ZIP Annual Report 2019-20

Annual Report 2019–20

ABOVE:

ZIP field rangers cross a stream in the Lower Barlow area of the Perth River valley field site, carrying prototype remote reporting ‘ZIPinn’ rat and stoat traps for field testing, autumn 2020 (CHAD COTTLE) Designed by Rory Harnden Images by Al Bramley, Briar Cook, Chad Cottle, Jenny Dent, Alex Edwards, Rory Harnden, Robyn Janes, Caroline Wallace, Philip Wisker, and our trusty trail cameras COVER IMAGE:

Morning light over the Butler Range, viewed from the Perth River field site during a kea survey in March 2020. The Perth River can be seen below (CHAD COTTLE)

Contents Forewords

2

Devon McLean, Board Chair

2

Al Bramley, Chief Executive

3

New Zealand’s biodiversity crisis

4

Responding to the biodiversity crisis with fast-paced innovation

6

Our people

8

ZIP Board

8

ZIP team

9

Organisation chart

Remove and Protect Key milestones and achievements

10

12 12

Remove and Protect in action: Eliminating predators in the Perth River Valley

14

Job done! How we eliminated possums

15

What do we mean by predator elimination?

16

Getting closer: Our progress towards eliminating rats

16

Almost there… Preventing stoats re-establishing

18

Using lured trail cameras to detect possums, rats and stoats

19

Other key projects during 2019–20

21

Minimising reinvasion

22

Initial removal

26

Detection

27

Response

32

Support for other predator free projects

33

Future directions

36

Financial summary

38

Founding partners

38

Other funders during 2019–20

38

Financial statements

38

Glossary

39

Acknowledgements

41 1 CON TE N T S

Forewords Devon McLean Board Chair Tēnā koutou katoa, This has been, in many ways, an extraordinary year.

For the ZIP team, it has been a hugely successful period. The team has now eliminated possums in the Perth River valley—a remarkable achievement. Not only that, but they have also demonstrated they are very close to achieving the same result for rats and stoats. These significant milestones are described in more detail on pp. 14–20.

All of this would not be possible without the generosity and foresight of our partners—the NEXT Foundation, Department of Conservation, Jasmine Social Investments and Predator Free 2050 Limited—who have continued to support and empower ZIP in a variety of ways (more about this on pp. 6–7). In 2020, we were delighted to have the Biological Heritage National Science Challenge join us as a funder (to support a new detection camera project, briefly described on p. 27).

Throughout the year, my fellow ZIP Board members Charles Daugherty and David Flacks, supported by ZIP/DOC Senior Liaison Mike Slater, have continued to provide excellent guidance to Al and the ZIP team. I thank them for this valuable contribution.

It’s sometimes said of organisations that ‘culture eats strategy for breakfast’. In ZIP’s case, a focused yet agile strategic direction is underpinned by a caring, connected, empowered and innovative team culture, set by the outstanding leadership of Al Bramley and his team of directors.

2 F O R E WO R DS

ABOVE:

ZIP Board Chair Devon McLean (AL BRAMLEY) It has been my great pleasure to be a part of, and witness to, ZIP’s achievements during what has, at times, been a challenging year—and, indeed, over the past five and a half years since ZIP’s inception. Their success in the Perth River valley gives me great hope for New Zealand’s predator free goal, and the future of our precious and vulnerable native taonga.

Ngā manaakitanga,

Devon McLean, Board Chair

Al Bramley

Chief Executive Kia ora tātou, Well, we did it! We have now eliminated all resident possums from the remote and rugged 12,000 hectare Perth River valley—the first time such a result has ever been achieved at this scale on mainland New Zealand.

Equally importantly, one year on from the initial removal, we are now confident we can detect and remove any possums that invade into the site.

More than that, a pathway to achieving rat and stoat freedom in remote back-country sites is becoming increasingly clear to us.

These achievements are the result of an enormous amount of effort by the entire ZIP team into researching, developing, and rigorously field testing new knowledge, tools and techniques. I’m extremely proud of what the team has achieved, and it’s a huge pleasure to work alongside and learn from all of our team members.

These achievements would also not have been possible without the support of many other people, too numerous to list here, but acknowledged on pp. 41–42. In particular, however, I want to acknowledge the ongoing engagement and frank advice of Te Rūnanga o Makaawhio for the work we are doing within their rohe, the support and encouragement of Mark Davies and Wayne Costello at the Department of Conservation, and the guidance of Devon McLean and the ZIP Board of Directors.

We are already beginning to see positive outcomes of the Perth River valley predator removal for kea, kākāriki, kererū and whio (including a particularly memorable encounter one of our rangers had with a flock of 27 juvenile kea earlier this year!)

ABOVE:

Al Bramley, Chief Executive (BRIAR COOK) We are now very well positioned to apply and refine the knowledge, tools and techniques we have learned and developed, to create an even larger predator free haven for these and other native species.

Over the next two years, we plan to eliminate possums, rats and stoats from a further 10,000 hectares in the neighbouring Butler Range, finding operational efficiencies to drive down the cost of the initial removal. The combined site of over 20,000 hectares will then be protected in perpetuity.

Tihei mauri ora!

Al Bramley, Chief Executive

3

New Zealand’s biodiversity crisis Over 80 million years, New Zealand’s native species evolved in isolation from the rest of the world, developing a host of unique characteristics and behaviours. Without mammalian predators, many birds—including the kiwi, kākāpō and takahē—lost the ability to fly.

Others, like kea, mōhua and kākāriki, learned to nest in tree cavities, or to forage or nest on the ground. When possums, ship rats and stoats arrived in New Zealand in the 1800s, our native species were ill-prepared for these unfamiliar new threats. What has followed can only be described as an ecological disaster.

Ship rats and stoats alone have been directly responsible for the extinction of nine native bird species since the late-19th Century1, and have pushed many more birds, bats and invertebrates to the brink of extinction during the same period. Possums are voracious browsers—with catastrophic results for native tree species such as pōhutukawa, kāmahi, kōtukutuku and rātā—but they also devour

invertebrates, and disturb the nests of birds (including kea, kākā and kererū), and eat the eggs and chicks. Today, a staggering 80% of native birds are classified as endangered or threatened2, and in almost all cases invasive predators are recognised as the main cause of decline. Without a doubt, New Zealand is in the midst of a biodiversity crisis.

1. Tennyson A, Martinson P 2006. Extinct Birds of New Zealand. Te Papa Press

2. Wright J 2017. Taonga of an Island Nation: Saving New Zealand’s Birds. Parliamentary Commissioner

for the Environment

4 NE W Z E A L A N D’S B I O D IVER S ITY CR IS IS

ABOVE LEFT:

Possum browse on rata in the Perth River valley (AL BRAMLEY) ABOVE RIGHT:

Rata in flower in the Perth River valley (CHAD COTTLE) Over the last 60 years, conservationists have successfully eradicated predators from over 100 offshore islands within our waters, creating safe havens for native species. But on the mainland of Aotearoa, native ecosystems are in a perilous state. While current approaches to mainland predator control generally work to safeguard biodiversity in the places they are applied, their high ongoing costs limit the scale at which they can be used. Monitoring consistently shows indigenous biodiversity declines at an alarming rate when predators are not controlled3. If we are to halt, and ultimately reverse, this decline, it is clear that we need to do more.

When the New Zealand Government set the goal of achieving predator freedom on the New Zealand mainland by the year 2050, it was widely acknowledged that achieving this goal would require a range of new approaches, knowledge and technological advancements. The good news is that, four years on, thanks to the efforts of a diverse range of New Zealanders (including researchers and innovators, local and national government, iwi, the commercial and philanthropic sectors, and the wider New Zealand public), we are already well on our way.

BELOW:

A tĹŤÄŤ in the Perth River valley, South Westland (CHAD COTTLE)

3. Department of Conservation 2020. Biodiversity

in Aotearoa: an overview of state, trends and pressures.

5

Responding to the biodiversity crisis with fast-paced innovation A ZIP field ranger at work in the Perth River valley, winter 2020 (CHAD COTTLE)

6 RE S P O N DI N G TO T H E B IO D IVER S ITY CR IS IS WITH FAST-PACED INNOVATION

In 2014 a small group within the Department of Conservation (DOC) began to explore a new approach to predator management. The goal would be to eliminate predators from large mainland areas, and then prevent these predators from re-establishing. If successful, this approach could replace the need for never-ending predator control, making it possible to secure significant biodiversity gains across progressively larger mainland areas.

