If a group of prominent scientists has its way, cheetahs, lions, elephants, camels and other large wild animals could some day be roaming parts of North America.
“If we only have 10 minutes to present this idea, people think we're nuts,” said Harry Greene, professor of ecology and evolutionary biology at Cornell University. “But if people hear the one-hour version, they realize they haven't thought about this as much as we have.”
Transplanting African species into North America sounds warning bells from grade-school biology lessons that non-native species should not be introduced into an ecosystem.
The real-life lesson is exemplified by the scourge of rabbits in Australia after they were introduced from England in 1859.
The same lesson holds true for the cane toad. Originally introduced to the land down under to combat a beetle that was eating sugar cane, the toad's population spiralled out of control and now provide a bumpy ride for anyone travelling through the Outback.
The supporters of the proposal to bring African species to North America, however, say the idea could help save some endangered species from extinction in Africa, where protection is spotty and habitats are vanishing.
They say the relocated animals could also restore the biodiversity in North America to a condition closer to what it was before humans overran the landscape more than 10,000 years ago.
The scientists' plan appears in Thursday's issue of the journal Nature. It is attracting interest from some influential circles, including media mogul Ted Turner, the United States' largest private landowner. He has huge ranches in several states to support his commercial bison operation and personal conservation initiatives.
In fact, the plan grew from a retreat at Mr. Turner's New Mexico ranch – a 155,000-acre property in the foothills of the Gila Mountains that contains a mix of ecosystems ranging from desert grasslands to pine forests.
Ecologists are using the ranch to experiment with reintroducing the Bolson tortoise to the region. These 45-kilogram burrowers were once found across the Southwest but now survive only in a corner of northern Mexico's Chihuahuan Desert.
The scientists' discussion expanded to consider long-extinct species from North America's Pleistocene era – between 1.8 million and 10,000 years ago – that have modern counterparts elsewhere in the world.
Mr. Greene and his colleagues argue that being hunted for four-million years by the now-extinct American cheetah may have been responsible for the blinding speed of the American pronghorn, an antelope-like animal native the Southwest.
Relocation of the cheetahs could help both species retain important traits, the plan's proponents say.
The pronghorn can reach speeds nearly 100 kilometres an hour. Introducing an African species of cheetah into the Southwest, the scientists argue, could restore strong interaction with the pronghorn and provide the endangered cheetahs with a new habitat.
The plan does have its critics.
“It is not restoration to introduce animals that were never here,” University of Washington anthropologist Donald Grayson said. “Why introduce Old World camels and lions when there are North American species that could benefit from the same kind of effort?”
Others wonder whether people would support African lions' making a home on the range, given the opposition to the reintroduction of native wolves in the rural West.
“We are not saying this is going to be easy,” said Cornell University ecologist Josh Donlan, the lead author of the proposal. “There are huge and substantial risks and obstacles.”
Other living species that are counterparts to Pleistocene-era animals in North America include wild horses and asses, Bactrian camels, elephants and lions.
Mr. Donlan concedes that lions would be a tough sell to Americans.
“Lions eat people,” he said. “There has to be a pretty serious attitude shift on how you view predators.”
With reports from the Associated Press
