Authors: William Stolzenburg
Chapter 11
A
S THE FEARS
for Kiska mounted with the carnage, those tending the Alaska Maritime National Wildlife Refuge were already busy considering the deeper ramifications. In their jurisdiction were at least a dozen islands with rats chewing holes in the ecosystems they were charged with defending. The concerns went far beyond seabirds. It was about the missing songbirds and Kamchatka lilies, the shorebirds and the dune grass and the intertidal communities languishing in the post-rat age of the Aleutians.
And now Kiska, among the finest jewels of the chain, was being robbed beneath their noses. Art Sowls, in his years defending the harbors of the great Pribilof rookeries against incoming rats, had come to assume that prevention was the islands' only salvation. He and his boss, Vernon Byrd, had repeatedly characterized the invasion of a single rat as a fate worse than any oil spill.
Prevention on Kiska was obviously no longer an option. Neither was neglect. Sowls and Byrd had seen for themselves the corpses. They had heard their worst-case scenarios emphatically confirmed by the experts in Auckland, and now by the world's leading expert on auklets, staring directly into the rats' lairs at Sirius Point. The question was no longer whether Kiska needed saving, but how.
In the forty years since Bob Jones had committed himself to taking back the Aleutians, he and his followers had cleared foreign foxes from forty islands. They'd seen seabirds piling back into the predator-free vacuums; they'd celebrated the Aleutian cackling goose rebounding from assumed extinction to some thirty thousand birds, flying itself off the U.S. register of endangered species. But here was a scarier foe, a more suspicious creature than the curious fox (which had a reputation for helping itself into traps and walking up to men aiming rifles). The rat presented logistical problems far beyond the purview of a few underpaid hunters laying lines of leghold traps by hand.
Up until 2001 the stewards of the Aleutian refuge had considered the invasion of rats as the sentence of an incurable cancer. That year, even as the auklet bodies were stacking like cordwood, Kiska's terminal prognosis took a heartening turn.
M
C
C
LELLAND
'
S
C
AMPAIGN
In July 2001 a team of New Zealanders under the direction of the wildlife officer Pete McClelland reported that they had just poisoned what they hoped was every last rat on an island larger by far than any ever attempted. Campbell Island, a forty-four-square-mile, starkly beautiful, foul-weather paradise in the Southern Ocean of the subantarctic, had become the giant new standard in the campaign for island conservation.
Unwelcoming by all outward appearances, Campbell had nonetheless come to host a massive gathering of wildlife. Great colonies of penguins, albatross, petrels, shearwaters, prions, and cormorants and immense rookeries of seals and sea lions gathered in Campbell's paradise of seclusion. And all had eventually come to suffer the familiar plague of discovery. By the late 1700s, Campbell Island's seals had brought the inevitable shiploads of seal hunters, and with them their rats. The sealers bludgeoned their way through the herds; the brown rats chewed their way through the flocks.
McClelland, charged with saving the endangered, had two monsters to deal with. One was the rat; the other was Campbell Island. Campbell had long been deemed undoable for good reason. Bounded by thousand-foot cliffs, it sat far alone in the Southern Oceanâjust getting there meant crossing 440 miles of heaving seas through the storm-lashed latitudes so reverently named the Roaring Forties and the Furious Fifties. McClelland spent the better part of five years planning and organizing for what would closely approximate a military invasion. It would be a blitzkrieg without compromise. If one pregnant rat were left in one little cranny of Campbell's rugged enormity, future eradications, careers, and two million dollars of taxpayers' money would be lost. Failure was not to be discussed. Any naysayer among McClelland's crew was immediately surrounded and shouted down. It was better to lower the head and trudge forward than to look up and contemplate the impossibility of the looming task. Over the final six months of preparation, McClelland took to sleeping with a notebook next to his pillow, jotting down scraps of thought and reminders as they woke him through the night.
On June 26, 2001, the beginning of the New Zealand winter, five helicopters and two ships loaded with 210 drums of helicopter fuel and 132 tons of rat bait left Invercargill, at the southern terminus of New Zealand, heading for the Southern Ocean. By the second week of July, McClelland and company had dropped their first load of brodifacoum on Campbell. Ten days and two hundred thousand dead and dying rats later, they dropped their last. In the following years the crews returned to find no evidence of survivors.
