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Publications archive - Biodiversity


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Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time.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.

Review of existing Red Fox, Wild Dog, Feral Cat, Feral Rabbit, Feral Pig, and Feral Goat control in Australia. I. Audit

Ben Reddiex, David M. Forsyth, Eve McDonald-Madden, Luke D. Einoder, Peter A. Griffioen, Ryan R. Chick, and Alan J. Robley.
Department of the Environment and Heritage, 2004

6. Methods

6.1 Identification of agencies conducting pest animal control and survey process

We identified the key Federal, State and Territory government agencies that undertake pest animal control, via researchers and published literature, web based searches, and personal contacts. Key types of land management were classified to aid in the identification of appropriate state-level organisations. These included federal land, national parks and reserves, silvicultural and agricultural lands, and private and local government land.

The key focus of the audit was to evaluate the effectiveness and efficiency of existing control activities in terms of benefits to native species and ecological communities. Therefore, we focused on organisations that have undertaken or are undertaking pest control on 'public' land, as opposed to 'private' land. Organisations that manage 'public' land largely undertake pest control for conservation objectives such as preservation of threatened species and habitats. However, pest animal control may occur for reasons other than conservation benefit by these organisations (e.g., 'good neighbour' relations). The key private land agencies throughout Australia were contacted to determine their objectives for pest animal control. Most of these agencies co-ordinated private landholders to undertake pest control and therefore had limited detail on the information we aimed to collect. Where detailed information could not be obtained, summary information was collected. Universities and federal organisations within Australia were individually contacted to determine if research regarding pest animal control had been undertaken.

We identified the key personnel responsible for pest animal control within each organisation. That person was contacted, and we outlined the reasons for the survey and what it would involve from their organisation. A sample survey was usually sent to this person. Individuals surveyed were in most instances determined from within each organisation, and ranged from staff involved with carrying out operational control work to regional pest managers who had collated information from operational staff, either previously or actively for this audit. One organisation, Parks Victoria, supplied us with a database on their pest control activities instead of allowing interviews with their staff. The limitation of this approach was that the database supplied did not include information on a number of the areas for which we desired information (see Section 6.4).

Meetings were then arranged with the appropriate staff in each organisation. In preparation, participants were sent an overview of the project and an example of the type of information required. This process avoided potential misinterpretation of the survey questions that may have arisen if the surveys were posted. Importantly, this process ensured a high survey response rate and avoided the need to recontact survey participants to clarify ambiguous responses. In some instances it was not feasible to meet in person, so in these cases surveys were undertaken by phone or post.

Every attempt was made to include all pest control operations for the six species of interest where we knew information was available to complete our survey. In some cases, despite numerous requests we were unable to organise meetings, and/or posted surveys were not returned, or some survey questions were not answered. Surveys were completed between August 2003 and May 2004.

6.2 Survey and database structure

The survey form used in each meeting is shown in Appendix 1. Pest control activities were classified on survey forms as operations (see Figure 6.1). Operations were defined as pest control of one or more species at the same time, using the same control techniques, in a geographically distinct area. In most cases, parks or reserves were used to define and then name control operations. Operations predominantly targeted only one species, but in some cases multiple species were targeted (e.g., foxes and wild dogs targeted with the same control activity). Information reported for each control operation is summarised below.

Detailed information on the control activities undertaken within each operation were defined as control actions (see Figure 6.1). Information reported for each control action is summarised below. Since an operation may include multiple control actions the total number of actions collected for this review is greater than the number of operations. The main justification for having multiple control actions was to enable significant temporal changes in the control area or control methods to be recorded (see Figure 6.1 for an example). Most analyses in this report are based on control actions; we note when analyses were not based on actions.

Threatened species and monitoring information was collected for each action. However, threatened species information did not vary between actions within an operation. Monitoring was deemed to occur if changes in any variable in relation to the application of pest animal control were assessed. Monitoring was classified as assessing either 'pest species', 'native species', 'resource', or 'other'. Multiple monitoring events may have occurred for each action (see Figure 6.1 for an example where pest species, native species, and a resource was monitored for a single action).

To enable easy interpretation and comparison of the audit responses we endeavoured to design the survey so that responses could be categorised and standardised (e.g., number of baits per km2; area of control operation in km2). Numerical responses were recorded in predefined units.

The survey was divided into four key areas: 1) general information on the control operation, 2) details of the control actions undertaken, 3) presence of threatened species, and 4) monitoring details. The key information collected for each of the four key areas that is presented in this report is as follows (see Appendix 1 for an example of a completed survey form):

6.2.1 General information on control operations

6.2.2 Control actions

For each action the following information was recorded.

Figure 6.1. Hypothetical example illustrating the key components of the survey structure. The example comprises one control operation, that has two associated control actions (1 and 2), with one and four monitoring events, respectively.

Figure 6.1. Hypothetical example illustrating the key components of the survey structure. The example comprises one control operation, that has two associated control actions (1 and 2), with one and four monitoring events, respectively.

6.2.3 Threatened species

The following information was recorded for each control action.

