Where the Wild Things Were

by William Stolzenburg

  Coming upon a curious commotion in the water, they found a pod of sperm whales huddled face-to-face in a ring of bodies radiating tail-out, against a gathering mob of killer whales. As the crew watched, waves of killers converged from all points in the sea, taking turns battering and mauling the ring of sperm whales. One of the sperm whales was hauled from the circle and savagely set upon. Two others broke from the ranks of the rosette to retrieve their comrade, nudging it back to the group. “We see this same heroic scenario several times,” Pitman and Chivers later wrote. “We are aware of our own tangled emotions as we watch in horror and fascination.”

  By the time night fell, Pitman and Chivers had recorded one fatality for sure and could only speculate gravely about the survivors. One whale had been filleted alive, dragging “a yawning slab of blubber … as trig as a mattress.” Another had been conspicuously ripped to the ribs. One whale was dragging its intestines in the water, while yet another had its jaw broken to a right angle. As the whales were left to the darkness, it was hard not to conclude that this entire herd of sperm whales may have succumbed to injuries from this single ferocious assault.

  So much about the attack suggested to Pitman and Chivers that this was no fluke encounter between two otherwise unfamiliar species. The reflexive marguerite formation of the sperm whales (a cetacean forerunner to “circling the wagons”), and the coordinated, sequenced attack of their killers, suggested an innate choreography rehearsed and honed over many generations of high-stakes testing between the two —no matter the minuscule number of witnesses. After considering the odds of seeing just one, let alone ten attacks in such an immense, unmanned theater as the open ocean, sperm whale expert Hal Whitehead later calculated a typical female sperm whale in her sixty-year lifetime suffering, on average, 150 attacks by killer whales.

  Before witnessing the attack, Pitman and Chivers were among the majority who had assumed the killer whale all but incapable of bringing serious harm to such a beast as a grown sperm whale. Five hours later, they saw the ocean’s apex predator in a reverent new light. In their popular account written for Natural History magazine, the two expressed their epiphany: “This image of gentle giant may be ingrained in many people’s minds, but the name ‘killer whale’ is an appropriate reminder that this species consumes huge numbers of marine mammals annually and that its predatory habits are a significant force in shaping marine communities.”

  But to many minds, a few extra sightings and a lot of killer whale potential still did not add up to the sequential collapse of marine mammals as proscribed by Springer et al. And to those minds, it was their professional duty to publicly say so. Between 2005 and early 2007, a fleet of papers appeared in the marine science literature harpooning the sequential megafaunal collapse hypothesis, saving a few subtle barbs for its authors. The brigade of rebuttals culminated with a remarkable thirty-seven-page broadside in the journal Marine Mammal Science, written by marine biologist Paul R. Wade of the National Marine Mammal Laboratory in Seattle and a crew of no less than twenty-three coauthors, who concluded their critique with a dismissive sniff: “Hypotheses which tender neat explanations for apparent changes in trophic relationships are often wrong; in this regard, it is all too easy to confuse parsimony with oversimplification.”

  Landward

  Springer and Estes returned fire to Wade and his crew, submitting a defiant little volley of diplomatic thank-you’s and point-well-taken’s, and by the way, we still believe and dutifully maintain that our argument remains a plausible one worthy of serious consideration.

  Whatever one believed —whether an era of bygone whalers had or hadn’t triggered such ecological mayhem nearly half a century earlier — either side could hardly be proven wrong. The trail of evidence was, in some cases, half a century too cold. And on that, both sides agreed. What stunned the Springer camp was not the disagreements over the murky facts of history, but the seeming allergic reaction to the notion that predation quite plausibly had sent a biological tsunami through an oceanic ecosystem.

  “People don’t like it because they don’t want to think of killer whales as having a role in the ecosystem so potentially profound,” Springer speculated. “It just doesn’t jibe with their sense of nature.”

  “The thing people have forgotten is that the title of that article ends with a question mark,” said Bob Paine, observing from ringside. “All the adversaries are forgetting that question mark.”

