Is rewilding of modern species a good idea? The answer: sometimes

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Building off of my previous rant against the idea of pleistocene rewilding I would like to discuss the idea of rewilding modern species. Unlike pleistocene rewilding, which suggests modern descendants of ice age megafauna should be introduced to habitats where their ancestors roamed, modern rewilding involves reintroducing an extirpated species, or at least a closely related subspecies, into an ecosystem which it was known to live in recent times. Probably the greatest example of this would be the reintroduction of wolves to the American west. Since most  gray wolf populations were completely eradicated from the lower 48 a closely related subspecies of gray wolf was brought in from Canada to repopulate American parks such as Yellowstone.

Unlike pleistocene rewilding this effort should not upset the ecological balance of habitats these modern species are reintroduced to. These species have evolved in these ecosystems and the ecosystem relies on them for certain services. Continuing with my gray wolf example, in the absence of wolves prey species exploded in population. These increased populations began to destroy their habitats, literally eating themselves out of house and home as there was no predator efficient enough to keep their populations in check. Restoring wolves to these habitats has returned the natural balance. Prey populations have fallen to more natural, sustainable levels and the plant community has begun to rebound.

While I still contend that pleistocene rewilding is a terrible idea, modern rewilding can be beneficial. However, I do not recommend we place modern rewilding as the highest priority. Some areas should strive for this if it is necessary to restore the habitat and there are no greater conservation concerns upon which they should focus. For example, I do not believe India should focus so much of its time and resources on the rewilding of cheetahs when the protection of their tigers and rhinos from poaching should be their highest concern at this time.

Additional Readings:

The first wolf family in Denmark since centuries? » Rewilding Europe A new beginning. For wildlife. For us.

Project to ship cheetahs from Africa to India totally misconceived – Telegraph.

WII Plans Rs 260 Crore Project for Reintroducing Cheetah in India – The New Indian Express.

African cheetah sourced for reintroduction to India – Big Cat Rescue.

Cheetah reintroduction stirs up debate – The Times of India.

Pleistocene Rewilding: Is it really a good idea?

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Recently a concept known as pleistocene rewilding has arisen within the conservation community. This idea is the cause of great controversy as it suggests we should introduce descendants of extinct pleistocene megafauna to ecosystems where their ancestors once roamed. This would mean releasing species such as lions (Panthera leo), tigers (Panthera tigris), and elephants (Loxodonta africana) into the Great Plains region of North America or bringing a species of rhino into Europe.

While restoring species to an ecosystem in which they, or at least their ancestors, evolved may seem like a good idea at first we must take a closer look at the implications of such an action. These species have been absent from these habitats for thousands of years, most since the end of the last ice age. These systems have continued to evolve without these species. In many places new species have arisen to fill the ecological void left by the extinction of these ancient species. Sure, there are examples of niches which have not been filled (for instance, no predator other than man has found a way to hunt the American pronghorn since the extinction of the American cheetah), but this does not mean we should intervene. More often than not introductions of species do not end well. I of course must cite the example of introduced species such as pythons and kudzu.

Some argue that it was the actions of ancient humans rather than natural selection which pushed these species into extinction. Whether this is true or not it does not justify the introduction of their modern descendants into ecosystems which have adapted to the lack of these pleistocene megafauna. Currently we have greater conservation issues at hand such as deforestation, poaching of rhinos, declining grassland birds, and deterioration of reefs to worry about something frivolous like pleistocene rewilding.

Additional readings:

Bringing wild rhinos into Europe proposal “red herring and won’t fly” – News – News – Voice of Russia UK, Voice of Russia – UK Edition.

Pleistocene Rewilding– in North America

Pleistocene Rewilding, Frankenstein Ecosystems, and an Alternative Conservation Agenda – Oliveira-Santos – 2010 – Conservation Biology – Wiley Online Library.

JSTOR: The American Naturalist, Vol. 168, No. 5 November 2006, pp. 660-681.

Rants from the Hill: Pleistocene rewilding — High Country News.

Movers, Shakers, and Habitat Shapers: A tribute to keystone species

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All species have an intrinsic value to them. However, from an ecological standpoint there are some species which are more valuable due to their effects on their ecosystems. This is not to say we should not appreciate all species or only work to conserve the “more important” species. The species I am referring to our known as keystone species; a species that has a disproportionately large effect on its habitat compared to its population size. So I would like to take a moment to recognize the function and value of those keystone species that help build and maintain ecosystems so all species in that system may thrive.

As an Africa buff the first image in my head when I think about keystone species is the African elephant, Loxodonta africana. These large pachyderms trample trees and shrubs as they forage literally beating the forests into submission to create open grasslands. This opening of savannas allows Africa’s ecosystems to support the vast herds of zebra, impala, and wildebeest that the continent is so famous for. In turn, greater prey abundance allows for larger numbers of predators and scavengers. Thus the sustainability of Africa’s ecosystems is largely dependent on elephants.

Here in the US one of our greatest examples of a keystone species is the gray wolf, Canis lupus. Before humans pushed wolves to the brink of extinction this species played a major role in keeping deer  numbers at sustainable levels. When the wolves were removed from most of their habitat range deer populations exploded. This lead to over browsing, essentially the deer ate themselves into starvation. Ecosystems such as Yellowstone were in noticeably poor health due to this overpopulation. I believe Aldo Leopold summed up this issue best when he said, “just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer.” It is for this reason wolves were originally reintroduced to many areas, so they may once again keep prey populations in check.

Keystone species are an important part of maintaining healthy ecosystems. Without them habitats would quickly become ill. However, this does not mean these species should be allowed to continue unchecked. Just as these species can build or maintain ecosystems they can also destroy them. Wolves can become too numerous and deplete prey species. If they become over populated elephants can completely remove all forests from an ecosystem and trample grasslands into bare dirt; leaving themselves and all other species which rely on these habitats starving and without shelter. As the ultimate keystone species it is our responsibility as humans to maintain balance. We must protect keystone species so they may thrive, but we must also be willing to knock their numbers back down when they become overly abundant.

Related readings:

Here’s What Might Happen to Local Ecosystems If All the Rhinos Disappear | Articles | Smithsonian.

keystone species – National Geographic Education.

keystone species (ecology) — Encyclopedia Britannica.





AOL.com Video – Monster Goldfish Are Breeding in Lake Tahoe

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Don’t flush your goldfish. Better yet do not turn any pet out into the wild. If you cannot take care of it give it to someone that can or have it put down. Turning domesticated or exotic pets out into the wild only causes problems within the local ecosystem. If the goldfish link does not convince you of this I recommend you do some research into the damage caused by pythons in the Everglades or the devastation of Hawaii’s honey creepers by non-native predators such cats and snakes.

AOL.com Video – Monster Goldfish Are Breeding in Lake Tahoe.

Wildlife officials looking for escaped Nile crocodile – KeysNet.com

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The Everglades are becoming a giant experiment in how non-native species can destroy an ecosystem. First pythons and now nile crocodiles. Hopefully officials can get this resolved before it gets out of hand.

Wildlife officials looking for escaped Nile crocodile – KeysNet.com.