these areas, there have been virtually no extinctions or none that could be attributed to feral cat predation,

The situation is complicated by land-use changes since European settlement, in particular the spread of pastoralism, land clearing and the removal of Aboriginal people and their fire regimes from arid and semi-arid desert, grasslands, shrublands and woodlands. Paltridge et al. (1997) observed that watering points were used as daytime shelter for feral cats as a consequence of the taller vegetation behind fenced-off bores. Furthermore Paltridge et al. (1997) noted that many species of birds taken by feral cats in central Australia were those that regularly required free water, and that during drought feral cats consumed carrion from dingo kills near watering points. Landsberg et al. (1997) stated that little is known of the effects of feral cats on native animals that require free water. Anecdotal information confirms that predation occurs, but the impact on species or faunal assemblages has not been quantified.

In addition, other introduced animals that have become feral have had significant impacts both on habitats and on native animals. As an example of the complexity of these interactions, the spread of rabbits has provided a ready food source for introduced predators such as feral cats and foxes, although some native species such as Wedge-tailed Eagles have also benefited.

Predation is a feature of virtually all ecological systems. Raw estimates of the total number of prey animals taken by cats (eg Paton 1990; Reark 1994) and studies of diet are of limited value in determining the ecological impact of the predation. Cat predation becomes a significant threat to native species only where the level of predation by cats exceeds the capacity of individual populations to replace themselves. Australia's pre-European fauna included a suite of native predators including large reptiles, raptorial birds, quolls and dingoes. The degree of threat posed by cat predation hinges upon:

the behavioural, morphological and physiological characteristics of cats which enable them to be more efficient predators than native predators;
factors that make cats more abundant or persistent than native predators;
the small size and isolation of populations of some threatened species; and
the vulnerability (naivety) of native prey to cat predation.

From a wildlife management point of view, the key question is: "Will the removal of feral cats result in significant increases in the populations and/or the distribution of particular native species?"

Dramatic recoveries of species on islands after the removal of feral cats are evidence of their impact (Dickman 1996). Some comparable work has commenced on the mainland, but the results are yet to be fully analysed (Dickman 1996). A significant impediment to answering this question is the technical difficulty of measuring and manipulating the numbers of feral cats. They are very difficult to detect and count and at present there are no effective techniques for their broad scale control.

Although the damage to conservation values is unclear, there is sufficient concern among scientists, wildlife managers and the community to warrant further research and field trials to develop and improve methods for controlling feral cats in conjunction with measuring the benefits to wildlife.

Interactions with other introduced species

Rabbits

Although all feral cats prey on native animals, in areas where rabbits occur rabbits are the main prey item. In rabbit areas feral cats will prey upon native animals opportunistically, particularly when rabbit numbers decline (Williams et al. 1995; Newsome et al. 1996), but only in areas without rabbits do native species form the staple diet of feral cats.

There is good evidence that environments are made more suitable for feral cats by the presence of rabbits (Taylor 1979; Newsome 1990), as they are a preferred food item and create burrows that provide shelter for feral cats. Feral cat numbers have been observed to rise and fall with fluctuations in rabbit numbers (Williams et al. 1995), and control of rabbits, particularly in rangelands and on islands, is considered important in lowering feral cat numbers and possibly reducing feral cat damage to conservation values (Newsome 1990).

Feral cats show a preference for young rabbits but are able to survive on alternative prey when rabbit populations decline (Catling 1988). Impacts on alternative prey can be particularly severe in island situations such as Macquarie Island, where it has been suggested that winter nesting petrels are preyed upon when rabbit numbers are low (Brothers 1984).

In semi-arid New South Wales, Newsome et al. (1989) found that rabbit numbers increased significantly in areas where feral cats and foxes were systematically removed, compared to areas where the predators were left alone. The response was most marked after about 14 months of continual predator removal. The study showed that, in semi-arid habitats, shooting predators can effectively release an introduced prey population from the suppressive effects of introduced predators. There are no comparable studies showing such a response in native prey populations and the design of this study did not allow the relative roles of feral cats and foxes to be differentiated.

Dingoes

Dingoes and rabbits have been shown to influence the abundance of feral cats (Williams et al. 1995; Corbett 1995). Dingoes are common in the northern and central parts of Australia, but have been effectively controlled in the south-east and far south-west of the mainland (Corbett 1995). Dingoes may protect a range of native species by controlling exotic predators like feral cats through direct predation (Palmer 1996a & 1996b) and by excluding them from carrion during droughts (Pettigrew 1993; Corbett 1995). The potential to introduce dingoes to control exotic predators in areas where they are now absent is remote, due to their potential impact on agricultural interests. Foxes and rabbits are absent from tropical northern Australia and from Kangaroo Island, but both species occur in the semi-arid lands where most extinctions and severe declines have occurred. Tasmania is free of dingoes and foxes, but has rabbits.

Foxes

The magnitude of competition between foxes and feral cats for food is not fully known (see Kinnear et al. 1984 & 1988), nor is the spatial overlap in their habitat known. Both feral cats and foxes are known to prey heavily on rabbits, but have the capacity to eat a wide variety of foods (eg Catling 1988). The degree of dependency of foxes and feral cats on rabbits is indicated by the decline in their populations after a crash in rabbit numbers (Newsome et al. 1989). Recent CSIRO studies suggest that foxes are dominant to cats and may restrict their full use of resources in an area as well as possibly killing them (Molsher unpub. 1996).

Rodents

Smith and Quin (1996) modelled the decline and extinction of a diverse range of native rodents, finding that introduced predators, and the presence of rabbits and house mice explained much of the decline. In particular, the presence of foxes and rabbits led to the most severe declines, but declines were less severe where dingoes were present. The abundance of feral cats explained the loss of conilurine rodents less than 35 grams. Where all predators were sustained by mice and rabbits, the declines in native species were uniformly severe (Smith and Quin 1996). What is not fully understood is the relationship between feral cats and raptors or wild dogs.

