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Isolation Proves Dangerous On 'Rat Island'

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Isolation Proves Dangerous On 'Rat Island'

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Isolation Proves Dangerous On 'Rat Island'

Isolation Proves Dangerous On 'Rat Island'

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The kakapo, an enormous flightless parrot from New Zealand, was once one of that country's most populous species, but vulnerability to invasive species has decimated its population. AP hide caption

toggle caption AP

The kakapo, an enormous flightless parrot from New Zealand, was once one of that country's most populous species, but vulnerability to invasive species has decimated its population.


Island. The very word connotes isolation — an isolation that has allowed pockets of animal species to evolve in safety over the course of thousands of years. But, as author William Stolzenburg writes in a new book, isolation can also be a weakness.

In Rat Island: Predators in Paradise and the World's Greatest Wildlife Rescue, Stolzenburg gives an account of the damage done to island ecosystems by invasive species like cats, weasels and rats — all animals that have at one point overrun new island environments and nearly destroyed native species.

One species Stolzenburg focuses on is the kakapo, a large, green, nocturnal parrot that is found only in New Zealand.

Stolzenburg tells NPR's Renee Montagne that because its only predators were in the sky, the kakapo had no need to fly and, therefore, couldn't.

"It exuded this particular scent also that was supposed to attract other kakapos," he says. "Of course, when the invaders got to New Zealand — when the rats and the cats and the weasels came to New Zealand — this was a bird that was just set up for massacre, and that's exactly what happened."

Saving New Zealand's Kakapos

Stolzenburg explains that in the 1800s, settlers arriving in New Zealand brought sheep and rabbits with them for game. Sheep ate much of the vegetation, and the rabbits, being rabbits, exploded in population. With their huge numbers and voracious appetites, they began eating the sheep's rangeland. So to deal with the rabbit problem, settlers introduced stoats — a member of the weasel clan and a terrific predator. But the stoats quickly found much easier prey than rabbits — kakapos.

Rat Island: Predators in Paradise and the World's Greatest Wildlife Rescue
Rat Island: Predators in Paradise and the World's Greatest Wildlife Rescue
By William Stolzenburg
Hardcover, 288 pages
Bloomsbury USA
List Price: $26

Read An Excerpt

Kakapo numbers quickly shrank so that, once New Zealand's third most populous bird, they soon only lived in small enclaves scattered around the country.

The New Zealand government made its first efforts at saving the bird in the 1890s, when it appointed a hunter and self-taught naturalist by the name of Richard Henry to be the birds' caretaker. He was tasked with establishing a refuge for the birds on an island off the southwest corner of New Zealand, known as Resolution Island. Henry spent the next 10 years gathering up as many kakapos as he could find — over 500 — and releasing them on the island.

Unfortunately for both Henry and the kakapo, Stolzenburg says, Resolution Island was within swimming distance of the mainland — and stoats can swim. Ten years after he began his project, Henry discovered a stoat on the island and realized his life's work had been in vain.

Conservation efforts slowed after Resolution Island, with kakapo sightings few and far between. But in the mid-20th century, the New Zealand government renewed its efforts to save the bird.

Conservationists were disheartened by their first efforts to find the parrots — old kakapo haunts were empty, and only a handful of birds were located. But an expedition in the 1970s was lucky enough to come across a population of close to 200 birds. It was the mother lode of the remaining kakapo population, and it provided conservationists with another opportunity to rehabilitate the species.

They began incubating the kakapos, protecting and guarding their eggs, and setting traps to ensure that no predators could get to the birds. But eventually, Stolzenburg says, even that sanctuary was invaded by feral cats. So scientists staged an emergency rescue and moved most of the remaining kakapo to Codfish Island, which had been cleared of all predators.

"It is basically about as pristine as you can find in New Zealand," Stolzenburg says. "They are now basically refugees; they're exiles from the mainland, and they are living their lives out on this island where they are being watched 24/7 by kakapo rangers who make sure that every egg, every mating now is a grand event, and they are watched very closely."

In Alaska, A 'Perfect Score' For Rats

Stolzenburg says there have been other, similar catastrophes across the globe. In the United States, Kiska — part of the Aleutian Islands off the coast of Alaska — was a pristine island environment until World War II, when the Japanese invaded and the U.S. became intent on taking it back.

Troops were sent ashore on Kiska, and at some point during their deployment, several rats also made their way onshore. Over the intervening years, the rats crossed 12 miles of rocky terrain — including a more than 4,000-foot volcano — and made their way to one of the world's most spectacular colonies of seabirds.

