Hunters on the trail of Miramar stoat
This article was originally written by Nikki Macdonald and published by The Post on 1 June 2024. See original article here.
A stoat has been caught on camera a dozen times since December 2023 on predator-free Miramar Peninsula.
He was first seen on December 15 – a full daylight snapshot of a white-bellied, bird-killing machine prowling the pines above Shelly Bay. On Christmas Day, he sauntered through Lyall Bay Bowling Club.
January was a bunch of night-time arse shots streaking through Mahanga Bay. A dozen sightings in five months, the last on April 12. But nothing but empty traps.
“If you were a stoat, where would you go?” Dan Henry asks himself.
The Predator Free Miramar founder is mulling where to re-home Bush Trap 299. Perched on a grassy hillside on Miramar Peninsula, overlooking Wellington Harbour, it’s been part of a neat grid of traps spaced every 100m around the promontory.
They might be low-tech – two steel traps inside a wooden box, plus attached bait station – but they did the job, with Miramar declared free of rats and mustelids in November 2023.
But the rules have changed. A male stoat has moved back in. And, as Henry’s band of volunteers are learning, a lone re-invader is a very different challenge.
“It’s one thing to have a huge network of traps that’s set up to fill in every little bit of real estate to try and catch rats,” Henry says. “But when you’re hunting one individual animal, it’s so much harder, because they’ve got the run of the place.
“They’re not just going to blindly walk into a trap, just because it happens to be there …You have to think like a stoat.”
This, says veteran predator-hunter John Bissell, is what we’ll increasingly see as Predator Free campaigns nationwide wipe out pest populations.
Re-invasion is inevitable, but the survivors are alpha animals.
“They’re the pinnacle of their species, they’ve adapted and evolved in an environment where everyone is trying to kill them. So to catch the uncatchable is quite something.”
And that calls for a change in strategy, says Bissell, who runs Backblocks Environmental Management.
“You need to take science, and you need to add hunt … Nobody sends in the regular army to resolve a hostage situation.
What you need in this situation is SAS predator hunters.”
Today’s SAS predator hunters are eight mostly retired blokes.
They gather at 8.30am on a Sunday outside the old Mt Crawford Prison high on the peninsula to check traps and cameras in the hope of discovering – or luring in – the invader.
Henry has assigned each pair a colour-coded zone. Every trap and camera is mapped and its visiting schedule diaried. Today’s cameras mostly haven’t been checked in 28 days – so if the stoat has been photographed, it’ll likely be long gone.
But any sightings will still give valuable intel – where it’s moving and why.
Volunteers Mike Arnerich and John Herrick, both 64, join the purple team for what Henry jokingly calls “bush yoga”.
Getting to the traps and cameras involves bending and stretching, scrambling down unstable banks, clutching at branches to clamber back up.
Henry started Predator Free Miramar in 2017, after the national Predator Free movement launched. The 50-year-old didn’t want to sit on the sidelines while someone else ran the show.
Unlike most of today’s volunteers, he has a day job, as associate producer for TV’s Country Calendar. He doesn’t dare count the hours this work takes, but it’s at least a day a week.
“Ask him what drugs he’s on,” Arnerich jokes. “He never sleeps.”
Briefing the team, Henry fishes out the latest weapon in the SAS arsenal – a ziplock bag of grey fluff. It’s stoat bedding from Landcare Research down south.
It’s mildly musky, but must be good stuff as when Henry opened the bag at home, his cat suddenly appeared.
He’s also brought new bait, as peanut butter won’t cut it with a proteinhungry stoat.
“As volunteers, that’s a bit of a barrier. It’s easy to store a big bucket of peanut butter on the shelf, but it’s harder keeping a supply of fresh rabbit without it going off, or without getting divorced.
“I’ve got a long-suffering wife who will no longer go to the chest freezer in the basement to get a loaf of bread, because there’s an ice cream container labelled ‘dead things’ in there. It’s an occupational hazard.”
In the absence of fresh rabbit, Henry has brought offcuts of a stag he shot. The rest went in last night’s venison stew.
This is the kind of detail needed to catch a lone animal with the run of the place, says Bissell, who recently visited from Wairarapa to school up the volunteers and Predator Free Wellington workers.
“Removing a species is broad-brush, removing one animal is very fine detail. It’s a mallet versus a scalpel.”
Past the fallen tree Bissell thought made a perfect stoat playground, past the spot where a stoat dog found traces of scent, and down the hill is Bush Trap 299.
It’s currently in the open – that’s bad news for catching stoats seeking cover from hawks and falcons. So Henry trudges it up the bank to the fenceline, where Arnerich and Herrick grub out a flat grounding.
Henry wires in a wad of stoat bedding to waft in the breeze, and Herrick baits the trap with a venison chunk from his builder’s belt.
Herrick retired about 14 years ago, at the age of 50, and signed up to Predator Free Miramar to help build trap boxes.
“You’ve got to stay busy. Everyone needs social interaction as well. You can’t retire and just sit around talking to the missus all day. She kept going out.”
When Arnerich bought his first house here, it had rats in the roof. He told the kids they were angels. He used to mountainbike at Zealandia, before it became the country’s first predator-free fenced sanctuary, and was blown away by the transformation.
