Saturday, April 02, 2011

Pleistocene Rewilding: its not what it sounds like

Or, perhaps it is what it sounds like. The idea: "reinstituting ecological and evolutionary processes that were transformed or eliminated by megafaunal extinctions" (Donlan et al 661). The main reason for wanting to "re-wild" places that lost their megafauna (what scientists like to call large animals) due to various pressures is that since the demise of these animals, the ecosystems have been out of balance (Caro 281).

North American megafauna aren't available, but several authors have suggested that other species could serve as surrogates for the extinct animals, for example, endangered Bactrian camels for the camelids that used to reside here, or Asian elephants for the North American mammoth (Donlan et al 666-671).

Why am I interested in this when I'm not an ecologist, a vertebrate biologist, or a geologist interested in the Ice Age? I grew up visiting National Parks with my family and as an adult am a member of the National Parks Foundation and the Yellowstone Association. I visited Yellowstone National Park for the first time last year, heading up there the day after my PhD commencement. A really big attraction we have for Yellowstone is the chance to see larger animals -- and we did see quite a few, mostly buffalo, elf, deer, and moose. We did not see wolves, but overhead a lot of people talking about their sightings. Even though we don't seem to understand that our very presence in the park changes the behavior of the animals, we still want to go and get a glimpse of them. Here is my photo of a grouping of buffalo in the early morning:

Growing up in the Los Angeles area brought me into contact with the La Brea Tar Pits when I was about 9 or 10. The idea that mastodons, sabertooth cats, dire wolves, ground sloths, giant short-faced bears, and many other species used to roam the LA basin was one of my early educational experiences that showed me that the earth was a lot older than I was being taught in Sunday School.

I'll also point out that Homo neandertalensis went extinct around the same time as America's megafauna (though on different continents). The science isn't clear what happened to the megafauna or to the Neandertal, though we know part of the Neandertal genome survived in modern humans, thanks to some now obvious inter-breeding. Theories regarding Pleistocene extinctions vary from climate change to a large meteor/cometary impact. Some scientists are sure that humans didn't "overkill" the megafauna to extinction, though that theory has enough traction to be part of the rationale for rewilding programs.

I really can't speak to the idea of Pleistocene rewilding from a scientific standpoint; it's not my field. From a mythologist's viewpoint, there is something romantic about recreating the past in the present, in this case trying to recreate (or just approximate) an ecological system we have never seen ("we" meaning modern humans), one that existed 13,000 or so years ago. There is a little bit of a "back to the Garden" aspect in the idea of rewilding, even when couched in technical ecological concepts. There is a hubris in the thinking that we understand a natural system so well that we can tinker with it, even with all of the careful monitoring and pilot studies outlined.

While one of the papers observes that "Humans have strong emotional and cultural relationships with large predators and herbivores that began in the Pleistocene and have reached forward to contemporary times" it goes on to mention "ancient rock art, cars, and sports teams," but this seems to me to be a pretty thin argument (Donlan et al 666).  Continued loss of biodiversity is a tragedy most of us would agree impoverishes nature and would like to see reversed. That diversity may possibly be maintained in new environments, even if those species did not evolve there, but there are many uncertainties in such a rewilding program. Suggested reading is below and I do recommend spending some time with the rewilding idea and some of the counter-arguments contained.

Pleistocene Rewilding References and Links
The Rewilding Institute --  TRI has three broad goals:
1) To effectively integrate conservation biology and wildlands and wildlife conservation.
2) To provide a long-term, hopeful vision for conservation in North America.
3) To create a North American Wildlands Network Vision and a strategy to implement it.
You'll find even more resources and links at TRI's Resource page.
Pleistocene Park -- LiveScience story about a preserve in northern Siberia where a number of species have been re-introduced, and not just megafauna.

Rewilding Megafauna: Lions and Camels in North America?'s informative and well-rounded interview with Connie Barlow discussing the idea of Pleistocene rewilding (if the science papers bore you, read this instead). There are a lot of resources and outlinks on this page as well.


Anonymous said...

One of the first steps towards rewilding is to get the BLM to end it's campaign to exterminate wild horses and burros. They evolved in North America and are a natural part of our landscape-even though they were absent from 13,000ya until about 500 ya.

Chris said...

If you take a look at Paul S. Martin's book "Twilight of the Mammoth," he includes a really extensive list of animals that went extinct but are candidates, and the equids are well-represented. In a way, the feral burros and horses ARE a rewilding population, they're even Old World introduced species.

I can't imagine BLM being ever interested in rewilding, as they are all about using the land (meaning people). If rewilding is to happen, I see it happening with private land and private funding.