Addressing this conservation challenge would require new knowledge, tools and techniques.

It quickly became apparent that the effort to develop these would need to be: • strongly led by people who passionately believe in the goal; • tightly focussed, and therefore not distracted by the competing demands of a broader work programme; • agile in order to quickly respond to new learning and opportunities; and • funded to pursue the goal as fast as possible.

As a result, in 2015 DOC and the philanthropic NEXT Foundation partnered to found a new stand-alone non-profit research and development entity—Zero Invasive Predators, or ZIP—which was charged with the mission to “rapidly develop operationally-ready and socially acceptable techniques and tools that completely remove possums, rats and stoats from large areas on the New Zealand mainland and protect such areas from predator re-establishment.” We refer to this as a ‘Remove and Protect’ approach to predator management (described on pp. 12–13).

There is no doubt that the establishment of the NEXT Foundation, and the extremely generous endowment from Neil and Annette Plowman, has been fundamental to ZIP’s story. Without this support it is highly unlikely that ZIP would exist. The vision and drive of NEXT Foundation has catalysed further investment in predator free initiatives, including into ZIP and into other projects around the country (some of which are mentioned on pp. 33–35).

With a challenge as complex and urgent as mainland predator elimination, there is a balance to be struck between building an understanding of a specific problem and rapidly developing the tools and techniques to address it. Typically, our approach is to rapidly prototype a trial or design, then field test while continually analysing the results/data.

If something appears to be working well, we amplify the research and development effort, and conversely, we don’t hesitate to stop any work that fails to show promise.

Our ability to work this way is only possible because our founding partners have trusted and empowered us to initiate, undertake and end projects as required, within the parameters of an overall research and development work programme. Changes to the work programme are approved by the ZIP Board, who remain closely connected to the work and witness to our evolving context and thinking. This freedom to operate enables us to rapidly pursue promising ideas, and to quickly adapt projects without an exhausting paper trail.

Further enhancing this freedom to operate is the support we continue to receive from our DOC colleagues. Their frank engagement and advice sharpens our thinking and helps ensure that our approach is both technically and logistically sound. The trust and backing of the Department has also enabled us to carry out multi-year research and development programmes at dedicated field sites on public conservation land. Working at specific sites grounds us in the challenges of a particular place, and provides the unique constraints in which to design and develop solutions that work.

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Our people ZIP Board

Devon McLean Board Chair

David Flacks Board Director

Charles Daugherty Board Director

Mike Slater DOC Senior Liaison

The ZIP Board met four times during 2019–20, including two in-person meetings in Wellington, and two virtual meetings during the COVID-19 travel restrictions.

Senior liaison with the Department of Conservation (DOC) is through Mike Slater (Deputy Director-General—Operations). Mike is not a Board Director, but represents the Department as a partner at Board meetings.

8 OU R P E O P L E

Team members photographed at ZIP’s 2019 end-of-year gathering at Forest Lodge, Mt Cheeseman, December 2019 (CHAD COTTLE)

ZIP team February 2020 marked the fifth anniversary of our establishment.

At the same time, our work at Bottle Rock Peninsula in the Queen Charlotte Sound—the original ZIP field site—came to an end.

During the national COVID-19 Level 4 lockdown in autumn 2020, we were required to press ‘pause’ on our field operations in South Westland, and trials at our animal behaviour facility in Lincoln, for several weeks. The ZIP team stayed productive as we took this opportunity to take stock, review and refine our work programme, write up and publish some of the results of our research, and focus on some particularly tricky conservation challenges. We also remained strongly connected, despite our separate bubbles, through frequent phone conversations, increasingly creative Zoom meetings, and our weekly team newsletter.

Outside of this period of self-isolation, we have continued to provide opportunities for every team member to join the work at our Perth River valley field site and at the Lincoln predator behaviour facility.

The health, safety and wellbeing of our team has always been our number one priority.

We investigate and review every incident (including near-misses), and share the findings across the team to minimise the risk of a repeat incident. This year, our team collectively spent approximately 1,900 days in the Perth River valley field site. This is a remote place, accessed by helicopter, where the conditions are frequently wet, cold and unpredictable.

The rugged terrain in the site ranges from exposed alpine areas of snow and ice, to steep and slippery slopes and deep valleys, with challenging stream and river crossings.

We recorded 11 work-place incidents during the year, eight of which occurred in the field site. Five of these incidents resulted in minor injuries, none of which led to permanent harm.

9

Organisation chart

CHIEF EXECUTIVE

Al Bramley

EXECUTIVE ASSISTANT

Danielle Pullen

OPERATIONS DIRECTOR

Duncan Kay

OPERATIONS COORDINATOR

FIELD TEAM LEAD, PERTH RIVER VALLEY

Tom Agnew

Nate St Hill

PREDATOR BEHAVIOUR TEAM LEAD

Jenny Dent

Matt Chisnall FIELD RANGER

Lorena Cárdenas FIELD RANGER

Chad Cottle FIELD RANGER

Cameron Eddy FIELD RANGER CASUAL FIELD RANGERS

Jono Dobbs FIELD RANGER

Alex Edwards

Rhianna Hughes Eddy Reuben Lane

FIELD RANGER POSSUM DOG

Michael Tunnicliff

Pepper FIELD RANGER RAT DOG

Baxter

10 OR G A N I SAT I O N C HAR T

Chelsea Price

Ash Cassin

PREDATOR TECHNICIAN

FIELD RANGER

Piper Douglas

PROJECT LEAD, SOUTH WESTLAND

Becky Clements

PREDATOR TECHNICIAN

Katie Coster

INNOVATION DIRECTOR

PREDATOR SYSTEMS MODELLER

STRATEGY & SYSTEMS DIRECTOR

ENGINEERING DIRECTOR

Phil Bell

Nick Mulgan

Joseph Arand

John Wilks

INNOVATION ADVISOR

COMMUNICATIONS & DEVELOPMENT LEAD

Courtney Hamblin

Susannah Aitken

PREDATOR ECOLOGIST

PROJECTS & PRODUCTS SUPPORT

Helen Nathan

Caroline Wallace

PREDATOR ECOLOGIST

ACCOUNTS ADMINISTRATOR

Maggie Nichols

Kristin Kennedy

GIS & DATA ANALYST

OFFICE CLEANER

Nic Braaksma

ENGINEER

William Wilks

James Wallace

SCIENCE & TECHNICAL RANGER

Briar Cook SCIENCE ADVISORS

Elaine Murphy James Ross James Russell

As usual, there have been a range of changes to roles and sites to support our evolving work programme and the development of our team members.

To ensure that it remains a useful reference for as long as possible, this organisation chart is current as at 30 September 2020.

In February 2020, we bid farewell to field rangers Ben Blain and Robina Brock, who left ZIP to pursue new challenges.

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Remove and Protect We are developing the ‘Remove and Protect’ approach to predator management to enable communities across New Zealand to restore native biodiversity to levels normally only seen on predator free offshore islands, or within fenced sanctuaries—without the ongoing widespread use of aerial toxins.

As well as bringing New Zealand one step closer to predator freedom, the complete removal of possums, rats and stoats will help eliminate bovine tuberculosis (TB) and other diseases spread by predators, and minimise the associated costs to farmers.

Investing in predator freedom is expected to have other positive impacts for local economies by creating work opportunities and providing a valuable ‘predator free’ brand for tourism and productive sectors.

