In the days—perhaps weeks—it had spent in the trap, the stoat had lost most of its fur, so it looked as if it had been flayed. Its exposed skin was the deep, dull purple of a bruise, and it was coated in an oily sheen, like a sausage. Stoat traps are often baited with eggs, and this one contained an empty shell. Kevin Adshead, who had set the trap, poked at the stoat with a screwdriver. It writhed and squirmed, as if attempting to rise from the dead. Then it disgorged a column of maggots.
“Look at those teeth,” Adshead said, pointing with his screwdriver at the decomposing snout.
Adshead, who is sixty-four, lives about an hour north of Auckland. He and his wife, Gill, own a thirty-five-hundred-acre farm, where for many years they raised cows and sheep. About a decade ago, they decided they’d had enough of farming and left to do volunteer work in the Solomon Islands. When they returned, they began to look at the place differently. They noticed that many of the trees on the property, which should have been producing cascades of red flowers around Christmastime, instead were stripped bare. That was the work of brushtail possums. To save the trees, the Adsheads decided to eliminate the possums, a process that involved dosing them with cyanide.
One thing led to another, and soon the Adsheads were also going after rats. With them, the preferred poison is an anticoagulant that causes internal hemorrhaging. Next came the stoats, or, as Americans would say, short-tailed weasels. To dispatch these, the Adsheads lined their farm with powerful traps, known as DOC 200s, which feature spring-controlled kill bars. DOC 200s are also helpful against ferrets, but the opening is too small for cats, so the Adsheads bought cat traps, which look like rural mailboxes, except that inside, where the letters would go, there’s a steel brace that delivers an uppercut to the jaw.
The Adsheads put out about four hundred traps in all, and they check them on a regular rotation. When I visited, on a bright blue day toward the end of the Southern Hemisphere winter, they offered to show me how it was done. They packed a knapsack of supplies, including some eggs and kitty treats, and we set off.
As we tromped along, Kevin explained his trapping philosophy. Some people are fastidious about cleaning their traps of bits of rotted stoat. “But I’m not,” he said. “I like the smell in there; it attracts things.” Often, he experiments with new techniques; recently he’d learned about a kind of possum bait made from flour, molasses, and cinnamon, and Gill had whipped up a batch, which was now in the knapsack. For cats, he’d found that the best bait was Wiener schnitzel.
“I slice it thin and I tie it over the trigger,” he told me. “And what happens with that is it starts to dry out and they still go for it.”
I’d come to watch the Adsheads poke at decaying stoats because they are nature lovers. So are most New Zealanders. Indeed, on a per-capita basis, New Zealand may be the most nature-loving nation on the planet. With a population of just four and a half million, the country has some four thousand conservation groups. But theirs is, to borrow E. O. Wilson’s term, a bloody, bloody biophilia. The sort of amateur naturalist who in Oregon or Oklahoma might track butterflies or band birds will, in Otorohanga, poison possums and crush the heads of hedgehogs. As the coördinator of one volunteer group put it to me, “We always say that, for us, conservation is all about killing things.”
The reasons for this are in one sense complicated—the result of a peculiar set of geological and historical accidents—and in another quite simple. In New Zealand, anything with fur and beady little eyes is an invader, brought to the country by people—either Maori or European settlers. The invaders are eating their way through the native fauna, producing what is, even in an age of generalized extinction, a major crisis. So dire has the situation become that schoolchildren are regularly enlisted as little exterminators. (A recent blog post aimed at hardening hearts against cute little fuzzy things ran under the headline “Mrs. Tiggy-Winkle, Serial Killer.”)
Not long ago, New Zealand’s most prominent scientist issued an emotional appeal to his countrymen to wipe out all mammalian predators, a project that would entail eliminating hundreds of millions, maybe billions, of marsupials, mustelids, and rodents. To pursue this goal—perhaps visionary, perhaps quixotic—a new conservation group was formed this past fall. The logo of the group, Predator Free New Zealand, shows a kiwi with a surprised expression standing on the body of a dead rat.