Amensal impacts

Although amensal impacts are not listed as a key threatening process, native species may also be deleteriously affected through parasites and diseases transmitted from cats. Toxoplasmosis gondii is known to be able to infect a range of marsupial and other mammalian hosts including man (Jones 1989). Exposure to this disease may be detectable through disease symptoms or blood tests but significant or sustained damage to the faunal assemblage from Toxoplasmosis may have already occurred historically and the impact can only be guessed at (Dickman 1996). Future action may be necessary to examine the possibility for control or management of the impact of disease on vulnerable populations of endangered species.

Cultural Values

The cultural value placed on feral cats varies according to the observer’s own value system. Australia’s unique fauna is widely valued by society and many perceive feral cats to be a threat to the native fauna. Nevertheless, there are concerns that domestic cats may be threatened by actions taken to control the impacts of feral cats.

Aboriginal people recognise introduced animals as part of the landscape and see them as newcomers rather than feral (Rose 1995). In particular, some Aboriginal people argue that the feral cat pre-dated European settlement and is part of Aboriginal law (Rose 1995). With the decline and extinction of many arid zone mammals with a mean adult body mass of between 35 grams and 4200 gram (defined by Burbidge and McKenzie 1989 as the critical weight range mammals) introduced mammals are viewed by Aboriginal people as a welcome addition to their diet.

Consideration of the differing cultural values attached to domestic and feral cats must be an important component of any control program.

Animal Welfare Concerns

Animal welfare issues related to feral cat control were thoroughly discussed at a workshop that preceded the preparation of this plan (Carter 1994). Organisations were invited to submit position statements covering animal welfare issues, with the RSPCA and Australian and New Zealand Federation of Animal Societies (ANZFAS) providing such statements (Carter 1994). Both these organisations accepted that there is a need to control feral cats to protect environmental values and wildlife. Both strongly emphasised the need for control methods to be humane. Neither organisation supported the use of mechanical hold fast traps, such as steel-jawed leg-hold traps, that are widely considered to be inhumane, however the recent development of the Victor Soft-catch trap may overcome this concern (Meek et al. 1996).

ANZFAS was prepared to support research and development into biological reproductive control of feral cats, as long as it was humane and environmentally safe. The RSPCA was prepared to review its position on this issue if the technique could be shown to be humane, and environmentally safe, and if the safety of owned cats could be guaranteed.

Both organisations recognised the need to control feral cats from time to time. ANZFAS argued for live trapping and humane dispatch, while the RSPCA accepted that lethal baits could be used, under appropriate supervision, in the absence of an alternative. ANZFAS did not support any ‘method of repetitive, lethal control indefinitely...without concurrent research into alternative methods which assure long-term humane control’. In recent comments ANZFAS stressed the need to clearly define the problem caused by cat predation. It is accepted that where the removal of cats would contribute to the balance of the environment, humane control methods must be developed.

DEVELOPING A NATIONAL APPROACH TO FERAL CAT CONROL

Planning Nationally Coordinated Action

State and Territory wildlife agencies have a long history of practical feral cat management and it is largely through their efforts, often supported by Commonwealth programs, that major technical and strategic advances have been made. An important function of this plan is to ensure the most effective application of Commonwealth resources to augment and enhance the existing work of the States and Territories, local government, community groups and the private sector, to gain the best outcome for nature conservation.

In March 1994, Environment Australia organised a workshop to discuss feral cat management and the development of a threat abatement plan. The workshop was attended by a wide cross-section of wildlife experts and public interest groups. It provided an overview of the task, and advice on principles of feral cat management, community attitudes and approaches, research and animal welfare (Carter, 1994).

Following that workshop, in 1995 Environment Australia contracted Dr Chris Dickman (Institute of Wildlife Research, University of Sydney) to produce an overview of the known impacts of feral cats on Australian wildlife. The resulting document, Overview of the Impact of Feral Cats on Australian Native Fauna, was published in 1996.

In recent years, in addition to funding programs to control feral cats on its own lands, the Commonwealth has provided funding to State, Territory and community organisations for feral cat control activities (Table 2). Activities have included:

developing a felid-specific toxin;
control of feral cats on Macquarie Island; and
trials of a cat-attractive bait.

Table 2. Commonwealth expenditure under the Feral Pests Program and National Feral Animal Control Program (1992-93 – 1998-99) on feral cat management for nature conservation

Research Category	1992-93 $,000	1993-94 $,000	1994-95 $,000	1995-96 $,000	1996-97 $,000	1997-98 $,000	1998-99 $,000
Ecology and control methods	0.0	275.2	264.9	360.2	0	70	30
Impact and endangered species protection	23.6	101.8	149.2	202.8	0	148*	299*
Total	23.6	377.0	414.1	563.0	0	218	329

*includes management of cats & rabbits on Macquarie Island

The knowledge documented by Dickman (1996) on the known impacts of feral cats, the results of the 1994 workshop and the results of research and management programs funded by the Commonwealth have provided the information base from which this threat abatement plan has been developed. Comments provided in response to the publication of a draft plan, and input from an advisory group of experts actively involved in feral cat control, have contributed significantly to the plan’s development. These processes have led to a high degree of consensus on the approaches proposed to reduce the impact on threatened species and native wildlife of predation by feral cats.

Identifying priority areas for action

Total eradication of feral cats throughout Australia is impossible with the humane control techniques currently available. Identification of those species and populations that will benefit most from feral cat control is therefore particularly important. A nationally agreed methodology for ranking areas on a consistent basis is required in order to maximise the conservation benefits derived from expenditure on feral cat control. Such a methodology needs to take account of protecting existing populations of threatened species, facilitating their expansion and preparing areas for translocation.

