[Robert Siegel:] From Nature magazine comes an extraordinary proposal. How about a home where the buffalo roam and the deer and the antelope play for some of those critters' bigger and more exotic cousins: elephants, lions, camels, African cheetahs? Cornell University ecologist Josh Donlan is the lead author of a piece in nature called Re-wilding North America. The `re'is in there because those animals-the lions and the elephants-had distant relatives that lived on this continent some 13,000 years ago, during the Pleistocene.
[Mr. Josh Donlan:] Our vision begins immediately and spans the coming century. When we talk about the now, we're advocating bringing back large tortoises that were once present in North America 13,000 years ago and are now restricted and critically endangered in a small part of North America. And that moves on forward in time, in terms of the vision, talking about treating horses as ecological analogs for the 13 species of horses that were present in the late Pleistocene, and on to elephants and cheetah and lions, all of which were present and played a very important role in North American ecosystems.
[Robert Siegel:] How do you answer the problem of the rancher who has enough problems with mad cow disease already, think, you know, `Well, the last thing I need is to have wild predators around in the environment who are going to be taking a calf now and again'?
[Mr. Josh Donlan:] Right. That is a huge cultural obstacle in terms of convincing people the benefits of having predators on the landscape. I can give you an example in terms of elephants and camels.
[Robert Siegel:] Mm-hmm.
[Mr. Josh Donlan:] We know now in the southwestern United States that woody species-that is mesquite, creosote and other bushes-are overtaking and replacing the grasslands of the Southwest. This is a very serious threat, not only to biodiversity, but it's also an economic threat to ranchers. One might ask if Asian or African elephants can serve as a proxy for the five species of elephants we had in North America, perhaps they can knock back these woody species that happen to be overtaking the grasslands of the Southwest, a threat to biodiversity, but also an economic threat to ranchers.
[Robert Siegel:] If we, in fact, did reintroduce elephants or lions or camels to wild areas in the American Plains, would they have a dramatic effect on the environment with respect to other species that we enjoy having around? In other words, would they, in turn, prey upon other animals, not just the livestock, but other wild creatures, which would disappear because we've introduced these bigger-or, as you say, megafauna-into the American environment?
[Mr. Josh Donlan:] Well, it's clear that there is the definite possibility for unexpected ecological consequences. Having said that, we do know from decades of research now that large vertebrates-that is, large herbivores and large predators-often play a disproportionate role in an ecosystem in terms of structuring the ecosystem and in terms of maintaining biodiversity. We know that from long-term studies in Africa; we also know that from long-term studies in North America and elsewhere.
[Robert Siegel:] What kind of feedback have you gotten to your article today?
[Mr. Josh Donlan:] One of the main purposes of putting forth this plan and putting out this paper is to invoke a debate: to get people thinking about ecological history, to get people thinking about ecological function and to address the inconsistencies in our conservation strategies. I think it's obviously going to be highly controversial, but we hope it'll get people talking.
[Robert Siegel:] So people talking right now might be a more likely result of the paper than elephants braying in Oklahoma anytime soon.
[Mr. Josh Donlan:] Time will see.
[Robert Siegel:] Well, Josh Donlan, thanks a lot for talking with us about it, in any case.
[Mr. Josh Donlan:] Thanks for having me.
[Robert Siegel:] Mr. Donlan, who is an ecologist at Cornell University, is the author of an article in Nature magazine titled Re-wilding North America. He spoke to us from Flagstaff, Arizona.
[Michele Norris:] This is NPR, National Public Radio.