REPORT ____________________________________________________________________________

Island feral cat eradication workshop

___________________________________________________________________________

Kangaroo Island

26 – 28th June 2017

This project is supported by Natural Resources Kangaroo Island, through funding from the Australian Government’s

National Landcare Program

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Contents 1. Background ..................................................................................................................................... 2

2. Island eradication: broad concepts ................................................................................................. 2

3. Lessons learnt ................................................................................................................................. 4

3.1 Funding ................................................................................................................................... 4

3.2 Community support ................................................................................................................ 4

3.3 Planning................................................................................................................................... 5

3.4 Staff capacity ........................................................................................................................... 5

3.5 Strategy ................................................................................................................................... 5

4. Challenges ....................................................................................................................................... 6

4.1 Funding ................................................................................................................................... 6

4.2 Legislation and regulation ....................................................................................................... 6

4.3 Operational challenges ........................................................................................................... 6

4.4 Community .............................................................................................................................. 7

5. Eradication tools ............................................................................................................................. 7

5.1 Baiting ..................................................................................................................................... 7

5.2 Trapping .................................................................................................................................. 8

5.3 Detection dogs ........................................................................................................................ 9

5.4 Grooming trap ......................................................................................................................... 9

5.5 Shooting ................................................................................................................................ 10

5.6 Sentinel cats .......................................................................................................................... 10

5.7 Monitoring ............................................................................................................................ 10

6. Island cat eradication programs ................................................................................................... 11

6.1 Bruny Island .......................................................................................................................... 11

6.2 Christmas Island .................................................................................................................... 11

6.3 Dirk Hartog Island ................................................................................................................. 12

6.4 French Island ......................................................................................................................... 12

6.5 Kangaroo Island ..................................................................................................................... 13

6.6 Additional island cat projects ................................................................................................ 13

7. Animal welfare considerations ..................................................................................................... 14

8. Future collaboration ..................................................................................................................... 15

Appendix 1: List of workshop delegates ............................................................................................... 16

Island representatives ................................................................................................................... 16

Guest Speakers.............................................................................................................................. 17

Additional workshop delegates .................................................................................................... 18

Appendix 2: Desirable behaviours workshop ....................................................................................... 19

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Report prepared by Hannah Bannister

Cover photo: Patrick Hodgens (Terrain Ecology)

1. Background Five Australian islands have been prioritised for feral cat eradication under the Australian Government

Threatened Species Strategy: Bruny Island, Christmas Island, Dirk Hartog Island, French Island and

Kangaroo Island. A workshop was conducted on Kangaroo Island in June 2017 to share learnings from

current eradication programs, including successes and challenges, and build a network of

practitioners for future collaboration and sharing. Delegates from an additional six islands (West

Island, Tiwi Islands, Phillip Island, Lorde Howe Island, Rakiura/Stewart Island (NZ) and Groote Eylandt)

currently undertaking feral animal control and/or research were also invited to attend. Several guest

experts delivered presentations about animal welfare, island eradication concepts, the use of toxins

and community engagement. Natural Resources Kangaroo Island hosted the workshop, which was

supported by the Office of the Threatened Species Commissioner through funding from the Australian

Government’s National Landcare Program.

2. Island eradication: broad concepts Invasive species are responsible for around 60% of island animal extinctions, and the removal of such can have both ecological and economic benefits. Broad island eradication concepts are not species specific. Eradication involves the complete removal of all individuals of a pest species, in comparison to control, which requires a sustained effort to maintain pests at a low density. The Pacific Invasives Initiative (www.pacificinvasivesinitiative.org) suggests a 6-step project process for island eradications, with ongoing stakeholder engagement, monitoring and evaluation and biosecurity throughout the lifetime of the project:

1. Project selection - Define selection criteria - Notify the stakeholders

2. Feasibility study - Assess biosecurity issues. - All individuals of the target pest species

must be put at risk by the eradication techniques used in order for eradication to be feasible.

- The kill rate must exceed the breeding rate, regardless of density.

- The probability of re-establishment must be manageable to near-zero.

- The project needs to be socially acceptable on a local, national, scientific and political scale. Community opposition can derail a project.

- The impacts on non-target species need to be considered, and this needs to be upfront – keep the big picture in mind.

- Risk-assessment (eg. mesopredator release, costs of inaction).

Source: Pacific Islands Initiative

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3. Project design - The project needs to have the ability to adapt to changing circumstances. - Look at everyone else’s experience and don’t try and reinvent the wheel. - Define project governance, the goals and objectives, monitoring, timelines and estimate

costs. - Plan a risk assessment.

4. Operational planning - Secure permits and consent (eg. landholder

access). - Sustained pressure can ensure no successful

juvenile recruitment, leading to population collapse.

- Successful hunters: show persistence and dedication as well as a belief in the outcomes of the project, understand the effort required, know the target species and how they operate in that environment, recognise and solve motivational challenges and understand that a search may not find anything, revel in the island conditions and lead by example.

- Identify the target species’ weaknesses (eg. for social species, Judas animals are effective).