Key milestones and achievements

DOC and NEXT Foundation formally establish ZIP Possums and rats are eliminated from 400 ha Bottle Rock Peninsula; virtual barrier trials commence

2015 12 RE M OV E A N D P R OTECT

Opening of ZIP’s predator behaviour facility in Lincoln, Canterbury, with support from Fonterra, Open Country Dairy, Synlait, Tatua, Westland Milk Products and Miraka

Successful ‘1080 to Zero’ predator removal trial in 2,200 ha Jackson-Arawhata field site, South Westland

Ministry for Primary Industries (MPI), with ZIP’s assistance, publish guidelines for the remote monitoring of live-capture traps

Trial in Orongorongo Valley, Remutaka Forest Park, confirms that rivers can be an obstacle to possum movement following control

2016

2017

The Remove and Protect approach comprises four tactics: 1. Minimising reinvasion by establishing and maintaining barriers to predators (see pp. 22–25); 2. Completely removing predators from an area protected by the barrier(s) (see p. 26); 3. Detecting any predators that survive the initial removal or breach the boundary (see pp. 27–32); and 4. Removing any predators that survive the initial removal or breach the boundary before they are able to re-establish a viable population.

Trials at Lincoln facility demonstrate that a 1.1m high predator fence (with cap) is an effective barrier to predators Confirmation that a virtual barrier, accompanied by a lean network of remote-reporting devices, is sufficient to prevent possum re-establishment at Bottle Rock Peninsula Rat virtual barrier at Bottle Rock Peninsula found to intercept 95% of rats (a promising initial result, but not yet sufficient to maintain rat freedom)

2018

The majority of our work programme is the development, testing and application of new tools and techniques to address each of these specific challenges. Over the last two years, we’ve been pleased to begin supplying some of these tools and lending our technical expertise to an increasing number of community groups, to help them achieve predator freedom and restore biodiversity across a range of mainland ecosystems (see pp. 33–35 for more information).

Since early 2018, we have been developing and refining the Remove and Protect approach in the Perth River valley, South Westland, with the aim of eliminating possums, rats and stoats from 12,000 hectares of rugged back-country.

This work is described in detail on pp. 14–20.

An unsuccessful attempt to remove a breeding population of rats from Bottle Rock Peninsula using traps and ground-based toxins demonstrates the need for more timely detection and more effective tools for removal Establishment of 12,000 ha Perth River valley field site for first landscape-scale application of the Remove and Protect approach Development of measures to mitigate risks to kea from planned 1080 to Zero predator removal operation Tools developed by ZIP begin to be supplied to other predator free projects around the country

Completion of Perth River valley predator removal operation, eliminating stoats and reducing possums and rats to very low numbers

2019 13

Remove and Protect in action: Eliminating predators in the Perth River valley Background Following discussions with DOC and Te Rūnanga o Makaawhio in late 2017, a 12,000 hectare site in the Perth River valley, South Westland, was chosen as the first landscape scale area to develop the Remove and Protect approach. Our goal was to eliminate possums, and potentially rats and stoats, from the site, and then protect the site in perpetuity.

Predator removal operation We carried out the initial predator removal operation during autumn/winter 2019.

The operation followed the ‘1080 to Zero’ methodology developed by ZIP. It was carried out in two phases, each consisting of two pre-feeds of non-toxic bait followed by a single application of toxic bait. Bait was applied across all predator habitat within the field site, in such a way as to leave no gaps in coverage.

14 RE M OV E A N D P R OTECT IN ACTIO N

The first phase was completed in April 2019, and the second was completed in July 2019.

The operation also incorporated a range of measures to mitigate potential risks to kea.

More information about the operation, and the associated kea risk mitigation measures, is available on our website, zip.org.nz, and in our 2018–19 Annual Report.

Following the predator removal operation, we used our network of 142 lured trail cameras, along with approximately 3,000 peanut butter-lured chew cards (replaced every 4–6 weeks) at 20 metre intervals along all routes within the area, to detect any survivors of the operation.

BELOW:

The final resident possum in the Perth River valley, seen on camera shortly before it was caught in a remote-reporting cage trap (pictured, left)

Job done! How we eliminated possums Before the predator removal operation, 98% of our lured trail cameras detected a possum. Based on these detections, and research from similar habitat, we estimated a starting population of around 15,000 possums.

In the seven months following the predator removal operation, we detected an estimated 5–6 possum survivors within the field site.

We decided not to immediately remove these individuals, as they were some distance apart.

Possums are slow to breed, so we were confident that time was on our side even if these individuals did come into contact with one another. Instead, we focused our initial efforts on detecting, and then removing, surviving rats (more on this below).

On 5 March 2020, we carried out a targeted aerial ‘spot treatment’ operation to remove an emerging population of rats before it could spread. Although rats were the target of the treatment, footage from our detection network indicates that this operation removed 2–3 of the surviving possums. This left us with two known possums to remove.

In June, the final two survivors of the operation were successfully removed by deploying our possum dog Pepper and her handler Michael to the locations of trail camera sightings, in order to zero-in on the locations of these animals. We then deployed remote reporting cage traps that successfully caught these last known survivors, completing the elimination of possums from the Perth River valley. This is the

first time such a result has ever been achieved at this scale on the New Zealand mainland!

Based on the results of previous trials, and our current detection effort, we are confident that the strong rivers bordering the Perth River valley field site are a sufficient barrier to reduce possum invasion to a manageable level.

We estimate that just three possums entered the field site during the past year, on the basis that the first of these possums was detected almost a year after the predator removal operation. All were detected near the headwaters of the Barlow River—an area we anticipated would be most vulnerable to reinvasion due to the lower flow and braided nature of the river. We were able to catch all of these possums in cage traps after detecting them in our lured camera network, with help from Pepper’s powerful nose to confirm their locations.

We are continuing to systematically survey the field site for possums, to keep building our confidence in the rivers as effective barriers to possum reinvasion. In the event that more possums arrive, we are confident that we will be able to quickly detect and remove them!

BELOW:

Field ranger Michael and his possum detection dog Pepper, pictured here in July 2020, are critical to preventing possums re-establishing in the Perth River field site (CHAD COTTLE)

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What do we mean by predator elimination?

Predator elimination means that the existing population of possums, rats and/or stoats has been completely removed. When we detect reinvasion, we respond quickly to target and remove those animals before a viable population can take hold.

Once predators have been eliminated, they must be prevented from re-establishing using a range of interventions, including: • Protecting the borders of a predator free area using natural barriers such as large or swift rivers and alpine ranges, ‘virtual barriers’ made up of intensive lines of traps and/or bait stations, and/or predator fences; • A highly sensitive detection system to provide assurance that, should a possum, rat or stoat arrive in the protected area we will quickly become aware of its presence; and • The tools and techniques to quickly remove the possums, rats or stoats detected within the protected area before they are able to re-establish a viable population.

Preventing predators re-establishing requires a balance across these interventions; and this balance is different for each species due to their unique behavioural and physiological characteristics.

For example, we are now confident that the large rivers that border the Perth River valley field site are an effective barrier to minimise reinvasion by possums, and are likely to be an effective barrier to rats when reinforced.

While these rivers present little barrier to stoats due to their strong swimming ability, this may not be a concern, as we are growing increasingly confident that we can quickly detect invading stoats as they arrive, and then remove them by targeting sites of detection.

16

ABOVE:

A rat caught on camera in the Perth River valley during December 2019

Getting closer: Our progress towards eliminating rats The predator removal operation appeared to remove all but a very small number of individual rats from the field site.

Unfortunately, in mid-December 2019 we discovered evidence that localised rat breeding had occurred at a handful of locations over a combined area of approximately 50 hectares. We anticipated that we would be able to remove the emerging population using a targeted aerial ‘spot treatment’. Rather than immediately carrying out this treatment, we took the opportunity over the following weeks to observe and learn about the speed of population growth and the spatial ‘footprint’ covered by this emerging population. Our intent was to further inform the design of our detection network, and more clearly delineate the size of the area requiring treatment.

We completed the spot treatment on Thursday 5 March 2020, which consisted of two applications of non-toxic cereal prefeed bait (at a rate of 1 kg/ha) followed by a single targeted application of 1080 bait (at a rate of 2 kg/ha), over the emerging rat population and a surrounding buffer zone—a total area of 860 hectares (or 7% of the protected area).

The spot treatment was then followed by intensive ground-based detection around sites where rats were known to be present, to determine whether we had succeeded in removing these rats. This detection effort was cut short after three weeks, when the COVID-19 Level 4 lockdown required our team to stay out of the field site, but footage recovered immediately before the lockdown indicated that at least one rat had survived the spot treatment. In the right conditions, rats can increase their population by 50% every four weeks, so we knew there was a high likelihood that by the time the team was able to return to site, we would once again need to respond to an emergent population.

