Case study: Coordinated group fox programs

Historically, fox control in Australia has been conducted by individuals in an ad hoc manner, with limited cooperation between neighbouring landholders.

Since the 1990s, large-scale baiting programs involving cooperative groups have been promoted to more effectively limit the impact of fox predation.

Benefits to biodiversity from this landscape-scale approach to fox control have been demonstrated by many conservation programs across Australia. However, it has been difficult to prove that this approach is also effective on farms, due to logistical problems in doing long-term broadscale field experiments.

This study took advantage of existing agricultural fox management programs across 4.5 million hectares in regional New South Wales (NSW) to look at their impact on lamb survival.

Data was collected from a range of landholders participating in fox control activities, ranging from no control or isolated individual programs, to control on a larger scale with coordinated groups.

Aim

To determine if there is a relationship between lamb survival and the frequency, timing and spatial coverage of fox control programs.

Partners and management

This project was a partnership between Industry and Investment NSW (I&I NSW) and the Livestock Health and Pest Animal Authority (LHPA), with participation from the Department of Environment, Climate Change and Water.

All 1080 baiting projects were coordinated by the local LHPA. Data was collected and analysed by I&I NSW. Funding was provided by the National Feral Animal Control Program through the Natural Heritage Trust.

Process

Fox management programs were observed across 4.5 million hectares in regional NSW over an eight-year period.

The amount of 1080 bait laid in the programs was used as the indicator of how much effort was put into fox control. Baiting data was gathered from the 1080 poisons register, which is kept by each agency that handles 1080 in NSW.

Lamb survival data was collected from 1,034 properties over the eight-year period, using postal and/or phone surveys. Data were standardised to remove the influence of other factors on lamb survival such as birth weight, litter size, maternal nutrition and exposure to bad weather.

The results were analysed using a linear mixed-effects model, taking into account the effects of sheep breed, rainfall, year and season. For statistical analysis, each property was considered a single management unit, and was stratified (subgrouped) according to its baiting history and that of neighbouring properties.

Features of the study

The logistical and financial problems of conducting a large-scale field trial were avoided by taking advantage of existing fox control activities. The results were statistically powerful, since data were collected from many properties across a large area and over an extended time period.

Results

The frequency and timing of fox control were correlated with lamb survival. Lamb survival was higher in areas where foxes were baited twice a year: in late winter/spring (when foxes breed) and autumn (when foxes disperse).

The area covered by the control program was positively correlated with lamb survival. So, properties that had near neighbours participating in group fox control programs had higher survival of lambs than properties with no neighbours involved.

What worked and why

  • There was good communication and cooperation between participants and agencies, due to a range of incentives offered to the landholders.
  • There was support for the current best-practice strategy of encouraging a high level of group participation in fox control programs across the landscape.
  • Financial constraints were overcome by using in-kind contributions from partners and landholders.
  • The timing and frequency of control programs were considered to maximise their effect.
  • The results had a high statistical power because of the large number of treatments analysed.

What didn’t work

  • There was a low response to postal questionnaires, meaning follow-up phone interviews were needed.
  • Other methods of fox control such as shooting, trapping and the use of guard animals were not able to be included in this study.

Conclusion

Coordinated group baiting programs for fox control in an agricultural setting can improve lamb survival.

Targeting control activities to when fox populations are most vulnerable (eg when they are breeding or dispersing) can add value to current management programs.

Group programs should be promoted across all areas where ongoing fox control programs are needed, to benefit both agriculture and biodiversity.

Author Invasive Animals CRC
Year 2011
Publisher Invasive Animals CRC
Pages 2 pp
Control method 1080 (sodium monofluoroacetate)
Region NSW
Documents

PestSmart Case Study: coordinated group fox programs (270 kb PDF)

Links

PestSmart Toolkit: Foxes

Number PestSmart code: FXCS1