This list comprised native species listed under the EPBC Act that are known or perceived to be threatened by at least one of the pest animals reviewed (see Table 7.4; Pg 48, for a complete list). This table was constructed from the relevant Threat Abatement Plans (Environment Australia 1999a, 1999b, 1999c, 1999d; Department of the Environment and Heritage 2003) and recovery plans as at 2002. The list also included those species perceived to be threatened by wild dogs even though this species is not listed as a key threatening process. The list is unlikely to constitute a comprehensive list of all native species threatened by these pests, particularly species that may be regionally but not nationally threatened. Participants could also list species that were not on the provided list.

6.2.4 Monitoring

The following information was recorded for each control action.

6.3 Data Storage

We designed a Microsoft Access database to store the data in (Appendix 2).

6.4 Analyses

Surveys were collected and entered into the database on a state-by-state basis, but analyses are almost exclusively presented for each pest animal species for all of Australia. For each pest animal species analyses are undertaken on both control operations and the underlying control actions.

Where the same operation had multiple species targeted, information from those operations and the resulting actions and monitoring events were used for analyses of each targeted species (see Section 7.1.4 for details on the extent of operations where multiple species were targeted). Therefore, all of the results presented are accurate for an individual species, but in many instances the results cannot be summarised across all species. For example, if an operation targets both foxes and dogs, many of the attributes such as area of control and staff time are included in analyses for each species, and any attempt at combining the total area of control or staff time across combination of species would overstate these attributes.

Sample sizes vary between analyses in this report because not all information has been provided for all fields in our survey and in many cases there are multiple actions per operation, and/or multiple monitoring events per action. Sample sizes are stated in the text or on associated figures. In all cases, the accuracy of analyses were dependent upon the quality of the information provided by survey participants. The Parks Victoria database only provided information on a limited number of survey questions, but monitoring information was collected from Parks Victoria staff. For control operations no information was provided on the pest animal species present or the status of control operations. For control actions no information was provided on the duration of control per year and intensity of control. No threatened species information was provided.

The extent of integrated control (i.e., where multiple species were targeted in the same area) was measured in two ways. First, the number of control operations where two or more species were listed as being targeted. Second, the number of different control operations that were undertaken in the same tenure (e.g., the same national park).

Arcview GIS (Version 3.2) was used to produce maps of the distributions of control actions for each species. AMG co-ordinates were used to draw the central point of each action. In many cases AMG's were not provided, or were inaccurate and not mapped (see Figures 7.12-7.17).

All analyses, excluding general information on control operations (see Section 6.2.1), threatened species (see section 6.2.3), and area of control are based on control actions. Threatened species information was collected for each action and did not vary between actions within an operation, and is therefore reported at the operation level.

Area of control was presented for each year (from 1998-2003). Due to the fact that some operations had multiple actions where control was carried out in the same year, the maximum area of control per year per operation was used. Although this may underestimate the total area of control, we believe that a greater error would occur if we used all action data (i.e., the total area of control per year would be overestimated) as in many instances multiple control actions were undertaken in the same geographical area in the same year.

The total cost of staff time per year (from 1998-2003) was calculated by multiplying staff days by $320 per day (i.e., 8hrs @ $40/hour). The daily rate of $320 was estimated to cover the average salary/wage plus organisational overheads. The estimated total labour cost per targeted pest species was calculated by extrapolating the average cost for those actions where labour time was not supplied.

Analyses of control techniques were based on the sum of all techniques across all control actions. We also assessed the frequency of different numbers of control actions per control operation.

The majority of information was collected for control actions during 1998-2003 (see below). Therefore, results are only presented for the period 1998-2003 for analyses where we desired to comment on temporal patterns.

Aside from the percentage of control actions that had some form of monitoring, all subsequent monitoring analyses were based on those actions where monitoring was conducted.

As previously noted, each action may have had a number of different monitoring events (e.g., two different types of pest species monitoring and one type of native species monitoring). Analyses based on monitoring events were calculated on whether each monitoring event did not occur, or occurred one or more times for each action (i.e., no or yes).

For control actions where monitoring was undertaken, we attempted to obtain the monitoring results. However, in most instances summary information was not available, either because it had not been written-up, or the 'owners' did not wish to release the information to us.

6.5 Non-survey data

In addition to pest control information that could be entered into the database we also obtained information that was unsuitable for inclusion. The majority of the information that was unsuitable for entry into the database was collected from local governments and agriculturally focused agencies. Where local governments conducted pest animal control, it was often on council land, and records often only identified that control had been conducted in a certain area, with no information on control intensity, duration, or area treated. A significant amount of pest animal control is undertaken by the agricultural sector. Control activities are commonly co-ordinated by agricultural based organisations such as the Rural Land Protection Boards in New South Wales, the Department of Natural Resources, Mines and Energy (DNRME) in Queensland, and the Animal and Plant Control Boards in South Australia. In most cases the primary role of these organisations is the issuing of baits, or pest control equipment to farmers/farmer groups/community groups, who undertake most of the control work. In most cases the detailed information required for this review had not been collated.