Parkes and Nugent (1995) offer a weighted or ranked system that measures risk from the pest species and the ability to manage it. This ‘worst pest–priority places’ model maximises action against the pest animal for the benefit of conservation in the affected place. Parkes (1993) noted that for this to happen, the response of the affected resources to pest densities must be known in order to determine the optimal point where the benefits are maximised and when control should cease. The level of variation in the system must also be known to enable the effects of management actions to be separated from the effects of environmental changes.

The knowledge gap about the impacts of feral cats on the biota of mainland Australia (Dickman 1996) precludes an accurate estimation of the environmental or other costs imposed by feral cats or the benefits to be derived by their control. Increasing resolution of the deficiencies in our knowledge will allow a better assessment of the value of control activities. A discounted cost-benefit analysis can then be used to indicate the future value of different management options (Bomford and O’Brien 1995; Bomford et al. 1996).

Dickman (1996) identified areas where extant native species are most at risk from predation by feral cats and the ecosystems where this impact is likely, or known to be, greatest. The analysis did not include areas where the reintroduction of species into their former range may occur. The priority regions, with the corresponding bioregions (in brackets) (Thackway and Creswell 1995), are ranked as:

South-west Western Australia (Warren, Jarrah Forest, Swan Coastal Plain, Esperance Plains, Mallee and Avon Wheatbelt);
Channel Country of Queensland/South Australia (Channel Country);
Top End of the Northern Territory (Top End Coastal, Pine Creek-Arnhem, Central Arnhem);
The Kimberley (North Kimberley, Central Kimberley);
Tasmania (Woolnorth, West and South West, Central Highlands, Tasmanian Midlands, D’Entrecasteaux, Freycinet, Ben Lomond, Furneaux, Macquarie Island);
Norfolk Island;
Victoria (South-east Corner, South-east Coastal Plain, Victorian Volcanic Plain); and
The Pilbara (Pilbara).

The priorities identified by Dickman are not universally accepted, with some State conservation agencies identifying other areas as higher priority. In addition the continuing development of recovery plans is likely to identify further species which are threatened by feral cat predation, and the areas of habitat critical for the species survival. Priorities must evolve with new information and experience to ensure an efficient national approach to management of feral cats.

Implementation of such recovery plans must be accorded the highest priority in terms of action to nationally abate the threat created by feral cats. Landholders and managers, local community groups and the private sector should be encouraged to become involved in coordinated feral cat control programs in their area. The tasks ahead are to greatly increase our knowledge of feral cat impacts on wildlife and to develop better tactical methods for reducing those effects. It is a long-term process and the threat abatement plan offers a framework for undertaking these tasks.

National Strategies

Abating the threat posed by feral cats and securing threatened species is a long-term process requiring careful planning, research, frequent review, the adoption of new knowledge and an adaptive management framework. As has been stated previously, the total eradication of feral cats throughout Australia is impossible with the humane control techniques currently available. In addition, resources will never be sufficient to deal with all feral cat problems so this plan must ensure the strategic allocation of resources to give the best outcome for threatened species conservation.

There are two main approaches that can be taken, with current techniques, to reduce feral cat damage. The first is to use conventional methods to eradicate or suppress feral cats in manageable areas of high conservation value and to eradicate them from small islands. The second approach is preventative–ensuring that feral cats do not become established on islands of high conservation value where they do not presently occur. At the same time development of more effective and humane techniques to control feral cats must be actively encouraged and supported.

As a strategy, local eradication of feral cats is applicable only to small islands or small mainland sites that are surrounded by predator exclusion fences. Local eradication is a viable option only for areas which meet strict criteria:

the chances of reinvasion must be nil or very close to it;
all animals must be accessible and at risk during the control operation; and
animals must be killed at a rate higher than their ability to replace losses through breeding.

Maintaining an area free from feral cats requires a sustained control operation to prevent reinvasion from surrounding areas. Buffer zones may be a necessary component of managing small areas, to reduce the threat from continual reinvasion from surrounding areas replacing cats killed during control operations. Development of such buffer zones will require the active participation of surrounding land managers and a clear identification of the benefits to be obtained by all participants. Significant benefits can be obtained through cooperative implementation of plans across different land tenures.

Where local eradication is not possible there are two broad strategies which can be used for localised management. These are: sustained management, where control is implemented on a continuing regular basis; and intermittent management, which seeks to apply control at critical periods of the year when damage is greatest and short term control will reduce impacts to acceptable levels. Sustained control is generally necessary for protecting habitats of endangered species or reintroduction sites. Intermittent control may be effective as a temporary seasonal measure to protect areas such as nesting or resting sites of migratory bird species. It may also be useful when transient feral cats are moving into an area where threatened species have been reintroduced, during periods of drought, prey shortage, disease or other stress when the feral cat population is vulnerable and likely to crash.

Recovery plans for a number of species identify feral cats as a perceived threat (Table 1). To ensure efficient and effective use of resources, an experimental approach must be used to determine the significance of feral cat predation in the decline of these species. By approaching local control on an experimental basis, the true significance of predation by feral cats will be better understood. If the hypothesis that feral cats are a significant threat is confirmed, this will justify expanding control activities to other sites where the species occurs. Alternatively, if cat control is shown to be irrelevant to recovery of the species, efforts can be re-directed to those activities that are effective in promoting its recovery.

Programs to control feral cats must be integrated with other pest control activities whenever possible. The pest species management series published by the Bureau of Resource Sciences provides guidelines for the application of an integrated approach to pest management (Braysher 1993; Williams et al. 1995; Saunders et al. 1995).

The steps used by Braysher (1993) for planning and evaluating integrated pest management programs are as follows:

problem definition, including some measure of the deleterious impact;
development of well defined objectives, performance criteria and criteria for failure;
identification and evaluation of management options;
implementation of the plan; and
monitoring and evaluation of the plan against its objectives.

A focus on integrated pest management and local action will provide a good mechanism for integrating feral cat control with other biodiversity conservation actions such as Bushcare and other programs funded through the Natural Heritage Trust.

