Now I read an article, On Newsweek [link]

The Europeans are doing something called, "Pleistocene Rewilding" at first I thought, WTF???

And then I read that introducing American beavers actually help Britain's dwindling wetland ecosystems. The article said beavers build dams needed for a wetland environment, but when humans intervened, it is becoming much harder to conserve these lands (no surprise though, humans have fucked up ecosystems, since 10,000 B.C)

And then I learned, Americans and Russians were already trying out these projects before the Europeans.
Here are two links

American: [link]

Russian: [link]

And then I thought to myself, this is suprisingly plausible.

The Americans already released the currently endangered (or to be more precise, Vulnerable) Bolson Tortoise. They are also introducing the mustang and wild boar (both considered vermin, especially in the south) into the Great Plains. And the upside is, they are feeling right at home. They are even introducing camelids, and in Australia, they found out that Dromedaries can go wild in weeks, that's faster than most feral horses. This raises confidence that camels can roam the states with ease.

The Russian's equivalent also involves cloning, on National Geographic, a frozen mammoth baby, had so much DNA, it helped scientists complete 70% of the Mammoth DNA sequence. Like the Americans, Horses have already been introduced, but also moose.

Now in my perspective this a very plausible, maybe a good idea. For example feral horses and wild boar are thriving, and became a nuisance, because the United States lacks animals swift and powerful enough to take down these animals. The Brown bear is too slow to catch horses, as mustangs not only have high stamina, but is much faster than the brown bear even though the bear can reach speeds of up to 26mph, plus the bear is an omnivore, eating large amounts plant material as well as meat. Wolfs and cougars are also inefficient at killing both the horse and the boar, they are social, the boar lives in groups about the same size as wolf packs and are stronger than both cougar and wolf, while horse is fast and has a kick strong enough to kill a cougar and a wolf.

Introducing animals that can kill fast, high stamina prey efficiently would help keep horse and pig population in check.

The United States would benefit having elephants in a way that they keep forests in check, as there is no herbivore that is strong enough or large enough to keep forest areas from becoming too large

Another benefit of rewilding is tourism, everybody loves to see big and exotic animals roam, especially children, and now since the animals they loved since childhood are in their own country instead of another continent, tourism would no doubt increase.

However I have one criticism, how will the current ecosystem cope with the new one?

Now lets see, since Russia's ecosystem is quite stable, lets use the United States for an example:

Large Herbivores:
Bison, Equids, Several kinds of deer

Large Carnivores/Omnivores:
Grey wolf, Brown and Black Bears, Cougar

The herbivores being introduced each have their own specific diet, so competition between them would be very minimal, carnivores on the other hand, are a completely different story.

I'm not worried with the bears, they are omnivorous, so they can adapt to any source of food available. They are also large and strong enough to cope with new large predators, in Russia, the brown bear has no problem competing with Siberian Tigers, and they fight back when tigers come to steal their kills. If lions were introduced, it is most likely that the large and intimidating bear would probably scare of the lions, or they just fight the lions.

I'm not worried with the cougar either, they are by far the most adaptable of the group, they can live anywhere in the United States. They can scavenge, they can hunt, they can stay away from trouble with ease, pretty much like leopards.

The wolf however, is going to find it very hard to survive. Contrary to the hardcore DA wolf fanboys/fangirls, wolves are the most vulnerable large predator in the US. In Russia, Tigers, actually wipe off wolves from the ecosystem, because they are larger, stronger, more aggressive, and can take on several enemies at once. Lions can do the exact same thing, however, they live in groups, increasing competition against the wolf. A major handicap to the wolf is that today, their packs aren't even half as large as they were in 11,000 B.C. These mixture of handicaps would make them almost incapable of competing with Lions.

So in a nutshell, Pleistocene Rewilding may seem like a good idea, but be careful, while one beast thrives, the other could fall.