New Zealand can be thought of as a country or as an archipelago or as a small continent. It consists of two major islands—the North Island and the South Island, which together are often referred to as the mainland—and hundreds of minor ones. It’s a long way from anywhere, and it’s been that way for a very long while. The last time New Zealand was within swimming distance of another large landmass was not long after it broke free from Australia, eighty million years ago. The two countries are now separated by the twelve-hundred-mile-wide Tasman Sea. New Zealand is separated from Antarctica by more than fifteen hundred miles and from South America by five thousand miles of the Pacific.
As the author David Quammen has observed, “Isolation is the flywheel of evolution.” In New Zealand, the wheel has spun in both directions. The country is home to several lineages that seem impossibly outdated. Its frogs, for example, never developed eardrums, but, as if in compensation, possess an extra vertebra. Unlike frogs elsewhere, which absorb the impact of a jump with their front legs, New Zealand frogs, when they hop, come down in a sort of belly flop. (As a recent scientific paper put it, this “saltational” pattern shows that “frogs evolved jumping before they perfected landing.”) Another “Lost World” holdover is the tuatara, a creature that looks like a lizard but is, in fact, the sole survivor of an entirely separate order—the Rhynchocephalia—which thrived in the early Mesozoic. The order was thought to have vanished with the dinosaurs, and the discovery that a single species had somehow managed to persist has been described as just as surprising to scientists as the capture of a live Tyrannosaurus rex would have been.
At the same time, New Zealand has produced some of nature’s most outlandish innovations. Except for a few species of bats, the country has no native mammals. Why this is the case is unclear, but it seems to have given other groups more room to experiment. Weta, which resemble giant crickets, are some of the largest insects in the world; they scurry around eating seeds and smaller invertebrates, playing the part that mice do almost everywhere else. Powelliphanta are snails that seem to think they’re wrens; each year, they lay a clutch of hard-shelled eggs. Powelliphanta, too, are unusually big—the largest measure more than three and a half inches across—and, in contrast to most other snails, they’re carnivores, and hunt down earthworms, which they slurp up like spaghetti.
New Zealand’s iconic kiwi is such an odd bird that it is sometimes referred to as an honorary mammal. When it was first described to English naturalists, in 1813, they thought it was a hoax. Kiwi are covered in long, shaggy feathers that look like hair and their extended, tapered beaks have nostrils on the end. They are around the size of chickens but lay eggs that are ten times as large, and it usually falls to the male, Horton-like, to hatch them.
New Zealand’s biggest oddballs were the moa, which, in a feathers-for-fur sort of way, stood in for elephants and giraffes. The largest of them, the South Island giant moa, weighed five hundred pounds, and with its neck outstretched could reach a height of twelve feet. Moa fed on New Zealand’s native plants, which, since there were no mammalian browsers, developed a novel set of defenses. For instance, some New Zealand plants have thin, tough leaves when they are young, but when they mature—and grow taller than a moa could chomp on—they put out leaves that are wider and less leathery. The Australian naturalist Tim Flannery has described New Zealand’s avian-dominated landscape as a “completely different experiment in evolution.” It shows, he has written, “what the world might have looked like if mammals as well as dinosaurs had become extinct 65 million years ago, leaving the birds to inherit the globe.” Jared Diamond once described the country’s native fauna as the nearest we’re likely to come to “life on another planet.”
With about half the population of New Jersey, New Zealand is the sort of place where everyone seems to know everyone else. One day, without quite understanding how the connection had been made for me, I found myself in a helicopter with Nick Smith, who was then the country’s minister for conservation.
Smith, who is forty-nine, has a ruddy face and straw-colored hair. He is a member of the country’s center-right National Party, and calls himself a “Bluegreen.” (Blue is the National Party’s color.) He got interested in politics back in the nineteen-seventies, when, as an exchange student in Delaware, he met Joe Biden. We set off from Smith’s district office, in the city of Nelson, on the northern tip of the South Island, and drove out to the helicopter pad in his electric car.
