The Best American Science and Nature Writing 2018

by Sam Kean

  At the end of his account in the 1999–2000 annual report, Peterson concludes with this description of the pair: “Two individuals, one focused on mere survival and the other on reproductive imperatives, neither with much chance of success outside the existing territorial packs.”

  However.

  The map of wolf territories shifted. They fought over borders. They staged coups. Fortunes rose and fell. Packs gathered strength, then disappeared.

  When Ferocious Warrior recovered from her injuries, she and Prince Charming founded the Chippewa Harbor Pack on the east end of Isle Royale. She had a scarred nose, a scarred throat, and a broken canine tooth, but she and her mate raised litter after litter of pups and killed two alpha males of the East Pack, one after the other, as they ate into East Pack territory, eventually controlling a fourth of the island.

  But by the winter of 2006–2007, the Chippewa Harbor Pack was weakening. The East Pack ambushed and killed Prince Charming as he ate a moose calf on the territory border between McCargo Cove and Chickenbone Lake. As Vucetich described it, after making a beeline toward the dead moose through thick snow, then stopping to howl, the East Pack lunged at the male in a clump of trees: “In less than three minutes, [the East Pack] left only a lifeless carcass and blood in the snow,” he wrote in that year’s annual report. Ferocious Warrior lived for another year and gave birth to more pups, but the East Pack eventually killed her, too. The researchers found her skull and radio collar at Angleworm Lake.

  The same year, Old Gray Guy died. His body was never found, leaving behind only his genetic legacy—in every single wolf on the island.

  Just as they hadn’t seen his death, the biologists hadn’t seen Old Gray Guy’s arrival. They still thought the island was a closed system with no wolves coming in or out. They still puzzled over unexplained population leaps and drops. They were in the habit of collecting whatever they could get their hands on. This included wolf scat, which they kept for more than a decade, waiting for funds for DNA tests. After they finally had the money and commissioned the tests, Peterson, on a rare mainland visit in July 2010, got a call from DNA expert Jennifer Adams requesting he come to her office. The results from the tests glowed on her computer screen.

  “Sit down,” she said.

  The DNA tests showed that Isle Royale was not an isolated lab at all. It was just another part of the messy, complex world. Fresh genes had come in with Old Gray Guy in 1997 and possibly in the late 1960s as well, triggering the wild population fluctuations Peterson had witnessed. But Old Gray Guy chose his daughter as a second mate, and then she chose her son. Inbreeding depression—which scientists thought wolves avoided—haunted the Isle Royale population. As relatives mated, negative traits carried on recessive genes had an opportunity to express themselves. The parvovirus outbreak worsened matters, severely limiting the gene pool, a situation eased only briefly by the arrival of the virile new male (Old Gray Guy). Looking back through decades of field notes, Peterson saw them in a different light: the black wolves that skulked through the island when he started on the study; the fact that in the 2000s, a number of males turned white as they aged—these coat colors were genetic traits brought in by newcomers. He’d been looking for answers in weather and pack dynamics, but genes were the unseen engine of it all.

  The Isle Royale study, over its lifetime, has shown all kinds of unexpected things, including information about the effect of diet on arthritis and evidence of a decline in mercury pollution documented through moose teeth. But when scientists were finally able to track genes, it was as though a map was pulled back to reveal another map underneath, one with unimagined mountains and strange rivers. The DNA tests uncovered the power of chance events (a tourist ignoring the rules and bringing his sick dog to the island) and individual personalities (the dominance of Old Gray Guy, the resilience of Ferocious Warrior) to shape populations. It undermined the notion of a natural balance.

  On the bulletin board at Isle Royale’s Daisy Farm campground, a hand-scrawled sign announces a talk about the moose and wolves of the island. It’s a chilly evening, and eight people—this early in the season, mostly park employees—sit on stumps or in the tall grass. Carolyn Peterson, a longtime field assistant married to Rolf, unpacks a collection of bones. She used to stress that wolves don’t suffer from inbreeding depression. Now she holds up a moose jaw and says, “Things are much more complicated than we thought . . . Things are changing all the time. We don’t use the word balance anymore.”

