A hundred feet away, an elephant wrests limbs from a tree with its snorkely trunk; in the distance, a lion crouches behind a clump of sagebrush, watching a herd of antelope. The grass waves in the warm breeze as tourists, hanging from the open windows of a van, snap pictures. Sound like East Africa? Guess again. It's the American Midwest a couple of hundred years from nowas a group of prominent ecologists imagine it this week in the journal Nature.
Elephants, lions, and cheetahs roamed North America until about 13,000 years ago, when they were wiped out by hunting, many scientists now think. (Not by the ice age, as schools have taught.) So, says conservation biologist Josh Donlan, why not bring those animals back?
"If we talk to someone for five minutes, they think we're nuts. But if we talk to someone for a half hour or 45 minutes, they're intrigued by the idea and can see the value of debating it," says Donlan, who is a graduate student at Cornell University.
The point, Donlan says, is that when big mammals disappeared from North America, ecosystems collapsed. For example, when predators disappear, their prey flourishes. Ecologists have measured this kind of change more recently; after wolves disappeared from a national park in Canada, populations of elk boomed, chomped on willows, and drove out beavers and songbirds that depend on the willows for food and shelter.
So bringing lions, elephants, cheetahs, and camels to North America might help restore ecosystems to the way they were before hunting picked up several millenniums ago. It wouldn't be immediate change.
"By no means are we arguing, 'Let's back up a van with a handful of cheetahs and let 'em go,' " Donlan says. Instead, he says, the process would be slow, careful, and science-based; the writers propose starting with experiments on private land. A similar project is already underway in eastern Siberia, where musk oxen have recently been reintroduced and where the government aims to bring back the biodiversity that once existed.
The crazy side of the idea is pretty obviouspeople complain enough about the predators already here, like bears, wolves, and mountain lions. And ecologists spend a lot of time worrying about the impacts of exotic species, so setting elephants loose seems a little nutty. But the writers say this is a huge opportunity for people who care about the environment to do something positive.
"Currently, conservationists and environmentalists are portrayed as gloom and doom," Donlan says. "This proposal switches that."
Anyway, the writers point out, people are leaving North America's Great Plains in drovesso why not bring in a little ecotourism?
A regular feature of usnews.com, Science News investigates what's going on in the laboratory, trends in the environment, and other scientific research.