  Springer’s name may have come first on the incendiary SMC paper, but it was the second author, Estes, who received the brunt of the backlash. He had been its main messenger from the start, and he had come away with bruises and a darkened view of his profession. One day in October 2006, nearly ten years into the battle that was never intended to be, Estes reflected with the tone of a wearied but unyielding warrior. “It could be we’re both wrong. After all, I have spent a hell of a lot of time working on this. I’m humble enough that I have some respect for the other possibility.

  “On the other hand,” he added, “I’m arrogant enough to think that I’m not that naive. I’ve seen enough of this part of nature —the broad-ranging and important impacts of predators —to the point that I really believe in my heart that it is a recurrent and important phenomenon across much of nature. The part of nature I’ve seen most clearly has made me feel some confidence that this is an issue that’s real, and the world needs to recognize that it’s real despite the fact we don’t know very much.”

  To be fair, Estes’s view of nature had not exactly developed in a North Pacific vacuum. Nearly ten years before at a workshop near Tucson, he had met an ecologist named John Terborgh. Terborgh, along with conservation biologist Michael Soulé, had organized a gathering of thirty experts for a sky’s-the-limit discussion of what it would take to save the wild nature of North America. Terborgh’s session, to which Estes contributed, was “The Role of Top Carnivores in Regulating Terrestrial Ecosystems.” After some twenty-five pages of anecdotes and experimental evidence marshaled from across the western hemisphere (citing, among others, Paine’s starfish and Estes’s otters as paragons of proof), the synthesis was summed by Terborgh and his conferees in decidedly strong terms: “Our current knowledge about the natural processes that maintain biodiversity suggests a crucial and irreplaceable regulatory role of top predators. The absence of top predators appears to lead inexorably to ecosystem simplification accompanied by a rush of extinctions.”

  One of the darker developments leading to Terborgh’s bleak assessment had come from Terborgh himself, whose team had just begun sending dispatches from a series of forested islands in a Venezuelan lake. If Estes had harbored any doubts about his worldview of predators —schooled as it was on sea otters and killer whales —Terborgh’s frightening news from his terrestrial laboratory would ultimately shatter them.

  FIVE

  Ecological Meltdown

  Chance favors the prepared mind.

  —Louis Pasteur

  IN 1986, NEAR THE confluence of the Orinoco and Caroní rivers in east-central Venezuela, the gates finished closing on a huge hydroelectric dam. The rising waters flooded a tract of tropical forest as broad as the state of Connecticut under a lake that came to be named Guri. Left poking above the surface of Lago Guri was an archipelago of hundreds of hilltop islands, ranging in size and quality from half-acre islets to sprawling 1,800-acre semiwildernesses. The disparities in size had created one critical distinction: All but the very biggest among them were too small for large predators. The birth of the Guri archipelago was the scientific windfall the ecologist John Terborgh had been waiting for.

  By the time he caught wind of Lago Guri in 1990, Terborgh, had established himself as a premier tropical ecologist, a multifaceted master of the rainforest’s unrivaled roster of life-forms. In the field, Terborgh could hold his own with the foremost botanists, ornithologists, and primatologists. He had published major treatises over an unheard-of breadth of tropical ecology, from the ecology of migrant songbirds to the sociolo
gy of neotropical monkeys. To travel a quarter mile on the trail with Terborgh was to spend five hours examining every insect, snake, frog, bird, flower, and tree along the path, addressing each by Latin name, occupation, and relation to all others. Terborgh had a special ability for seeing all as a working whole, linking bottom dwellers to treetop specialists, big and fierce, small and meek. Among the inner circles of tropical ecology, he was “the guy who knows what’s going on.”

  Terborgh was also fearless (opponents would say reckless) about reaching into his bottomless rucksack of natural history knowledge and pulling out big sweeping theories of ecology. Over the previous decade in particular, Terborgh had begun “harping on a theme”—a theme he had most baldly declared in a 1988 essay titled “The Big Things That Run the World.” At the top of Terborgh’s list of big things perched the big predators.

