How Wolves Changed a River: The Incredible Rewilding of Yellowstone

Yellowstone National Park is a massive, wild wonderland in the USA. It's full of geysers, forests, rivers, and loads of amazing animals.

Back in the 1920s, humans thought wolves were the villains of the animal world. So they chased them out of Yellowstone and for nearly 70 years, not a single wolf howled in the park. Scientists realised that the ecosystem had been damaged without wolves prowling the landscape and back in 1995 they decided to bring the wolves back!

So what happened?!

1. They Put the Deer in Check!

Without wolves around, elk were having a HUGE party, eating every tree and plant they could find. But when the wolves came back, they started hunting the elk. This meant the elk had to stay on the move and stopped munching in one place for too long. The trees and plants finally had a chance to grow again!

2. Trees Made a Comeback

With fewer elk gobbling up young trees, something incredible happened, the forests started to grow back! Willow, aspen and cottonwood trees returned, and who loves trees?! BEAVERS! Beavers are the engineers of the wild. Their dams help create ponds and wetlands, which are perfect homes for ducks, frogs, and even fish.

3. The Rivers Changed Course

With more plants and trees growing along riverbanks (thanks to less elk grazing), the rivers became stronger and healthier. The roots of all those plants held the soil in place, which helped the rivers stop wobbling all over the place. The wolves helped fix the rivers without even getting wet!

4. A Wildlife Party Started!

The return of the wolves set up a rewilding chain of events to this valuable ecosystem. With more trees and plants, birds returned. With more beaver ponds, fish and frogs came back. Even bears got a tasty bonus as berries grew better in the new forests, and they also got to munch on leftover elk from the wolves.

Find out more about the amazing story of the Wolves of Yellowstone!