High priority must be given to monitoring the outcomes of feral cat control in terms of conservation benefits derived, and not simply a body count of dead cats. Ineffective control may result in high body counts but little reduction in predation due to cats maintaining a sustainably high reproductive rate, bait-shy and trap-shy cats maintaining predation pressure, or immigration.

Cat control programs must evolve with new information and experience from all these activities, to ensure a national approach to management of feral cats to enhance nature conservation. The success of this plan will initially be judged in terms of the benefits to nature conservation from the clarification of the impact of feral cats, and from the application of improved control methods developed through research. Success may also be measured by the effectiveness with which attitudes are changed through adequate provision of information.

THREAT ABATEMENT OBJECTIVES AND ACTIONS

The aims of this plan are to promote the recovery of endangered or vulnerable native species and communities, and to prevent further species becoming endangered by reducing predation by feral cats to non-threatening levels. These aims will be achieved by implementing currently available cat control techniques at sites of high conservation value, providing for the development of new control techniques, and collecting information to improve our understanding of cats and their impacts. The key performance indicators will be the development and application of a cat-specific control measure and the degree of security achieved for species that are currently or potentially threatened by feral cat predation.

Key objectives for this plan are to:

Objective 1: Eradicate feral cats from islands where they are a threat to endangered or vulnerable native animals.

Objective 2: Prevent feral cats occupying new islands in Australia where they may threaten species or ecological communities with extinction.

Objective 3: Promote the recovery of species and ecological communities that are endangered or vulnerable as a result of predation by feral cats.

Objective 4: Improve the effectiveness and humaneness of cat control methods.

Objective 5: Improve knowledge and understanding of the impacts of feral cats on endangered or vulnerable native animals and the interactions of feral cats with other pest species.

Objective 6: Communicate the results of the threat abatement plan actions to management agencies, landholders and the public.

Objective 7: Effectively coordinate feral cat control activities.

Cost-effective and efficient control measures will, wherever possible, be applied through regionally coordinated management partnerships involving landholders, community groups and all levels of government. Management of cats will be integrated with other natural resource management activities and, where relevant, with the management of other pest species identified as contributing to key threatening processes.

To achieve the objective of threat abatement, actions in four key areas are prescribed:

implementing feral cat control programs in specific areas of high conservation priority;
encouraging the development and use of innovative and humane control methods for feral cat management;
collecting and disseminating information to improve understanding of the ecology of cats in Australia, their impacts and methods to control them; and
educating land managers and relevant organisations to improve their knowledge of the impacts of predation by feral cats and ensure skilled and effective participation in control activities.

CAT MANAGEMENT

Cat Free Islands

Objective 1: Eradicate feral cats from islands where they are a threat to endangered or vulnerable native animals.

As indicated above, predation by feral cats has been demonstrated to be a significant threat to many island populations of native animals. Eradication of feral cats from an island may be a feasible option with long-term benefits to threatened species. Currently there is a major integrated pest management program to remove feral cats, among other introduced species, from the sub-Antarctic Macquarie Island to protect nesting sea bird colonies, including albatrosses. The program is based upon existing control methods such as trapping and shooting, but would be significantly enhanced if the cat-specific baiting control system currently being researched should become available for broadscale use.

Actions

Continue to implement the feral cat eradication program currently being conducted on Macquarie Island.

Identify other islands with feral cats present and determine priorities for eradication programs based on the species to be protected from predation.

Objective 2: Prevent feral cats occupying new islands in Australia where they may threaten species or ecological communities with extinction.

Given that predation by feral cats is known to have caused the decline or extinction of island populations of native species, a priority of this plan is to minimise the risk of cats becoming established on any more islands. Preventing the introduction of cats to islands of high conservation value requires identification of potential routes of invasion, a risk analysis to determine the probability of such an event and procedures to manage and minimise the risk. There must also be the ability to detect incursions before feral cat populations have a chance to become established, and contingency plans which identify the most appropriate control measures and funding sources to implement the required control.

Actions

Identify islands of high conservation value and rank the level of risk of cats being introduced and establishing populations on these islands.

Identify measures to ensure that islands known to be of high conservation value remain free of feral cats.

Develop and implement contingency plans to contain and exterminate any incursion by cats onto islands with high conservation values.

Environment Australia will provide funds from its operating budget to enable staff to work with relevant State authorities to implement these actions. Identification of islands of high conservation value will be based on existing data. Additional costs of these actions will be determined by the results of the risk analysis.

Objective 3: Promote the recovery of species and ecological communities that are endangered or vulnerable as a result of predation by feral cats.

Local Control Plans

Predation by feral cats has been confirmed as a significant threat to a small number of listed endangered and vulnerable species (Table 1). Recovery plans for these species identify control of feral cats as a necessary component of the recovery process. Implementation of local control plans in areas identified as critical habitat for these species must be a top priority of this threat abatement plan.

Predation by feral cats has also been identified as a perceived threat for a number of listed endangered or vulnerable species (Table 1). For these species there is a need to test whether cat predation is a serious threat to recovery. Development and implementation of recovery plans for these species should determine the significance of predation by feral cats as a threat to these species and the level of control necessary to secure recovery of the species. Cat control activities promoted under these recovery plans must be designed to help quantify the significance of predation by feral cats compared to other threats to the species concerned.

Translocation has been identified as an important strategy for expanding existing populations of endangered species. Some of the most successful examples of conservation of endangered species have been on islands or within enclosures from which feral predators are excluded. Preparing areas to receive translocated populations is an important component of the recovery plans of a number of species known, or perceived, to be threatened by predation by feral cats. Implementation of local control plans in areas designated as translocation sites for such species should be a high priority and be consistent with the recovery plans for these species.

Actions

Implement local control for species where predation by feral cats is a known threat.

Implement local control programs in areas designated as translocation sites for species where predation by feral cats is a known threat.

