Best practice guidelines for fox control for the conservation of biodiversity

The spotted-tailed quoll (Dasyurus maculatus) was identified in the Interim Guidelines as the threatened species at greatest risk from 1080 baiting programs. At the time, this assessment was based on results from a series of non-lethal trials that clearly identified quolls as being able to locate and consume both manufactured and meat baits routinely used in canid control (Belcher 1998, Murray and Poore 2004, Claridge et al. 2006).

However, related trials where quolls have been exposed to baits with 1080 have demonstrated that mortality from poisoning is uncommon and that population-level effects are not apparent (Körtneret al. 2003, Körtner and Watson 2005, Claridge and Mills 2007, Körtner 2007). This is either because quolls reject baits after locating them, or because they are more robust to 1080 in a field situation than earlier laboratory trials would otherwise have indicated.

Given these findings, free feeding and daily monitoring of bait stations to reduce the risk of quolls taking baits are not deemed necessary.

Control of foxes (and wild dogs) may be of direct benefit to quoll populations through reduced predation and competition.

The Work Health and Safety (WHS) Act 2011, the Work Health and Safety Regulations 2011 and relevant codes of practice (including How to manage work health and safety risks and Managing risks of hazardous chemicals) specify the requirements for individuals and businesses undertaking work.

While the majority of the risks specific to the use of 1080 are addressed in the Pesticide Control Orders and label instructions, compliance with the requirements of WHS Act and regulations needs to be assessed. A Job Safety Analysis is required before fox control actions may be undertaken on the NPWS estate.

The following recommendations are provided as a guide. Monitoring changes in fox and/or animal activity allows these recommendations to be refined for each site.

1. Buried 1080 baits are often the primary method of fox control.
2. Fox control should be undertaken throughout a buffer extending well beyond the biological asset (target threatened species) at risk. A buffer of at least 2 fox home ranges is an appropriate starting point depending on ease of access across the site (that is, availability of roads, complexity of tenure). As a guide, a buffer of at least 4 km may be appropriate in resource-rich areas (that is, where fox home ranges will be relatively small, typically ≤ 3km², such as coastal New South Wales and the Great Divide). A buffer of at least 8 km may be warranted in resource-poor areas (that is, where fox home ranges are larger, typically ≤ 12km2, for example in western New South Wales). The aim is to remove resident foxes and intercept immigrating foxes before they get to the threatened species.
3. Unless it can be justified otherwise, baiting programs should be continuous and ongoing: that is, baits should be checked and replaced on an ongoing basis so that baits might be available continuously to foxes (see the definition of ongoing baiting in the Pesticide Control (1080 Bait Products) Order 2017). Note that it may be appropriate to discontinue baiting temporarily when there is a high risk to domestic dogs or excessive disturbance by goannas.
4. The frequency of baiting required to reduce fox activity and to maintain it at low levels will depend on the size and patchiness of the control area, the nature of the environment and the associated potential for fox reinvasion. The reduction in fox activity required to minimise impacts on native fauna will depend on individual predator-prey relationships and on the objectives of the program. As a guide, bait replacement should be frequent (for example, once per 2 weeks) in small (≤ 5000 ha) or fragmented control areas (but see guidelines for shorebird sites below) and less frequent (for example, once per 4–6 weeks) in large (> 5000 ha) continuous control areas. Note that there is a potential for foxes to receive a sub-lethal dose if they consume baits that have been buried for extended periods, but further research is needed to assess how often this might occur and the extent to which it may reduce the efficacy of control programs (Saunders and McLeod 2007).
5. Repeated discrete programs (that is, where baits are deployed for relatively short, discrete periods several times throughout a year) may be appropriate at some sites for logistical and other reasons. Where possible, discrete programs should include bait replacement (that is, where bait stations are checked and baits replaced as required on at least one occasion within a program). Again, the frequency of discrete programs required to maintain low fox activity will depend on a range of factors, including the size of the control area.
6. Baits should be buried alongside roads, tracks and other potential animal pathways. Baits should be spaced between 500 m and 1, 000 m apart depending on likely fox home range size (as above, home range size varies with resource density). Where feasible, bait density should be between 1–4 baits/km². These densities should provide most foxes adequate opportunity to access to baits.
7. Meat baits are preferred to manufactured baits because they are consumed more readily by foxes and are less likely to be cached (Van Polanen Petel 2001, Gentle 2008). However, it is useful to vary the bait type periodically.
8. Only toxic baits should be used. Free feeding is not required. Risks to domestic animals should be minimised through appropriate public notification, signs and education.
9. The presence of dingoes does not preclude fox control, especially at priority sites identified in the NSW Fox Threat Abatement Plan 2010. This includes lands listed under Schedule 2 of the Pest Control Order for Wild Dogs. Rather, it may be appropriate to incorporate fox control actions into the relevant wild dog management plans for the site.
10. Additional fox control measures such as M44 ejectors, shooting, trapping and den fumigation should be employed to increase the effectiveness of control.

