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Dave Foreman selects and reviews them—and recommends the most important.


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Pleistocene Rewilding

Ecological Wounds of North America

TRI Comments on Mexican Gray Wolf Project

The Pleistocene-Holocene Event:
The Sixth Great Extinction

Books Available from the Rewilding Institute

Rewilding North America
by Dave Foreman

Lobo Outback Funeral Home:
A Sexy Novel About Conservation Biology!

Continental Conservation:
Scientific Foundations of Regional Reserve Networks

What is Continental Conservation and Rewilding?

Click Here For A Primer!





Here, we outline a bold plan for preserving some of our global megafaunal heritage — one that aims to restore some of the evolutionary and ecological potential that was lost 13,000 years ago, and which offers an alternative vision for twenty-first century conservation biology.

--Josh Donlan, et al. 

Pleistocene Rewilding 

pleistoceneWhen paleontologists look at the North and South American large animal fauna of the late Pleistocene (50,000 to 10,000 years ago) and then compare it with that in Africa and Asia, something immediately leaps out: the Americas and Africa and Asia are comparable in the number of species weighing 100 pounds or more. 

When mammologists and other zoologists look at today’s large animal fauna in North America and then compare it with those of Africa or Asia, something else immediately leaps out: North America is greatly lacking in the number of species weighing 100 pounds or more. 

What gives?  Why the precipitous decline in large critters in the Americas? 

The most reasonable answer is that when behaviorally modern humans, who were skilled big-game hunters, spread to the New World about 13,000 years ago they disproportionately slaughtered big animals and drove many species into extinction in those parts of the world where big animals lacked experience with such a predator.  Some of those big animals were classic keystone species having disproportionate effects on their ecosystems.  Thus their loss precipitated a wave of secondary extinctions. 

Of living kinds of horses, Prezwalski’s Horse, or the P. Horse, is the closest to the horse found in North America 13,000 years ago.  Surviving P. Horses lived on the steppes of Asia, including the vast, wild plains of Mongolia.  They nearly became extinct in the nineteenth and twentieth centuries, but captive breeding has increased numbers to a couple of thousand.  Many of these are in the United States with the largest single group on private ranch land on the high steppes of northeastern New Mexico, where this photo was taken.  The Sangre de Cristo Range of the Rocky Mountains rises in the background.  Tentative plans are being discussed to bring P. horses, bison, elk, pronghorn, and maybe llamas together on a private ecological research ranch in northeastern New Mexico to study the ecological interactions of this group of herbivores that have not been together for 13,000 years.  Photo by Dave Foreman. 

Prezwalski’s Horses don’t look like domestic or feral horses.  They look like they should be hanging out with mammoths.  Photo by Dave Foreman.

Given that the several thousand years since those extinctions are but an eye-blink in geological and ecological time, it stands to reason that the New World is still reeling from the draconian loss of big animals.  Therefore, it becomes reasonable to at least ponder the possibility of carefully restoring appropriate big animals to North America from Asia and Africa to see if they have beneficial impacts on truncated ecosystems and to study whether such beasts, some of which are highly imperiled in their current homes, might find secure homes where their relatives once flourished. 

One would also assume that the most visionary paleontologists and conservation biologists would have already figured this out. 

Indeed, they have. 

And we call it Pleistocene Rewilding. 

After meeting at the Ladder Ranch in New Mexico, a group under the lead of Josh Donlan at Cornell University and including Paul Martin and Michael Soulé prepared two articles on Pleistocene Rewilding: a short one in Nature and a longer, more detailed one in the America Naturalist. Both are available as PDFs on this page, as are stunning displays of what Pleistocene Rewilding might look like by sculptor Sergio de la Rosa. Josh Donlan has also written popular articles on Pleistocene Rewilding in Slate, Grist, and Scientific American. 

Think big, think long, think deep. 

--Dave Foreman


      More resources will be added to this page as they become available. 


      Twilight Of The Mammoths: Ice Age Extinctions and the Rewilding of America by Paul S. Martin (University of California Press, Berkeley, 2005).  Paul Martin traces his career as a paleontologist seeking the whodunit truth about the extinction of North America’s megafauna 13,000 years ago, and makes a thoughtful yet passionate call to restore the ecological richness and evolutionary potential of North America by returning the ecological equivalents of North America’s lost camels, elephants, cheetahs, lions, horses, and other large species.

      The Ghosts of Evolution: Nonsensical Fruit, Missing Partners, and Other Ecological Anachronisms by Connie Barlow (Basic Books, New York, 2000).  By looking at odd, rare plants, whose fruits are no longer being dispersed, Barlow shows how the extinction of the North American megafauna discombobulated ecosystems and ecological and evolutionary processes throughout the continent.

      Quaternary Extinctions edited by Paul S. Martin and Richard G. Klein (University of Arizona Press 1984). A magnificent anthology discussing the role of Stone Age humans in causing the Pleistocene megafauna extinctions. Paul Martin’s chapter “Prehistoric Overkill: The Global Model” is one of the most important scientific papers of the last 50 years.

      The Call of Distant Mammoths: Why the Ice Age Mammals Disappeared by Peter D. Ward.  Ward, a distinguished paleontologist at the University of Washington, gives a clear, highly readable study of mass extinctions and their causes.  His main focus is the Pleistocene extinction, however, and by drawing on a sweep of research he makes a solid, convincing case that humans caused the extinction of megafauna around the world.  Copernicus, New York, 1997. 


      Available as a PDF:

      Josh Donlan, Harry W. Greene, Joel Berger, Carl E. Bock, Jane H. Bock, David A. Burney, James A. Estes, Dave Foreman, Paul S. Martin, Gary W. Roemer, Felisa A. Smith, and Michael E. Soulè, “Re-wilding North America,” Nature, Vol. 436, No. 18, August 2005, 913-914.

      Josh Donlan, Joel Berger, Carl E. Bock, Jane H. Bock, David A. Burney, James A. Estes, Dave Foreman, Paul S. Martin, Gary W. Roemer, Felisa A. Smith, Michael E. Soulé, and Harry W. Greene, “Pleistocene Rewilding: An Optimistic Agenda for Twenty-First Century Conservation.” The American Naturalist, Vol. 168, No. 5, November 2006, 660-681.  This article is the basic document for Pleistocene Rewilding, with several illustrations and a boatload of references.

      Josh Donlan, “Claws and Effects,” Grist, November 8, 2005.

      Josh Donlan, “Lions and Cheetahs and Elephants, Oh My!Slate, August 18, 2005. 

      Not yet available as a PDF:

      Paul S. Martin and David Burney, “Bring Back the Elephants!” Wild Earth, Spring 1999, 57-64.

      Connie Barlow, “Rewilding for Evolution,” Wild Earth, Spring 1999, 53-56.

      “Serengeti in the Dakotas,” editorial, Scientific American, June 2007, 8.

      C. Josh Donlan, “Restoring America’s Big, Wild Animals,” Scientific American, June 2007, 70-77. 

Introduction for Sergio de la Rosa’s Gallery of Pleistocene Rewilding:

No artist has thus far been so captivated by the excitement and vision of Pleistocene Rewilding as has Sergio de la Rosa.  He has artistically recreated the guilds of Pleistocene large carnivores around the world and what new guilds taken from existing species around the world might look like in North America.  Sergio also created the stunning and captivating masthead for the Rewilding Website.  We are pleased to offer for your inspiration and fascination a Gallery of Pleistocene Carnivores from renowned artist Sergio de la Rosa.



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