Implement experimental control programs in areas of critical habitat for species perceived to be threatened by cat predation, to determine the significance of the threat and the level of control necessary to secure recovery.

Support regional organisations, community groups and conservation agencies to collaboratively develop and implement local feral cat control programs to protect endangered or vulnerable native species.

Identify incentives to promote and maintain on-ground feral cat control on private or leasehold lands that contain populations of endangered species, or where control is necessary, to provide a buffer zone around a population of a listed species.

The Commonwealth will make funds available, through the Endangered Species, and Feral Animal Control Program, and other programs of the Natural Heritage Trust, to support projects involving local feral cat control. Commonwealth funding will assist the development of local partnerships, where appropriate, to integrate management of feral cats on public and private lands. Where local feral cat control confirms that feral cat predation is a significant threat to particular species, this plan will promote the expansion and integration of local site-specific control plans into regional control plans for the species, as well as promoting direct links with other relevant biodiversity conservation initiatives in the region.

Regional Control Plans

Regional control plans are designed to provide protection to, or to provide a substantial expansion of suitable habitat for, a number of threatened species. They are also valuable in preparing areas for the reintroduction of species to sites within their former range.

It is debatable whether control of feral cats at a regional level is feasible using existing control methods. Existing control methods (baiting and shooting) are expensive and have varying success due to intermittent susceptibility of many populations of feral cats to these control measures. There are also problems in developing and managing control programs that involve large areas of land under different tenure. Nevertheless, South Australia is attempting to control feral cats at a regional level under Operation Bounceback 2000, which is developing an integrated approach to the control of foxes, feral cats, goats and rabbits, involving national parks, neighbouring landholders and community groups. Implementation of this regional control plan will identify the potential effectiveness of broadscale control of feral cats using existing technology. It will also substantially enhance the ability of land managers to develop and apply an integrated approach to feral animal control, which must be a priority of this threat abatement plan. Further investment in regional feral cat control programs will be contingent upon the development of new control systems suitable for broad-scale application or the demonstration by Operation Bounceback 2000 that the application of existing control methods can achieve cost-effective control at the regional level.

Continue implementation of Operation Bounceback 2000 in South Australia. This will test the effectiveness of applying existing feral cat control methods at a regional scale to minimise predation on remnant populations of threatened species and facilitate the reintroduction of locally extinct species.

The Commonwealth will make funds available, through the programs of the Natural Heritage Trust, to support the further development of this regional feral cat control program. Where possible, management of feral cats on public and private lands will be integrated with other regional biodiversity conservation measures through the development of regional partnerships.

Innovative and Humane Control Methods

Objective 4: Improve the effectiveness and humaneness of cat control methods.

Humane Poisoning

Recent studies funded under the National Feral Animal Control Program have identified a potentially cat-specific toxin which appears to be a humane method of control. Further detailed studies are needed to confirm that the toxin causes a humane death and can be effectively applied in the wild, and to provide the information necessary for the new compound to be nationally registered as an approved method of control for feral cats. Recovery of species threatened by feral cat predation will only occur if the amount of predation can be reduced rapidly to non-threatening levels. Development of a new and effective method of humane lethal control for feral cats is the highest priority of this threat abatement plan.

Control of feral cats has only received significant attention in recent years because of concerns about the impacts that predation by feral cats may be having on threatened species of native animals. As a consequence, there is not an agreed code of practice for the humane capture, handling or destruction of feral cats. Identification of acceptable humane control methods is a priority of this threat abatement plan.

Actions

Support studies to develop, test and register a more humane, cat-specific toxin for the control of feral cats.

Develop a code of practice for the humane capture, handling and destruction of feral cats.

Funds will be made available through the National Feral Animal Control Program of the Natural Heritage Trust to support these actions. The costs of these actions cannot be accurately determined as they will depend upon the nature of the tests required to evaluate and register a new poison bait system to control feral cats.

Fertility Control

Cats have a high rate of reproduction, usually producing two litters a year with up to seven young in each litter. Females become sexually mature at 10 to 12 months old while males mature at 12 to 14 months. In good seasons feral cat numbers can increase rapidly. In these circumstances, control methods that result in only temporary sterility would be unlikely to provide any effective level of population control. Currently there are no effective chemical sterilants for cats that will result in permanent sterility (Moodie 1995).

The development of a non-lethal method of cat control may be particularly important for use in urban and peri-urban areas where the risk to domestic animals may prevent or severely restrict the use of poison. However, fertility control is still at an experimental stage of development and has yet to be successfully applied to a free ranging population of wild mammals over a large area. In addition, fertility control does not address the immediate problem of predation by feral cats being at levels that are detrimental to the continued survival of the threatened species population.

Given the high cost of research on fertility control agents and the existing research on other species, this plan recommends that progress in the development of fertility controls for foxes, rabbits and mice be monitored, but that no additional funds be invested in work on cats until the benefits of current research have been demonstrated.

Action

Monitor progress with the development of fertility control methods for foxes, rabbits and mice. Should these studies demonstrate the effectiveness of fertility control methods for any of these species, review the potential applicability to feral cat control and identify the research necessary to develop and apply the methodology to feral cats.

Funding support for this action may be made available through the National Feral Animal Control Program of the Natural Heritage Trust.

Delivery Systems

Whether the intention is to control cats through poison or fertility control agents, a suitable delivery system or bait is required. Tradition and convenience have usually determined the selection of bait materials, although a wide range of products has been employed.

It is important to ensure that the most cost-effective delivery systems are used and the risk of bait shyness developing in feral cats is minimised. A priority of this plan is to identify the most attractive bait for feral cats that could be used in conjunction with a cat-specific toxin to produce an effective feral cat control system. It is also important to ensure that the risks of non-target poisoning are minimised.

Actions

Identify the most attractive bait materials for use with feral cats and the conditions under which different baits will be most effective by reviewing the results of previous studies on a range of potential baits.

Assess existing delivery systems for their effectiveness in delivering control substances to feral cats and minimising the risk of non-target impacts.