  And that is the conclusion many researchers are drawing as models falter. A recent article in Nature argued that the concept of trophic cascades is flawed in its simplicity. Studies at Oregon State University are showing that the idea of a keystone species, a lynchpin for an ecosystem, may also be too basic: other species and environmental conditions play essential roles.

  In a paper evaluating the case for trophic cascades in the Annual Review of Ecology, Evolution, and Systematics, Peterson, Vucetich, and Douglas Smith, who trained on Isle Royale and now is a project leader for the Wolf Restoration Project at Yellowstone, argue that ecosystems are too complex to trace neat relationships, particularly in Yellowstone where grizzly bears, black bears, cougars, and wolves eat bison, deer, and elk. They also point out that, when you follow the threads of prey fluctuations, you often find at the source not wild-animal predators but human beings. We are part of these ecosystems too. We decide to kill off bison, decide to bring them back, conclude there are too few elk, then too many. Perhaps we are always, forever, just studying ourselves, like Pooh and Piglet tracking the Woozle around and around a clump of larch.

  There’s no doubt that wolves and other large predators have an effect on ecosystems—that effect is just growing harder to graph. And there’s no doubt that some questions are dangerous to ask. What are the conservation implications of questioning an idea that made such a reasoned case for wolves’ importance? Peterson, Vucetich, and Smith remind their readers that, whatever their conclusions about trophic cascades, “the answer is also a weapon.”

  It’s difficult for agencies to make management decisions without a sense of the way things will unfold, and one of the main lessons of Isle Royale is that the future is unpredictable. What if, for example, you had a highly inbred wolf population, developing extra vertebrae and bad eyes, failing to reproduce? And what if the moose population were spiraling upward, chewing trees to bits, just at the time that balsam fir might have recovered enough to drop the first seeds in a century? Should you bring more wolves from the mainland and stage a genetic rescue? No model can say.

  In February 2015, an ice bridge from Isle Royale reached the mainland. Looking for the island’s remaining wolves in a wind-buffeted plane, John Vucetich glimpsed something out of the corner of his eye. On the western side of the island, on a hillside near Mud Lake, two wolves slept curled against the fierce gusts. One, a solid female with brown and tan fur, patchy with mange, wore a radio collar. The other, slender and long legged, had lighter fur, almost cream-colored toward the feet. They were strangers to the island.

  The two had been sniffing around for three days. The collared one liked to roam. Before her radio signal died, biologists with the Grand Portage Band of Lake Superior Chippewa charted her explorations south toward Duluth and west to Voyageurs National Park. Whatever she and her companion smelled at Isle Royale—maybe a lodge of fat beavers or a scrap of ancient moose hide—it wasn’t many wolves.

  Three years prior, three of the island’s wolves had drowned in an abandoned mine shaft. A park biologist found their bodies floating in the pit. The carcasses included a vigorous male, alpha of the Chippewa Harbor Pack, and a young female. Other wolves simply disappeared, leaving only three on the island: a couple (who were half-siblings and father and daughter) and a crippled pup unlikely to make it through the winter. Together they were the remains of the Chippewa Harbor Pack, grandchildren of Ferocious Warrior, with a healthy mix of Old Gray Guy thrown in.

  The new wolves trotted south alon
g the shore. The future of the population was right there, listening to raven calls echo off the ridges, exploring snow-buried creeks, catching a rank whiff of fox. Natural genetic rescue, without any environmental impact statements, fighting, or government funding. But when they reached Cumberland Point, the southern tip of Isle Royale, the newcomers headed back to Grand Portage, through hills that looked like piles of broken glass and beaches of fine ice. Not long after, the ice bridge melted away.

  “For whatever reason, they went home.” Peterson shrugs as he tells me the story. “That’s what wolves do—they do what they want.”

