Pleistocene Re-wilding

We talked about Pleistocene re-wilding in my Natural History of the Southwest class last semester, and I CAN'T STOP THINKING ABOUT IT. The idea is this:

13,000 years ago, humans had a major hand in the extinction of North American megafauna. Ancestors of modern camels, giant tortoises, horses, elephants, cheetahs, and lions used to roam the American plains, before we emigrated here and hunted them. Now, the system is out of balance. Surviving American pronghorns, for example, who co-evolved alongside prehistoric cheetahs, are too well-adapted for their current predators. "Pests and weeds" like rats and dandelions have come to dominate the landscape, unmanaged by a failing sytem of ecological checks and balances. Etc.

And now--today--modern large animals (and mammals in particular) are facing extinction worldwide, but most noticably in troubled sub-Saharan Africa. Clearly this problem requires a paradigm shift. Modern conservation is largely reactive--trying to stop or halt extinction instead of "actively restoring natural processes." However, what if we were to try and reverse course, and bring these dying mammals--elephants, lions, cheetahs, etc.--back to their 'original' habitats where they can be better managed in giant wildlife refuges in North America? What if we were to try and be proactive, by re-thinking what words like 'original habitat' or 'ecosystem' really mean? If we really want to see lions, for example, survive into the next century, what are we willing to do to make it happen? What do we owe the planet, in return for what we have taken?

If we can return, not the 'original' animals, but at least suitable proxies (the African cheetah for the American cheetah) to the plains of North America, should we? Some scientists argue just that, based on four observations. 1) The Earth is nowhere pristine. Humans, and our technology, economics, politics, commercialism, etc., pervade everywhere. And human influence is tending to make things worse. 2) Environmentalism is generally an act of pessimism. And it is difficult to get people to pay attention to an issue when it is commonly seen as a lost cause, or that it is all "doom and gloom." 3) Some parts of the United States, like the Great Plains, are actually declining in population, creating vast areas of open space suitable for conservation. 4) Humans were at least partly to blame for these Pleistocene extinctions, and our current activities are curtailing the evolutionary potential of most remaining large vertebrates.

So why not? Why not start with small wildlife refuges populated by extant giant tortoises (now limited only to small areas in Mexico)? Well, it's already being done here in New Mexico. So what if that works out well, and the tortoises thrive, and the ecosystem thrives, and biodiversity rises? This is the proposition: taking small steps, seeing what works and what doesn't. Re-wilding does not mean the immediate release of wild lions just outside of Albuquerque. But, maybe, someday there could be a huge wildlife refuge 50 miles outside of town, where lions live free, along with camels and elephants, and people are actually excited about conservation. The local ecosystem wins, the lions win, and the economy wins, too (think of how many people visit the San Diego Zoo in a year).

Of course there are arguments on the other side. Safety, of course. And not just the surreal possibility of lion and cheetah attacks in the Jemez. New animals bring new diseases. But the biggest argument against re-wilding is that we simply don't know how it would work. Habitats do not remain static; how have things changed? Would these animals still 'work' here? And would human populations be accepting of such a drastic change?

I have no answers, as to whether this is a good idea or not. However, I do like what re-wilding makes me think about: What are we willing to do to save endangered animals, especially if things continue to get worse for them? In conservation planning--or, heck, in any sort of planning with a historical basis--how do we choose our benchmark to compare to? How much of our thinking is limited by what we can imagine, i.e., why is the thought of cheetahs and elephants prowling the West Mesa disconcerting, even though there are no "rules" that say it's impossible? And what is our ethical responsibility to the planet and to the other organisms that populate it?

I thought these sorts of questions were particularly relevant to our discussions of the future.


I cannot summarize the argument completely--please read the original article published in Nature, or many of the other online resources, to get the full story. Arguments against re-wilding are just as fascinating.