  After spending a third of his adult life probing their place in the tropical forests, Terborgh was convinced of the predators’ disproportionate and heretofore unheralded importance. “If what I suspect is true, the top predators in this system—jaguar, puma, and harpy eagle—hold the key to its stability and to the maintenance of its extraordinary diversity of plant and animals.”

  But Terborgh’s suspicion wasn’t to be answered by a few stubborn starfish on a point of rock. His subjects of concern were out there slinking like phantoms through great vastnesses of dark jungle, not to mention armed with tools capable of dismembering intrusive field biologists. Long-lived and wide-ranging, the superpredators’ impacts were to be measured on the scale of years and decades, not the months of a master’s project. Terborgh needed a place where the big predators could be systematically removed, the ecological consequences rigorously gauged. He needed something on the order of a miracle. But as Pasteur once declared, “Chance favors the prepared mind,” and when the dam created the archipelago of Lago Guri, John Terborgh was more than ready. In truth he’d been training for the moment from the time he was a toddler.

  The Boy Naturalist

  John Terborgh was born in Washington, D.C., in 1936, the eldest of three children who grew up across the Potomac River in what was then the rural outskirts of Arlington, Virginia. His home was a small white house built on an abandoned pasture at the end of a country lane. Young John played no ball; there were no boys his age. There was instead a forested stream that ran more than a mile from his backyard to the palisades of the Potomac, crossing but one street along the way. By the time he was five, John had taken to disappearing into the greenery of Donaldson Run, roaming wood and stream, turning up snakes and turtles and salamanders, many of which would eventually end up in the home menagerie. The Terborgh home became one of snake cages on the porch, turtles in the bathtub, flying squirrels in the bedroom. For a time the Terborgh family also had a cleaning lady, whose visits abruptly ended the day she met one of John’s serpentine specimens slithering down the hall.

  Nights, Terborgh’s mother would read to him tales of wild places and exotic creatures, with John imagining himself in the living cathedrals of James Fenimore Cooper’s American forest primeval or tracking pythons and crocodiles through the jungled tropics with herpetologist Raymond Ditmars. Weekends the Terborgh kids followed in the footsteps of Uncle John Murray, who led the family on field trips to Shenandoah National Park. The kids would follow behind like a brood of ducklings, poking and putzing and rummaging in Murray’s wake, hailing him with questions: What’s this flower, what’s that tree, whose bird song is that? In the shadow of Uncle Murray, John developed his signature style, a meticulous, all-things-considered exploration of nature, from the tiniest to the grandest forms of life.

  Terborgh burned his way through the field guides, exhausting the inventories of his backyard Mid-Atlantic flora and bestiary, building an encyclopedic grasp of all things nature. By his teens, he was bird-watching under the wing of Chandler Robbins, one of the country’s leading ornithologists and author of the Golden Guide to Birds, one of the most popular field guides to birds in U.S. history.

  As sure as the arrival of warblers in May, the post—World War II baby boom and its bulldozers inevitably came to Terborgh’s end of the road and rapidly squeezed his seemingly boundless backyard wilderness to a green ribbon between suburban housing lots. Along with the forests, they took away both playground and playmates of the young naturalist. Terborgh fled for college and yet untrammeled places in the tropics, bringing with him memories of flowers and fauna at their richest, images that would serve as yardsticks against the coming changes. It was a habit Terborgh would find himself practicing all too many times in his career.

  In between professorial duties as biology instructor at the University of Maryland, John began making good on his boyhood fantasies, trading his romps in Donaldson Run with excursions to the tropics. In the foothills of the Peruvian Andes, Terborgh came upon a valley he later declared as “the most beautiful place I had ever seen”—a valley that was soon destroyed in reminiscent fashion of his Arlington environs. “By 1972, the year I last saw the Apurímac valley, the population of colonos had swollen to more than a hundred thousand and was still growing steadily. By then, hardly a tree remained of the magnificent forest that had so recently filled the valley bottom,” he wrote.

  Over the next twenty years Terborgh explored some eighty forests in fifteen countries, visiting tropical wildernesses in every state of ecological repair. Along the way, he developed an eye for distinguishing the pristine from the pathological. He saw through the façades of idyllic green forests that unbeknownst to the inexperienced observer had been stripped of their distinguishing fauna.

