Nature 437, 951 (13 October 2005) | doi:10.1038/437951a; Published online 12 October 2005

Re-wilding: a bold plan that needs native megafauna

Martin A. Schlaepfer1

  1. (on behalf of TNC-Smith Fellows, classes 2003/4), University of Texas, Austin, Texas 78712, USA


In their Commentary article "Re-wilding North America" (Nature 436, 913–914; 2005), Josh Donlan and colleagues offer a vision of a North America populated with roaming throngs of megafauna such as cheetahs, elephants and tortoises. This is a welcome change from conservationists' too often reactive and rearguard action against a tidal wave of human impacts and extinctions. But the proposal neglects people's needs and political realities. Being bolder and more ambitious is the right idea — but Donlan and his colleagues have the wrong vision.

The Great Plains of North America are, in many areas, dominated by ranchlands and agricultural fields, as Steven Shay points out in Correspondence (Nature 437, 476; 200510.1038/437476b).

There are substantial social and economic problems associated with the presence of large animals on private lands, including, as the authors acknowledge, the enormous costs of building and maintaining fences to control them, as well as the environmental problems highlighted by Christopher Irwin Smith in Correspondence (Nature 437, 318; 200510.1038/437318a).

Most studies have shown that importing non-native species comes at huge economic and ecological cost.

A positive vision can catalyse a movement and generate real change, so it is critical for such visions to be grounded in reality.

As an alternative, we — 11 Smith postdoctoral fellows and three senior scientists with the Nature Conservancy (see — suggest that conservation efforts in North America should focus on restoring the megafauna native to this continent and ensuring that native species retain the evolutionary potential to adapt to novel environmental conditions, including those created by humans.

This approach, already adopted by the World Wildlife Fund and the American Prairie Foundation (see Nature 437, 476; 200510.1038/437476a), is more likely to be successful in the long run, as it respects the ecological conditions and environmental context to which these species are already adapted.