Campbell's eradication raised the bar by frightening degrees. The island exceeded the area of former record-holder, Langara, by eight times. McClelland, who took three years before returning to Campbell, had trouble believing what he'd done. “I looked at those cliffs and the size of that island and I said, âNo. There's no way we did that. It was too big, too rugged to get rats off that island.' ”
Campbell Island came as both fresh hope and forewarning for those now contemplating Kiska. In many ways Kiska was Campbell's big brother of the north. Both lay at the high latitudes nearing fifty-two degrees. Both were far adrift in forbidding seas, pummeled daily by winds gusting to fifty miles per hour, and stung by cold, incessant rains. There was good reason that neither was inhabited or blithely happened by. Stormy spells could last weeks, when landing a boat or flying a helicopter would threaten lives. Yet somehow, on Campbell, McClelland and the can-do Kiwis had managed to breach the impenetrable fortress. To the minds of their North American allies, if Campbell, why not Kiska?
T
ARGET
P
RACTICE
Conversations began. Sowls and Byrd of the Aleutians, to McClelland of the New Zealand territories, to Gregg Howald of Island Conservationâtogether they started pondering first steps toward tackling Kiska, the very first of which was to go nowhere near it.
Attacking Kiska outright was a fool's game. Kiska was twice the size of Campbell, and of any rat island ever attempted. It was one hundred square miles of fog-shrouded rock and tundra, fifteen hundred air miles from Anchorage, plus a twenty-four-hour cruise through cranky seas from the nearest working harbor. To reach Kiska alive was only half the ordeal. Inescapably there was that volcano to deal with, a snow-covered monolith whose upper reaches remained hidden for all but a few days by the Aleutians' notorious gray curtain of cloud. And at the base of it lay ground zero, Sirius Point, that all-but-impenetrable maze of Volkswagen-size lava boulders, tantamount to the world's largest bomb shelter for rats. Kiska was the worst of places to pick the first rat fight in the Aleutians.
The sane approach would start smaller, someplace challenging but manageable, someplace not so little as to be yawned at, not big enough to risk humiliating defeat. As McClelland would warn, “If you don't succeed, you don't get the chance to do another.”
Among the chain of Aleutian candidates, one particular island all but nominated itself by name. It had been infested since 1778, when a Japanese fishing vessel had run aground on its reef and spilled a few rats ashore. The native Aleut people had earlier named the island Hawadax, meaning “entry” or “welcome.” When the Russian explorer Fyodor Petrovich Litke came by in 1827, he renamed it for what had by then apparently become its most striking feature. Litke named it Rat Island.
Rat Island was but a tenth of Kiska's size, but at seven thousand acres it would rank as the world's third largest rat eradication ever attempted. Rat Island was classically Aleutian: windy and cold, thirteen hundred miles west of Anchorage, and a twenty-four-hour boat ride from the closest port, at Adak.
It was not a venture for the fainthearted, but victory there promised big returns. The Aleut people had left indications of what could be expected. Long ago they'd piled their trash heaps high with the bones of seabirds. Their ancient middens revealed a former avifauna of impressive diversity, including puffins, petrels, murrelets, gulls, and cormorants. All were species that would presumably come spilling back once Rat Island was rescued.
By all accounts, the island would provide a challenging warmup for the title bout with Kiska. “It was a mama bear, papa bear kind of thing,” said refuge biologist Jeff Williams. “Not too big, not too little. We knew from our earliest stage of thought that if we were going to do an island, it would have to be Rat Island.”
In the summer of 2001, Williams, his refuge colleague Sowls, and Howald visited Rat Island for an early reconnaissance to see for themselves what they might be getting themselves into. How big and steep and manageableâor notâwas the terrain? Where might the ground crews camp? Where on the tundra slopes would the helicopters land and load? How bad, really, were the rats?
All three were well traveled and intimately familiar with some of the great seabird colonies of the Pacificâwith the quintessential cacophony and commotion of birds, the acrid essence of guano. When they landed their Zodiac inflatable on the beach, the overwhelming essence of Rat Island was that of silence and sterility.
All knew from looking at the empty cliffs that this was a place that should have been far busier with the air traffic of tufted puffins and ancient murrelets, the headlands pocked with the burrows of whiskered auklets and storm petrels. “Rat Island was almost a dead zone,” said Howald, “except for the rats.”
