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Searching for the magic bullet

Self-resetting Goodnature traps will likely be an important tool in making New Zealand predator-free. Photo: Supplied
What are the chances New Zealand will be predator-free by 2050? Dave Hansford investigates

That screech – like a football rattle going off in a tin – has to be a kaka. In fact, it’s a pair of them, alighting in a beech tree just ahead. “This is all for you guys,” says Maryann Ewers. A gentle rain of bark and beech bits falls as the kaka start prospecting for grubs. We’re halfway through a line of traps set and maintained by the volunteers of Friends of Flora in the east of Kahurangi National Park. It’s going to be a long day: it took two hours and a 400m climb, practically to the summit of Mt Hodder, just to reach the start of this line of DOC 150 traps (downtime Ewers begrudges as “dead walking”), and though there’s only 35 of them, they’ll bring us out at Ghost Creek, which will mean, all up, a seven-hour, 14km excursion.

Ewers chortles and whistles at the kaka for a bit (she’s a convincing bird whisperer), before we get back to work. Ewers and Rooke have a system, refined by years of graft: they leapfrog, each attending alternate traps in the line, opening, (and, occasionally, emptying corpses, but we didn’t catch a thing this day), checking mechanisms and pressure plates, re-baiting and screwing shut each box in turn. The couple started FoF, to use the local vernacular, 15 years ago to control pests in this popular part of Kahurangi, because they knew DOC had no money to do it.

The group now runs around 1100 traps in 127km of lines across more than 8000ha – one of the largest volunteer projects anywhere – but the sheer effort has taken a toll: Rooke is nearly 70, and has arthritic knees. Ewers is asthmatic, and suffers a sore hip. They lead a ‘soft’ core of around 40 volunteers, says Rooke, the hard core is more like 20. Finding volunteers is a constant drudge – keeping them is tougher still: “You’re talking about physically demanding work, going off-track into a wilderness area, pulling dead animals out of traps,” she says. “Not everyone wants to do it.”

But somebody has to do something: according to an estimate by Landcare Research’s John Innes, introduced pests – rats, mice, stoats, weasels, ferrets, cats, hedgehogs, pigs and possums – devour around 25 million eggs and chicks of native forest birds each year. “If you were to add the adult birds killed on the nest, and those in exotic forests, shrublands, wetlands, pasture etc., the total number would be vastly larger,” he says. In 2015, the Endangered Species Foundation listed some 4000 New Zealand creatures and plants facing some kind of threat — 800 of them staring quite hard at extinction. We have one of the highest proportions of doomed biodiversity anywhere on Earth, and that’s in large part down to the depredations of vermin.

None of this is news. People have quipped for decades that conservation in New Zealand is all about killing things. The Wildlife Service launched a counter offensive as far back as the seventies, to be relieved by the Department of Conservation in 1987. But the war on pests – now officially branded as a Battle for our Birds – for all its apparent strategy and logistics, still has a desperate rearguard air about it. Climate change will only make things worse: more frequent mass seedings in the forest – masts – are set to pump fuel into already volatile rodent throngs.

The Million Dollar Mouse operation on the Antipodes Islands is the largest pest-eradication programme undertaken so far. Photo: Stephen Horn

The Million Dollar Mouse operation on the Antipodes Islands is the largest pest-eradication programme undertaken so far. Photo: Stephen Horn

In July this year, some surprisingly senior cabinet ministers assembled behind Prime Minister John Key to nod gravely as he declared an end to the carnage – at least provisionally. Predator-Free New Zealand (PFNZ) Ltd (not to be confused with the trust, launched in 2013, of the same name) is a line in the distant sand, scribed across 2050, that marks the eviction date for rats, stoats and possums. This is conservation by capitalism: for every two dollars raised by the private sector for pest control and eradication projects, the Government will chip in another dollar, capped at $7m a year for the next four years. Nobody pretends it’s anywhere near enough. The total bill for notional, national pest-free status has been calculated by Auckland University of Technology at roughly $9b, but National’s turnout to the pest control meeting isn’t about the money, says Devon McLean.

Manager of public/private restoration initiative Project Janszoon, in Abel Tasman National Park, McLean says the gesture is the important thing: “This is a really big message that we intend to care. It has clearly connected the predator-free concept to where big chunks of our economy are headed – nature tourism in particular, which is the reason a high proportion of people come to New Zealand. It’s not just about predator-free; it’s about biodiversity and caring about our landscapes. I think that’s a huge step.”

Project Janszoon, like Friends of Flora, was born out of the realisation that government funding alone was never going to keep the listing ship – our biodiversity – afloat, let alone turn it around. Janszoon is bankrolled to the tune of $25m over the next 30 years by Auckland philanthropists Annette and Neal Plowman’s Next Foundation (DOC has also put in money). Many other groundbreakers – the Cape Sanctuary in Hawke’s Bay, Reconnecting Northland, Million Dollar Mouse (the eradication of mice from the Antipodes Islands) – rely heavily on the generosity of private funders and represent the way conservation has been heading for some time. McLean says philanthropists will be reassured by the Government’s gesture: “It’s allayed what has always been a fear in the philanthropic sector – that if they started putting money into conservation, the government would start backing out.”