  A year and a half after the mainland wolves turned around, a moose stands up to its chest in a lake tucked against a hot slope covered with trees in pale May leaves, soaking. Desiccated wolf scat curls on the trail nearby. Another moose dunks its whole head underwater to yank up last year’s water shield rooted at the bottom, vanishing for what must be a very long breath. When he resurfaces, the splash of the ungainly head breaking the surface, the water draining off antlers and through ratty, tick-filled spring fur, is the wettest sound in the world.

  Nothing disturbs the young bulls this afternoon. The wolves are down to two. But maybe not for long. After delaying for years, the National Park Service recently released a draft environmental impact statement that advocated importing as many as 30 wolves in a three-year span, for the sake of the moose, for the sake of the plants. Human judgment about the value of wolves will reshape the predator-prey landscape yet again. And the future of both the wolf and moose populations will depend, in part, on who those wolves are as individuals—cautious, brave, aggressive, intelligent.

  An accident in a mine; the spread of a mutant virus; a stranger coming to town; a survivor, left for dead, beating the odds and flourishing; a dynasty overthrown. We know these stories; we just don’t think of them in terms of wolves. But maybe Seton was right. Maybe there’s value in discussing Big Jim, Old Gray Guy, and Ferocious Warrior, in looking at the impact of specific personalities, as much as there’s value in searching for universal models. Maybe looking at the impact of specific personalities will help us to understand what is actually going on.

  “What if nature is a little more like human history? When the Berlin Wall fell, when the Soviet Union collapsed, no one predicted that,” Vucetich says. Isle Royale now “allows us to understand the stories of individual wolves,” he adds. “This is Shakespeare in the nonhuman world.”

  PART III

  “At the Start of Every Disaster Movie Is a Scientist Being Ignored”

  Environmental Science

  DOUGLAS FOX

  Firestorm

  from High Country News

  Aircraft n2uw has flown through all kinds of weather. The twin-propeller plane is sleek, petite, and so packed with scientific gear for studying the atmosphere that there’s barely room for two passengers to squeeze into its back seats. Monitors show radar reflections, gas concentrations, and the sizes of cloud droplets. The plane has flown through tropical rainstorms in the Caribbean, through the gusting fronts of thunderheads over the Great Plains, and through turbulent downslope winds that spawn dust storms in the lee of the Sierra Nevada. But the four people on board August 29, 2016, will never forget their flight over Idaho.

  The plane took off from Boise at 4 p.m. that day, veering toward the Salmon River Mountains, 40 miles northeast. There, the Pioneer Fire had devoured 29,000 acres and rolled 10 miles up Clear Creek Canyon in just a few hours. Its 100-foot flames leaned hungrily into the slope as they surged uphill in erratic bursts and ignited entire stands of trees at once.

  But to David Kingsmill, in the plane’s front passenger seat, the flames on the ground two miles below were almost invisible—dwarfed by the dark thing that towered above. The fire’s plume of gray smoke billowed 35,000 feet into the sky, punching into the stratosphere with such force that a downy white pileus cloud coalesced on its underside like a bruise. The plume rotated slowly, seeming to pulse of its own volition, like a chthonic spirit rising over the ashes of the forest that no longer imprisoned it. “It looked,” says Kingsmill, “like a nuclear bomb.”

  Undaunted, Kingsmill and the pilot decided to do what no research aircraft had done: fly directly through the plume.

  Orange haze closed around them, then darkened to black, blotting out the world. Kingsmill felt his seat press hard against his back as the plane lifted suddenly, like a leaf in the wind. Then the black turned back to orange. The plane jolted and fell. Pens, cameras, and notebooks leaped into the air and clattered against windows. A technician slammed headlong into the ceiling. A moment later, N2UW glided back into daylight.

  According to the plane’s instruments, it had been seized by an 80 mile per hour updraft of hot, buoyant air, followed by a turbulent downdraft. It was “the strongest updraft I’ve ever flown through,” says Kingsmill, a precipitation and radar scientist at the University of Colorado in Boulder. Even stronger forces were at work several thousand feet below: the plane’s radar waves, reflecting off rising smoke particles, had registered updrafts exceeding 100 mph.