Seven weeks after the spot treatment operation, our team returned to the site. Rats were detected at multiple locations within the spot-treated area, primarily near the confluence of the Perth and Barlow Rivers, and near the lower Barlow River (two locations where rat breeding was initially discovered in December 2019). Rats were also discovered near the upper Barlow River, an area that had not been spot-treated. Our model estimates that this population may have reached 170 rats at its peak.

We are now working to remove the emerging rat population using a range of ground-based measures, including: (i) remote-reporting traps; (ii) Delilah traps (with a live rat as a ‘social lure’); and (iii) a targeted network of brodifacoum bait stations around known sites of detection.

BELOW:

A rat exits a bait station in the Perth River valley field site, May 2020

As at 1 September, this approach appears to be working! Rat detections have significantly reduced in the last four months, and we now estimate that less than 50 rats remain in the field site, across an area of approximately 200 ha.

On the basis of earlier trials, we anticipated that the rivers surrounding the field site would be a strong, but not impenetrable, barrier to reinvasion by rats. We have reinforced the 20 km river boundary of the field site with a line of Goodnature A24 traps, fitted with excluders to keep kea safe, at 50 metre intervals. We manually modified these traps to enable them to be lured with ZIP MotoLure automated lure dispensers, which reduce the servicing requirement to once every 12 months.

Despite dispensing a bio-marker every 50 metres outside the river boundary of the field site, to enable us to confidently identify invading rats caught in the protected area, we haven’t yet seen any direct evidence of rats crossing the river into the protected area. That said, it is possible that one or more of the rats detected near the headwaters of the Barlow River are invaders, based on the timing and locations of these detections.

Individual rats often occupy very small ranges. This means that an intensive network of devices would be required to detect an invading individual, which is prohibitively expensive at the landscape scale. Our detection and response strategy for ship rats involves detecting an emerging population of rats after a breeding event (or events), when that emerging population covers a larger geographic ‘footprint’—making it easier to detect—but is still small enough to be removed using a targeted approach.

We are currently working on some options to improve the timeliness of detection, and our ability to respond efficiently.

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Almost there‌ Preventing stoats re-establishing ABOVE:

A stoat caught in a prototype ZIPinn trap in the Perth River valley field site, February 2020 (ALEX EDWARDS) We always anticipated that some level of stoat reinvasion was likely to occur, given their strong swimming capability and roaming behaviour. Sure enough, between November 2019 and March 2020, approximately 15 stoats entered the field site. This timing coincides with the juvenile dispersal season.

ABOVE:

A stoat caught on camera eating mayonnaise from a MotoLure dispenser in the Perth River valley during January 2020

Before the predator removal operation, stoats were detected by 36% of our network of 142 lured trail cameras, indicating that there was an established low-density population throughout the field site.

No stoats were detected for seven months after the first phase of the operation in April 2019, indicating that we had eliminated the resident population. This is an extraordinary result, and suggests that a ‘1080 to Zero’ approach is likely to be an effective method for eliminating stoats (provided enough rodents are present in the operational area to enable secondary poisoning to occur).

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So far, we have trapped 6 of these stoats.

We are actively targeting the remainder with a novel technique that involves placing 1080-poisoned rat carcasses in front of trail cameras where recent, repeated, stoat detections have occurred. 15 of these toxin-laced rats were deployed in early July 2020. Stoats were recorded removing the rats from seven locations over the following four weeks, and have not subsequently been detected at these locations.

This is very encouraging, and suggests that a consistent food reward (such as the mayonnaise dispensed by the ZIP MotoLure) can be used to habituate invading stoats to specific locations, which can then be individually targeted. We are now on the verge of being able to prevent stoats re-establishing in large, remote landscapes like the Perth River valley!

BELOW:

A stoat investigates, and then removes, a toxin-laced rat from a camera location within the Perth River valley, July 2020

Using lured trail cameras to detect possums, rats and stoats LEFT:

A ZIP field ranger installs a trail camera to detect possums, rats and stoats in the Perth River valley field site (CHAD COTTLE)

The use of trail cameras has increased across the conservation industry in recent years, as they have become more affordable, and as it has become increasingly evident that they are a highly sensitive tool for survey, monitoring and detection relative to other available methods4. Cameras also provide a wealth of data, allowing researchers and conservationists to make inferences wider than simple presence/absence of a species5—such as animal behaviour6 and activity patterns7.

4. Smith D, Weston K 2017. Capturing the cryptic: a comparison of detection methods for stoats

(Mustela erminea) in alpine habitats. Wildlife Research 44 (5): 418–426

5. Dilks P, Sjoberg T, Murphy E 2020. Effectiveness of aerial 1080 for control of mammal pests in the

Blue Mountains, New Zealand. New Zealand Journal of Ecology 44(2): 3406

6. Caravaggi A, Banks P, Burton C, Finlay C 2017. A review of camera trapping for conservation

behaviour research. Remote Sensing in Ecology and Conservation.

7. Kays R, Kranstauber B, Jansen P, Carbone C, Rowcliffe M, Foundtain T, Tilak S 2009. Camera

Traps as Sensor Networks for Monitoring Animal Communities. The 34th IEEE Conference on Local Computer Networks.

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ABOVE:

A tahr on camera in the Perth River valley, June 2020 The automated ZIP MotoLure dispenses a mayonnaise ‘food reward’ each night to attract predators. Trail cameras require the lowest interaction effort from predators, and are consequently our most sensitive detection tool. In the Perth River valley ZIP MotoLures are paired with a lean network of trail cameras. This allows us to confidently detect all individual possums and stoats within an otherwise predator free area. Our team can then initiate a response to remove these individuals. We are still determining whether or not this approach is sufficient to quickly alert us to the presence of an emergent population of rats, while this population is still small enough to be removed using a targeted approach.

BELOW:

A ruru (morepork) on camera in the Perth River valley, July 2020

20

ABOVE:

A kākā on camera in the Perth River valley, July 2020 An additional benefit of trail cameras is their ability to detect other species, which enables us to assess how predator management activities are impacting on, or benefitting, these species. The Perth River valley camera network has detected native birds such as kea, kakaruai (South Island robin), kākā and ruru (morepork), along with game animals such as tahr, deer and chamois.

For more information about ZIP’s use of lured trail cameras for detection, check out the associated Finding and Field Guide at zip.org.nz.

BELOW:

A kea on camera in the Perth River valley, July 2020

ABOVE:

The upper Perth River, one of the large, cold, fast-flowing rivers that bound the Perth River valley field site and act as a barrier to invasion by possums and rats (CHAD COTTLE)

Other key projects during 2019–20 The main knowledge/tool gaps that we planned to address in 2019–20, and the results of the work, are outlined in the following tables. Several of these projects are also described in more detail on our website (zip.org.nz).

21 OTHER KEY PROJE C T S

Minimising reinvasion The large, cold, fast-flowing rivers bordering the Perth River valley field site are likely to be a strong, but not impenetrable, barrier to possums and ship rats. Some reinforcement may be required to reduce invasion to a manageable rate.

Projects

Results

1. Undertake a field trial to determine the strength, or otherwise, of river valley headwaters (where the river starts at glaciers, and braids before the main flow forms) as barriers to possums

A field trial was carried out during the main sub-adult dispersal season, when possum pressure was expected to be greatest, to determine the possum invasion rate at the headwaters of the Barlow River.

2. Reinforce Perth River boundaries to reduce rat invasion pressure

A line of A24 rat traps at 50 m spacing, fitted with excluders to reduce risk to kea and lured with MotoLure dispensers, have been installed to reinforce the river boundary along the Perth and Barlow Rivers. We are continuing to assess the effectiveness of this approach.

No possums were detected within the protected area adjacent to the headwaters of the Barlow River during the trial. However, three possums, believed to be invaders, were detected—and subsequently caught—after the trial’s completion. All three were first detected during the tail end of the sub-adult dispersal season, when the Barlow River had very low flow (ref. p. 15 for more information). Based on these results, we are confident that the majority of the river boundary, with the exception of the Barlow River headwaters, is very unlikely to need reinforcement in order to minimise possum invasion to a manageable level.

