Pleistocene rewilding: an optimistic agenda for 21st century conservation. 2006. C. J. Donlan et al. The American Naturalist 168: 660–681.
A group of 12 ecologists and conservationists provide a detailed proposal for the restoration of North America's lost megafauna. Using the same species from different locales or closely related species as analogs, "Pleistocene Rewilding" is conceived as carefully managed experiments in an attempt to learn about and partially restore important natural processes to North American ecosystems that were present for millennia until humans played a significant role in their demise 13,000 years ago.
"Over the past 30 years, more and more evidence suggests that if we lose large animals from ecosystems, they often collapse and biodiversity, along with society, are the ultimate losers." Josh Donlan states, "for millions of years, large animals were the norm all over the world–perhaps we should start thinking about reintroducing these large animals and restoring these important processes back to ecosystems."