  Hundreds of miles away, Kingsmill’s research partner, Craig Clements, a fire meteorologist at San José State University, watched the plane’s flight path creep across a map on his laptop screen. The unfolding drama offered a tantalizingly detailed glimpse into the anatomy of an extreme wildfire. “It’s amazing,” says Clements. “We’ve never seen this kind of structure in a fire plume, ever.” For decades, scientists have focused on the ways that topography and fuels, such as the trees, grass, or houses consumed by flames, shape fire behavior, in part because these things can be studied even when a fire isn’t burning. But this line of inquiry has offered only partial answers to why certain blazes, like the Pioneer Fire, lash out in dangerous and unexpected ways—a problem magnified by severe drought, heat, and decades of fire suppression.

  A mere 1 percent of wildfires account for roughly 90 percent of the land burned each year in the western United States. Some of these fires “really are unprecedented,” says Mark Finney, of the U.S. Forest Service’s Missoula Fire Sciences Laboratory. Their behavior “is particularly threatening because we don’t have a good way to anticipate or predict [it].” So Finney, Clements, and a handful of others are increasingly turning their gaze to fire’s invisible and diaphanous incarnations: the hot, roiling gases and smoke swirling among the flames, and the rising plumes they coalesce to form.

  There, they believe, lies the key to understanding the way a wildfire breathes—roaring into conflagration with bigger gulps of oxygen or sputtering along more slowly on little sips. How it moves, spawning lethal fireballs or hurling burning logs ahead of the flames. The way it grapples with the upper layers of the atmosphere, sending embers in unexpected directions to propagate itself across the land. Even, perhaps, the role its elemental opposite—water—plays in driving its explosive growth.

  Nailing those connections could provide new tools for monitoring fires and predicting their behavior. This could give firefighters precious minutes of advance warning before potential catastrophes, and better inform the difficult decision to order an evacuation.

  But it won’t be easy. “The plume is orders of magnitude harder to study than the stuff on the ground,” says Brian Potter, a meteorologist with the Pacific Wildland Fire Sciences Laboratory in Seattle who sometimes works with Clements. Indeed, it took a global conflagration much darker than any forest fire to even begin laying the foundations of this work. Kingsmill’s observation about the bomb, it turns out, isn’t far off.

  The evening of July 27, 1943, was stiflingly hot in Hamburg, Germany. The leaves of oak and poplar trees hung still in the air as women and teenagers finished factory shifts and boarded streetcars. They returned home to six-story flats that lined the narrow streets of the city’s working-class neighborhoods. They opened windows to let in cooler air, and folded themselves into bed. It was nearly 1 a.m. when British planes arrived.

  Searing yellow flares drifted down ov
er the city, dropped to mark the city’s eastern quadrant as that night’s target. Bombs followed, tearing open buildings and exposing their flammable contents to a rain of incendiary canisters that hissed as they fell.

  Thousands of small fires sprang up. Families retreated into basements. The buildings above them roared into flame, and these growing fires greedily sucked air from their surroundings. Their collective inhalation drew winds through the narrow urban canyons, pulling along embers that ignited yet other buildings. Within minutes, the fires were merging.

  The British historian Martin Middlebrook has collected the accounts of survivors who dampened their clothing, fled their bunkers, and crawled through the streets. They described the inflowing winds as “shrill,” “shrieking,” and “howling”—the scream of “an old organ in a church when someone is playing all the notes at once.” Gales exceeding 110 mph uprooted trees, pushed struggling full-grown adults deeper into the fire zone, and sucked babies and elders into burning buildings.

  The winds swirled into flaming tornadoes that swept up people and turned them into “human torches.” Balls of fire shot out of buildings. Within 60 minutes, a spiraling pillar of smoke had swelled into an anvil-shaped thunderhead that towered 30,000 feet over the city.