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Key departmental publications, e.g. annual reports, budget papers and program guidelines are available in our online archive.

Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time. It may contain references to activities or policies that have no current application. Many archived documents may link to web pages that have moved or no longer exist, or may refer to other documents that are no longer available.

Threat Abatement Plan for Predation by Feral Cats

Biodiversity Group Environment Australia, 1999
0 642 2546339

Note: This publication has been superseded by Threat Abatement Plan for Predation by Feral Cats 2008

Developing a National Approach to Feral Cat Control

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:

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:

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 impacts. 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:

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:

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.

Published June 1999 by Environment Australia under the Natural Heritage Trust.

Commonwealth of Australia