The NSW Fox Threat Abatement Plan 2010 seeks to establish across-tenure control programs at priority sites for the conservation of biodiversity. Priority sites include national parks, state forests, crown lands and private lands. Irrespective of where native species at risk from fox predation persist, across-tenure collaboration is essential to the success of fox control because foxes may reinvade rapidly from untreated areas.

There may be significant risks to domestic dogs on other tenures and hence continuous baiting may be inappropriate. Land managers should determine what baiting regime is appropriate, noting that frequent and intensive control is ideal to counteract the rapid reinvasion of foxes:

1. Individual agreements must be sought with each land manager for fox control on their land. Agreements should stipulate the conditions of control, especially where the landholder has concerns (for example, for the safety of domestic pets). For example, land managers may prefer that 1080 baits be laid over short discrete intervals only – laid on a Monday and picked up on a Friday.
2. Where NPWS staff or other government employees lay baits on private property then written consent will be required to enter private land and undertake fox control.
3. The guidelines as for the national parks estate should be followed in the absence of any specific guidelines stemming from individual agreements.

There are more than 25 priority sites identified in the NSW Fox Threat Abatement Plan 2010 along the NSW coastline which are critical nesting sites for threatened shorebirds. Fox control for shorebird protection is unique because:

a. the sites are often characterised by complex land tenure
b. nesting shorebirds are often concentrated in small areas and thus individual foxes are capable of killing all eggs and chicks at a site
c. impacts on shorebirds are largely restricted to the breeding season.

The following principles should be adopted at shorebird sites:

1. Fox baiting should commence at least one month prior to nesting at sites where it can be predicted reliably (that is, regular sites). Fox control should be undertaken continuously until fledging is completed. The timing of nesting and fledging varies with species and latitude, but it is typically late winter to late summer.
2. Fox control should be undertaken throughout a buffer area extending approximately 4 km from the nest sites (coarsely based on the diameter of 2 large fox home ranges). Such control efforts seek to remove resident foxes and intercept immigrating foxes before they get to the eggs and chicks.
3. Bait stations should be checked at least weekly for the duration of the shorebird nesting season. More frequent checking may allow the fate of eggs and chicks to be monitored more reliably and will ensure that baits are always available to foxes.
4. Note that there are additional requirements within the Pesticide Control (1080 Bait Products) Order 2017 when baiting on properties less than 100 ha.

Snow cover presents a number of conundrums for ground baiting in alpine areas: first, because it may not be possible to reach the ground surface through the snow; second, because high moisture levels may leach 1080 from baits buried in wet snow; and, third, because the formation of surface ice may make buried baits inaccessible to foxes. The following are recommended:

1. Baits may be buried under snow (as opposed to below the ground surface) during periods of extended snow cover.
2. Avoid baiting in wet snow. Accordingly, avoid baiting early or late in the snow season or near the edge of the snow line where thawing snow may leach 1080 from baits.
3. Avoid baiting if there is a high probability of baits icing in.
4. Intensive efforts in and around ski resorts in winter may reduce fox populations over a broader area as animals may frequent resorts to take advantage of abundant food resources. Control should target entry points into ski resorts to intercept immigrating foxes before they become habituated to resort food.
5. Alternative fox control measures such as den fumigation, night-shooting and trapping should be undertaken in summer to complement fox baiting.

Aerial baiting for the protection of a threatened species may be carried out where ground baiting is impractical. The Pesticide Control (1080 Bait Products) Order 2017 identifies the conditions under which aerial baiting may occur.

Ejectors can enhance the performance of fox baiting programs by extending control in time and space within existing resource commitments. They can also increase the number of control point interactions by foxes, address fox caching behaviour and add a level of bait security not possible when using buried baits alone. The Pesticide Control (1080 Ejector Capsules) Order 2011 has a unique set of regulations for use of ejectors which need to be followed in conjunction with these guidelines:

1. Ejectors should be placed along trails at 1 km intervals or can be alternated with ground bait sites.
2. Ejectors can be used at ground bait sites where foxes have been identified as caching baits.
3. Ejectors can be used in areas where bait security is an issue: for example, where adjoining landholders have domestic or working dogs at potential risk from cached baits. Ejectors do not move and cannot be cached. They can also be shut down with confidence that no poison baits remain in an area. This is of particular benefit if wild dog trappers are used within fox control areas.
4. Ejectors can be used as long-term control points checked every 4 weeks or moved to another area every few months as a pulse baiting technique.
5. Remote areas can be treated with ejectors and left for up to 4 months prior to checking where vehicle access is not available. However, it should be noted that ejector viability as a control method is limited by the longevity of the bait head.
6. Multiple bait head types should be presented and regularly changed to increase fox interaction with multiple ejectors.