- Use all control methods available and use them in the right order; don’t use all available methods at once.

- Look out for new technologies. - Manage non-target risks and biosecurity concerns.

5. Implementation 6. Sustaining the project

- Continue to engage with stakeholders, maintain biosecurity procedures and respond to incursions.

- Conduct post-eradication monitoring. - Complete a project report – share your findings.

The eradication of pest species from islands can have immense biodiversity gains and they can be rapid, dramatic and sustained. Eradications offer opportunities for reintroductions or translocations of species that were historically present (and became locally extinct) or that are unable to persist with predation pressure on the mainland. Further reading:

Pacific Invasives Initiative ‘Resource kit for rodent and cat eradication’ http://www.pacificinvasivesinitiative.org/rce/index.html ‘The project process summary’ http://www.pacificinvasivesinitiative.org/site/pii/files/resources/posters/Rodent%26CatProjectProcess.pdf

Feasibility

Kill rate exceeds breeding rate

Probability of re-establishment = 0

Project is socially acceptable

Benefits outweigh costs

Figure 1: Five eradication principles, as suggested by Keith Springer

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3. Lessons learnt

3.1 Funding Securing a funding commitment for the duration of an eradication project was generally considered the most important factor in a successful island eradication, despite not all island attendees having secured such funding. Long-term funding gives confidence in the project delivery and saves time as grant applications do not constantly need to be prepared. Funding should include pre- and post-removal monitoring as well as a contingency plan. It is critical that funding is not wound back as pest numbers dwindle – the last few individuals are usually the most difficult and expensive to remove, and it is vital that funding is not redirected or withdrawn. Precedents can make funding easier to obtain – eg. Island X did it, and so can we.

3.2 Community support Achieving community support for an eradication was also considered vital for success, particularly for inhabited islands. Understanding that different people have different motivations can be an important factor – for example, on West Island, an ecologist is driven by wanting to achieve native mammal recovery, whereas Traditional Land Owners can be motivated by seeing the importance of people working on and being connected to country. Throughout the workshop it was stressed that cats should not be vilified. Showing an understanding that some people have personal connections to cats was more likely to result in community support. Responsible pet ownership was identified as one of the most important factors in not only achieving eradication but preventing future reinvasion. Several islands were faced with difficulties because of non-existent or non-enforced by-laws regarding cat containment. In these cases, having community support was seen as the best way to overcome this, as residents would comply without being forced to. There was considerable debate around whether by-laws and the enforcement of by-laws were constructive or would hinder progress, and it may be context specific. Where the majority of residents want cat removal (eg. Kangaroo Island), a change to by-laws shows a commitment to the eradication project – without them, people think you’re not taking the project seriously. The delivery of the rules is important, for example a two-strike policy (no fine for strike one) often results in cat owners simply being happy to get their cat back and prompts them to investigate containment options. Phillip Island highlighted the importance of using vet clinics as advocates for responsible cat ownership. Focusing on human health was seen as one way of encouraging community support for cat eradication, while agricultural health (disease transmission) was seen as an avenue for economic benefit. Education was another key tool to address common misconceptions such as that fertility control was a better option than lethal control, that a bounty alone could achieve an eradication, that poisons would contaminate people’s water supplies and that there would be significant non-target impacts. Education was also important for responsible pet ownership, with some campaigns aimed at showing people that indoor cats have happy, safe lives, and showing people the damage that cats can do to native wildlife when allowed to roam. Community support can be achieved by building trust, employing a resident community engagement officer, maintaining constant one-on-one engagement with residents, driving home key facts and calling out misinformation. Encouraging the community to take ownership of and show pride in the project was seen as a positive step. Providing an accessible avenue for feedback was also crucial. Offering locals employment through the project can have a positive effect on community support. Monitoring throughout a project enables a story to be built, as well as enabling additional funding to be obtained and keeping motivation high. Encouraging the community to come on the journey can be important for garnering support. Building on local skills and knowledge can help an eradication achieve

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its goals faster. Proactive, open and honest communication with the community helps build trust, and it is important to maintain confidentiality, comply with landholder conditions (eg. close the gate) and notify landholders when accessing properties and notifying them if those plans changed. Barriers to engaging the community in desirable behaviours included a perceived increase in other pests such as mice, attachment to pet cats, costs imposed by new by-laws, not wanting a change to their lifestyle, tradition, anti-government mentality, an opposition to toxic compounds and relying on pet cats as medical, psychological support or companion animals. Most of these barriers could be overcome by providing education backed by scientific research, combined with options such as subsidies to encourage responsible pet ownership and the option to have an alternative pet other than a cat.

3.3 Planning Detailed planning is essential for a successful eradication, and should include a contingency plan should eradication not be feasible. Peer review during the planning process was highlighted as being critical and enables improvement of the planning process. It was also suggested that seeking field assistance from other experts would aid in achieving success faster. Assumptions and trial field techniques should be tested under all conditions. Several methods should be used, beginning with passive techniques and progressing to more aggressive techniques so that animals have less chance to learn.