Since the predator removal operation, we have observed no direct evidence of rat invasion across the river boundaries of the field site (more about this on p. 17), which suggests that the rivers have been effective in minimising reinvasion by rats to date.

3. Measure rat density outside the river boundary, to help understand the likely invasion pressure on this boundary

Since the predator removal operation, rat density has been measured using temporary lines of lured trail cameras at three locations within, and one outside, the operational sowing boundary. During this time, we have observed the rat density in these areas slowly building. In June 2020, 11 months after the operation, the rat pressure measured within the aerial buffer zone was still less than half that in the untreated area, suggesting the river barriers have not yet been fully tested.

The Perth River, a barrier to reinvasion by possums and rats (CHAD COTTLE)

22

A ZIP team member dwarfed by rocky outcrops near the headwaters of the Barlow River, the site of the possum invasion trial carried out during 2019–20 (BRIAR COOK)

Predator fencing is typically custom-designed and built, making it an expensive option for large sites. A productionised low height predator fence could make this tool affordable and suitable for use in a wider range of places (e.g. around farms and residential areas, where standard predator fences might not be desirable).

Projects

Results

4. Productionise the low height predator fence for possums, rats and stoats to support other projects

The latest fence design, at a height of 1.1 m with a 110 mm diameter plastic pipe cap, successfully contained 19/20 stoats. Based on the results described in (6) below, this design is also expected to contain rats. It will soon be tested against possums.

5. Test a possum-specific fence designed by the Otago Peninsula Biodiversity Group to slow possum reinvasion onto rural farmland during a staged eradication

A fence based on a standard stock fence fitted with chicken mesh and three hotwires contained 10/16 possums during trials. Male possums were significantly more likely to escape (5/8 individuals) than their female counterparts (1/8 individuals). Despite the relatively high rate of escapes, this low-cost fence may offer benefit to control operations as a means of slowing migration or funnelling possums toward control devices. The higher containment rate of females is also a promising aspect as it suggests male-skewed invasion, which would limit the breeding potential of the population.

6. Assist the development of a low height rat-specific fence and solutions for road and coastal ends, to support the Predator Free Miramar Peninsula project (within Predator Free Wellington)

An 800 mm high fence, constructed with 12mm mesh and capped with a 110mm diameter HDPE pipe, was found to prevent 15/16 ship rats, and 3/3 Norway rats, from escaping during trials at Lincoln.

7. Develop and test a robust predator fence for deployment at high altitude, in Te Manahuna Aoraki project

Fence testing is proceeding well. Winter weather conditions for the area have been relatively favourable to date, with a maximum snow load of 45 cm and maximum wind speed of 197 km/h. No damage to the fence has been recorded.

BELOW:

We expect that the productionised version of this fence will be significantly cheaper than traditional predator fencing.

While the fence performed well during trials, Predator Free Wellington ultimately decided to instead install a virtual barrier to minimise rat invasion onto Miramar Peninsula.

A prototype possum aversion fence, based on a design by Otago Peninsula Biodiversity Group, undergoes testing in the Lincoln predator behaviour facility (JENNY DENT)

BELOW:

A rat climbs over a prototype rat-specific fence with 90mm diameter pipe capping, during trials in July 2019

23

The possum virtual barrier we have developed appears to be sufficiently effective at intercepting possums at Bottle Rock, but has not yet been deployed or tested in different environments. Testing of the Bottle Rock virtual barrier ceased in late 2019.

Projects

Results

8. Analyse performance data of possum virtual barrier and detection system at Bottle Rock to provide progress updates and identify areas of improvement

A virtual barrier, comprising four lines of remote reporting PosStop traps at 10 metre spacing, when used alongside a lean detection network, was found to be sufficient to prevent possums re-establishing at the 400 ha field site.

9. Deploy a possum virtual barrier at other sites, to protect these sites against reinvasion by possums and determine the barrier’s efficacy in new environments

In 2019 we worked with the Taranaki Taku Tūranga project team to deploy a possum virtual barrier to protect the Kaitake Range against reinvasion by possums. Between July 2019 and September 2020, this barrier has caught 116 possums.

10. Continue to develop a hybrid system for remote data transmission, using a long-range, low powered radio (LoRa) backbone, our ‘daisy chain’ technique to get into hard to reach terrain, and the Iridium satellite network

Ongoing improvements are being made to the LoRa system, including optimised timing of satellite communication and a new antenna design to increase the range of remote reporting nodes (currently estimated at 250–300 m in favourable terrain, or 50–150 m in dense bush).

A journal manuscript covering the performance of the possum virtual barrier, including the multiple trials tested within that context, is currently in draft. Publication is due 2020–21.

After some initial hiccups—not unexpected in an R&D context—the barrier is performing well as the project team works to eliminate possums from the site.

The new node design is now being manufactured and productionised for deployment in the Perth River valley, along with several partner projects, where it is expected to enable timely response to predator incursions.

Innovation Director Phil Bell and Operations Coordinator Tom Agnew with a prototype remote reporting node, November 2019 (ROBYN JANES)

24

The rat virtual barrier we have developed to date does not yet intercept enough rats to make the Remove and Protect model cost efficient in the absence of natural barriers.

Projects

Results

11. Upgrade the virtual barrier for rats, to reduce the rate of leakage to <1% of rats that encounter the barrier

Analysis of the performance of the virtual barrier at Bottle Rock between August 2017 and August 2018 indicates that, in order to reduce leakage to the desired rate of <1%, 10 lines of TUN200 traps would be required. Therefore, in order for the barrier to be cost efficient in the absence of natural barriers, a more effective trap is needed.

As the ZIPinn rat and stoat trap is still under development (see below), and no immediate need for a rat virtual barrier has been identified either by us or by a partner project, work to upgrade the rat virtual barrier is currently on hold.

12. Develop a highly effective â&#x20AC;&#x2DC;tunnelâ&#x20AC;&#x2122; trap for rats and stoats, and productionise it through tooling to final manufacture

This device is also designed for use as a response tool, to target invading rats and stoats within a protected area

Field testing of a ZIPinn network in the Perth River valley revealed that the original treadle design was vulnerable to false spring offs (with an estimated false trigger rate of 30%). As a result, a new single-treadle design was developed and is proving much more robust against false trigger events.

This design is also able to be simultaneously internally lured and externally pre-fed using a MotoLure, which may increase efficacy.

Three possible configurations of this design are being investigated: 1) single entry, with a solid end; 2) single entry, with a mesh end; and 3) double entry.

Preliminary results from testing at the Lincoln predator behaviour facility indicated that the double entry was the more promising configuration. Surprisingly, all rats that interacted with this design were caught within 10 minutes, even though it was possible for them to access the lure without crossing the treadle.

Ongoing trials and deployments of ZIPinns, both in the field and in the lab, will guide the ultimate configuration design for retooling.

The prototype ZIPinn trap, designed to catch rats and stoats with a high level of effectiveness and efficiency, undergoes field testing in the Perth River valley, October 2019 (DAVE KWANT)

25

Initial Removal Standard approaches to using aerial 1080 to control possums and rats over large areas do not completely remove them. The continued presence of predators limits the ecological outcomes of the operation and generates significant ongoing control costs.

Projects

Results

1. Test a new approach to completely remove predators through the aerial application of 1080 at a site in the Perth River valley, South Westland

Ref. pp. 14–20

2. Assess effect of ‘1080 to Zero’ operation, carried out with kea risk mitigation measures developed by ZIP, on Perth River valley kea population

In early 2020, kea were surveyed in the field site using trail cameras lured with tahr carcasses, and then visually with support from members of the South Westland community. In both cases, the numbers of kea observed were comparable to the numbers seen prior to the predator removal, indicating that the kea population is unlikely to have been impacted by the operation.

3. Assess survival of whio through a ‘1080 to Zero’ operation

We visually surveyed whio in the Perth River valley before and after the operation, and observed no negative impact on the whio population.

ZIP field rangers continue to report frequent kea sightings, including one encounter in April 2020 with a flock of 27 juvenile kea by the headwaters of the Barlow River.

During the 2019–20 breeding season, whio ducklings were observed on several occasions by members of the ZIP field team in the upper Barlow River area—for the first time since we began work in the site in early 2018.