“When the first settlers came here, they tried to create another England,” Smith told me. “We were Little Britain. The comment about us was, we were more British than the British. And, as part of the maturing of New Zealand, there’s the question, What do you connect your nationhood to? You know, for America it’s very much the flag, the Constitution, those sorts of things. The connection with species that are unique to New Zealand is increasingly part of our national identity. It’s what we are as New Zealanders, and I make no bones of the fact that the government is keen to encourage that. You need some things for a country to hold together.”
He went on, “I say to people, If you want your grandkids to see kiwi only in sanctuaries, well, that’s where we’re headed. And that’s why we need to use pretty aggressive tools to try to turn this around.”
My visit happened to coincide with the application of one of these aggressive tools. The country’s Department of Conservation was conducting a massive aerial drop of a toxin known as 1080. (The key ingredient in 1080, sodium fluoroacetate, interferes with energy production on a cellular level, inflicting what amounts to a heart attack.) New Zealand, which has roughly one-tenth of one per cent of the world’s land, uses eighty per cent of its 1080. This year’s drop—the department was planning to spread 1080 over nearly two million acres—had been prompted by an unusually warm winter, which had produced an exceptionally large supply of beech seed, which in turn had produced an explosion in the number of rats and stoats. When the beech seed ran out, the huge cohort of predators was expected to turn its attention to the native fauna. Smith had approved the 1080 operation, which had been dubbed Battle for Our Birds, but the timing of it troubled him; owing to the exigencies of rat biology, the drop had to take place right around the time of a national election.
“If you ask the cynical politics of it, people don’t like poisons but they like rats even less,” he told me. “And so I’ve been doing a few quite deliberate photo opportunities with buckets of rats.”
On this particular day, Smith was attending a more cheerful sort of photo op—one with live animals. When we arrived at the helicopter pad, three other people were already there, all associated with a privately funded effort to restore one of the country’s most popular national parks, named for Abel Tasman. (In 1642, Tasman, a Dutch explorer, was the first European to reach New Zealand—though he didn’t quite reach it, as four of his sailors were killed by Maori before they could land.) Smith and I got into the helicopter next to the pilot, the other three climbed into the back, and we took off. We flew over Tasman Bay, and then over the park, which was studded with ghostly white trees.
“We like to see all those dead trees,” Devon McLean, the director of the restoration project, announced cheerfully into his headset. He explained that the trees were invasive pines, known in New Zealand as “wilding conifers.” I had a brief vision of scrawny seedlings rampaging through the forest. Each dead tree, McLean said, had been individually sprayed with herbicide. He was also happy to report that the park had recently been doused with 1080.
After about half an hour, we landed on a small island named Adele, where we were greeted by a large sign: “Have You Checked for Rats, Mice and Seeds?” A few years ago, after an intensive campaign of poisoning and trapping, Adele was declared “pest-free.” The arrival of a single pregnant rat could undo all that work; hence the hortatory signage. In another helicopter, the conservation department was going to deliver two or three dozen representatives of one of New Zealand’s rarest species, the South Island saddleback. The birds would be released onto Adele, where, it was hoped, in the absence of rats, they would multiply.
More people began to arrive by boat—reporters, representatives of several regional conservation groups, members of the local Maori iwi, or tribe. By this point, it was drizzling, but there was a festive mood on the beach, as if everyone were waiting for a celebrity. “Hardly any New Zealanders have ever seen a saddleback,” a woman whispered to me.
In anticipation of the birds’ appearance, speeches were offered in Maori and English. “It has taken us Pakeha New Zealanders a little while to gain an appreciation of what is special here and to really be committed to its protection and survival,” Smith said, using the Maori word for European. “It’s kind of scary to think of South Island saddlebacks—there are only about six hundred that exist on the planet.”