3.4 Staff capacity A ‘can-do’ attitude and determination to overcome obstacles are key factors in achieving a successful eradication. Team members need to be highly dedicated to the task and have a genuine belief in what they are doing. It is critical to fully appreciate the difficulty of completing the task and to have the stamina to see it through to the end. Ideally project staff can be focused on the project and do not have their time diluted by needing to perform other tasks. Project champions and an accountable project manager are also key ingredients for the success of a project.

3.5 Strategy It is important to take multiple approaches as what works one year may not work the next – for example, baiting on West Island was much more successful after a dry year and with burning, but rainfall hindered bait uptake in a different year. An understanding of the local diet of cats was considered important as it aids in determining when cats are hungrier and can be targeted using baiting or cage traps. The geography of islands provides unique opportunities for eradication – several islands were able to build (or propose to build) a fence, splitting the island into management units: Dirk Hartog Island, Kangaroo Island, Phillip Island and Stewart Island. Peninsulas provided cost-effective fencing options. Eradication can then be focused on one area before moving onto the next and reducing the risk of reinvasion. Habitat was also identified as being a potential driver of cat populations and distribution, and should be considered when planning an eradication.

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Figure 2: Workshop delegates discussing the location of Kangaroo Island’s fence, aiming to minimise habitat loss by having a slightly longer fence on farmland with no requirements for native vegetation removal. (Photo: Hannah Bannister)

4. Challenges

4.1 Funding While whole funding packages are considered key to successful eradication, presenting a large, long-term budget often seems daunting, and to decrease costs items such as monitoring are sometimes removed to make the project more palatable to funders – this needs to be overcome. Sustained and adequate funding is difficult to secure because of the lengthy timeframe most eradication projects require. It is therefore vital to be realistic about costs when planning, and consider contingencies when developing the project budget. Long-term projects also need to consider within their budget that some costs (eg. fuel, wages) may change over time.

4.2 Legislation and regulation Regulation challenges were highlighted throughout the workshop with regards to responsible cat ownership. Working with local council to ensure the legislation reflects the needs of the project was considered vital. In addition, many control techniques are banned for use on feral cats in certain states. For example, the only tools available for cat control in Victoria are cage trapping and shooting, which when used alone are unlikely to result in a successful eradication. Other tools such as leghold trapping are permitted for the use on other species but not cats. Delegates from French Island and Phillip Island suggested part of their projects involved advocating for legislation change. In Western Australia, where many more techniques are approved or used under experimental license, the eradication of cats from Dirk Hartog Island was achieved relatively quickly and efficiently.

4.3 Operational challenges Operational challenges such as terrain and limitations to different techniques should be considered – for example, alternative presentation of leghold and cage traps as well as baits is essential on Christmas Island where crabs have a negative impact on most standard control techniques. Staff must continue

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to develop innovative ideas based on their knowledge of local conditions to achieve an eradication. A strong mindset is required to remove the last few individuals.

4.4 Community Community opposition has proven a challenge for several presenting islands. Lack of trust of outsiders and a focus on pure science rather than the emotional issues surrounding island eradications were identified as problems. Consultation with community prior to commencing an eradication project was highlighted as a key factor in achieving success. Don Hine (UNE/Invasive Animals CRC) outlined four key principles for achieving a change in community behaviours during a feral animal control project:

1. Focus on behaviour – awareness is not enough to facilitate engagement by everyone. Interventions should focus on a small number of high impact behaviours. Consider the impact on the pest, the probability of the adoption of the behaviour and how many people already do that behaviour (current penetration) – behaviours can be ranked and then one is selected to target for change, creating a behaviour prioritisation matrix (McKenzie Mohr and Smith 2011). Behaviours should be as specific as possible – eg. for responsible cat ownership, break into components such as 24-hour containment, no feeding of strays etc. Need clear measures of success and clear objectives. See Appendix 2 for workshop.

2. Know your audience – values, attitudes and beliefs vary, influencing individual responses to engagement strategies. Audience segmentation (dividing the population into subgroups) can enable you to design interventions that match the characteristics of specific segments.

3. Match interventions to the primary causes of behaviour – techniques must match the context, and techniques should be tailored to the differences in subgroups. People must be convinced of how the problem is related to them (or could be in future).

4. Employ rigorous, science-based evaluation – evaluations of social science strategies enables researchers to determine whether interventions have been effective and why.

Further reading:

McKenzie Mohr, D and Smith, W 2011. ‘Fostering sustainable behavior: an introduction to community-based social marketing’. New Society Publishers, British Columbia.

5. Eradication tools The general consensus within the workshop was that eradications need to start with passive techniques (eg. baiting, leghold traps) before progressing to more aggressive techniques (eg. detection dogs, spotlight shooting, cage trapping) which are more likely to disrupt the population, encouraging target individuals to become smarter and thus harder to remove. Passive methods are less likely to teach individuals to avoid the control methods. An animal’s first encounter with a control method needs to be lethal – don’t give them a chance to learn.

