Happy Nice Mall

WELLINGTON, New Zealand — The volunteer climbed down cliffs on a thin rope along a series of knots as he made a perilous trek to the small box that was supposed to fill with poison about 100 feet down a steep rock surface.

It’s one of thousands of such boxes, many of which are located in equally inaccessible spots, that were deployed on the Miramar Peninsula south of New Zealand’s capital, Wellington, last month.

Like Dan Henry clinging to the abyss, conservationists and volunteers set traps with fresh rabbit meat, spew poison tainted with aromatic bait, and survey footage from local cameras to address the area’s cactus problem.

A problem that seems to consist of a single stool.

The willingness of humans to go this far in pursuit of a predatory mammal is testament to the severity of the biodiversity crisis in New Zealand. Native birds, lizards, and bats have evolved only in the absence of mammalian predators that have emerged in recent centuries.

Many of its most iconic native creatures cannot fly. As a result, they are vulnerable to predators such as macaws brought to New Zealand to control rabbits in the 19th century – weasel-like creatures with serrated teeth and exceptional agility. About 4,000 of the country’s native species are classified as “at risk” or “threatened” – the highest proportion of threatened native species in the world.

Activists on the Miramar Peninsula are dedicated to saving the peninsula, which until the 2010s was populated with unwanted mammals, from nearly all predators. (Domestic cats, who are politically untouchable despite their capacity to kill, are an exception.) Their goals may seem unrealistically ambitious, but this has become normal in New Zealand, where the government committed in 2016 to eliminate most non-native predators by 2050.

“Many of our species give our country a sense of identity,” said Kiri Allan, New Zealand’s conservation minister. “We have a sense of nationhood at risk.”

Six years later, the campaign had significant success. The New Zealand Department of Conservation has placed over one thousand square miles of land under permanent predator control, wiped out predators on 117 of its nearly 600 islands, and created numerous fenced-off predator-free reserves across the country.

But now, the nation’s conservation community grapples with whether it can achieve that goal and at what cost.

In Miramar, which is home to tens of thousands and connected to the rest of Wellington by a large, unfenced isthmus, the department worked with local volunteers to eradicate rats, ferrets and brown mice. The stoas are about to emerge and the black rats have reached their lowest numbers since measurements began.

Mr. Henry, co-founder of the Predator Free Miramar volunteer group, is dissatisfied. “I don’t think the wins are coming fast enough,” he said.

Nicola Toki, CEO of conservation advocacy group Forest & Bird, agreed. “The risk at the current speed and scale is that we don’t get there.”

But some in the conservation community doubt whether it’s viable to get there, given how resource-intensive predator eradication has proven.

In Miramar, for example, 5,878 traps and 6,607 poison stations were placed on three square miles of the peninsula. Each must be checked regularly, requiring dozens of paid staff and local volunteers.

Another approach would be to focus on creating more places, such as Zealandia, near Wellington, a fenced-in reserve of about a square mile where local wildlife can thrive. New Zealand has such a network of non-predatory spots, some on offshore islands.

Sanctuaries are expensive to build and maintain and can only protect relatively small areas. But New Zealand’s predator-free campaign aims to eliminate predators in the long run, while fenced reserves provide instant safety.

Conservation advocates want the government to pursue both. But with limited protection spending, prioritizing one may hinder full adoption of the other.

Ms Allan described the predator-free target as “aspirational”. In a written statement, he said the government has made significant progress but will focus on “innovation and learning” with the aim of exploring “more effective and efficient ways to conserve our biodiversity on a much larger scale” going forward.

Toki, on the contrary, insists that a complete elimination is possible, but requires much more funding and focus from the government. “Make America’s Predator Free Cup,” he said, referring to the nearly $250 million New Zealand spent to host the America’s Cup sailing competition in 2021.

Local activists agree. “The Predator Free 2050 is definitely achievable if that’s what we’ve decided to do,” said Mr. Henry. “I guess when we started I thought we would start with old tools and a silver bullet would come out and we would all breathe a sigh of relief.” But that wasn’t the case, he said. “We just take the boot skin, the traps, and the poison and put them wherever we can.”

There was a sudden flutter and chirping in his shoulder as he bent over a trap with a stick to show what had happened when the mechanism sprung. A pīwakawaka resembling an extended accordion with tail feathers settled on a nearby branch. The number of native birds on the peninsula has increased since the predator free campaign began.

Mr. Henry admits that total elimination is not the only measure of victory. Still, he and the other members of Predator Free Miramar are determined to achieve their goals to show that this is possible at the national level.

“People see the success we have had here,” said Mr. Henry. “They want to reproduce it. We are a true demonstration of what you can achieve if you work on it and the community lags behind.”

This includes tracking down the last poop. Sue Hope, a local volunteer, is optimistic that she has been poisoned or trapped. To be safe, though, he spends every Sunday morning roaming the slopes to reset traps and refill poison stations.

“The meatballs are terrible,” he said. “They kill things for no reason, even for not eating it.” He then dives off the rail and burrows under a thorn bush in search of the next trap to check.