Identify and develop the most attractive bait(s) for use in combination with the cat-specific toxin to provide a feral cat control system suitable for broadscale use.

Funding support will be made available through the National Feral Animal Control Program of the Natural Heritage Trust.

Fencing

Exclusion fences have been promoted as a suitable means of minimising predation on threatened species of native animals. The threat abatement plan for foxes has identified the need to evaluate the effectiveness of existing fence designs to exclude foxes. Fence designs should also be evaluated in terms of their effectiveness in excluding cats. A recent review of fence designs (Coman and McCutchan 1994) highlighted the need for a comprehensive evaluation of the cost-effectiveness of different fence designs, to ensure that future investment in predator resistant fences is directed towards the most effective designs. Any review of the ability of fences to exclude foxes should also include an evaluation of the effectiveness of the design in excluding feral cats.

Actions

Evaluate and disseminate information on existing fence designs for their suitability to particular habitats or topography and determine the relative cost-effectiveness of individual fence designs as a means of excluding feral predators.

Investigate the behaviour of predators at electrified and non-electrified fences to determine potential weak points in fence designs that may compromise their effectiveness.

Implementation of these actions may be supported with funding made available through the National Feral Animal Control Program of the Natural Heritage Trust.

Information

Objective 5: Improve knowledge and understanding of the impacts of feral cats on endangered or vulnerable native animals and the interactions of feral cats with other pest species.

Documenting Cat Impacts

Although cats are known to have been present since the earliest days of settlement, and some data suggest a possible earlier presence, there are only limited data available on the impacts of predation by feral cats on populations of native species. Animals that are known to affect primary production values such as rabbits, goats and foxes have been the subject of a variety of studies aimed at defining the problems which they cause to primary production and identifying suitable methods of control. In contrast, knowledge of the ecology and behaviour of feral cats is still inadequate and methods of control suitable for use on cats are still being investigated. Ensuring that field experience and research are applied to further improve feral cat control programs is an important element of this plan. There is a recognised need to improve understanding of the impact of feral cats on a range of native species. This will be best achieved through the application of effective control methods to reduce cat numbers while measuring the response of particular species to the consequent reduction in predation. Such information is critical to determining if predation by feral cats is a significant threat to survival of the species concerned and the degree of control necessary to ameliorate that threat.

Adaptive management approaches that experimentally test different control techniques and treatment frequencies will be encouraged. By measuring the effectiveness of different control strategies in achieving recovery of threatened species, the ability to effectively abate the threat posed by feral cats will be improved. Simple and cost-effective means of monitoring the impacts of feral cats on threatened species will be necessary to assist in evaluating the effectiveness of particular control activities.

In addition to direct impacts through predation, feral cats may also affect native carnivores through competition. Where native carnivores are present with feral cats, studies should be initiated to identify the relative importance of competition and predation by feral cats on the native species.

Actions

Develop simple and cost-effective methods of monitoring the impacts of feral cats on threatened species as a means of evaluating control activities.

Investigate interactions between feral cats and native carnivores to identify relative significance of competition and predation by feral cats to these native species.

Environment Australia will provide funds from its operating budget to enable staff to work with relevant State authorities to ensure the necessary data are made available.

Understanding Interactions with other Feral Pests

Rabbits are one of the preferred foods for feral cats. The occurrence and abundance of rabbits has been shown to influence cat numbers. Rabbit control is therefore of critical importance to achieving long-term suppression of feral cat numbers.

Recent studies suggest that feral cats may be excluded or their numbers suppressed where foxes are common, and reducing fox numbers may lead to increased cat numbers. Should these suggestions be confirmed, it will have implications for the way in which fox control is applied and integrated with the management of feral cats.

Given the high level of interaction between foxes, cats and rabbits, activities identified in this plan must, wherever possible, be integrated with the threat abatement plans for the fox and rabbit.

Actions

Identify the importance of rabbits for maintaining high cat numbers so that control of both species can be integrated to minimise risks to native species.

Determine the nature of interactions between cats and foxes (competition and/or predation) in order to more effectively integrate feral cat control activities with fox control activities.

Funding support may be made available through the National Feral Animal Control Program of the Natural Heritage Trust.

Refining Priority Setting Mechanisms

Identification of species and regions which will benefit most from coordinated feral cat control activities is vital. Recovery plans identify those species at risk and areas of habitat critical for their survival. Implementation of these plans must be accorded the highest priority in national action to abate the threat posed by feral cats. Available resources will seldom, if ever, be sufficient to fully implement all the cat control measures recommended in recovery plans. Increasingly, areas will need to be ranked on a nationally consistent basis to ensure that decisions about funding for control activities can maximise the conservation benefits to be derived. An agreed national methodology for ranking areas should be developed to cover protecting and facilitating the expansion of existing populations of endangered species, and preparing areas for translocation.

Actions

Prioritise areas for investment in feral cat control to take account more effectively of the degree of threat that cats pose to the survival of an endangered or vulnerable species or ecological community, the potential that species or ecological community has to recover, and the cost efficiency and likely effectiveness of cat control.

Develop decision support systems to assist land managers to identify locally appropriate control method(s) and the circumstances and times to apply them in controlling feral cats.

Map the distribution of susceptible species, high risk habitats and feral cats to produce a national overview of priority regions.

The cat threat abatement team, specified in the actions relating to Objective 7, will take responsibility for the implementation of these actions. Environment Australia will provide funds from its operating budget to enable staff to work with relevant State authorities to ensure the available data are collated and analysed.

Education

Objective 6: Communicate the results of the threat abatement plan actions to management agencies, landholders and the public.

Education and Extension

The success of this threat abatement plan will depend on a high level of cooperation between all key stakeholders, including landholders, community groups, local government, State and Territory conservation and pest management agencies and the Commonwealth Government and its agencies. Educating land managers and community organisations to ensure their skilled and effective participation in feral cat control activities and to improve their knowledge of cat impacts, is an essential component of the plan. The plan is also intended to assist in documenting significant advances in knowledge, techniques and practices for abating the feral cat threat. A number of actions identified require an extension/education effort to ensure effective implementation.

