North America may become a 'Pleistocene Park'

Elephants, lions, cheetahs and camels could one day roam the western US under a proposal to recreate North American landscapes as they existed more than 13,000 years ago, when humans first encountered them.

The plan, proposed in a commentary in Nature and co-authored by 13 ecologists and conservation biologists, would help enrich a North American ecosystem that was left almost devoid of large mammals at the end of the Pleistocene period. It would also help preserve wildlife that faces the threat of extinction in Africa and Asia.

Between 50,000 and 10,000 years ago, 97 of 150 genera of large mammals disappeared from around the world. Although a warming climate played its part, the consensus is that over-hunting by humans probably had a significant role.

In North America, by about 13,000 years ago, humans were leaving evidence of big-game hunting using sophisticated stone tools. This hunting probably helped to drive many animals to extinction, including North American mammoths and mastodons, lions, cheetahs, camelops (a relative of the modern camel), horses and asses.

50-year plan
Although those animals are gone forever, related African and Asian species could serve as proxies, the authors say. They propose introducing the animals over 50 years, starting with horses, asses and camels, working up to elephants, and finally bringing in the big cats.

Eventually, the animals could roam in preserves hundreds of thousands of hectares in size. The best place to create this “Pleistocene Park” would be in the North American Great Plains, where the human population is relatively low and the grazing animals would have a ready supply of food.

But other conservationists think it is a bad idea. Chris Haney, a conservation biologist at Defenders of Wildlife in Washington, DC, US, says that substituting modern equivalents of extinct species will not be the same as restoring the ancient ecosystem. And he thinks it would detract from more pressing and “realistic” goals, such as restoring wolves, grizzlies, elk and other animals to their historic North American ranges. Even those reintroductions have faced bitter opposition from ranchers, farmers, and residents.

"I need to work on wolves, not mastodons," agrees Douglas Inkley, senior science adviser to the National Wildlife Federation in Reston, Virginia, US.