The Opposite of Apocalypse

We climb into Truett’s pickup and rattle from Armendaris Ranch to the freeway, Truett knuckling the wheel against the wind-suck through the gulches, heading southwest to another Turner property. Ladder Ranch is half the size of Armendaris, but still a lot larger than you’d want to walk across under any kind of sun. They keep the baby tortoises there, hatchlings already the size of baseballs, but I am more interested in a century-old stone and mortar ranch building overlooking the improbable green swale of Las Animas Creek. “It was a good place for a discussion,” says Truett, “insulated from reality.”

In September 2004, he joined thirteen other leading conservation thinkers at the Ladder Ranch lodge for a two-day brainstorm on the restoration of North America’s “evolutionary and ecological potential.” In an easy chair beneath the trophy head of a mule deer sat the guru of the gathering, Paul Martin, the desert zoologist whose overkill hypothesis first championed the idea that the spread of humankind is largely to blame for the worldwide megafaunal extinctions of the past 50,000 years. Seated along a Last Supper–style table were a dozen other luminaries — what Josh Donlan, the Cornell University graduate student who helped organize the meeting, called “National Academy, silverback, rock star scientists,” among them Michael Soulé, considered by many to be the father of conservation biology; and Dave Foreman, a founder of the direct-action Earth First! environmentalist network. Up for discussion: the possibility that conservation is on the wrong path as it fights to preserve an archipelago of “pristine” wilderness areas from the juggernaut of humanity.

To understand the hollow promise of these parks and protected areas, it is necessary to revisit the late Pleistocene. The landscape of North America at that time, say 15,000 years ago, was in many ways familiar. The last ice age glaciers were still receding toward the Arctic, but they were doing so through seasons much like ours today. There were mountains where we have mountains, plains where we have plains. Streaming throughout was a bestiary of giants that strains the imagination.

The best known are probably the mammoths and mastodons, which ranged in size from Columbian mammoths two storeys tall at the withers to pygmy varieties that stood only head high to a human being. On the grasslands, they may have roved in densities similar to those of elephants in African parks today, more than three animals per square kilometre. But these trunked and tusked beasts were nothing more than the Pleistocene’s comforting opening act. North America was home to pampatheres, which resembled armadillos the size of overturned dories, and another armoured family, the glyptodonts, at their largest the size of a subcompact car. There were ground sloths — amiable-looking herbivores that, standing on their hind legs to browse the woodlands, would have been an awesome presence, with the largest weighing in at nearly three tonnes. There were herds of wild horses, some as heavy as today’s draft horses; and tapirs rooting through the wetland; and an antelope called the saiga, with a pouchy snout that acted as an air filter (it still exists today, as a critically endangered species in Central and Northeast Asia). Wild oxen drank at watering holes alongside camels that would tower over today’s dromedaries. One such humped species, the camelops, could be found in herds from the US Southwest to the Subarctic, where its bones sometimes washed out in Klondike gold digs. There were giant moose, giant llamas, giant elk, giant boars. There was a vampire bat twice the size of any known today. There was a beaver the size of a black bear.

Consider the carnivores. Packs of dire wolves were widespread, the animals heavier by ten kilograms than modern wolves but still far from the most fearsome predators in the Pleistocene wilderness. That title might go to the giant shortfaced bear, a dedicated flesh eater large enough to look into your eyes while still on all fours. The greatest feline, still haunting the pop-up book nightmares of children, was the sabretoothed cat, the ultimate ambush predator, with serrated canine teeth as long as chef’s knives, and a body smaller than that of today’s lions but nearly twice as heavy. And there were prides of American lions, akin to those in Africa and India in every way but one: they were larger. Many of these species still survived as recently as 10,000 years ago, in climes similar to ours. Put another way, lions and sabre tooths lived within the myth time of North America’s First Nations. They lived at a time only as distant from the founding of farming in Europe as that founding is from us today.

The list goes on, from scavenging birds with wingspans of nearly five metres to beetles adapted to rolling the dung of giants, but lest we forget: there were tortoises. Six big species roamed widely below the glaciers, enduring the coming and going of ice ages. Among them was the bolson tortoise, which might once have grown to 160 kilograms, ten times the size of the largest individuals today.^{3Anecdotal evidence suggests that very large bolson tortoises — perhaps up to a metre long — survived into the twentieth century. For example, in 1946 a Mexican mule herder told a story of waking up in the Chihuahuan Desert to find his saddle missing. He followed a set of tracks from the place where it had been, and eventually found it on the back of a tortoise. The animal had apparently taken shelter beneath it, then walked away with it stuck on its shell.} Picture the tortoise basking. Picture it in its burrow, the heavy tromping of megafauna overhead. Picture it at its peak as a species, roaming the breadth of today’s Chihuahuan Desert from what is now New Mexico, Arizona, and western Texas to almost the entire Mexican Plateau, an area larger than the Yukon Territory.

The men and women who came together for the Ladder Ranch workshop concerned themselves with a simple question: do modern human beings have ecological, aesthetic, and even moral reasons to attempt to recreate the Pleistocene? The answer they arrived at was “maybe”. The group began to moot what they would later describe as “a series of carefully managed ecosystem manipulations using closely related species as proxies for extinct large vertebrates.” This “Pleistocene rewilding,” the group agreed, had the potential to revitalize conservation biology (and, by association, the environmental movement) by steering it away from “managing extinction” in last-ditch protected areas. The discussion was, despite the rather cautious language of science, the makings of a manifesto that would declare an end to the conservation century and the dawn of an age of restoration.

The proposed manipulations — introducing experimental wild populations of horses, camels, and elephants, for example — had as a natural end point “the ultimate in Pleistocene rewilding for North America”: a free-living population of lions, limited only by the kind of perimeter fencing that encloses African parks, somewhere among the southern Great Plains states of Colorado, Kansas, Oklahoma, New Mexico, and Texas. But the program needed an initial stepping stone, a species that could test the rewilding hypothesis on a short timeline, with few ecological risks, and a comparatively low level of controversy. What was needed, as one tortoise researcher would later put it to me, was “the medical marijuana of Pleistocene rewilding.”

It was pure serendipity that two grasslands ecologists, Carl and Jane Bock, now professors emeriti at the University of Colorado, Boulder, had arrived at the Ladder Ranch with tortoises on their minds. During a break in the meeting, the Bocks approached Joe Truett and his colleague Steve Dobrott. Might the Turner Fund be interested in the little-known bolson tortoise? The Bocks had worked for thirty years near Elgin, Arizona, on a research preserve founded by a naturalist, Ariel Appleton, who in 1973 had taken a colony of Mexican bolson tortoises into captivity as a backstop against the species’ possible extinction. Appleton had died earlier in 2004, and the animals needed a new home. It was Harry Greene, a Cornell reptile expert, who overheard the conversation and made a synaptic leap: the bolson tortoise met all the group’s criteria for the rewilding experiment. “The bolson tortoise would be perfect,” he said.

In August 2005, the rewilding proposal appeared as a commentary in the journal Nature. The response was explosive. Some opposing scientists pointed out that the article ran in the same issue as a study showing that lion attacks on humans in Tanzania had risen 300 percent in the past fifteen years. Good Morning America broadcast a brief interview with rewilding proponents, followed by a clip from the film Jumanji of elephants crushing cars. It was the first time many people had heard that North America was once home to giants and monsters, and reactions tended toward the visceral. Several threatening letters sent to Cornell were judiciously turned over to the authorities. Surprise offers of rewilding habitat rolled in from ranchers in Texas, Arizona, Kansas.