Actions

Prepare and distribute extension material to promote understanding of the actions to be undertaken under this plan, the use of humane and cost-effective feral cat control methods, a wider knowledge of species recovery plans and the importance of predation by feral cats as a key threatening process.

The cat threat abatement team, specified in the actions relating to Objective 7, will guide the development and implementation of an education, extension and information transfer program. Environment Australia will provide funds from its operating budget for the initial development of a communications strategy. This strategy will include detailed budgets for future years of the five-year life of this plan.

Administration

Objective 7: Effectively coordinate feral cat control activities

National Coordination

The activities and priorities under this plan will need to evolve with, and adapt to, changes as they occur and thus ensure that field experience and research are applied to improve management of feral cats further. Success will only be achieved if all key stakeholders are involved in its further development and cooperate in its implementation. The Threat Abatement Plan Advisory Group was of considerable assistance in the development of this plan and a similar body will be needed to direct the plan's implementation.

Implementation will require: the establishment of national priorities for local control plans based on individual species recovery plans and an evaluation of the evidence that predation by cats is a significant threat for species where this has not previously been established, the identification of opportunities for integrating individual local control plans to enhance efficiency of control and recommending regional priorities for funding. As identified above, the development of material to assist in extension and information transfer would be materially assisted by input from an advisory group comprising persons with relevant technical and practical experience in cat control. Similarly, a group with both technical and practical experience to draw upon could assess the potential broader application of control methods or approaches developed through local control plans.

Actions

A Cat Threat Abatement Team composed of people with relevant technical and practical experience, and convened by Environment Australia, will be established to advise the Minister on implementation of the plan.

An independent expert will be commissioned before the end of the five-year life of the plan to conduct a comprehensive review of the progress made in its implementation.

Environment Australia will provide funds from its operating budget to enable staff to convene the threat abatement team and provide it with secretariat support. Costs of a comprehensive review of progress with implementation of this plan will be met from the National Feral Animal Control Program of the Natural Heritage Trust.

Evaluation And Review

Section 34 (2) of the Act requires that a threat abatement plan identify organisations or persons who will be involved in evaluating the performance of the plan.

Section 43 (2) requires that plans must be reviewed at intervals of no more than five years. These statutory requirements for assessment and review are intended to ensure that each threat abatement plan is an evolving document, able to build upon achievements and to be modified in the light of new knowledge or resources.

As specified in the actions relating to Objective 7, a Feral Cat Threat Abatement Team, similar in structure to the Threat Abatement Plan Advisory Group which assisted in the development of this plan, will be established to monitor the implementation of the plan. The team will include representatives from State/Territory conservation agencies, non-government conservation organisations, and experts on feral cat management and ecology. Environment Australia will provide a convenor and act as the secretariat for the team. The team will monitor achievement of the performance criteria and milestones set out in the plan and provide regular annual reports on progress.

The Act provides for a review of the threat abatement plan at any time at the discretion of the Director of National Parks and Wildlife. Environment Australia will advise the Director to request a revision of the plan if evidence is found that a feral cat control technique recommended in this plan is resulting in adverse impacts on a native species such that the species is becoming endangered.

Before the end of the five-year life of the plan an independent expert will be commissioned to examine the plan and the supporting technical documents, and the success or otherwise of management actions undertaken. Recommendations from the review will then be used to prepare another threat abatement plan for the next five year phase.

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Acknowledgments

Environment Australia would like to recognise the significant contribution of those representatives from Commonwealth and State agencies forming the Threat Abatement Plan Advisory Group, namely: Peter Copley (Department of Environment and Natural Resources, South Australia), Tim Clancy (Queensland Department of Environment), Geoff Copson (Department of Environment and Land Management, Tasmania), Glen Edwards (Parks and Wildlife Commission of the Northern Territory), Alan Newsome (CSIRO), Andrew Leys (New South Wales National Parks and Wildlife Service), Roger Armstrong and Dave Algar (Department of Conservation and Land Management, Western Australia), Chris Dickman (Institute of Wildlife Research, Sydney University), Kim Lowe and John Seebeck (Department of Natural Resources and Environment, Victoria) and Clive Marks (Victorian Institute of Animal Science).

Officers of Environment Australia have made major contributions to the preparation of this document, notably Mark Armstrong, David Carter, Gerry Maynes, Bruce McLaren and Robert Moore.

Appendix 1. Endangered Species Protection Act 1992, Sections 33–43

The following extracts from the Act highlight the main requirements.

Threat abatement plans

33.(1) The Commonwealth must prepare and implement a threat abatement plan for each key threatening process that occurs in Commonwealth areas.

(2) If the key threatening process also occurs outside Commonwealth areas, the Commonwealth must seek the co-operation of the States in which the threatening process occurs outside Commonwealth areas with a view to the joint preparation and implementation of a threat abatement plan for the threatening process throughout Commonwealth areas and those States.

Content of threat abatement plans

34.(1) The threat abatement plan must provide for the research and management actions necessary to reduce the key threatening process to an acceptable level in order to maximise the chances of the long-term survival in nature of native species and ecological communities affected by the process.

(2) In particular, the threat abatement plan must:

(a) state an objective to be achieved; and

(b) state criteria against which achievement of the objective is to be measured; and

(d) state the estimated duration and cost of the threat abatement process; and

(e) identify organisations or persons who will be involved in evaluating the performance of the threat abatement plan; and

(f) specify any major non-target ecological matters that will be affected by the plan's implementation.

(3) In preparing a threat abatement plan, regard must be had to:

(a) the objects of the Act; and

(b) the most efficient and effective use of the resources that are allocated for conservation of species and ecological communities; and

(c) consistent with the principles of ecologically sustainable development, minimising any significant adverse social and economic impacts.