4. Assess survival of tahr through a ‘1080 to Zero’ operation

ZIP worked with the Game Animal Council (GAC), New Zealand Deerstalker Association, Professional Hunting Guides Association, and DOC, to monitor 15 radio-collared tahr through the predator removal operation. All radio-collared tahr survived, suggesting there was no negative impact on tahr. A report on this work has since been published online by GAC and ZIP.

Two juvenile kea caught on camera during the March 2020 kea survey (ALEX EDWARDS)

26

Whio in the Perth River valley, winter 2020 (CHAD COTTLE)

Detection A network of lured trail cameras is a highly effective method for detecting low densities of possums, rats and stoats. However, the technique is expensive due to the high labour cost associated with (i) changing batteries and SD cards every 3–6 weeks and (ii) processing footage from the cameras.

Projects

Results

1. Develop a software tool that makes it easier and more efficient to manually review trail camera footage and record detections of target species

We have developed a software tool that (i) enables a reviewer to record detections using ‘quick keys’, each of which is associated with one of up to 26 target species or other items of interest; (ii) automatically extracts metadata associated with each detection (e.g. time and date); (iii) is capable of exporting results into a spreadsheet (in CSV format); (iv) sorts footage into folders for each quick key classification (for easy reference at a later date); and (v) can be used offline.

The tool is currently undergoing further refinement and testing at our Perth River valley field site, where it is saving our team an estimated 20 hours per camera servicing check.

2. Develop a thermal camera with on-board artificial intelligence (A.I.) video analysis software, and remote reporting capability, to provide timely notification of detections

We are currently field-testing five prototype A.I. detection cameras in the Perth River valley. The first set of footage has been collected, and the camera performance has exceeded expectation. We are now installing additional cameras into the field, to increase our testing of the camera hardware and to capture footage, in order to train the A.I. algorithm. Testing to date has demonstrated such promising results that we are now investigating whether it is possible to use a lower grade thermal camera model, which could substantially reduce the cost of the A.I. camera (ref. p. 36 for more information).

This project is supported by DOC, NEXT, PF2050 Ltd and NZ Biological Heritage Science Challenge.

BELOW:

ZIP’s software tool, which we are developing to enable efficient classification of species detections from trail camera footage

27

It is unknown how long it takes for a possum to be detected by a lean network of lured cameras (i.e. the ‘lean detection system’). The longer a possum is free to roam within a protected area, the greater the risk that it will encounter another possum, then stop roaming (making it harder to detect) and breed.

Projects

Results

3. Release radio-collared possums in Perth River valley field site, in order to learn about the roaming behaviour of ‘lonely’ possums

Planning is underway for these trials. Two approaches are being considered: (i) collaring and releasing a possum which has invaded the site, and (ii) catching a possum adjacent to the river boundary or in a nearby catchment and relocating it to the Perth River valley field site.

The three invading possums at the Perth River valley site (p. 15) have given us a real-world opportunity to begin this learning. These possums only appeared to occupy ranges of 3–5 ha, but may have been influenced by the presence of one another in the same area of the site.

We do not have proven ‘social’ lures for possums or rats. In areas with very low predator density and abundant food, social lures may be important for attracting individual predators to devices.

Projects

Results

4. Investigate the effectiveness of olfactory and audio lures for possums

Trials to assess possum calls and scent trails as potential social lures for possums are due to get underway early in 2020–21.

5. Explore the efficacy of a Delilah rat trap (using a live rat as a lure)

Delilah traps showed promise during preliminary lab trials, with 2/2 rats caught. The trap design has since been refined to a flat-pack design for easier field use. Field trials of the device are ongoing, but no captures have yet been recorded in a low-rat environment.

No reliable method has been identified for dispensing Pic’s peanut butter, our most effective rat lure, using the ZIP MotoLure.

Projects

Results

6. Test different compositions of peanut butter, oils and emulsifiers to determine the combination required for effective (long-term) use in a MotoLure under field conditions

Trials conducted in partnership with Massey University indicated that two different peanut butter lure formulations will likely be required to achieve reliable dispensing across the range of temperatures experienced in the Perth River valley field site (i.e. a summer and a winter ‘recipe’).

28

Work is ongoing to confirm palatability of the lure formulations, and develop productionising processes.

Individual stoats are notoriously difficult to detect in large, remote, low-predator environments. This makes it challenging to measure the impact that management activities are having on stoat populations.

Projects

Results

7. Determine whether it is possible to â&#x20AC;&#x2DC;trainâ&#x20AC;&#x2122; stoats to visit the MotoLure dispenser, by virtue of accessing a food reward

Since mid-November 2019, stoats have been detected within the Perth River valley field site, at a small number of clustered locations (ref. p. 18 for more information). The mayonnaise lure appears to be highly attractive to stoats in a post-toxin landscape, with several lured camera sites receiving daily visits.

BELOW:

A stoat feeds on mayonnaise lure from a ZIP MotoLure dispenser in the Perth River valley, January 2020

29

The ability to reliably bio-mark possums and stoats using a single, long-lasting bio-marker would enhance our ability to efficiently measure the effectiveness of management activities (e.g. by tracking movement of animals through a â&#x20AC;&#x2DC;barrierâ&#x20AC;&#x2122; system).

Projects

Results

8. Develop reliable bio-marking of possums and stoats

Trials at Lincoln during 2017â&#x20AC;&#x201C;18 indicated that egg mayonnaise laced with rhodamine B bio-marker, delivered via ZIP MotoLure, is highly palatable to both possums and stoats.

A high dose (2 ml) of mayonnaise laced with 2% rhodamine B was found to mark at least one whisker of most possums.

A lower dose (1 ml) of mayonnaise and concentration of rhodamine B (1%) was found to reliably mark stoat whiskers. In July 2020, a stoat was caught in the headwaters of the Barlow River that was later found to have traces of rhodamine B in its whiskers (which is likely to have been consumed during the possum invasion at river headwaters trial (p. 22).

BELOW:

The whisker of a possum fed a high dose of rhodamine B biomarker during trials at Lincoln; glowing area indicates rhodamine B consumption (BRIAR COOK)

30

How to efficiently detect a ship rat incursion at landscape scale? Rats often occupy very small home ranges, and therefore a very dense network of devices would be required to reliably detect a single invader or survivor. However, the footprint of an emerging population of rats is expected to be much larger and, provided they can be removed quickly, could require fewer detection devices.

Projects

Results

9. Refine the ‘Gen One’ model, to inform the detection network layout for the Perth River valley and other sites

Development of theoretical aspects of the model continues, and model inputs are being updated on an ongoing basis as new data from the Perth River valley field site becomes available.

The smaller than anticipated ‘footprint’ of the emerging rat population in the Perth River valley suggests that attempting to detect the first generation of ship rats before they themselves breed may not be feasible at scale (given the required intensity of the detection network). Rather, our emphasis has shifted to detecting an emerging population while it is still spatially restricted and can be removed using a targeted approach.

We are preparing a paper on a general population estimation technique based on average population density values, while continuing to develop our understanding of very low-density populations.

Can we improve our detection toolset for confirming the presence/absence of predators within our field sites?

Projects

Results

10. Continue to develop predator detection dog capability within the ZIP team

Pepper, the possum detection dog, and Baxter, the rat detection dog, have been based at Perth River valley field site since 9 December 2019, assisting with the survivor detection effort. Both dogs have been critical in narrowing down our responses to invading possums and surviving rats, making our targeted efforts more efficient.

11. Explore eDNA (environmental DNA) sampling as a method to identify which species are present throughout the Perth River valley field site.

A series of water samples were taken from 10 locations around the Perth River valley field site in June 2020, and analysed by Wilderlab. The diversity of eDNA detected in the samples was surprisingly low, and no possum, rat or stoat DNA was detected. The purity of the water due to the proximity of the collection sites to their glacial sources may explain the limited DNA detected. Further samples are planned for collection from the field site using larger quantities of water, as we continue to collaboratively explore the limits of this emerging technique.

This project is supported by EPA, Wilderlab and the University of Otago.