That night, as the three pitched their tents, Howald, knowing better from his experience, steered clear of what was sure to be a riot come nightfall. He shouldered his gear and headed up the hill for a sheltered spot in the tundra. Sowls would later wish he'd followed. Sowls in a lazy moment decided to forgo the hike with Howald and brave the beach. As a precaution he surrounded his tent with snap traps. He zippered down the door, crawled into his sleeping bag, and, almost before his head hit the pillow, jumped to the
bang
of a trap going off. The next morning Sowls climbed outside to find all six traps clutching dead victims. One of the rats had been stripped to the bone, cannibalized by its cohorts.
Sowls and company returned from their little adventure, and the talks about taking the rat out of Rat Island got serious. They had seen up close an impoverished ecosystem needing repair and the stepping-stone to the biggest endangered prize in the Aleutian refuge, Kiska. It turned out that their seat-of-the-pants impressions from a few days' visit, of the destructive power of a novel predator unleashed, were even then being backed by a spate of new science, some of it conducted in familiar surroundings.
T
HE
R
AT
K
ING
That summer another team of biologists descended on the Aleutians, with the idea of testing, in particular, a well-informed hunch about foxes and seabirds and, more broadly, an emerging curiosity of science known as the ecological cascade. The cascade was a sequence of life and death triggered by disruptions at the top of the food chain, and it appeared to be playing out in grand fashion across the Aleutians. Veterans of the islands had come to recognize a certain qualitative difference between those still harboring introduced foxes and those without. It wasn't just the missing seabirds; it was something about the landscape. The fox-infested tundra seemed browner, more barren. It seemed to lack that certain profusion of Kamchatka lilies and tall green swards of cow parsnip and seacoast angelica. More foxes to fewer seabirds to duller landscapes, went the hypothetical cascade. And the converse.
To test their hunch, the biologists hopscotched across the Aleutians, sampling islands with foxes and without. If they could land a skiff without killing themselves, they sampled it.
On uninvaded islands like Buldir and Chagulak, with seabirds amassing by the millions, the avian populations outnumbered those on fox islands by orders of magnitude. Where the foxes had invaded, the soils supported a crusty cast of mosses and lichens and low-lying crowberry shrubs, an impoverished, poor-cousin rendition of the Aleutian maritime tundra. Yet where the seabirds still reigned, so rained their guano, rich in nitrogen and phosphorous, the food of plants. The vital nutrients measured sixty-three times richer on islands without foxes. The fertilized soils grew tall grasslands, blooming with those Kamchatka lilies and towering green herbs. The seabirds were no bit players in the Aleutian ecological theater. They were chief gardeners of the maritime tundra, transformers of landscapes, and conspicuous in their absence.
Which raised again the question of rats. They were as likely as foxes to be cleaning out Aleutian seabird colonies, to be starving the tundra. There were hints that they were cutting swaths in the marine communities as well. One hypothesis held that rats, by driving away gulls and shorebirds from the Aleutian beaches and tide pools, were allowing the birds' prey to flourish to destructive densities. Freed from pecking beaks, snails and limpets grazed unhindered through the coastal kelps and seaweeds, gutting a critical organ of the intertidal ecosystem.
It seemed that wherever inquiring minds looked, the rat's reputation as ecological kingpin was gaining scientific weight. One such place was the Hawaiian island of Oahu, in an ecological enigma called the Ewa Plain. The plain was a grassy expanse once covered in a rich forest of palms. Botanists for years had blamed the missing forest on the fires of the colonizing Polynesians, if not on the axes of Captain Cook and his successors. By the late 1990s, archaeologist Stephen Athens had good reason to believe that those supposed fires and axes had in fact featured four legs and a naked tail.
Athens in his excavations found that the palm forests had begun collapsing in about
A.D.
1020, some four hundred years
before
the first Hawaiians had come to settle there. Athens postulated that the rats, arriving in the canoes of the first Hawaiians, and finding themselves loosed in a predator-free land of plenty, had swelled to monstrous masses and rolled like a living tsunami across Oahu, hitting the Ewa palm forest long in advance of their people. Once arrived, the swarms lived large on palm nuts. No more palm nuts, no more palms. Without spark or blade, the forest of the Ewa Plain had toppled of a rat-borne decay.