Pleistocene Rewilding - Possible Fauna For Reintroduction

Possible Fauna For Reintroduction

The Pleistocene rewilding project aims at the promotion of extant fauna and the reintroduction of extinct genera in the southwestern United States. Native fauna are the first genera for reintroduction. The Bolson tortoise was widespread during the Pleistocene era, and continued to be common during the Holocene epoch until recent times. Its reintroduction from northern Mexico would be a necessary step to recreate the soil humidity present in the Pleistocene, which would support grassland and extant shrub-land and provide the habitat required for the herbivores set for reintroduction. However, to be successful, ecologists will support fauna already present in the region.

The pronghorn, which is extant in most of the US southwest after almost becoming extinct, is a candidate for the revival of the ancient ecosystem. The pronghorn are native to the region, which once supported large numbers of the species and extinct relatives from the same genus. It would occupy the more arid and mountainous ecosystems within the assigned area.

The plains bison numbered in the millions during the Pleistocene era, until European settlers drove them to near-extinction in the late 19th century. The bison has made a recovery in many regions of its former range, and is involved in several local rewilding projects across the Midwestern United States.

Bighorn sheep and mountain goats are already present in the surrounding mountainous areas and therefore should not pose a problem in rewilding more mountainous areas. Reintroducing extant species of deer to the more forested areas of the region would be beneficial for the ecosystems they occupy, providing rich nutrients for the forested regions and helping to maintain them. These species include white-tailed and mule deer.

Herbivorous species considered beneficial for the regional ecosystems include the collared peccary, a species of New World wild pig which was abundant in the Pleistocene. Although this species (along with the flat-headed and long-nosed peccaries) are extinct(wrong, collared peccary is not extinct), their relatives survive in Central and South America. The horse which is today extant as the mustang is, in fact, a native species reintroduced by the Spanish in the 15th century. Horses originated in North America and spread to Asia via the Ice Age land bridge, but became extinct in their evolutionary homeland alongside the mammoth and ground sloth. The Pleistocene grasslands of North America were the birthplace of the modern horse, and by extension the wild horse. The only remaining species of wild horse is a part of the prairie ecosystem and grazes alongside bison. The plains were home to an equid resembling a zebra, called the Hagerman Horse, which could be represented by the plains zebra. It would be introduced into the Great Plains from Africa as part of the project. The mountainous region was also once home to the extinct Yukon Wild Donkey but its close relative (the onager) survives in central Asia today, and can be reintroduced to boost biodiversity in the more arid regions of the rewilding area.

Alongside the wild donkey, camels evolved in the drier regions of North America. Proof of this can be seen in the camelids of South America: the llama, alpaca, guanaco and vicuna. North America, therefore, links the South American camelids with those of the Old World (the dromedary and Bactrian camel). Pleistocene rewilding suggests that the closest relatives of the North American species of camel (Camelops) be reintroduced. The best candidates would be the dromedary for the arid desert regions and the guanaco or vicuna in the arid mountain regions, but there have been suggestions of breeding and wilding the fertile hybrid camelids (Cama).

During the Pleistocene there existed two species of tapir in North America: the California and Florida tapirs. They became extinct at the end of the Pleistocene era, but their relatives survive in South America. The mountain tapir would be an excellent choice for rewilding humid areas, such as those near lakes and rivers. The mountain tapir is the only non-tropical species of tapir extant.

During the Pleistocene large populations of Proboscideans lived in North America, such as the Columbian mammoth, the Imperial Mammoth, and the American mastodon. The mastodons all became extinct at the end of the Pleistocene era, as did the mammoths of North America. However, an extant relative of the mammoth is the Asian elephant. It now resides only in tropical southeastern Asia but the fossil record shows it much more widespread, living in temperate northern China as well as the Middle East (an area bearing an ecological similarity to the southwestern United States). The Asian elephant is, therefore, a good candidate for the Pleistocene rewilding project. It would probably best be suited to occupy the same humid areas as the tapir, as well as dense forest regions where it would cause soil regeneration and control the spread of forests. Meanwhile the African elephant may be the best extant candidate to refill the niche left empty with the extinction of the mastodon.

During the Pleistocene era North, Central and South America were populated with a group of large animals which moved north as part of the Great American Interchange caused by the junction of the North and South American continents. Today species such as the ground sloth and glyptodon are extinct, although a few "dwarf" species of sloth survived in remote Caribbean-island forests until a few thousand years ago. Their close relatives, the tree sloths and armadillos, are a remnant of this once-diverse group of mammals. The reintroduction of armadillos (such as the nine-banded armadillo and the giant armadillo) could help regenerate soils in the arid and prairie regions of the rewilding project. Other relatives, such as the giant anteater, have also been proposed.

Pleistocene America boasted a wide variety of dangerous carnivores (most of which are extinct today), such as the short-faced bear, saber-toothed cat, Homotherium, the American lion, dire wolf, American cheetah and (possibly) the terror bird. Some carnivores and omnivores survived the end of the Pleistocene era and were widespread in North America until Europeans arrived, such as grizzly bears, mountain lions, jaguars, grey and red wolves, bobcats, and coyotes.