Finally, the birds arrived, in a helicopter that had been loaned for the occasion by a wealthy businessman. Three crates were unloaded onto the beach, and Smith and a pair of local dignitaries were given the honor of opening them. South Island saddlebacks are glossy black, with patches of rust-colored feathers around their middles and little orange wattles that make them look as though they’re smiling. They are another example of an ancient lineage that persists in New Zealand, and they have no close relatives anywhere else in the world. The birds hopped out of their crates, flew into the bush, and were gone.
There are two quick ways to tell a Norway rat from a ship rat. One is to look at the ears. Ship rats have large ears that stick out from their heads; Norway rats’ ears are shorter and less fleshy. The other is to look at their tails. Again, Norway rats’ are shorter. With a ship rat, if you take its tail and fold it over its body—here it obviously helps if the rat is dead—it will extend beyond its nose.
These and many other facts about rats I learned from James Russell, an ecologist at the University of Auckland. Russell’s office is filled with vials containing rat body parts in various stages of decomposition, and he also keeps a couple of dead rats at home in his freezer. Wherever he goes, Russell asks people to send him the tails of rats that they have trapped, and often they oblige. Russell then has the rats’ DNA sequenced. Eventually, he hopes to be able to tell how all of New Zealand’s rat populations are related.
“I would be inclined to say rats are our biggest problem,” Russell told me. “But I have colleagues who spend their career on stoats, and colleagues who spend their career on cats. And they open all their talks with ‘Stoats are the biggest problem,’ or ‘Cats are the biggest problem.’ ”
Russell, who is thirty-five, is a slight man with tousled brown hair and a cheerful, let’s-get-on-with-it manner which I eventually came to see as very New Zealand. I ended up spending a lot of time with him, because he volunteered to guide me along some of the country’s windier back roads.
“New Zealand was the last large landmass on earth to be colonized,” he told me one day, as we zipped along through the midsection of the North Island. “And so what we saw was the tragedy of human history playing out over a short amount of time. We’re only ten years behind a lot of these things; that’s as compared to countries where you’re hundreds or thousands of years behind the catastrophe.”
New Zealand’s original settlers were the Maori, Polynesians who came around the year 1300, probably from somewhere near the Society Islands. By that point, people had already been living in Australia for some fifty thousand years. They’d been in continental North America for at least ten thousand years, and in Hawaii, which is even more remote than New Zealand, for more than five hundred years. In each case, it’s now known, the arrival of humans precipitated a wave of extinctions; it’s just that, as Russell points out, these “tragedies” were not recorded by the people who produced them.
When the Maori showed up, there were nine species of moa in New Zealand, and it was also home to the world’s largest eagle—the Haast’s eagle—which preyed on them. Within a century or two, the Maori had hunted down all of the moa, and the Haast’s eagle, too, was gone. A Maori saying—“Ka ngaro i te ngaro a te moa”—translates as “Lost like the moa is lost.”
In their ships, the Maori also brought with them Pacific rats, or kiore. These were New Zealand’s first introduced mammals (unless you count the people who brought them). The Maori intended to eat the kiore, but the rats multiplied and spread far faster than they could be consumed, along the way feasting on weta, young tuatara, and the eggs of ground-nesting birds. In what, in evolutionary terms, amounted to no time at all, several species of New Zealand’s native ducks, a couple of flightless rails, and two species of flightless geese were gone.
The arrival of British settlers, in the middle of the nineteenth century, brought in more—many more—new invaders. Some of them, like the Norway rat and the ship rat, were stowaways. Others were introduced deliberately, in an effort to make New Zealand feel more like home. The “importation of those animals and birds, not native to New Zealand,” an 1861 act of the colonial Parliament declared, would both “contribute to the pleasure and profit of the inhabitants” and help maintain “associations with the Old Country.” What were known as “acclimatization societies” sprang up in every region. Among the many creatures the societies tried to “acclimatize” were red deer, fallow deer, white-tailed deer, sika deer, tahr, chamois, moose, elk, hedgehogs, wallabies, turkeys, pheasants, partridges, quail, mallards, house sparrows, blackbirds, brown trout, Atlantic salmon, herring, whitefish, and carp. Brushtail possums were specially imported from Australia, in an attempt to start a fur industry.
