Rat Island

by William Stolzenburg

  RAT ISLAND

  Predators in Paradise and the

  World’s Greatest Wildlife Rescue

  William Stolzenburg

  CONTENTS

  Cover

  Title Page

  Dedication

  Prologue: Kiska, Kakapos, and a Note About War

  Chapter 1 Over the Blue Horizon

  Chapter 2 Resolution

  Chapter 3 Fox Fire

  Chapter 4 Cape Catastrophe

  Chapter 5 The Night Parrot

  Chapter 6 Battle for Breaksea

  Chapter 7 Baja Cats

  Chapter 8 Anacapa

  Chapter 9 Escalation

  Chapter 10 Sirius Point

  Chapter 11 Rat Island

  Chapter 12 Whither Kiska

  Epilogue: Island Earth

  Ackowledgments

  Bibliography

  Notes on the Sources

  A Note on the Author

  By the Same Author

  Imprint

  For Don Merton and Richard Henry Kakapo

  Prologue

  KISKA, KAKAPOS, AND A NOTE ABOUT WAR

  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 offshore, 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 offshore, 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 ag
ainst the rocky slopes, only to break off and circle for another surge. Behaviorists explain these false approaches as antipredator 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 offspring 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.

  Chapter 1

  OVER THE BLUE HORIZON

  Let it be remembered how powerful the influence of a single introduced tree or mammal has been shown to be.

  —CHARLES DARWIN

  SEVEN CENTURIES AGO, from a tropical beach in the South Pacific, a boat set sail. From Tahiti or Rarotonga, Tubuai or Rangiroa, the precise port of departure long since lost in the haze of cultural memory, the clan of Polynesian seagoers sliced into the surf on a double-hulled canoe, a catamaran buoyed by two great hollowed trees. Its crew steered south by southwest, into unexplored waters.

  Why they set sail remains a question for the ages. Their leader may have been a young man with political ambitions, whose only hope for becoming island chief was to find an island of his own. They may have been outcasts, forced seaward by crowding or banned by society. Perhaps they were simply explorers, heeding the human itch to know the other side of the horizon.

  Moved by whatever push or pull, into the blue unknown they went. They steered by the stars, by Alpha Centauri and Beta Centauri, by the familiar beacons and bearings of distant galaxies. By day they watched for signs of land, in the passings of coconuts and driftwood, the swim-by of a sea turtle. They marked subtle changes in the behavior of waves and swells, reading currents for the particular curves imparted by intervening shores. They scanned the skies for clouds signaling the billowing of air over sun-heated hills, or the purposeful flight of a seabird, suggesting a nest not too far away.

  Several weeks and three thousand miles into the void, the Stone Age seafarers at last sighted shore. Behind it rose the tall green jungles and mountain gorges and rushing rivers of a land spreading far
ther than any they had ever known. Aotearoa, they would come to call it—land of the long white cloud. As they unpacked their stores of taro and sweet potato, their fishing hooks and axes, one among them retrieved a length of hollowed log, an elegant vessel carved in the likeness of a canoe and capped at the ends. It was handled only by its tohunga, its expert, with a purpose deserving of precious cargo, and was soon to be carried into the forest, accompanied by prayer. At the proper place, the tohunga ceremoniously lowered the vessel and opened its latch. And onto the ground and into the forest scurried a family of rats. Kiore, the rats were called.

  PACIFIC BONEYARDS

  The Polynesians’ landing of Aotearoa, the last great unpeopled landmass of Oceania, was in a grander sense the end of a far longer voyage that had begun three thousand years before, when their ancestors set sail from somewhere in the Bismarck Archipelago, north of New Guinea. Beginning as small forays between islands beckoning from the horizon, the trips grew longer, penetrating tens and hundreds of miles eastward into the Pacific. Onward the people sailed and settled. On a New Caledonia beach named Lapita, they left a buried cache of pottery, of a signature design that twentieth-century archaeologists would later unearth like calling cards across Melanesia. The archaeologists would name the Pacific pioneers the Lapita.

  The Lapita set up seaside villages, sheltered in thatched-roof houses raised on stilts. They cleared forests and cultivated crops, hunted and gathered wild foods from forest to shore to sea, and fired their elegant pottery. And inevitably, either with a shove from society or a romantic pull of the beckoning horizon, another band of explorers would sail eastward into the unknown. By 1000 B.C. they had pushed nearly four thousand miles, to the shores of Tonga and Samoa. By 600 A.D. the Lapita’s Polynesian descendants had reached Hawaii, with the coast of South America soon on the horizon. By the time they made their last great push, south by southwest against the prevailing trade winds to Aotearoa, there was hardly a mote of land in the South Pacific that they had not either settled or inspected for its livability.