Pleistocene America.

There are no cheetahs running wild in Arizona. For ecologist C. Josh Donlan of the Department of Ecology and Evolutionary Biology at Cornell University, that's a problem. Going far, far beyond any previous vision for rewilding North America, Donlan and his collaborators have begun arguing for "Pleistocene re-wilding," in which "megafauna" that have been absent from North America since the end of the last Ice Age are reintroduced. In the November 2006 issue of the journal American Naturalist, Donlan and his 11 coauthors write: "we advocate Pleistocene rewilding--reinstituting ecological and evolutionary processes that were transformed or eliminated by megafaunal extinctions--as a conservation priority in North America."

According to author William Stolzenberg, writing in the January-March 2006 issue of Conservation in Practice, the idea for Pleistocene re-wilding began to come together for Donlan and his partners in 2004 at, of all places, Ted Turner's ranch. According to Stolzenberg, the group gathered at "Turner's Ladder Ranch in the Chihuahuan Desert of New Mexico. Over easels and PowerPoint and after-hours beers, they discussed the rewilding idea and broke it down to its factual nuts and bolts, its practical challenges and criticisms, its societal costs and benefits." The group, which included Earth First eco-terrorist Dave Foreman, came up with what Stolzenberg described as "several sobering premises," including: "That human influence had utterly pervaded the planet. That what qualifies for wildness today is a paltry facade of the awesome Pleistocene bestiary we stumbled upon only 13,000 years ago. That the difference between then and now is at least partly, if not principally, our own doing and therefore our duty to repair."

The answer, according to Donlan and his coauthors, is to reestablish megafauna to North America. This would include certain rather mild steps like continuing to protect populations of the California condor and encouraging the growth of wild horse populations. From there the ideas get progressively stranger, like introducing populations of camels, cheetahs, elephants, and lions to the North American environment.

How best to accommodate and manage the new North American megafauna? Establish a huge wildlife preserve, probably funded and maintained by the government. "A third and more ambitious scenario would be exemplified by an enormous ecological history park encompassing thousands of square miles in ... parts of the Great Plains," Donlan and his coauthors write. What would happen to landowners in the area is anyone's guess, but according to the plan's authors, there would be "adequate incentives for local landowners."