William Stolzenburg is the author of Where the Wild Things Were and the screenwriter for the documentary Lords of Nature: Life in a Land of Great Predators. Kathy Stolzenburg hide caption

toggle caption Kathy Stolzenburg

William Stolzenburg is the author of Where the Wild Things Were and the screenwriter for the documentary Lords of Nature: Life in a Land of Great Predators.

Kathy Stolzenburg

Known as auklets, Stolzenburg explains that the seabirds are tiny — about the size of a robin — and travel Kiska once a year to reproduce and nest in the crevices of the hardened volcanic rock.

"This was a perfect, perfect score for the rats," he says.

Here was this tremendous food supply that arrived every year, like clockwork. The rats would tear into the colony and massacre the auklets, hoarding them to survive the harsh Kiska winters.

Naturally, Stolzenburg says, scientists are concerned about the long-term impact the rats might have on the auklet population. Attempts to eradicate the rodents — largely with poison — have been difficult due in part to the island's remoteness as well as its rugged nature. The volcanic rock formations have essentially created a safe haven for the rats, and the logistics involved in dropping rodenticide over 100 square miles of terrain would require a gargantuan expedition — and one that is not guaranteed to succeed.

Between the auklets of Kiska and the kakapos of New Zealand, scientists have reason to both hope and be cautious. Stolzenburg says the islands essentially serve as metaphors for how the world's invasive species can irreparably alter fragile ecosystems.

"We have a very clear view of what's going on, and these islands provide that," he says. "It puts it on us. We put them in this position. Now we have a decision to make. We can either stand back and say, 'Let nature take its course,' or we can decide that this is our responsibility and do something about it."

Excerpt: 'Rat Island'

Rat Island: Predators in Paradise and the World's Greatest Wildlife Rescue
Rat Island: Predators in Paradise and the World's Greatest Wildlife Rescue
By William Stolzenburg
Hardcover, 288 pages
Bloomsbury USA
List Price: $26



A massive wildlife rescue is under way, a rescue that may rank as the most promising ever waged in defense of so many creatures on the brink of oblivion.

If such rosy hyperbole reads a bit dubious in these, the dark ages of nature, the doubts come well grounded. Living species are now vanishing at an unprecedented pace in the sixth mass extinction in Earth's history— tens of thousands disappearing each year, with the body counts rising. So we're repeatedly told. We have been reminded to the point of numbness about the causes, about our clear- cutting of rain forests and bleaching of coral reefs, our melting of the ice caps and overfishing of the seas, our slaughter of the last whales and orangutans, tigers and elephants, wherever convenience or a quick profit can be had. These are the dreary tales that dominate the endangered species beat of environmental media. The victims are the poster children of conservation campaigns, and their prognoses smell of doom.

Theirs is not the story that follows. The imperiled ones covered here constitute a less familiar cast of creatures dying far from the front lines. Rarely heard is the fact that over the last three thousand years most of the planet's recorded casualties have taken place off shore, on oceanic islands. Islands have earned the ironic distinction as the most fertile crucibles and most fatal pitfalls of evolution. They have produced 20 percent of Earth's terrestrial animal species on just 5 percent of its landmass. They have also shouldered most of its extinctions, as many as two of every three missing birds and reptiles.

The survivors are still on the run. Nearly half of the species now populating world rosters of the critically endangered are island species. Their biggest threat comes in the form of animals introduced from the mainland— rats and cats and weasels, goats and pigs and rabbits, mongooses, snakes, and even ants— predators of defenseless prey, destroyers of fragile habitats, ferried to the farthest reaches of the oceanic archipelago during the human settlement of the globe.

But the tale that begins as just one more dispiriting reminder of the age of loss we live in contains a hopeful twist: An ambitious cadre of conservationists is out there now, rapidly amassing a lopsided record for rescuing these imperiled islanders. And its signature technique is astonishingly quick and thorough (if also, to some minds, brutally so). It is a technique that entails slaughtering the enemy wholesale.

Which brings up that note about war. This is a story of people who kill so that others might live. It is a theme that naturally lends itself to the rich vernacular of armed conflict. In this war for wildlife there will be combat of sorts, replete with battles and assaults, victories and defeats, bombing raids, blitzkriegs, and lines in the sand. There will be troops and battalions, SWAT teams and snipers, friendly fire and collateral casualties.

Many among those now waging this war will appreciate neither the anthropomorphisms nor the militaristic lingo, beginning most pointedly with the word "war." We are not fighting an enemy, they will say. These invaders did not come with intentions of doing harm, and we would just as soon not do them any harm in return. But time is short, extinction is forever, and there is just no other way, they will say.

