Josh Donlon, a graduate student in the Department of Ecology and Evolutionary Biology, is the lead author on a paper proposing a program under which wild African animals such as lions, elephants and cheetahs could be introduced onto large swaths of private land in the middle of the country.
These animals would essentially fill in the role once played by the megafauna from the Pleistocene era, which started around 1.8 million years ago and ended about 10,000 years ago.
During that era, the extinct American cheetah (Acinonyx trumani) likely fed on the pronghorn, a fast antelope that has flourished in the absence of predators. Other living species with counterparts to Pleistocene-era animals from North America include feral horses, wild asses, Bactrian camels, lions and Asian and African elephants.
While some obvious dangers exist, the program could also produce a number of benefits. For one thing, large animals have largely disappeared from most areas of the world due to hunting and the creep of civilization.
"If we only have 10 minutes to present this idea, people think we're nuts," Harry Greene, professor of ecology and evolutionary biology at Cornell, said in a prepared statement. "But if people hear the one-hour version, they realize they haven't thought about this as much as we have. Right now, we are investing all of our megafauna hopes on one continent--Africa."
Second, releasing predators back to the wild could help reset the environmental balance. Often, the disappearance of a predator will lead to changes that can reduce biodiversity.
For example, in the U.S., the near eradication of wolves and bears led to a population boom for elk. Because elk feed on willows, their increased feeding has led to a precipitous decline in the beaver population because beavers use willows for food as well as building material for dams.
The authors also theorized that introducing these animals in the wild could create quite a few adventure tourism jobs in the southwest and plains states.
A pilot study will test the rewilding notion by releasing the endangered Bolson tortoise on a private ranch in New Mexico. The tortoise, which can weigh up to 100 pounds and once thrived in Arizona, New Mexico, Texas and Mexico, now only survives in a small area of northern Mexico.