5.1 Baiting Three cat baits are currently produced in Australia – Eradicat® (direct injected 1080), Curiosity® (encapsulated PAPP) and Hisstory® (encapsulated 1080). All three are considered equally effective for cat control but offer different non-target impacts - encapsulated poisons can provide some target specificity as native species reject the pellet, while feral cats will readily eat the whole bait, or large pieces of the bait (Buckmaster et al. 2014). The Curiosity bait for feral cats has not yet been approved for use by the APVMA. Aerial baiting was generally considered to be an effective tool for cat eradication where it has been tried, although legislation prevents its use in some states. The technique is passive, with cats that do not encounter baits or choose not to eat them unlikely to actively avoid them in future. The challenge

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with feral cat baiting is the preference for live prey. This problem was highlighted on West Island where as cat densities decreased and prey populations recovered, the bait uptake reduced because of the higher availability of live prey. While baiting can offer effective cat control if the timing and conditions are ideal, it isn’t possible to prevent dingoes from also consuming baits, although they would need to consume more than one to obtain a lethal dose. Bait longevity is influenced by ants (need to use Coopex) and is highly dependent on climate. Baits desiccate quickly in summer – late autumn/early winter is better, but ideally rain needs to be avoided as it causes baits to become mouldy and alters the bait chemistry, reducing palatability. One key problem with aerial baiting is that flexibility in the timing of the bait drop is needed (due to weather etc.), however with planes covering large areas bookings often need to be in advance and have limited flexibility. GPS data from the flight path is essential to determine whether any areas have been missed, and where possible these can be followed up with hand baiting. The Department of Environment has assessed the humaneness of Curiosity® baits and the results are being published. While 1080 tolerance is often similar for closely related species, PAPP tolerances can vary widely even between closely related species. The net benefit of cat eradication needs to be considered when deciding whether to use baiting as a control tool – a proportion of the prey population may be lost due to baiting, however increased juvenile recruitment following cat control may outweigh this cost. Risk mitigation is sometimes possible, for example avoiding bait uptake by goannas by baiting when the weather is cool, or using aerial baiting instead of ground baiting to avoid corvids associating humans with baits. Both toxic and non-toxic baiting trials have been conducted on several of the islands that presented at the workshop; to assess the impacts on non-target species and to measure cat uptake so it can be used as a key tool for eradicating cats. Baiting appeared to be a preferred broad-scale, passive control technique that would provide a large initial knockdown if the timing was right. Further reading:

Buckmaster, T, Dickman, CR and Johnston, MJ 2014. ‘Assessing risks to non-target species during poison baiting programs for feral cats’. PLoS One. 9(9):e107788. DOI 10.1371/journal.pone.0107788

5.2 Trapping Cage trapping was seen as an effective technique on some islands (eg. Kangaroo Island, French Island, Christmas Island) but was of no benefit for others (eg. Dirk Hartog Island, West Island), therefore local environments play a huge role in determining which techniques are effective. Leghold traps were generally seen as a useful tool by island representatives, although legislation prevents their use for feral cats in Victoria. Leghold traps represent a passive control technique, whereby cats that are not caught (ie. do not encounter a trap) are not taught to avoid them. Trapping is limited by usually being restricted to road and track networks, which for many islands meant that large areas were inaccessible for trapping. This inherently introduces the problem of accessibility by the public, and highlights the importance of having community support for the project. Some islands had problems with the capture of or interference by non-target species, which resulted in alternative ways of presenting traps, such as cage traps on wheelie bins or elevated leghold traps placed on ½ 44 gallon drums (Christmas Island).

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5.3 Detection dogs Detection dogs can be a useful tool for both detecting cats during an eradication and detecting cats (or other pest species) at biosecurity points. Detection dogs have been used to aid in the eradication of or verification of the absence of cats on islands such as Macquarie, Wedge, Tasman and Dirk Hartog and are often used for verification that the final cats are gone. Dogs are able to access areas that are not accessible by vehicle and generally cover at least twice as much ground as their handler. Dogs fitted with GPS collars provide valuable information as to the areas that have been searched. Limitations and problems include the risk of snake bite during warmer months and the need to rotate dogs every few hours. This can partly be overcome by selecting a breed that is suited to working all day, such as a catahoula or border collie. Key considerations when choosing whether detector dogs are suitable for the project include: Training time – general obedience, regularity of training (part time training takes longer), the

availability of dogs from breeders and finding a dog with a suitable personality. Costs – dog, handler’s salary and training costs, time costs. Certification – currently no national certification in Australia, while in New Zealand both dogs and

handlers must be certified before being allowed to work in national parks. Sue Robinson suggested that an operating framework needs to be developed.

Animal welfare – both target and non-target species, a muzzle and bait aversion training are required when dogs are searching areas where toxic baits may be present.

An eradication project using detection dogs could choose to use either: Contract handler – only pay for the services required, can choose from a variety of handlers, no

on-going responsibility for the dogs, consider that there is no national certification. Useful for short projects.

The project owns a dog – the dog is available for the life of the project and can be trained with specific skills, the dog remains on site and can be an ambassador for the project, can have multiple handlers. High initial cost.