Fair enough— in a more perfect world. As it stands, the warriors come armed with their own emotional terminology. Alien, plague, invader— these are tags of the conservation community's own choosing, affixed to the creatures they are compelled to kill. Charles Elton, the man who more than fifty years ago wrote the bible of invasion biology, called them "ecological explosions."

So with combat clichés aforethought, let the battles begin. Let them begin, say, on a remote and rawboned island called Kiska, eleven hundred miles west of mainland Alaska, where it turns out that a few authentic bombs— of the more conventional, high- explosive, antipersonnel type— do come into play. During a pivotal episode in the North Pacific theater of World War II, Kiska came under regular poundings from American bombers and battleships, which on busier days rained more than half a million pounds of explosives, with intentions of routing and eradicating the invading Japanese enemy.

The relevance of that war story to this war story involves yet another invasion, under way and underfoot even as the artillery shook the hills. It seems that sometime during the commotion, under the clanking din of anchor chains and the droning of diesel engines, emerging from the hold of a battleship or a cargo container, a rat or two secretly accompanied the soldiers ashore to Kiska.

Some half century later this unheralded little footnote of biogeography would come to weigh as heavily on Kiska's destiny as any human intrusion ever has. It was around that time that the island's indomitable little castaways finally made their way over a dozen miles of tundra, past a four-thousand-foot, ice-encrusted volcano, to a tremendous field of black lava boulders sloping into the sea. There the rats discovered a gathering of birds, otherwise known to a few privileged people as one of nature's great spectacles.

The celebrated performance on Kiska commences with the long northern twilight of late June. It begins off shore, as a chain of living clouds rising over the gray horizons of the Bering Sea. The clouds billow on approach, morphing into fantastic forms. A sphere becomes a scythe, a serpent, a genie emerging from a lamp.

The masses have been variously likened to swarms of bees, plagues of locusts, herds of bison on a prairie sea. Boat pilots have mistaken one for a wall of water coming to swallow the vessel. The swarms are in fact composed of many hundreds of thousands, perhaps millions, of what on final approach become flocking birds.

The flocks combine two varieties of a rather diminutive seabird. Two out of ten in the crowd tend to be crested auklets, each jacketed in black over gray, with a rakish plume arching from the bridge of its beak. The remainder and bulk of the multitude are least auklets, a smaller, less gaily ornamented congener of the crested species, in the general life-form of a miniature, stub-billed penguin. Auklets are able fliers of two mediums, their wings propelling them underwater like submarine falcons in skilled pursuit of tiny planktonic animals, and flying them aloft in those dramatic aerial displays for which Kiska has become legend.

Against the softly glowing backdrop of Kiska's snowcapped volcano, the incoming flocks swirl. The auklets' flight is erratic yet precise, their split-second dodging and feinting synchronized en masse as if by the single mind of a superorganism. A tendril of thousands splits off and ascends the slope, climbing, climbing, all but disappearing into the distant heights, to finally turn as one and plummet seaward again, ripping the air with the roar of jet fighters.

It is beneath the lava boulders that their nests and progeny are waiting, but the auklets resist. They come sweeping landward, squall after squall of birds raining against the rocky slopes, only to break off and circle for another surge. Behaviorists explain these false approaches as anti-predator maneuvers. Peregrine falcons and bald eagles patrol the colony's airspaces, picking their moment to dive and snatch a conspicuous outlier from the masses. Glaucous-winged gulls lurk about the boulders to surprise the unwary auklet at its door. These are the high- stakes dances of predator and prey, choreographed over the eons since the birds first took wing. Only after all precautions and security protocols have been satisfied do the skittish swarms put down on the roof of their rock fortress, to preen and chatter before vanishing below into the maze of a million nests. For all the drama, a few auklets die, a few gulls and falcons feed, and the balance is overwhelmingly displayed in the auklets' favor, in the colossal summer flights that fill the skies above Kiska. Or at least that's the way it used to work.

Cue again the rats. The brown rat is native to the mainland of Southeast Asia; the least auklet to a few dozen islands of the Bering Sea. The two have never as a pair learned such a dance. The rat, upon finding an auklet on a nest, bites a hole through the back of its head, eats its brain and eyeballs, then stashes the rest. And repeats, the frequency depending on how many auklets it happens upon, a number that in the subterranean metropolis of Kiska rapidly mounts. Habit overriding hunger, a single rat has been known to gather one hundred fifty auklet bodies to its cupboard, most of them largely intact and destined to rot. The auklet, for its part, apparently sits confused through the slaughter. Its memories of such dangers were left behind in a distant past. Such four-legged predators were among the chief reasons that the auklet in its evolutionary beginnings abandoned the dangerous continents for the relative seclusion and safety of the islands.