A creek near the Upper Barlow River, one of ten locations from which water samples were collected during an eDNA trial in June 2020 (CHAD COTTLE)

31

Projects

Results

12. Investigate the pathway to rebuild high resolution thermal camera survey and hunting capability within New Zealand, to assist the rural and remote eradication of possums, goats, pigs, wallabies and feral cats (to support both ZIPâ&#x20AC;&#x2122;s work and the work of several partner projects)

This project is currently on hold as no immediate need for thermal camera survey and hunting capability has been identified either by us or by a partner project.

Response Our work to develop tools and techniques to prevent predators re-establishing across landscape-scale back-country sites is described in detail in Remove and Protect in action (14â&#x20AC;&#x201C;20 ).

ABOVE:

32

Possum detection dog Pepper on the hunt in the Perth River valley, May 2020 (MICHAEL TUNNICLIFF)

Support for other predator free projects LEFT:

Predator dog handler Chelsea Price and her rat detection dog Baxter help the Predator Free Wellington team to search for rats on the Miramar Peninsula during winter 2020 (PHILIP WISKER)

During the last year, ZIP has been pleased to work alongside an increasing number of predator free projects across New Zealand. In addition to the projects listed on the following pages, we also provide support and technical advice to assist candidate projects to prepare project plans, at the request of Predator Free 2050 Limited.

33

1

2

3

5

4

6

9

8 7

10

11

12

13

34 S U P P O R T FO R OT H E R P R EDATO R - F R EE P R O J ECTS

Whangārei Predator Free

1

layer-plus 12,904 ha

5

Taranaki Taku Tūranga – Towards a predator-free Taranaki layer-plus 71,000 ha

paw Possums, rats, stoats +

map-marker-question Rural, urban, public conservation land (including National Park)

We are helping with: » Design of technical plan for possum eradication

We are providing advice on:

» Advice on barriers to reinvasion 2

Te Korowai o Waiheke layer-plus 9,200 ha paw Rats, stoats map-marker-question Urban, rural, bush

» ‘Virtual barrier’ and lean detection network design and implementation

» Stoat detection

Korehāhā Whakahau

We are providing general technical advice. cog PosStop, OutPost, MotoLure

paw Possums

Predator Free Wellington

map-marker-question Urban, rural, bush Advice on: » Proposed possum eradication » Barriers to reinvasion

Predator Free Hawke’s Bay

7

layer-plus 53,300 ha paw Possums, rats, stoats + map-marker-question Rural, Urban

» Barriers to prevent possum reinvasion cog PosStop, OutPost, MotoLure

» Development and testing of a predator fence for use at high altitude » Advice on trap and detection networks for mustelids cog MotoLure

Predator Free Dunedin

We are helping with: » Co-design of technical plan for possum eradication

layer-plus 31,000 ha

» Advice on predator detection and response

map-marker-question Rural, urban

Pest Free Banks Peninsula layer-plus 115,000 ha paw Possums, rats, stoats +

layer-plus 30,000 ha

We are providing advice on:

paw Possums, rats, stoats +

» Trapping and detection networks

11

13

paw Possums, rats, stoats + We are helping with: » Advice on possum eradication and barriers to prevent reinvasion » Testing of fences to support eradication of possums from 9,500 ha Otago Peninsula cog PosStop

» Barriers to reinvasion

We are helping with: » Development and testing of traps, lures and barriers » Advice on the eradication of rats and mustelids from 1,000 ha Miramar Peninsula

We are providing advice on: » Ground-based removal of possums from 14,500 ha Māhia peninsula using bait stations and remote-reporting PosStop traps

10

layer-plus 38,751 ha

map-marker-question Bush, rural, urban

map-marker-question Urban 4

Predator Free Lake Brunner

cog MotoLure, PosStop, OutPost

map-marker-question National Park

layer-plus 4,700 ha

We are helping with:

map-marker-question Bush, rural, urban

paw Possums, rats, stoats + 3

» Kea risk mitigation

cog PosStop, OutPost, MotoLure

layer-plus 34,000 ha

» An adaptive management approach

» Potential trials

map-marker-question Rural, public conservation land (including National Park)

paw Possums, rats, stoats

Taranaki Mounga

12

paw Rats, stoats +

We are provIding advice on:

» Rural and urban trap network

6

Te Manahuna Aoraki layer-plus 310,000 ha

paw Possums, rats, stoats +

» Trapping and detection network design

» ‘1080 to Zero’ operation to remove possums from the 4,500 ha Kaitake Range

We are providing advice on: » Stoat elimination

layer-plus 22,530 ha map-marker-question National Park

paw Possums, rats, stoats +

map-marker-question Bush, rural, urban

9

Project Janszoon

D’Urville Island Stoat Eradication

8

layer-plus 16,800 ha paw Stoats Bush, rural We are providing advice on: » Stoat elimination » Stoat detection and response cog MotoLure, OutPost ABOVE:

A ZIP team member assists with the installation of a lean network of PosStop traps with OutPost remote reporting to aid the elimination of possums from the Mahia peninsula (CAROLINE WALLACE) 35

Future directions Our success to date in the Perth River valley has demonstrated for the first time that it is possible to eliminate possums across large back-country areas, and prevent them from re-establishing. We are also growing increasingly confident that soon it will be possible to eliminate rats and stoats at the same scale.

Right now, our lured trail camera network (ref. pp. 19–20) is vital for detecting possums, rats and stoats at scale. But it is very expensive to maintain, particularly in a remote and rugged location like the Perth River valley.

The high labour burden associated with regularly visiting each camera site to change batteries, SD cards, and often the cameras themselves, along with processing footage, is costing us approximately $60/ha each year. In addition, manually servicing trail cameras in remote areas doesn’t always provide timely notification of the detection of individual predators, given their mobility and/or reproductive capability.

36 F U T U R E DI R E C T I O NS

These limitations have led us to develop a new thermal camera with on-board Artificial Intelligence (A.I.) software that enables identification of predators and timely notification of these detections. By this time next year, we expect the Perth River valley will be watched entirely by these smart cameras— at a cost of less than $10/ha each year—and our team will be ready to quickly respond to all notifications.

BELOW:

A possum correctly identified by the A.I. detection algorithm

LEFT:

The Whataroa River winds its way through farmland to Te Tai-o-Rehua / the Tasman Sea (CHAD COTTLE) During the next year, we intend to step over into the neighbouring Butler Range, to repeat the elimination of predators across a combined area of more than 20,000 hectares. This will provide a valuable opportunity to repeat our predator removal operation in a non-mast year, which we anticipate will have a high chance of success—potentially reducing the need for a second application of toxin. We will also take the opportunity to further refine our Remove and Protect approach, seeking to drive down the cost of predator elimination while ensuring it remains robust and scalable.

BELOW:

A prototype thermal detection camera with on-board artificial intelligence and remote reporting capability undergoes field testing in the Perth River valley (JOHN WILKS)

Eliminating predators across the Perth River valley and Butler Range would effectively complete our research and development in the back country, and would achieve the New Zealand Government’s Predator Free 2050 interim goal of eradicating predators from blocks of at least 20,000 hectares without the use of fences—a few years ahead of schedule!

The COVID-19 public health response had a significant social and economic impact on South Westland. At the time of writing (September 2020), ZIP is facilitating conversations with Te Rūnanga o Makaawhio, the wider South Westland community, and potential funding partners, to explore new opportunities to create jobs and enhance biodiversity within the region. A ‘mountains to the sea’ concept would seek to deliver 100,000 hectares of predator freedom, in a staged multi-year programme of work, beginning around Franz Josef and Okarito.

To support this work, ZIP would initiate a programme of research and development to expand the toolset for predator elimination in lowland forest, farmland and settlements.

In addition, we will continue to provide advice, tools and other technical support to an increasing number of predator free projects across Aotearoa.

We recognise that there are some big challenges ahead. With the support of our partners, funders, and the community, we are excited and ready to take them on!

37

Financial summary Founding partners

Other funders during 2019–20

Financial statements ZIP’s 2019–20 financial statements were prepared by Hayes Knight and audited by PWC. A full set of statements will be available via charities.govt.nz in due course.

The chart to the right provides a summary of expenditure (excluding depreciation) in 2019–20.