But if PFNZ Ltd depends on yet more charity, how much have patrons left to give? Plenty, says McLean. “I don’t think we’re approaching anything like a ceiling at the moment. I’m very confident that there’s still more room to move.” Maybe not from within, he says, “But there are a lot of other people in the world who are interested in New Zealand’s biodiversity. I often say to people that our biodiversity is a little bit like the pyramids in Egypt, or the Roman ruins. It’s a taonga that we hold for the benefit of the entire world. A lot of people come here to see it, and they have money to invest in New Zealand – the James Camerons and the Julian Robertsons – who decide to put money into looking after their patch. The prospect of being a party to the transformation of this country’s biodiversity is a unique opportunity.”

Geoff Simmons agrees. “I don’t think we’re at the hard limits yet of what philanthropy is prepared to provide,” says the economist at the Morgan Foundation. But, he adds, a better articulated, more coherent conservation strategy would help loosen more wallets: “Philanthropists are happy to work in partnership, but generally, they expect a very clear public offer. With everything that’s been happening in DOC over the last few years – which is partly to do with funding, and partly DOC’s own making – that public offer isn’t entirely clear yet. We’re seeing a few cases of investor or community group fatigue, where they’ve entered into a partnership with DOC, only to see the terms of engagement change, for any number of reasons. That makes it very difficult for philanthropists.” Therein lies the biggest benefit from the Government’s commitment, he says; a firmer platform. “If we can demonstrate that this is doable, people will step up.”

So is it doable? New Zealand pioneered the science, and nebulous art, of island eradication – an endeavour that’s tracked a sort of bastardised Moore’s Law, in that every decade has seen pests cleared from islands roughly twice the size of the last, for less cost. In 1960, a boatload of Forest & Bird volunteers rid rats from Ruapuke Island, a 2ha outlier in the Hauraki Gulf. Since then, pests have been cleared from 117 New Zealand islands, culminating in 11,300ha Campbell Island in 2001. And all that was done using a meagre handful of rough-hewn tools, when weapons like self-resetting traps were just a sketch on the back of a napkin. Stu Barr – along with colleagues Robbie van Dam and Craig Bond – turned that sketch into the biggest boon to pest control: a humane kill trap you can set and forget for six months (or until its gas cartridge is exhausted). Ten years of R&D have produced what will likely be a mainstay – the Lee Enfield .303 – of this war on pestilence. As far as Barr is concerned, we’re ready to bring landscape-scale pest control ashore to the mainland: “We’ve got traps on test now that you can put out there and leave for a year. We’ve almost cracked it. What if you could put that thing out and forget about it for three years?”

Barr says Goodnature’s traps will form ranks beside the emerging – though still highly prototypical – technology being refined by Zero Invasive Predators (ZIP), a public-private pest control startup in part funded by the dairy industry.

A satellite transmitter on ZIP’s modified DOC 200 (called a TUN200) traps at Bottle Rock can alert staff to a trap going off. Photo: Supplied

A satellite transmitter on ZIP’s modified DOC 200 (called a TUN200) traps at Bottle Rock can alert staff to a trap going off. Photo: Supplied

ZIP’s is a quest for fenceless barriers – lines of traps and bait stations laid across the narrow waists of defendable tracts like peninsulas. Which sounds a bit last-century, until you see the technology at work at ZIP’s proving ground at Bottle Rock, in the Marlborough Sounds. The general idea, says CEO Al Bramley, is that no pest can cross a defensive zone without encountering at least one device. Which means that here, traps are set just 10m apart. Some are modified double-set DOC 200s, but this is no aging hardware: Bramley and his team have spent hundreds of thousands of dollars finding ways to improve efficiency, reduce labour, enforce biosecurity. Many traps feature a satellite transmitter that lets staff know within the hour when it’s gone off. Dotted further inside the sanctuary are detection devices, again connected by wireless relays, baited to attract any pest that somehow gets through the line, or arrives ashore by another means.

Bramley applauds PFNZ Ltd, but says we shouldn’t get too fixated on the ‘Free’ part. He’s confident we can eradicate possums (fairly soon), rats and stoats, which, he says, cause around 80 per cent of mayhem. But he acknowledges that will still leave others, like hedgehogs, cats and mice – and they could take a lot of killing. “Too often, we tend to paint these things as black and white,” he cautions, “but I think people need to be mindful that, just because we’re not necessarily getting a pest down to zero, doesn’t mean we’re not doing any good. Look at Zealandia: it’s a predator-free sanctuary, but it’s got mice in it. They simply keep their numbers low, so mice haven’t prevented them doing a single one of their (species) reintroductions. It’s not an all-or-nothing situation.”

