Elephants roaming North Dakota? Free-range camels and lions a couple hours' drive from Denver or Oklahoma City?
That's the vision behind a new call to "re-wild" parts of North America's Great Plains. Since people are leaving the region's rural areas, the logic goes, why not create large ecological reserves with animals that are kin to the mammoths, mastodons, and cheetahs that roamed the region 13,000 years ago?
The approach echoes other proposals and projects to restore habitat in the Great Plains - with a twist. It would use the Pleistocene fossil record as a rough guide for restoration, rather than the historical record from Europeans' first contact. It might also provide a haven for large animals that are struggling to survive in their home habitats in Africa and Asia.
Researchers summarized their proposal in today's edition of Nature. Some call it "Pleistocene Park."
While many researchers consider the proposal "pie in the sky," other scientists see it as a bold vision. But behind it lies an important dynamic. Some specialists believe they're losing the battle to save many large animals from eventual extinction.
"I've been involved in conservation for 40 years, and in that time, we've learned a lot about how to do it better," says David Burney, director of conservation at the National Tropical Botanical Garden in Kalaheo, Hawaii, and one of the plan's authors. Despite individual successes, overall "we're still losing the battle. Some of us are trying to look at bigger patterns" in crafting conservation strategies.
The idea of giving regions of the Plains a more Pleistocene-like look could achieve several objectives, Dr. Burney says.
Using reserves to build the populations of large animals such as Bactrian camels, Bolson tortoises, and rare species of horses, elephants, cheetahs, and lions would provide a pool of range-adapted animals available for return if their home habitats eventually are saved. It also could relieve pressure where animals are becoming too abundant in reserves overseas.
In addition, these animals could fill long-vacant ecological niches here, Burney and his colleagues argue. This could help prevent the Plains from degenerating into a "pest and weed" ecosystem. Instead, over time the grasslands involved could reach a level of ecological and evolutionary health not seen in the region since the end of the last ice age.
Beyond conservationists' frustrations, the proposal also puts a focus on the plight of grassland ecosystems, notes M.A. Sanjayan, a lead scientist at the Nature Conservancy in Arlington, Va. "Grassland conservation is maybe our top terrestrial priority," he says. "There's so little of it left because it tends to be agriculturally very productive."
Meanwhile, with the world's population expected to continue rising over the next 50 years, fewer spaces large enough to be thought of as sanctuaries will be left, notes Sean Gerrity, president of the American Prairie Foundation. "Where are the big spaces left? Grasslands."
Although Burney says he and his colleagues have been pitching the Pleistocene idea for several years in lower-profile journals, the Russians appear to be the first to give it a test drive. Writing in a May edition of Science, Sergey Zimov described a program just underway in the Republic of Sakha to help turn tundra back into a more steppe-like grassland ecosystem. Building on mammoth-era animals still there, his group also is reintroducing musk oxen, hares, marmots, and ground squirrels. Once these are well established, the "Pleistocene Park" project plans to import bison from Canada and, later, Siberian tigers, according to Dr. Zimov, director of the Northeast Science Station in Cherskii.
Here in the United States, the researchers say, restoration over the next 50 years would begin with plant eaters. Once large herbivores were well established over sufficiently large fenced tracts of land large predators such as lions would be introduced.
Pleistocene Park represents a "bold vision" that could be a natural long-term follow-up to projects such as that undertaken by the American Prairie Foundation, says Stuart Pimm, an ecologist at Duke University. The APF is working with the Bureau of Land Management and other federal agencies to acquire land in the northern Plains and populate it with genetically pure bison and other large mammals.
But the Nature Conservancy's Dr. Sanjayan sees problems - ranging from the possible introduction of invasive species or animal diseases to a siphoning off of resources from other important conservation projects. "For a fraction of the cost, you could save these animals in situ," he says.