Not all the new arrivals took; others took all too well. By the perverse logic of such affairs, some of the most disastrous introductions were made in an effort to control previous disastrous introductions. Within a few decades of their importation, European rabbits had overrun the countryside, and in 1876 an act was passed to “provide for the Destruction of Rabbits in New Zealand.” The act had no perceptible impact, so stoats and ferrets were released into the bush in the hope that they would be more effective.
“Our forebears tried most experiments that could possibly be conceived and some that would be difficult for anyone with any knowledge of ecology to seriously contemplate,” Robert McDowall, a New Zealand naturalist, has written in a history of introduction efforts. The combined effect of all these “experiments,” particularly the introduction of predators, like stoats, has been ongoing devastation. Roughly a quarter of New Zealand’s native bird species are now extinct, and many of those which remain are just barely hanging on. If current trends continue, it is predicted that within a generation or two the land of Kiwis will be without kiwi.
“The defence of isolation for remote islands has no fallback position,” John McLennan, a New Zealand ecologist, has written. “It is all or nothing, akin to virginity, with no intermediate state.”
Sirocco, a sexually dysfunctional kakapo, normally lives alone on his own private island. On occasion, though, he is brought, with great fanfare, to the mainland, and this is where James Russell and I set out to meet him, at a special mountaintop reserve ringed by a twenty-nine-mile fence. The fence is seven feet high and made of steel mesh with openings so narrow an adult can’t stick a pinkie through. At the base of the fence, an eighteen-inch apron prevents rats from tunnelling under; on top, an outwardly curved metal lip stops possums and feral cats from clambering over. To get inside, human visitors have to pass through two sets of gates, an arrangement that made me think of a maximum-security prison turned inside out.
Kakapo—the name comes from the Maori, meaning “parrot of the night”—are nocturnal, so all audiences with Sirocco take place after dark. Russell and I joined a group of about twenty other visitors, who had paid forty dollars apiece to get a peek at the bird. Sirocco was hopping around in a dimly lit plate-glass enclosure. He was large—about the size of an osprey—with bright green-and-brown feathers and a bulbous, vaguely comical beak. He gazed through the glass at us and gave a sharp cry.
“He’s very intense, isn’t he?” the woman next to me said.
Alone among parrots, kakapo are flightless, and, alone among flightless birds, they’re what’s known as lek breeders. During mating season, a male will hollow out a little amphitheatre for himself, puff up his chest, and let out a “boom” that sounds like a foghorn. Kakapo, which can live to eighty, breed only irregularly, in years when their favorite foods are in good supply.
Kakapo once were everywhere in New Zealand. In the late nineteenth century, they were still plentiful in rugged areas; Charlie Douglas, an explorer who climbed some of the steepest mountains of the South Island, described them standing “in dozens round the camp, screeching and yelling like a lot of demons.” But then their numbers crashed. By the nineteen-seventies, there was just one small population remaining, and it was threatened by feral cats. In the nineteen-eighties, every individual that could be caught was captured and “translocated.” Today, there are a hundred and twenty-six kakapo left, and all of them, save Sirocco, live on three remote, predator-free islands, Little Barrier, Codfish, and Anchor.
Sirocco’s chaperone, a Department of Conservation ranger named Alisha Sherriff, had brought along a little metal container, which she passed among the visitors. Inside was half a cup’s worth of Sirocco’s shit.
“Have a good sniff,” she suggested.
“It’s earthy!” one woman exclaimed.
“I think it smells smoky, with notes of honey,” Sherriff said. When the container came to me, I couldn’t detect any honey, but the bouquet did strike me as earthy, with hints of newly mown hay. Sherriff had also brought along a ziplock bag with some of Sirocco’s feathers. These, too, had a strong, sweetish scent.
New Zealand birds tend to smell, which was not a problem when the islands’ top predators were avian, since birds hunt by sight. But, as mammals hunt with their noses, it’s become yet another liability. (A few years ago, a Christchurch biologist was awarded a four-hundred-thousand-dollar grant to investigate the possibility of developing some sort of “deodorant” for ground-nesting birds.)