One of the project staff owns a dog – minimum responsibility for project management, the dog is readily available for work or to respond to incursions. Lower cost but loss of service if staff leave.

Detection dogs are the only control method that does not rely on target species coming to a fixed point and therefore have the ability to shorten the duration of an eradication project, however they alone will not achieve eradication. Most islands present at the workshop suggested trialling cat detection dogs at some stage (usually near the end) of their eradication project.

5.4 Grooming trap Several islands outlined a desire to include Felixer grooming traps in their eradication projects. Pat Hodgens (Terrain Ecology) and Dave Dowie (Natural Resources Kangaroo Island) demonstrated the set-up process for a grooming trap during the workshop field trip, and were met with enthusiasm from the delegates. Grooming traps have been trialled on Kangaroo Island (and other areas) in non-toxic mode to assess any risks to non-target species. Feedback from these trials is provided to the manufacturer to enable refinement of the trap. Grooming traps can be positioned in high cat use areas such as tracks and dry creeklines, however their use needs to be strategic as they cannot feasibly be deployed island-wide. Each grooming trap can hold 20 rounds of toxic gel, meaning the device can be left in-situ for lengthy periods of time before needing to be re-loaded. The trap stores images of all triggers (target and non-target), providing information such as which sensors were triggered, the date and time etc. A variety of audio lures are inbuilt into the

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trap and these can be pre-programmed and altered as necessary. The software can be updated, which will enable things like alternative lures (audio) to be trialled, and solar power ensures the battery will not run out. Current limitations include cost, the weight of the device (the area needs to be relatively accessible by vehicle) and that 1080 needs to be locked if it is being used in an area accessible by the public. Currently the Felixer grooming trap is used under research permit only.

Figure 3: Dave Dowie (Natural Resources Kangaroo Island) and Pat Hodgens (Terrain Ecology) demonstrate the Felixer grooming trap to an engaged audience. (Photo: Hannah Bannister)

5.5 Shooting Spotlight shooting was commonly used

as an effective supplemental form of control, or was used in combination with detection dogs. The use of recreational and professional shooters caused some debate, with some projects undergoing a high degree of scrutiny and achieving high welfare outcomes (eg. camel control project in Australia), whereas other projects have had some problems (eg. deer control in New Zealand, bow hunting). Di Evans (RSPCA Australia) suggested that certification as well as completing a short course on animal welfare and ethics could be a step forward in the effective use of shooters in control programs.

5.6 Sentinel cats Radio-collared female cats in oestrous could be used to attract or locate other cats. The cat could be given a lethal implant containing 1080 which would discharge after 20 days. Implants enable the release of radio-collared cats with the security of ensuring they are removed from the population after sufficient data has been collected. Dave Algar (DBCA) suggested sentinel cats and lethal implants were currently in pen trial phase in Western Australia but could be applied more broadly in future.

5.7 Monitoring Remote cameras were the most common monitoring method employed by islands to determine the distribution and activity of feral cats. Spatially explicit designs were preferable, although sometimes this was not feasible. Remote cameras also offer an opportunity to monitor native species simultaneously. Sand plots and active searches for spoor were other techniques used to look for cat sign and were also used to search for recovering native species (eg. tracks from a delicate mouse were found on West Island). The ability to conduct searches for cat tracks was largely dictated by the soil type, with sandy soils, beaches and vehicle tracks the easiest to detect tracks on. Cat detection dogs were often used after the removal of the last cats to ensure that none had been missed or that reinvasion had not occurred. Detailed monitoring techniques were not discussed at the workshop, however the importance of conducting rigorous monitoring of both the target species and native species recovery was highlighted. Poorly designed monitoring programs can lead to ineffective project outcomes.

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5. Island cat eradication programs

Figure 4: The location of five Australian islands selected for feral cat eradication under the Threatened Species

Strategy, and the location of additional islands undertaking feral cat eradication projects that were represented

by delegates at the workshop.

6.1 Bruny Island Bruny Island is a 362 km2 island off the coast of Tasmania, with around 770 residents and a mean annual rainfall of 930 mm. Biodiversity gains (including for tourism) are a key driver of the proposed eradication, with some interest in the effects of toxoplasmosis on the agricultural industry. The project is community driven, with 83% in support of the eradication of feral cats. The reluctance of some residents to comply with responsible pet ownership has been identified as an initial problem. Research is aimed at assessing the diet of feral cats on the island, determining cat, quoll and rabbit distribution across the island, analysing cat genetics and the prevalence of disease, researching cat movement (using GPS collars) and monitoring predator activity at ‘the neck’. Control methods need to be palatable to the community and are likely to include cage trapping and shooting – a cautious approach is initially being undertaken in order to retain community support for the project. A decision framework is likely to be developed. The construction of a fence across the isthmus is considered a long-term option but the feasibility needs to be investigated. Currently, the project is viewed as long-term, with a vision, plan and funding required.

