Pleistocene Rewilding - Recreating A Lost Ecosystem

Recreating A Lost Ecosystem

In order for a functioning and balanced ecosystem to exist, there must be carnivores that prey on the herbivores. In the mountains, the reintroduction of the mountain lion is necessary to keep mountainous herbivores such as the camelids, asses and mountain goats under control.

In the forest surrounding them, the reintroduction of the jaguar (which roamed much of southwestern America until recently) will control the populations of animals such as deer, tapirs and peccary. Alongside the jaguar will be the grizzly bear, an omnivore which was once distributed across North America but now survives only in the far north of the US and much of western and northwestern Canada. In heavily-forested areas, the Siberian tiger and dhole will be introduced to control the populations of deer, wild asses, camels, bighorns, and mountain goats.

In arid regions the Old World cheetah could be introduced to control the population of pronghorn, the fastest-running herbivore on earth (it can run so fast because it was once hunted by the American cheetah). The American cheetah was more closely related to the mountain lion, but evolved in a similar way to the Old World cheetah (an example of convergent evolution).

Reintroduced into its ancient environment, the grey wolf will spread across all ecosystems and compete for prey with all other predators; it may once again be seen hunting camels in arid regions, and bison on the grassy prairies of the Great Plains.

The final (and most-controversial) aspect of the rewilding project is the reintroduction of lions to the American southwest. Whilst many consider the lion to be a strictly an African species, this was not always true. The lion was, in fact, one of the most widespread of all megafauna (certainly of the carnivores). The lion once ranged from Africa through Pleistocene Europe and Asia, across Beringia and down through North America to Argentina in South America. A relict remnant of that distribution across the world is still found in India, where the Asiatic lion still survives in a small sanctuary in Gir Forest National Park. In Europe and northern Asia it existed as the cave lion, and in the Americas as the American lion. The American lion once hunted in prides across the grasslands of Pleistocene North America, taking down bison and wild horses as their African equivalents take down wildebeest and zebra. The reintroduction of lions is, however, the end of a long line of reintroductions, and will only have realistic prospects of occurring if all goes well with the others first.

The Pleistocene parks idea was first suggested for Arctic and South American ecosystems, and was less publicized. Mauro Galetti suggested that several plant species in South America lost their major megafauna seed dispersers at the end of the Pleistocene. Secondary seed dispersal, water and indigenous people were responsible for maintaining the seed-dispersal process over the past 10,000 years. Therefore, rewilding South American savannas will establish lost seed-dispersal services and also control unburned vegetation (due to a lack of megaherbivores). Brazilian savannas burn and release tons of carbon dioxide to the atmosphere yearly. Asian elephants, horses, llamas and other large mammals may be used to control fires.