Sherriff explained that Sirocco had been born on Codfish Island in 1997, but as a chick he had come down with a respiratory infection, and so had been removed from his mother and raised in isolation. By the time he was well enough to rejoin the other kakapo, he’d decided he preferred people. During breeding season, he’d try to mate with the rangers on Codfish while they were walking to the outhouse. A special barrier was built to try to prevent the encounters, but Sirocco turned out to be too determined.
“When you’ve got a three-kilo bird crashing through the bush in the middle of the night, there’s quite a high risk of people lashing out unintentionally,” Sherriff said. It had been decided that, for Sirocco’s own safety, he’d have to be moved. He now lives hundreds of miles from Codfish, on an island whose name the Department of Conservation won’t disclose. For the sake of genetic diversity, Sirocco’s semen had been collected, by means of what Sherriff described as a “delicate massage,” but his sperm count had proved too low to attempt artificial insemination.
After about half an hour with Sirocco, we were hustled out to make room for the next tour group. Russell and I passed back through the gates and drove down to a restaurant at the base of the mountain, where we’d arranged to have dinner with Matt Cook, the reserve’s natural-heritage manager. Cook told us that it had taken teams of exterminators three years to eliminate mammals from inside the fence and that they’d never managed to finish off the mice. The entire perimeter was wired so that when, say, a section of fence was hit by a falling branch, a call automatically went out to a maintenance crew.
“This always happens at 3 A.M. on a Saturday morning,” he said. If the fence was breached, Cook reckoned, the crew had about ninety minutes to repair it before rats would find the opening and sweep back in.
Today, invasive species are everywhere. No matter where you are reading this, almost certainly you are surrounded by them. In the northeastern United States, common invasive plants include burdock, garlic mustard, purple loosestrife, and multiflora rose; invasive birds include starlings, rock pigeons, and house sparrows; and invasive insects include Japanese beetles, gypsy moths, and hemlock woolly adelgid. Texas has more than eight hundred nonnative plant species, California at least a thousand. Even as New Zealand has been invaded by nonnative species, its native species have invaded elsewhere. Potamopyrgus antipodarum, or, as it is more commonly known, the New Zealand mud snail, is a tiny aquatic snail about the size of a grain of rice. It can now be found in Europe, Asia, Australia, the Middle East, and the American West, and it has proved such a successful transplant that in some parts of the world it reaches densities of half a million snails per square yard. In an irony perhaps only Kiwis can appreciate, a recent study in Utah found that mud snails were threatening populations of rainbow trout, a fish imported at great expense to New Zealand in the eighteen-eighties and now considered an invader there.
The project of reshuffling the world’s flora and fauna, which began slowly with the spread of species like the Pacific rat and sped up thanks to the efforts of acclimatization societies, has now, with global trade and travel, accelerated to the point that, on any given day, something like ten thousand species are being moved around just in the ballast water of supertankers. Such is the scale of this remix that biologists have compared it to reassembling the continents. Two hundred million years ago, all of the world’s landmasses were squished together into a single giant supercontinent, Pangaea. We are, it’s been suggested, creating a “new Pangaea.”
One response is simply to accept this as the planet’s destiny. Yes, the invaders will, inevitably, choke out some local species, and there will be losses, especially on islands, where, unfortunately, much of the world’s diversity resides. But people aren’t going to stop shipping goods and they aren’t going to stop travelling; therefore, we’re just going to have to learn to live in a Pangaea of our own making. Meanwhile, who even knows at this point what’s native and what’s not? Many species that people think of as a natural part of the landscape are really introductions that occurred before recent memory. For instance, the ring-necked pheasant, the official state bird of South Dakota, is an import from China.
“It is impractical to try to restore ecosystems to some ‘rightful’ historical state,” a group of American researchers wrote a few years ago, in Nature. “We must embrace the fact of ‘novel ecosystems’ and incorporate many alien species into management plans, rather than try to achieve the often impossible goal of eradicating them.”