6.2 Christmas Island Christmas Island is a 135 km2 island south of Indonesia, with around 2,000 residents and a mean annual rainfall of 2,183 mm. Key drivers of the cat eradication are protection and recovery of threatened species and ecological communities. Regular community engagement has required collaboration between several organisations on the island – a ‘no replacement’ policy is now in place on the island. The project has been divided into three

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stages – Stage 1 – responsible cat ownership, Stage 2 – control of stray and feral cats in residential and industrial areas, and Stage 3 – island-wide eradication. Control techniques include roadside baiting suspension devises (BSD), 1080 baiting (including forest string baiting), elevated leghold and cage trapping and shooting. Non-target species, particularly crabs, have resulted in creative techniques being adopted and can limit suitable control techniques at certain times of year. The ecological changes across the island as a response to cat control (and eventually eradication) are being investigated as NESP projects. Remote cameras are used to monitor feral cats across the island. Unprecedented rainfall in 2016 limited the amount that could feasibly be achieved. Baiting trials are still being undertaken, and research is aiming to develop and test novel ideas that will achieve cat control at very low densities.

6.3 Dirk Hartog Island Dirk Hartog Island is a 620 km2 island off the coast of Western Australia, with an Ecotourism business providing the only permanent residents on the island, and a mean annual rainfall of around 193 mm. Feral cats were successfully eradicated by October 2016. World Heritage Listing of the island as well as having 10 of 13 native terrestrial mammals declared locally extinct aided in garnering support for feral cat eradication. The eradication was achieved through careful planning (including a pilot study), implementation, verification of the eradication and ongoing surveillance. Security of funding for the duration of the project was considered essential. GPS data from radio-collared cats was used to identify suitable eradication techniques and the optimum scale at which they needed to be applied. A barrier fence was used to divide the island into two management units. Control techniques included aerial baiting using Eradicat® baits (~90% success) and leghold traps. Cage trapping was found to be ineffective. Remote cameras and searches for spoor were used as monitoring techniques and to determine where control efforts needed to be intensified. Cat detection dogs were used to verify the presence or absence of cats across the island towards the end of the eradication. The island is currently in a 2-year surveillance phase (post-eradication), after which the reintroduction of native species will occur. This provides an insurance policy to ensure no cats have been missed or reintroduced.

6.4 French Island French Island is a 170 km2 island off the coast of Victoria, with around 200 permanent residents and a mean annual rainfall of 574 mm. Biodiversity conservation is the key driver of the eradication, with an internationally significant wetland present on the island. Cage trapping is currently the main control method being utilised, supplemented with some spotlight shooting. Two local residents have been employed to conduct trapping during winter. Control efforts have, to date, focused on cage trapping within areas of high conservation significance – trapping alone is unlikely to achieve eradication, and an eradication plan is needed to move the project forward. Ongoing control efforts have resulted in the number of cats trapped per time unit plateauing, whereby the same amount of effort is resulting in fewer cats caught. Untrapped areas have been identified as refuges for feral cats. Research using GPS collared cats has aided in identifying the behaviour of cats on the island. Community engagement has been undertaken via community education days, articles in the local newspaper and free domestic cat sterilisation programs facilitated by Landcare.

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As there is no local government on the island, compliance with responsible pet ownership measures is not required and cannot be enforced, therefore community education and support is vital for the project to succeed. Ideally, tools for future use will include ground baiting, leghold and cage trapping, shooting, detector dogs, grooming traps and aerial baiting, although current legislation does not allow aerial baiting or leghold trapping for cats in Victoria.

6.5 Kangaroo Island Kangaroo Island is a 4,405 km2 island off the coast of South Australia, with around 4,500 residents and a mean annual rainfall of 490 mm. Key drivers of the eradication are biodiversity conservation and the spread of cat borne disease – the prevalence of toxoplasmosis and sarcosporidiosis is higher on Kangaroo Island than the mainland and presents a threat to both human and livestock health. This has aided in achieving 95% community support for feral cat eradication on the island. Stage One (non-lethal control trials) of feral cat eradication on Kangaroo Island is currently underway, with initial funding secured for 18 months. Rigorous trials of all available eradication techniques (grooming traps, cat detection dogs, baiting, cage trapping, lure trials etc.) are being undertaken to guide eradication on the Dudley Peninsula, at the eastern end of the island (Stage Two, 2018-2021), and research on feral cat ecology (including VHF and GPS collaring cats) will guide eradication efforts. A barrier fence will be used to split the island into two management units. Complications will include a main road that passes through the fenceline, where a physical gate is not an option. Virtual grids and cat aversion techniques are being investigated as alternative options. Diet analysis will be undertaken during control efforts. Goats and deer have previously been eradicated from the island and lessons learnt from these eradication techniques as well as community engagement will be applied for the feral cat eradication project. Radio-collared cats combined with remote cameras will be used to determine the efficacy of different control techniques and to measure reinvasion rates while cat removal is undertaken in research areas. A before-after control-impact (BACI) designed experiment will monitor changes to biodiversity on both sides of the fence, before and after cat eradication on the Dudley Peninsula, using cage trapping, pitfall trapping and remote cameras. Rodent monitoring is also being undertaken. A NESP project focussed on the KI Dunnart is commencing in July 17. Community engagement with landholders has been identified as a key priority for the project to move forward successfully, as well as seeking and securing long-term funding through private investment.