Which is to say that with rats having finally found them, the future of least auklets on Kiska, and of the whole mighty spectacle they have come to be, now lies in question. Which raises a few others: Should they, need they, can they be saved?

As of the summer of 2010, conservation specialists had conducted more than eight hundred eradications of destructive mammals from islands they had breached with human help (most of them coming with quickening pace in the last twenty years). The eradicators have covered islands across both hemispheres, from tiny tropical atolls in the sunny Pacific to howling wildernesses of snow and tundra in the high latitudes. Among them all, Kiska remains a singular prize. Those who would dare to defeat the rats of Kiska see a potential payoff amounting to millions of living birds rescued with one swipe, and the satisfaction of securing a living wonder of the world.

Those who would so dare have a few sizable obstacles in their path. The island is staggeringly huge, at more than a hundred square miles; hellishly stormy on all but a few rare days of the year; and eleven hundred miles from almost anywhere. It is lorded over by a snowcapped, fog- enshrouded volcano that still features the tail wings of errant warplanes poking out of its flanks. It also harbors great numbers of bald eagles and other birds very likely to die in the crossfire of what would most certainly entail an aerial assault with poison. As irresistibly tempting as they come, the most daunting battle yet in the war for the world's islands is the one to be waged for Kiska. If it's not the one to be waged for the kakapo.

The kakapo is an enormous, moss green parrot from New Zealand, with a life history almost perfectly contradicting the least auklet's. The kakapo does not swim, nor does it fly. The kakapo, at a hefty six to nine pounds, is the largest and least airworthy of all parrots; the least auklet, at five ounces, is the smallest of its clan of auks. The kakapo is one of the most painstakingly probed and pampered animals on the planet, every member of its species held under twenty- four- hour surveillance on two New Zealand islands groomed especially for the birds' comfort and safety, every moment of need met with offerings of food and shelter, medical care, or even assistance at mating. The far- lesser- known least auklet passes its summer tending subterranean nests typically far out of human reach; the remainder of its year is spent on the water in some far corner of the stormy sea where nobody has yet found it. The world population of the least auklet is wildly estimated at ten million, making it the most numerous seabird in the northern hemisphere; that of the kakapo is known to the single digit—the count at the moment, 122.

The two do share one critical piece of common ground. The kakapo, like the auklet, evolved in a world devoid of land-bound mammals. The greatest danger it typically faced, as a chunky walking parrot in its primeval New Zealand, was a limited suite of native raptors hunting from above. The kakapo's answer was its shrub green camouflage, a nighttime schedule of activity, and, as a last resort in the face of danger, a habit of freezing in its tracks.

Such cryptic defense eventually came to approximate suicide in a land invaded by terrestrial predators, particularly those with noses. (The kakapo exudes a scent variously described as that of honey, or freesia flowers, or perhaps like the inside of a clarinet case— if you've ever been there.) The flightless kakapo typically nests on the ground, in holes or tree pits readily located and looted by cat, dog, or weasel. The mother kakapo with egg or chick gets no help from the father; she wanders all night foraging for food, leaving her off spring unguarded for the taking, and herself vulnerable to attack on the trail at a time when foreign predators are most likely to be about. Her eggs are small for such a large bird, small enough for rats or maybe even mice to eat them. The point is, it would be challenging for even the most sadistic of bird gods to construct a specimen more flagrantly begging to be slaughtered by terrestrial carnivores than the kakapo.

Which is why, over the course of eight hundred years and a procession of invading humans, cats, dogs, weasels, and rats, the kakapo's status has fallen from the ranks of the most ubiquitous birds in the country to that of a precarious castaway huddled on two tiny makeshift homes under high security.

The kakapo and the least auklet, falling prey to a dangerous new world of foreign predators, cover the extremes of the worldwide rescue now under way. To free the auklets of Kiska will entail an assault harking back to World War II. To restore the kakapo's rightful home will require retaking great swaths of New Zealand. There are certainly more than a few who would consider such campaigns as hopeless, who see the continuing extinction of the masses as inevitable. But as mentioned above, theirs is not the story that follows.

Excerpted from Rat Island: Predators in Paradise and the World's Greatest Wildlife Rescue by William Stolzenburg. Copyright 2011 by William Stolzenburg. Excerpted by permission of Bloomsbury USA.

Books Featured In This Story

Rat Island

Predators in Paradise and the World's Greatest Wildlife Rescue

by William Stolzenburg

Hardcover, 279 pages |


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Predators in Paradise and the World's Greatest Wildlife Rescue
William Stolzenburg

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