New Zealanders are nothing if not practical. They like to describe the national mind-set as “the No. 8 wire mentality”; for much of the country’s history, No. 8 wire was used to fix livestock fences and just about everything else. Nevertheless, Kiwis refuse to “embrace” novel ecosystems. In the past few decades, they have cleared mammalian predators from a hundred and seventeen offshore islands. The earliest efforts involved tiny specks, like Mokopuna, or, as it is also known, Leper Island, which is about the size of Gramercy Park. But, more recently, they’ve successfully de-ratted much larger islands, like Campbell, which is the size of Nantucket. With its predator-free islands and its fenced-in reserves and its massive poison drops from the air, New Zealand has managed to bring back from the very edge of oblivion several fantastic birds, including the kakapo, the South Island saddleback, the Campbell Island teal, and the black robin. At its lowest point, the black robin was down to just five individuals, only one of which—a bird named Old Blue—was a fertile female. (When Old Blue died, her passing was announced in Parliament.)
Meanwhile, by tackling larger and larger areas, New Zealanders have expanded the boundaries of what seems possible, and they increasingly find their skills in demand. When, for example, Australia decided to try to get rid of invasive rodents on Macquarie Island, roughly halfway between Tasmania and Antarctica, it hired a New Zealander to lead the effort, and when the U.S. National Park Service decided to get rid of pigs on Santa Cruz Island, off the coast of Southern California, it hired Kiwis to shoot them. The largest rat-eradication effort ever attempted is now in progress on South Georgia Island, a British territory in the South Atlantic with an area of nearly a million acres. A New Zealand helicopter pilot was brought in to fly the bait-dropping missions. One day, when I was driving around with James Russell, he got an e-mail from Brazil: the government wanted to hire him to help it get rid of rats on the Fernando de Noronha archipelago, off Recife. David Bellamy, a British environmentalist and TV personality, has observed that New Zealand is the only country in the world that has succeeded in turning pest eradication into an export industry.
The idea of ridding all of New Zealand of its mammalian predators was proposed by Paul Callaghan, a world-renowned physicist, in a speech delivered in Wellington, in February, 2012. In scientific circles, Callaghan was celebrated for his work on nuclear magnetic resonance; to Kiwis he was probably best known for having recently been named New Zealander of the Year. At the time he gave the speech, Callaghan was dying of cancer, and everyone who heard it realized that it was one of the last he would deliver. (He died the following month.)
“Let’s get rid of the lot,” Callaghan said. “Let’s get rid of all the predators—all the damned mustelids, all the rats, all the possums—from the mainland.”
“It’s crazy,” he continued, referring to his own proposal. But, he went on, “I think it might be worth a shot. I think it’s our great challenge.” Callaghan compared the project to the moon landing. It could be, he said, “New Zealand’s Apollo program.”
I listened to Callaghan’s speech, via YouTube, on one of my last evenings in New Zealand. It seemed to me that what he was proposing was more like New Zealand’s Manhattan Project than its Apollo program, though I could see why he hadn’t framed it that way.
New Zealand’s North Island is roughly forty-four thousand square miles. That means that it’s nearly a thousand times bigger than the largest offshore island from which predators have, at this point, been eradicated. James Russell serves as an adviser to Predator Free New Zealand, the group that was formed to pursue Callaghan’s vision. I asked him about the feasibility of scaling up by such an enormous amount. In response, he showed me a graph: the size of the islands from which predators have been successfully removed has been increasing by roughly an order of magnitude each decade.
“It is a daunting scale that we’re talking about,” Russell told me. “But, then, you see the rate at which we have scaled up.”
“Some people think scientists should just be objective,” he went on. “They sit in the lab, they report their results, and that’s it. But you can’t separate your private life from your work life. So I do this science and then I go home and think, Wouldn’t it be great if New Zealand had birds everywhere and we didn’t have to worry about rats? And so that’s the world I imagine.”