6.6 Additional island cat projects West Island (Northern Territory) is moving from cat control to cat eradication, following a funding boost from the Office of the Threatened Species Commissioner. West Island is a significant breeding site for threatened marine turtles, and has had a severe decline in native mammal species since feral cats arrived. Long-term mammal monitoring has shown some species to reappear after a decade of zero trap success for small mammals following the implementation of cat control, however two species appear to have gone locally extinct. The number of monitoring sites with cat sign has decreased from 81% to 14% since control began. They aim to use as many techniques as possible to achieve eradication. Phillip Island (Victoria) has achieved fox eradication and is now looking towards feral cat eradication. The removal of foxes has facilitated several proposed reintroductions, however cats pose a threat to

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these species via predation and disease and their removal is considered essential for some to succeed. Current Victorian legislation means that cage trapping and shooting are the only control methods currently able to be used on feral cats, and the project is advocating for legislation changes. Research will focus on control efficacy and non-target risk should baiting be approved for use. Cat diet and the prevalence of disease is also being investigated. Groote Eylandt is an island with high conservation value, with little evidence of native species declines and numerous endemic species, several of which are threatened. Cats are known to be present at a low density, however their ecological impacts on the island remain largely unknown. Currently, cat management is being targeted towards the management of domestic and stray cats. Future research will determine the feral cat density across the island and assess the potential for non-target impacts should baiting be used to control cats. The feasibility of eradication is yet to be considered, with current options identified as eradication, management of community cats, no cat management, or improved fire and weed management and biosecurity. Stewart Island (Rakiura), in New Zealand, considered the feasibility of cat eradication in 2007, pushed by the presence of threatened species on the island including many endemics. Research on cat ecology on the island will inform the eradication process. Community support is considered vital and a social scientist will be engaged to facilitate this. The Tiwi Islands (Northern Territory) current focus is on preventing new pest incursions (especially cane toads). Cats are present on both Melville and Bathurst Island and were only identified as a significant problem around 10 years ago. The current focus on cat management on the islands is around education and community awareness, particularly with regards to responsible cat ownership. GPS collars are now being fitted to domestic cats to demonstrate to the community the behaviour of domestic cats. Recent mammal surveys have given people cause for concern with some native species significantly declining in correlation with cat activity, therefore cat management options are currently being explored.

7. Animal welfare considerations Animal welfare should be a paramount consideration for any pest control or eradication project. Thus any vertebrate pest control project should be justified (benefits v harm), effective (validated methods, monitoring and evaluation) and humane (humaneness model and the impact on non-target species). Eradication projects should consider the welfare of both target and non-target species as paramount, and ensure that control methods are delivered ethically. A Humaneness Model (Sharp and Saunders 2011, Fig. 5) and Standard Operating Procedures should be employed during project planning and implementation. It is important to recognise the human-cat relationship many people have. However, the welfare considerations of the native animals we are trying to save from predation by feral cats should also be a consideration, including the opportunity costs of non-action.

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Figure 5: The humaneness of selected cat control measures, based on the model developed by Sharp & Saunders

2011. Slide courtesy of Di Evans (RSPCA). The worksheet to assess humaneness is available at

www.pestsmart.org.au

Further reading:

Sharp, T. and Saunders, G. (2011). A model for assessing the relative humaneness of pest animal control methods (Second edition). Australian Government Department of Agriculture, Fisheries and Forestry, Canberra, ACT. Accessible via www.pestsmart.org.au

8. Future collaboration Delegates agreed that the workshop provided a useful means of sharing successes and challenges in controlling or eradicating pest species from islands and that ideally the forum would be repeated next year. The importance of sharing failures as well as successes was raised. Webinars were seen as being one possible vehicle for maintaining contact amongst the group and building a community of practice to facilitate on-going knowledge sharing. The workshop report will contain contact details for all delegates to allow networking opportunities to continue. Establishment of a peer review process or forum was considered a critical component of developing robust and defensible island eradication plans, perhaps modelled on the Island Eradication Advisory Group (IEAG) that operates in New Zealand. The OTSC agreed to establish a shared Dropbox to store workshop presentations and supporting material, and as a place for delegates to add project status reports to keep everyone informed about the progress of their eradication project.

