You might think that a wolf living in Yellowstone National Park has something of a cushy existence.

3,472 square miles to roam, plenty of prey to hunt… what more could a wolf really ask for?

Sure, in some ways this is the case. After all, wolves have no natural predators in Yellowstone, safe from the humans who might hunt them, with plentiful elk for them to hunt too.

But this was not always the case – and, in fact, until a conservation project in the 1990s that began to re-establish Yellowstone’s native wolves, the national park was devoid of one of its earliest species.

That’s according to Yellowstone Wolf Project, who explain that wolves roamed Yellowstones and contributed to its developing ecosystem over thousands of years, until, in the 1920s, they were hunted to extinction.

Of course, this had detrimental effects on Yellowstone’s biodiversity, with the elk population booming and other species – now lacking a natural predator – negatively affecting some of the native vegetation in the park.

It was only in the mid 1990s when this was rectified, with wolves from Canada and northwestern Montana introduced to the national park to rebalance the ecosystem.

And according to a recent paper published in the journal Global Ecology and Conservation, this was a very important – perhaps even crucial – step toward reshaping the ecosystem in Yellowstone National Park.

According to the author of the paper, William J Ripple of Oregon State University and the Conservation Biology Institute, the reintroduction of wolves has resulted in a trophic cascade, meaning a domino effect from the top to the bottom of the food chain.

In particular, Ripple’s research shows that the wolves have led to a significant regrowth of willows, with around a 1500% increase in average volume as a result of reduced consumption by elk, as Ripple explains in a statement:

“Our findings emphasize the power of predators as ecosystem architects. The restoration of wolves and other large predators has transformed parts of Yellowstone, benefiting not only willows but other woody species such as aspen, alder, and berry-producing shrubs.”

Thanks to conservationists’ efforts, Yellowstone’s natural balance has been restored.

If you thought that was interesting, you might like to read about why we should be worried about the leak in the bottom of the ocean.