Support Predator Free Projects $741 k

Initial removal $819 k

Minimising reinvasion $725 k Response $1,103 k Detection $1,938 k

38 F IN A N C I A L SU M M A RY

Glossary 1080 to Zero

modified approach to aerially applying 1080, developed by ZIP with advice A from DOC, OSPRI and Manaaki Whenua, to completely remove introduced predators. The approach differs from a ‘standard’ 1080 operation in the following ways: (i) it is carried out in two phases; (ii) the application of toxic bait is preceded by two non-toxic ‘prefeed’ applications; (iii) the toxic sowing rate is 4 kg/ha (as opposed to 2 kg/ha); and (iv) bait is sown with no exclusion zones and overlapping bait swaths, to ensure full coverage of the treatment area.

A24

self-resetting multi-species kill trap targeting rats and stoats, developed A

by Goodnature.

Elimination

he removal from an area of an existing population of possums, rats and/or T stoats, which are then prevented from re-establishing.

Gen One

An approach ZIP is developing to design a lean system to detect an emerging population of rats in an otherwise rat-free area, by determining the spatial ‘footprint’ of a litter of juvenile ship rats and then targeting their complete removal.

Lean detection

sparse network of devices to detect invading possums, rats or stoats in A a protected area and enable a rapid response before a viable population can establish.

LoRa

oRa is radio technology that has been developed to enable low data rate L communications to be made over long distances using very low power levels.

OSPRI

SPRI is a partnership between primary industries and the government, and O manages two national programmes—NAIT and TBfree. NAIT provides the national animal identification and traceability system and TBfree aims to eradicate bovine TB from New Zealand by 2055.

Protected area

n area under protection, which has been cleared of possums, rats and A stoats. The protected area is behind a barrier—either natural, physical, or virtual—and contains a ‘lean’ detection network to identify and respond to the presence of invaders.

Remove and Protect

The ZIP operating model whereby invasive predators are eliminated from an area, and that area is then protected against reinvasion.

Rhodamine B

chemical compound and dye, sometimes used as a bio-marker. Rhodamine A B fluoresces pastel orange under a UV light, and temporarily stains the fur and digestive tract of animals that have ingested it. It is also detectable in the growing whiskers of animals, when observed under a fluorescence microscope, as a glowing ‘band’.

Snap trap

wooden, metal, or plastic trap with a powerful snap hinge intended to kill A rodents instantly on contact. Snap traps are typically used with some form of bait to lure the rodent to the trap.

Suppression

he ongoing control of predator populations, where the target is not complete T removal and therefore re-population must be continually managed.

39 GLO S S A RY

TUN200

IP’s prototype rat and stoat trap box, which contained two side-by-side DOC200 Z kill traps in a ‘run-through tunnel’ architecture (superceded by the ZIPinn tunnel trap).

Virtual barrier

n intensive network of traps installed to minimise invasion by possums, rats A and/or stoats into an area under protection.

ZIP MotoLure

n automated lure dispenser designed by ZIP that is capable of holding and A dispensing a fresh food-based liquid or semi-liquid lure in the field every night for up to a year.

ZIP OutPost

LoRa-enabled automated reporting system designed by ZIP to enable timely A transfer of data from the field. The OutPost system is compatible with ZIP’s suite of devices, and can reduce the labour costs associated with monitoring a network of live capture traps by over 90%.

The OutPost system includes: (i) LoRa (low-powered radio)-enabled automated reporting trap nodes; (ii) satellite boxes to receive and transmit data; and (ii) a webserver to notify trap status and interface with the system.

ZIP PosStop

A PCR No. 1 Leg-hold trap presented in a raised platform developed by ZIP. Each component of this device has been carefully designed and extensively tested to maximise the effectiveness and efficiency of possum trapping operations (catching over 20% more possums than a ‘standard’ raised set), while reducing potential risks to non-target species.

ZIPinn

trap developed by ZIP for rats and stoats, which consists of a tunnel with a A spring-loaded door at each end. When a treadle plate within the centre of the tunnel is activated by a rat or stoat, both doors close. The caught animal is then automatically euthanised using CO2, a standard humane laboratory technique.

Currently undergoing testing at ZIP’s research sites, with regulatory approval.

40

Acknowledgements Blue Skies Weather and Climate Services

Manaaki Whenua – Landcare Research

West Coast Tai Poutini Conservation Board

Environmental Protection Authority

Massey University

Tararua Tramping Club

Media Fix

Te Rūnanga o Makaawhio

Federated Farmers

Ministry for Primary Industries

Te Rūnanga o Ngāi Tahu

New Zealand Deerstalkers Association

University of Otago

Callaghan Innovation

Federated Mountain Clubs Forest and Bird Game Animal Council Greater Wellington Regional Council Hawkes Bay Regional Council

OSPRI Predator Free New Zealand Trust

Westland District Council

University of Auckland West Coast District Health Board Wilderlab

Taranaki Regional Council

Willowbank Wildlife Reserve

West Coast Regional Council

Zealandia Eco Sanctuary

Action Plastics

CMI Springs

Active Electrical

Connect NZ Ltd

Excalibre Property Management

Adcorp

Connovation

Fanso

Agility Logistics Ltd

Contour Engineering Ltd

Fedex

Air New Zealand

Cougar Line

Fielden Metalworks

AJ Pietras IP

Cycle Science

First Training

Amuri Helicopters

David King Technician Ltd

Flacks and Wong

Anderson Helicopters

Department of Corrections

FLIR Systems, Inc.

Assembly Specialists Limited (ASL)

Digital Island

Fort Richard Laboratories

Don Hawinkels Builder

Fox/Franz Heli Services

Automatic Lathes

Fresh Choice Picton

Axis Routered Innovations

Dyhrberg Drayton Employment Law

Azelis

Eagle Technology Group Ltd

Garry Allan Contracting

Beachcomber Cruises

EAP Services

Gas Picton

Blacks Fasteners

Effective Speaking

Glacier Country Helicopters Ltd

Blenheim Shuttles

Elgas

Goodnature

Brush Technology

Energy Very Endure

Gotcha Traps

BW Electronics

ENI Engineering Ltd

H&H Firewood and Coal

Cactus Outdoor

Equiptech

Harris Training Services

Campbell Contracting

ESRI

Hayes Knight

Kea Conservation Trust Lincoln University

Suppliers

Central Fencing

Garmin

Highland Helicopters

41 ACKNOW LEDGE ME N TS

Hokitika Automotive

Pest Control Research

Hokitika Cycles & Sports World

Picâ&#x20AC;&#x2122;s Peanut Butter

Hokitika Guardian

Picton Manufacturing Ltd

Hokitika Security

Picton Self Storage

Human Dynamo Workshop

Pivotal

inFact

Precision 3D Printing

Integra Enclosures

PricewaterhouseCoopers

Integrated Mapping JacksonStone & Partners

Property Brokers West Coast

Jansen Synthetics

Prout Products

JBL Environmental Ltd

PZ Contracting

Knights Point Air Ltd

QuickCircuit

LDO Motors

Ray Moffat Pest Control

Lincoln Event Centre

Ray White

Lotek

Resolution Bay Cabins

Lynred USA

Rockgas Greymouth

MAE Ltd

Selwyn Rakaia Vet Services

Mainfreight

Sounds Air

Mann & Associates

Soundsnet

MBC Environmental

Spark

McMullan Timber ITM

Stager Sport

Meridian Energy

Stihl Shop

Mitre 10 Mega Christchurch

Strata Group

Mobil Fuel Card

Swazi Apparel

Motovated Design and Analysis

Talbot Technologies

MT Drums

The Business Advisory Group

National Springs and Wire Products NZ

Picton ITM

Tasman Pest Control

TrailCamPro

Nautech Electronics

Triple One Care

New World Hokitika

United Parcel Service

NTD Plastics Ltd

Urban Harvest

NZ Conservation Jobs

West Coast Film

NZ Wilderness Services Ltd

West Coast Physio

On Your Team

Western Builders Ltd

Orillion

Wildlife Protection Services

Outsider Mountain Sports

Wildtech

PBT Couriers

Wire Displays/ NZ Wire & Mesh

PBT Transport Ltd Peak Outdoor Safety and Emergency Training

Sunset from the Teichelmann area, within the Perth River valley field site 42

(CHAD COTTLE)

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