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Appendix 1: List of workshop delegates

Island representatives Bruny Island

Kaylene Allan Project Coordinator, Bruny Island kallan@kingborough.tas.gov.au

Brett Woodruff Field Officer

Christmas Island

Caitlyn Pink Australian Government caitlyn.pink@environment.gov.au

Scott Suridge scott.suridge@environment.gov.au

Dirk Hartog Island Dave Algar Senior Research Scientist, Department of Biodiversity, Conservation and Attractions dave.algar@dpaw.wa.gov.au

French Island

David Stephenson Ranger, French Island National Park david.stephenson@parks.vic.gov.au

Andrew Morrison andrew.morrison@environment.gov.au

Kangaroo Island

Martine Kinloch Manager Science & Program Planning, Natural Resources Kangaroo Island martine.kinloch@sa.gov.au Patrick Hodgens Project Manager, Terrain Ecology pat@terrainecology.com.au

Dave Dowie Field Officer, Natural Resources KI dave.dowie@sa.gov.au

Phillip Island

Richard Faulkner Vertebrate Pest Ranger, Nature Play rfaulkner@penguins.org.au

Duncan Sutherland Deputy Research Manager, Nature Play dsutherland@penguins.org.au

Tiwi Islands Kate Haddon Land and Resources Manager tiwilcnrm@bigpond.com

Willy Rioli Supervisor, Land Management Team

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West Island Rachel Paltridge Desert Wildlife Services desertws@bigpond.net.au

Anthony Johnson Ranger, West Island Steven Simon Ranger, West Island

Groote Eylandt Graeme Gillespie Northern Territory Government graeme.gillespie@nt.gov.au

Lord Howe Island

Anthony Wilson Assistant Project Manager anthony.wilson@lhib.nsw.gov.au

Stewart Island

James Reardon Threats Unit, Biodiversity Group, DOC NZ jreardon@doc.govt.nz

Guest Speakers

Keith Springer keith.springer@gmail.com

RSPCA

Di Evans Senior Scientific Officer, RSPCA Australia devans@rspca.org.au

Tasmanian Government

Sue Robinson Detection dog handler sue.robinson@dpipwe.tas.gov.au

Australian Government

Julie Quinn Assistant Director, Environmental Biosecurity Section, Australian Government julie.quinn@environment.gov.au

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University of New England Don Hine Environmental Psychologist, UNE / Invasive Animals CRC dhine@une.edu.au

Natural Resources Kangaroo Island Nick Markopoulos Pest Animal Control Officer, Natural Resources Kangaroo Island nick.markopoulos@sa.gov.au

Additional workshop delegates Australian Government

Casey Harris Advisor, TS Office

Oliver Tester Advisor, TS Office

Rapporteur

Hannah Bannister Contracted workshop report writer hannah.bannister@adelaide.edu.au

Appendix 2: Desirable behaviours workshop Task: In groups, identify desirable community behaviours to achieve cat control and complete the matrix. Include not only behaviours that need to be changed but also good behaviours that need maintaining.

Weighted impact = Effectiveness x Likelihood of adoption of behaviour x inverse Current penetration

Bruny Island

Behaviour Effectiveness (1-10)

Likelihood of adoption (1-10)

Current penetration (1-10)

Weighted impact

1. Feeding unowned cats (including control) 6 8 5 9.6

2. Desexing owned cats 8-9 9 9 8.5

3. Containment of owned cats 8-9 8 4.5 15

4. Ownership of the process

5. Community reporting of problem cats or people (eg. feeding). Needs to happen after (4)

7 3-4 3 8.2

Christmas Island

Behaviour Effectiveness (1-10)

Likelihood of adoption (1-10)

Current penetration (1-10)

Weighted impact

1. Non-adoption of feral cats 10 9 9 High

2. Reporting the location of strays 9 9 9 Medium

3. Consider adopting an alternative pet, as per steering committee actions

5 5 1 Low

4. Continued support of control measures 10 8 8 High

French Island

Behaviour Effectiveness (1-10)

Likelihood of adoption (1-10)

Current penetration (1-10)

Weighted impact

1. Record and report sightings 3 8 8 3

2. De-sex owned cats 9 8-9 6 12.75

3. Open land access for baiting on private land (willingness to cooperate)

10 8 0 80

4. Support phase-out of cat ownership 8 3 0 24

5. Stop feeding / supporting feral cats 8 9 1 72

Kangaroo Island

Behaviour Effectiveness (1-10)

Likelihood of adoption (1-10)

Current penetration (1-10)

Weighted impact

1. Responsible cat ownership 7 9.5 5 13.3

2. Willingness to approach NRKI or FCEP 4 3 8.5 1.4

3. Willingness to permit access to properties for control

10 9.5 9.5 10

4. Willingness to undertake feral cat control voluntarily

8 8 5 12.8

5. Report sightings 10 9 2-9 (6) 15

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Stewart Island

Behaviour Effectiveness (1-10)

Likelihood of adoption (1-10)

Current penetration (1-10)

Weighted impact

1. Report cat sightings 4 8 5?

2. Compliance with laws 9 8 5?

3. Landowner engagement in ops 3 7 2

4. Positive discussion of program ownership 6 7 8

West Island, Tiwi Islands, Groote Eylandt

Behaviour Effectiveness (1-10)

Likelihood of adoption (1-10)

Current penetration (1-10)

Weighted impact

1. De-sex pet cats 6 7 4 10.5

2. Stop keeping pet cats

3. Stop bringing pet cats to the islands

4. Keep cats inside 7 0-2 0-1 14

Increase participation in cat eradication 7 8 4 14