Eradication of non-native species

35. If:

(a) the actions specified under paragraph 32(2)(c) in a recovery plan, or under paragraph 34(2)(c) in a threat abatement plan, include the eradication of a non-native species; and

(b) the species is endangered or vulnerable in a country in which its native habitat occurs;

the recovery plan or threat abatement plan, must require the Commonwealth to offer to provide stock of the species to that country before the eradication proceeds.

Deadlines for preparing plans

36. A plan must be prepared within the period that:

(a) begins on the day (“listing day”) on which the species, ecological community or key threatening process in question became included in a list; and

(b) ends on the elapsing of the number of years, from the listing day, specified in the following table:

TABLE

Type of Plan

If the listing day is the day this Act commenced

If the listing day is a later day

Threat abatement

plan for a key

threatening process

6 years

3 years

Advisory Committee to advise on scheduling of plans

37.(1) The Advisory Committee is to advise the Minister on the times within which, and the order in which, draft plans should be prepared.

(3) In giving advice on preparation of a draft threat abatement plan, the Advisory Committee must take into account the following matters:

(a) the degree of threat that the key threatening process in question poses to the survival in nature of species and ecological communities;

(b) the potential of species and ecological communities so threatened to recover;

(c) the efficient and effective use of the resources allocated to the conservation of species and ecological communities.

Preparation of draft plans

38.(1) After considering the Advisory Committee’s advice, the Minister may, in writing, direct the Director to prepare:

(b) a draft threat abatement plan for a key threatening process.

(2) The direction must specify the period within which the daft plan is to be prepared.

(3) The Director must comply with the direction.

(4) The Director must cause a copy of the direction to be published in the Gazette.

Consultation on draft plans

39.(1) After preparing a draft plan, the Director must:

(a) take reasonable steps to ensure that copies of the draft plan are available for purchase, for a reasonable price, at each of the offices of the ANPWS and at one or more places in each State; and

(b) give a copy of it, together with a notice of a kind referred to in subsection (2), to the Advisory Committee; and

(i) in the Gazette; and

(ii) in a daily newspaper circulating in each State in which occurs the listed native species, listed ecological community or key threatening process to which the draft plan relates; and

(iii) in any other way required by the regulations.

(2) The notice must:

(a) state that the draft plan has been prepared; and

(b) specify the places where copies of the draft plan may be purchased; and

(d) specify:

(i) an address for lodgement of comments; and

(ii) a day by which comments must be made.

(3) The day specified must not be a day occurring within three months after the notice is published in the Gazette.

Consideration of comments

40. The Director:

(a) must consider all written comments made to the Director on or before the day, and at the address for lodgement, specified in the notice; and

(b) may revise the draft plan to take into account any of those comments; and

Approval by the Minister

41.(1) The Director must then give the draft plan to the Minister for approval.

(2) The draft plan must be accompanied by the Director’s report on the written comments.

(3) If the Minister thinks that the draft plan submitted under subsection (1) or (4) for his or her approval should be revised in some respect, the Minister may give to the Director a written notice:

(a) requesting the Director to make such a revision; and

(b) setting out the reasons for the request.

(4) On receiving such a request, the Director must:

(a) consider the request and the statement of reasons; and

(b) make such revision of the draft plan as he or she considers appropriate; and

(5) The plan comes into force:

(a) on the day specified by the Minister for that purpose in approving the plan; or

(b) if no such day is specified-on the day on which the Minister approves the plan.

Director to make plans available to the public

42.(1) As soon as practicable after the Minister approves a plan, the Director must:

(a) take reasonable steps to ensure that copies of the plan are available for purchase, for a reasonable price, at each of the offices of the ANPWS and at one or more other places in each State; and

(b) give notice of the plan’s approval to each person whose comments on the draft plan the Director considered under paragraph 40(a); and

(i) in the Gazette; and

(ii) in a daily newspaper circulating in each State in which occurs the listed native species, listed ecological community or key threatening process to which the plan refers; and

(iii) in any other way required by the regulations.

(2) The notice must:

(a) state that the Minister has approved the plan; and

(b) specify the places where copies of the draft plan may be purchased.

Variation of plans

43.(1) The Director may, at anytime, review a plan and consider whether a variation of it is necessary.

(2) Each plan must be reviewed by the Director at intervals of not longer than 5 years.

(3) If the Minister gives the Director a notice requesting that the Director vary a plan and

setting out the reasons for the request, the Director must consider, having regard to the reasons, whether the requested variation is appropriate.

(4) If the Director considers that:

(a) a variation of a plan is necessary; or

(b) a variation of a plan, requested by the Minister, is appropriate; the Director may, subject to subsection (5), vary the plan.

(5) Sections 39 to 42 apply to the variation of the plan in the same way that those sections apply to the preparation and approval of a draft plan.

FOREWORD

INTRODUCTION

Categories of Cats

Stray Cats

Feral Cats

Commercial Harvesting

Shooting

Aboriginal Expertise

Baiting

Toxins

Fumigants

Biological control

Fertility Control

Understanding the Extent and Nature of the Threat

Interactions with other introduced species

Rabbits

Dingoes

Foxes

Rodents

Amensal impacts

Cultural Values

Animal Welfare Concerns

Planning Nationally Coordinated Action

Identifying priority areas for action

National Strategies

Cat Free Islands

Local Control Plans

Regional Control Plans

Innovative and Humane Control Methods

Humane Poisoning

Fertility Control

Action

Delivery Systems

Fencing

Documenting Cat Impacts

In addition to direct impacts through predation, feral cats may also affect native carnivores through competition. Where native carnivores are present with feral cats, studies should be initiated to identify the relative importance of competition and predation by feral cats on the native species.

Actions

Understanding Interactions with other Feral Pests

Refining Priority Setting Mechanisms

Education

Acknowledgments