“We were just captured by what they’d done there and thought, wow, we want to be a part of this.”
That’s the beauty of this volunteer army, who number about 40, Henry says. Everyone comes for different reasons, from bringing back endangered birds, to camaraderie, to making rat-free homes.
And just as humans respond to different triggers, so do animals.
Kill first, and ask questions later
In fact, stoats have personalities, says Manaaki Whenua Landcare Research wildlife ecologist Andrew Veale.
“The animals that survive are the ones that don’t trust humans and don’t trust new objects, so they’re a different personality.”
Some avoid capture for years. When Veale finally caught an evasive Waiheke Island stoat in a live trap and did behavioural tests on it, he found it was “significantly abnormal”.
But how much damage can one stoat really do?
“A huge amount,” Veale says.
The Department of Conservation (DOC) calls stoats “public enemy number one” for native birds. Kiwi chicks can’t fight them off until they weigh about 1kg. And kākā and mohua nesting in tree trunks are easy prey for the adept climbers.
A stoat once got to an island off Mt Maunganui and killed 93 diving petrels in two weeks. Unlike ferrets, they have few fat reserves, so if they don’t eat for a couple of days, they die, Veale says.
“Therefore the correct hunting strategy is kill first, and ask questions later. Because if you kill too much today, you can always hide it and then come back tomorrow if you don’t find any food. So they do kill in excess when it’s available.”
On Hauraki Gulf island Motutapu, DOC eventually caught a trap-avoiding stoat by building an artificial penguin nest from driftwood, adding female stoat scent and sounds, plus a penguin egg.
“There are ways to get them, but it may be that it’s individually tailored, so you need to find out what that particular stoat wants.”
Bissell has done some 20 “resolutions” – hunting lone invaders on predator-free islands, or in fenced sanctuaries.
It’s high pressure, as the animal picks off beloved birds. Sometimes it takes two days. Sometimes it takes months. And because you’re trying to get inside their head, it’s personal. So when you finally catch it, “it’s probably the most bizarre array of emotions I’ve ever experienced,” Bissell says.
“Because I’ve connected with that animal, I have a huge amount of respect for them. So there’s a huge relief. There’s a degree of pride in a job well done, but also a real feeling of empathy and sadness for the animal. They didn’t ask to be there – they’re just doing what they do.
“The day we stop respecting these animals is the day we stop learning about them.”
Is eradication a pipe dream?
Henry always believed it was possible to rid Miramar Peninsula of rats and mustelids, because it had already been possum-free since 2006. The airport runway provides a natural pest-break, making it almost like an island. But Henry admits 1000 hectares is “a whole lot of real estate”.
While the thrill of catching rats initially motivated volunteer trappers, he hopes they’ll see the difference they’re making – the returning birds, the kohekohe seedlings coming away – and keep coming. “It’s just chalk and cheese. The difference between what it was and what it is now – it’s really exciting.
“It’s not just a nice, warm fuzzy thing – that’s nice to have a few birds. It’s climate crisis prevention, it’s mental health, it’s housing health. There are so many benefits beyond the pīwakawaka and tūī.”
Veale says the chances of removing Miramar’s stoat in the next year are “reasonably high”, with no rats for fodder and fluctuating mice populations. And it might get lonely.
But given stoats are good swimmers and can travel 65km, keeping them permanently out of Miramar – or any unfenced area – seems impossible.
“I’m yet to be convinced that trapping can eradicate stoats, just because there’s enough animals that can avoid … I think the only tools capable of doing that currently are toxins.”
That’s not an argument to stop trapping – holding down stoat numbers is the only reason Wellington’s parks are alive with the squawks of native parrot kākā, Veale says.
“If you stop, then the predation will ramp up and will lose those sensitive species. It has huge benefits. It just means that until we have a silver bullet, or fences, to fully protect areas, you’ll always have to do the stoat suppression.”
Bissell says Henry’s crew should be proud they even know the stoat is there. “Too often, we trap and hope and walk away and pat ourselves on the back for a job well done. We’re not measuring the living enough.”
Clearing predators from scrubby, suburban Miramar Peninsula is “an incredible thing and an icon amongst conservation projects,” Bissell says. To him, the value of the predator-free movement is the culture shift it’s creating.
“It’s changing the way the community engages with native wildlife, and thinks about native wildlife, and where native wildlife is.
“I’m not in this for Predator Free 2050. I’m in it for the gains that we’re making now, and the difference that we’re making now, and the things that we’re seeing.
“And it’s amazing what’s happening out there – returning wildlife to places they haven’t been for 100 or 200 years.”
Back at Miramar, Henry, Arnerich and Herrick finish checking their three cameras and re-baiting and shifting traps. None contain the elusive stoat.
On the way back to the car park, a couple from across the water at Hataitai are walking their labrador. They’ve noticed how much birdlife has increased, with kākā cawing outside their windows.
“Thanks for what you are doing,” they say. As if on cue, a kārearea glides overhead and perches on a power line.
Further up another couple, from nearby Seatoun, stop the trapping trio.
“Are you with Predator Free?” Henry nods. The guy claps: “Fantastic. Amazing.”
Posted: 1 June 2024