La Cucaracha
Well-Known Member
Although the AZA has already made a statement against using genetic technology for de-extinction, BioRescue and its partners continue making keen progress in de-extinction of the northern white rhinoceros. Through advanced reproductive technology, the long term goal is to reintroduce this all but extinct subspecies to Central Africa. Meanwhile in South Africa, the southern white rhinoceros often remains unsold at auction because of the high cost of security on game reserves to protect rhinos from poaching for horn-limiting their recovery in situ. Proposals have been made in the past by ex situ conservationists to breed rhinos on private reserves in Florida and Australia, but raised concerns about the impact of invasive species.
On islands such as Madagascar and Rodrigues, Aldabra giant tortoises are being used for rewilding where endemic giant tortoises were overhunted to extinction. They fill a long-vacant ecological niche as megafauna herbivores, similar to elephants; spreading and germinating seeds through digestion, controlling vegetation growth, fertilizing soil, and depending on age-as prey or carrion for endemic predators and scavengers. This is proxy rewilding.
The Great Plains ecosystem has been a man-altered landscape for millenia. Indigenous people traditionally used prescribed burning to provide habitat for game, and is still used by conservationists to manage prairie habitats today. Under the right circumstances, grazing domestic livestock acts as a proxy for migrating herds. Grazing activity can also sequester atmospheric carbon back into soil. Without human disturbances such as fire and grazing, the prairie would be a very different place than what groundnesting birds, migrating waterfowl, endemic pollinators, native flora, and other wildlife rely on. Often prairie restoration efforts involve rewilding bison within fenced areas. Why not then species that were present when man first arrived in North America, like the horse? Or even grassland giants like rhinoceros for a proxy of extinct megafauna, such as Mixotoxodon.
Humans hunt fourteen times more adult prey animals, and nine times more apex predators, than other carnivores. Because of slow sexual maturity, long gestation periods, and single births, megafauna are vulnerable to extinction from overhunting. Archeological evidence shows humans hunted and ate ancient megafauna. Computer simulations suggest overhunting played a factor in late Pleistocene mass extinctions. By the Holocene, some regions such as South America and Australia experienced loss in megafauna diversity as high as almost 90% after human arrival. Today, wild animals only make up about 3% of all mammal biomass.
“In habitat-based zoo plans, as opposed to taxonomic layouts, ecological areas are subdivided by geography. A section devoted to grasslands, for example, would not sensibly display rhinos, pronghorns, and kangaroos together, in spite of their all being grassland species, because they are from Africa, North America, and Australia respectively. It is useful, however, to also remember zoogeography offers merely a transitory view. Marsupials are now characteristically Australian, and rhinoceroses are characteristically African (although they arrived later there than anywhere else). But marsupials and rhinos originated in North America, about 120 million years ago. Elephants once ranged the entire globe, apart from Australia, including (in form of mammoths) North America until just a few thousand years ago. Modern elephants originated in Asia and migrated to Africa. Lions once ranged throughout Eurasia and deep into China. By definition of origin, neither elephants nor lions are African animals. Wild animal populations are not placed in or restricted to some particular geographic area. They live in a dynamic planet. Where we discover them is merely where they happen to be during our time on Earth. Colin Tudge (1995) speaks of ‘cascades of animals migrating, radiating, moving on or drifting back from whence they came.’”, quotes retired zoo director and architect David Hancocks, in A Different Nature: The Paradoxical World of Zoos and Their Uncertain Future.
On islands such as Madagascar and Rodrigues, Aldabra giant tortoises are being used for rewilding where endemic giant tortoises were overhunted to extinction. They fill a long-vacant ecological niche as megafauna herbivores, similar to elephants; spreading and germinating seeds through digestion, controlling vegetation growth, fertilizing soil, and depending on age-as prey or carrion for endemic predators and scavengers. This is proxy rewilding.
The Great Plains ecosystem has been a man-altered landscape for millenia. Indigenous people traditionally used prescribed burning to provide habitat for game, and is still used by conservationists to manage prairie habitats today. Under the right circumstances, grazing domestic livestock acts as a proxy for migrating herds. Grazing activity can also sequester atmospheric carbon back into soil. Without human disturbances such as fire and grazing, the prairie would be a very different place than what groundnesting birds, migrating waterfowl, endemic pollinators, native flora, and other wildlife rely on. Often prairie restoration efforts involve rewilding bison within fenced areas. Why not then species that were present when man first arrived in North America, like the horse? Or even grassland giants like rhinoceros for a proxy of extinct megafauna, such as Mixotoxodon.
Humans hunt fourteen times more adult prey animals, and nine times more apex predators, than other carnivores. Because of slow sexual maturity, long gestation periods, and single births, megafauna are vulnerable to extinction from overhunting. Archeological evidence shows humans hunted and ate ancient megafauna. Computer simulations suggest overhunting played a factor in late Pleistocene mass extinctions. By the Holocene, some regions such as South America and Australia experienced loss in megafauna diversity as high as almost 90% after human arrival. Today, wild animals only make up about 3% of all mammal biomass.
“In habitat-based zoo plans, as opposed to taxonomic layouts, ecological areas are subdivided by geography. A section devoted to grasslands, for example, would not sensibly display rhinos, pronghorns, and kangaroos together, in spite of their all being grassland species, because they are from Africa, North America, and Australia respectively. It is useful, however, to also remember zoogeography offers merely a transitory view. Marsupials are now characteristically Australian, and rhinoceroses are characteristically African (although they arrived later there than anywhere else). But marsupials and rhinos originated in North America, about 120 million years ago. Elephants once ranged the entire globe, apart from Australia, including (in form of mammoths) North America until just a few thousand years ago. Modern elephants originated in Asia and migrated to Africa. Lions once ranged throughout Eurasia and deep into China. By definition of origin, neither elephants nor lions are African animals. Wild animal populations are not placed in or restricted to some particular geographic area. They live in a dynamic planet. Where we discover them is merely where they happen to be during our time on Earth. Colin Tudge (1995) speaks of ‘cascades of animals migrating, radiating, moving on or drifting back from whence they came.’”, quotes retired zoo director and architect David Hancocks, in A Different Nature: The Paradoxical World of Zoos and Their Uncertain Future.
