Rrrroar! Lions on Plains?

DENVER — Lions stalking deer in the stubble of a Nebraska corn field. Elephants trumpeting across Colorado's high plains. Cheetah slouching through the West Texas scrub.

Prominent ecologists are floating an audacious plan that sounds like a "Jumanji" sequel — transplant African wildlife to the Great Plains of North America.

Their radical proposal is being greeted with gasps and groans from other scientists and conservationists who recall previous efforts to relocate foreign species halfway around the world, often with disastrous results.

The authors contend it could help save Africa's poster species from extinction, where protection is spotty and habitat is vanishing.

They also believe the relocated animals could restore biodiversity on this continent to a condition closer to what nature was like before humans overran the landscape.

They suggest starting with zoo animals. The perimeters of newly created reserves would be fenced.

"We aren't backing a truck up to some dump site in the dark and turning loose a bunch of elephants," insisted Cornell University ecologist Harry W. Greene, one of the plan's authors.

While most modern African species never lived on the American prairie, the scientists believe that today's animals could duplicate the natural roles played by their departed, even larger cousins — mastodons, camels and saber-toothed cats — that roamed for more than 1 million years alongside antelope and bison.

Relocating large animals to vast ecological parks and private reserves over the next century would begin to restore the balance, they said, while offering new ecotourism opportunities to a withering region.

The scientists' plan appears in today's issue of the journal Nature. It echoes the controversial 1987 Buffalo Commons proposal by Frank and Deborah Popper of Rutgers University to cut down fences of abandoned farms and reconnect corridors for native prairie wildlife.

A similar Pleistocene park is being established in Siberia. Scientists are importing bison from Canada to replace the native variety that vanished about 500 years ago.

Some ecologists said it is important to try such a bold plan. Otherwise, they said hundreds more species are likely to go extinct in coming decades and entire ecosystems like grasslands will fundamentally change.

"We're beginning to get backed into a corner," said Terry Chapin of the University of Alaska-Fairbanks. "It's something worth trying."