Listening to Callaghan on YouTube also reminded me of a point that Nick Smith had made the day of the saddleback release: in New Zealand, killing small mammals brings people together. During my travels around the country, I found that extermination, weird as it may sound, really is a grassroots affair. I met people like the Adsheads, who had decided to clear their own land, and also people like Annalily van den Broeke, who every few weeks goes out to reset traps in a park near her home, in the suburbs of Auckland. In Wellington, I met a man named Kelvin Hastie, who works for a 3-D mapping company. He had divided his neighborhood into a grid and was organizing the community to get a rat trap into every hundred-square-metre block.
“Most of the neighbors are pretty into it,” he told me.
Just about everyone I spoke to, including Hastie, expressed excitement about the latest breakthrough in extermination technology, a device designed by a company called Goodnature. And so, on my last day in the country, I went to visit the company’s offices. They were situated in a drab stretch of anonymous buildings, not far from one of Wellington’s best surfing beaches. When I arrived, I noticed a dead stoat in a plastic bag by the door. Apparently, it had been killed quite recently, because it was still very much intact.
Robbie van Dam, one of the company’s founders, showed me around. In the first room, several young people were working at standing desks, on MacBooks propped up on cardboard boxes. A small kitchen was stocked with candy and half-empty bottles of wine. In a back room, bins of plastic parts were being assembled into an L-shaped machine that resembled a portable hair dryer. Van Dam pulled out one of the finished products, known as the A24. At one end, there was a CO2 cannister of the sort used in bicycle pumps. Van Dam uncapped the other end and pulled out a plastic tube. It was filled with brown goo. In the crook of the L was a hole, and in the hole there was a wire. Van Dam gingerly touched the wire, and a piston came flying out.
The A24 is designed to be screwed to a tree. The idea is that a rat, smelling the goo, which is mostly ground nuts, will stick its head into the hole, trip the wire, and be killed instantly. The rat then falls to the ground, and the device—this is the beauty part—automatically resets itself. No need to fish out rotten eggs or decaying flesh. Each CO2 cannister is supposed to be good for two dozen rats or, alternatively, stoats—hence the name. (For stoats, there’s different bait, made of preserved rabbit.) Van Dam also showed me a slightly larger machine, the A12, designed for possums.
“The humaneness problem was probably the hardest part,” he told me. In the case of possums, it had turned out that a blow to the head wasn’t enough to bring about quick death. For that reason, the A12 is designed to fill the animal’s skull with carbon dioxide and emulsify its brain. Goodnature also sells cannisters of possum bait, laced with cinnamon. I picked up a tube. “12 out of 12 possums choose this as their final meal,” the label said.
Even taking the long view—the very long view—the threat posed to New Zealand’s fauna by invasive species is extraordinary. It may be unprecedented in the eighty million years that New Zealand has existed. But we live in an age of unprecedented crises. We’re all aware of them, and mostly we just feel paralyzed, incapable of responding. New Zealanders aren’t just wringing their hands, nor are they are telling themselves consolatory tales about the birth of “novel ecosystems.” They’re dividing their neighborhoods into grids and building better possum traps—ones that deliver CO2 directly to the brain.
A couple of miles from Goodnature’s headquarters is a rocky beach where little blue penguins sometimes nest. The beach is infested with rats, which can attack the nests, so Goodnature has installed some A24s along it, and van Dam took me down to have a look. It was a beautiful windy day, and the surf was high. Under the first A24, which was attached to a gnarly bush, there was nothing. Often, van Dam explained, cats or other rats drag off dead animals that have dropped from the A24, so it’s not always possible to know what, if anything, has been accomplished. This had proved to be something of a sales problem.
“If people didn’t find something dead under there, they were really disappointed,” he said. Goodnature now offers a digital counter that attaches to the A24 and records how many times the piston has been released.
Under the second A24, there was a dead mouse; under the third and fourth, nothing. Under the fifth were two ship rats, one freshly killed and the other just a clump of matted fur with a very long tail. ♦