Bottle Rock is PFNZ in microcosm. As a stretch goal, the Government strategy wants proof that we can eradicate the unholy trinity – rats, stoats, possums – from a 20,000ha block by 2025 and keep them out. ZIP’s patch here in the Sounds is just 400ha, but Bramley will soon go looking for a new one – 10 times bigger. “I think that, technically, when we get to 4000ha, 20,000ha will be doable. We can make it work.” Then he adds: “Community willing.”

And there’s the rub: if PFNZ Ltd fails, it won’t be down to a lack of technology, or money; it’ll be because it didn’t capture enough hearts and minds. “With a 4000ha project,” says Bramley, “there is usually only a small number of people involved. 20,000ha is a much bigger, socially complex challenge.”

You might assume that everyone wants to see native wildlife back and burgeoning, but that overlooks a thorny tangle of attitudes and agendas – as diverse as they are dogmatic – at play here. Some people object to inflicting pain and distress on animals, no matter what their provenance. Others suspect PFNZ Ltd is just the thin end of a wedge aimed squarely at their outdoor passion – hunting. But the biggest hurdle lies in the inescapable reality that the first strike in most eradications – that crucial initial knockdown – will have to be done with aerial poison, and there’s only one registered for that job: 1080.

“A significant proportion of the population – even if they don’t go out and march against 1080 – are philosophically opposed to spreading poisons on the landscape,” says Devon McLean, “and I totally understand that.” But, he adds, “… a reasonably high proportion of the population haven’t spent the time – or simply don’t have the interest – to understand what’s at stake here. There’s nobody really out there advocating for the 25 million birds a year that get scoffed by rats and stoats and possums.”

Within 24 hours of the Predator-Free announcement, some in anti-1080 circles were inciting sabotage: “If you want to help the environment,” implored one on Facebook’s 1080Eyewitness page, “the best thing you can do is trap rats and possums live and reintroduce them to 1080 dead zones.”

Goodnature's latest design can be left in the field for up to a year before someone needs to check on it. Photo: Supplied

Goodnature’s latest design can be left in the field for up to a year before someone needs to check on it. Photo: Supplied

How can advocacy turn such unbridled hostility? While McLean sees some value in social research, he says nothing speaks louder than success: “The most powerful thing would be to have more exemplars out there – proof that things are changing for the better. Take the example of Karori in Wellington – saddlebacks are nesting in people’s backyards, and much of that is down to a change in social attitudes. We’ve seen an element of that here, at Abel Tasman, too. People have seen birds returning to the park – that what we told them would happen, has happened. We’re doing another 1080 operation at the moment in the northern part of the park, and we’ve had no opposition whatsoever. The conversation has all been about the benefits.”

A predator-free nation, though, will be a different ask. Rather than happening out of sight in the backwoods, it’s going to mean controlling pests on farms and in backyards. Around schools, around pets. To date, that sort of thing has only been suggested once, on Stewart Island, and it’s had a luke-warm reception. “It’s no use putting the argument that the place would enjoy higher visitor numbers, and therefore increased revenue,” says McLean, “because those folks don’t actually want more visitors. The proposition doesn’t work for them.” Geoff Simmons, who’s done much of the work on the pest-free Stewart Island proposition, nevertheless thinks that “… a lot of people don’t even realise that our native species are still in decline, (but) some of those basic statistics can be quite startling. Most people don’t want blood on their hands, in terms of wholesale extinctions. We find that once you explain that sort of thing to people, they become more empathic.”

Over at Goodnature, Stu Barr is in no doubt: “I have an eight-year-old daughter, and for her generation, PFNZ is their nuclear-free New Zealand. I was five years old when the Rainbow Warrior was bombed, and that precipitated a galvanising national conversation. I think this will be the new conversation. These kids will grow up never questioning this movement. Whether we do it in 25 years, or 55 years; I don’t think it matters.” All the same, he says, “We have to acknowledge that this will be really hard work. We’ll have to graft our way towards this, through the brilliance of technology, through best practice and great leadership. It’ll be a sweaty and blistery process. We can’t just sit back and watch progress on the news – we’ll all have to roll our sleeves up and get muddy.”

Maryann Ewers and Bill Rooke have had their sleeves up for 15 years, got plenty muddy. Out here, walking the trap lines, they get time to think, and they worry that PFNZ could make deliverance day look like a distant deadline, when pest control needs to be stepped up right now. “My main concern, says Rooke, “is that PFNZ is distracting the public from the job at hand … if we don’t at least double 1080 usage in the near future we’re heading for a disaster.” Ewers agrees: “We’re in dire straits. We can’t be complacent in thinking an answer is on the way, when it’s not even on the horizon yet. If we don’t continue as we are, while still trying to find that magic bullet, we’re in danger of having nothing left to protect when, or if, we do.”

Then they do precisely that, barging through the bush to the next trap.

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