  He began imploring others to see this, too. As a professor at Princeton University, he would gather a hardy handful of ecology students during the winter semester break, pick a tropical spot on the map, and go explore whatever avifauna might await. The Princeton ornithology field camps, and their leader, became legend. “John was famous for having a place and a map and just kind of winging it as we went,” said Scott Robinson, a former Terborgh student and now a leading authority on migratory birds of the New World tropics. “The beauty of it was that he did it without any fancy stuff. He doesn’t need money, doesn’t need massive planning. He can make do with a machete, wood, and a tent.”

  Terborgh and the students would spread invisible nets across gaps in the woods and take inventory of the forest’s avifauna. They would come back with enough data for technical papers. But what the students valued most were those rare glimpses of the tropical forest as seen through Terborgh’s eyes.

  Said Robinson, “The thing that always boggled my mind when we would walk through the forest, he would always be grabbing at a plant, or looking at a flower, taking his glasses off, staring at it, pondering it, identifying it, looking at context—looking out from extreme structural detail all the way up to the structure of the canopy. You could see his eyes were always focusing up close and then looking at a distance up into the trees. Just seeing things. You could just tell he was seeing things we weren’t seeing. I’ve known many of the world’s great naturalists, but John is the finest I’ve ever known.”

  “The thing that struck me was the sort of breadth of his natural history knowledge,” added David Wilcove, now a decorated conservation biologist who has since inherited his professor’s old post at Princeton and takes students of his own to the tropics. “It was his ability to see patterns where the rest of us didn’t. We might gather around the campfire in the evening and he would say, ‘Did anyone notice that the bird community here is largely composed of nectar-eaters? Or that this area is very different from what you’d see in a lowland forest of South America?’ He would, say, observe a dot-winged antwren foraging in eastern Mexico, and he would remark that it occupied a much wider range of heights in the canopy here than one you saw in Peru, where there were many other competitors and therefore had a much narrower foraging range. That was the kind of amazing thing he could do.”

  Barro Colorado

  In 1970, Terborgh’s tro
pical peregrinations brought him to a bizarre, 3,800-acre island in Panama. Barro Colorado Island had once been the dominant hilltop in a mainland forest, until in 1913 the construction of the Panama Canal left it standing in the midst of the new Lake Gatun. Barro Colorado, not long after its creation, had been blessed with protection as a biological reserve and laboratory, run by the Smithsonian Institution. It should have been an idyllic tropical wilderness, but even as Terborgh was arriving, just over fifty years after its formation, the island was already showing aging signs of insidious decay.

  Terborgh on his first visit tagged along with the island’s resident ornithologist, Edwin Willis, who had picked up where a line of earlier ornithologists had left off. Willis had been following birds on BCI for nearly a decade. Willis had discovered that of the 209 species counted in the earliest censuses of BCI, 45 were no longer to be found on the island.

  Some of the disappearances were to have been expected. About half the island had once been slashed and burned by peasant farmers; as the forests grew back, those birds best adapted to field and pasture quite naturally fell out. But among the missing were also some eighteen forest dwellers, which, if anything, might have been expected to flourish in the returning forests of Barro Colorado. A few of them Willis had watched intently, year after year, as their numbers withered to single digits, then to single birds, then … poof.

  There was little in the way of science to explain it. And that became Terborgh’s challenge. “As concerned citizens and biologists we are anxious to understand how natural diversity can be maintained in a world of rapidly diminishing resources,” he began a 1974 article in the journal BioScience. It was by then becoming apparent to Terborgh in his wanderings—as well to many of his colleagues in their study sites around the world—that the diversity of living species was falling at a rate comparable to the greatest mass extinctions on record. A puzzle that had once fallen to the task of paleontologists, unearthing the die-offs from fossil beds and boneyards, had become the dilemma of modern biologists watching their subjects vanish before their eyes. Terborgh’s eyes were as sharp as anybody’s, and still those eighteen missing birds from Barro Colorado baffled him.