Data detailing the density, frequency and extent of each fox control method employed should be recorded to allow control programs to be reviewed to maximise their cost-effectiveness. The following minimum standards are recommended.

Ground-baiting (including M44 ejectors)

1. Date of activity
2. Coordinates of each bait station (point location).
3. Coordinate system (for example, GDA 94)
4. Action (set-up; monitor only; monitor and reset; monitor and close)
5. Observation (set up only, bait undisturbed, bait disturbed, bait taken or M-44 triggered)
6. Bait or bait-head type (for example, fresh meat, Foxoff)
7. Toxin (1080, PAPP)

Recording any species active at bait stations (including foxes) is not required: first, because free-feeding and daily monitoring to minimise non-target risk are not required; second, because monitoring prints is unreliable for determining what animals are taking baits; and, third, because there are better methods for monitoring fox activity.

Aerial baiting

The Pesticides Act 1999 and the Pesticides Regulation 2017 have specific record making and keeping requirements for aerial application of pesticides that must be complied with. Aerial baiting runs must be recorded using a GPS. The GPS equipment must have full data logging capabilities and have pre-programmed flight paths installed prior to dropping any 1080 baits. The following attributes must be recorded with the flight path:

1. Date of activity
2. Start and finish time (first bait dropped; last bait dropped).
3. Pilot name
4. CASA registration number for aircraft
5. Crew names
6. Occupier or owner name, address and contact details for all land where 1080 dropped
7. Bait type (for example, fresh meat, dried meat (≤ 50% wet mass))
8. Toxin (1080, PAPP)
9. Bait count for each property or land tenure.

Trapping

1. Date of activity
2. Coordinates of each trap set (point location).
3. Coordinate system (for example, GDA 94)
4. Action (set-up; monitor only; monitor and reset; monitor and close)
5. Observation (set up only, undisturbed, visited, sprung, capture)
6. Bait type (for example, fresh meat)
7. Trap type (soft-jaw, cage)
8. Species trapped

Shooting

Shooting programs often involve calling animals to specific points. The following attributes should be recorded at each point:

1. Date
2. Coordinates of each shooting location (point location).
3. Coordinate system (for example, GDA 94)
4. Species shot
5. Number shot
6. Number sighted.

Belcher C. A. (1998). Susceptibility of the tiger quoll, Dasyurus maculatus, and the eastern quoll, D. viverrinus, to 1080-poisoned baits in control programmes for vertebrate pests in eastern Australia. Wildlife Research. 25:33–40.

Claridge A. W. & Mills D. J. (2007) Aerial baiting for wild dogs has no observable impact on spotted-tailed quolls (Dasyurus maculatus) in a rainshadow woodland. Wildlife Research 34, 116–124.

Claridge A. W., Murray A. J., Dawson J., Poore R., Mifsud G. & Saxon M. J. (2006). The propensity of spotted-tailed quolls (Dasyurus maculatus) to encounter and consume non-toxic meat baits in a simulated canid control program. Wildlife Research 33, 85–91.

Gentle M. (2008). Fox management in south-eastern Australia – management strategies and cost-efficiencies. Verlag Dr Müller, Saarbrüecken, Germany, pp 337.

Körtner G. (2007). 1080 aerial baiting for the control of wild dogs and its impact on spotted-tailed quoll populations in eastern Australia. Wildlife Research. 34:48–53.

Körtner G., Gresser S. & Harden. B. (2003) Does Fox baiting threaten the spotted-tailed quoll, Dasyurus maculatus? Wildlife Research 30, 111–118.

Körtner G. & Watson P. (2005). The immediate impact of 1080 aerial baiting to control wild dogs on a spotted-tailed quoll population. Wildlife Research 32, 673–680.

Murray A. J. & Poore R. N. (2004). Potential impact of aerial baiting for wild dogs on a population of spotted-tailed quolls (Dasyurus maculatus). Wildlife Research 31, 639–644.

Saunders, G. & McLeod, L. (2007). Improving Fox Management Strategies in Australia. Bureau of Rural Sciences, Canberra.

Van Polanen Petel, M., Marks, C.A. and Morgan, D.G. (2001). Bait palatability influences the caching behaviour of the red fox (Vulpes vulpes). Wildlife Research, 28, 395–401.