Yellowstone Wolves Actually Changed The Park's Rivers

May 6th, 2019

If you’re a lover of national parks, you already know just how precious Yellowstone National Park is.

The park encompasses parts of Wyoming, Montana and Idaho and was officially signed into law as a protected national park in 1872. Since then, Yellowstone has become an iconic spot in America for its many sights such as Old Faithful and the Grand Prismatic Spring.

swiggle1 dot pattern2 Source:

Aside from the natural features, Yellowstone is also teeming with wildlife of all kinds, and the park managers and rangers do their best to protect those species and maintain an equilibrium throughout the park.

One unique example of that comes from a story about what the park’s management did with some wolves.

swiggle1 dot pattern2 Source:

The story begins in 1926, when wolves were no longer anywhere to be found in Yellowstone.

Although wolves used to be a natural species in the area, their population had dwindled because many of them were being killed off by hunters protecting their livestock.

swiggle1 dot pattern2 Source:

Although visitors had reported seeing some wolves in the park in the period between 1977 and 1995, they were few and far between—still, in the wolves’ absence, the park’s elk population had grown enormously.

To balance out the park’s ecosystem, a small pack of gray wolves was reintroduced in 1995—and it had incredible effects on the whole park.

swiggle1 dot pattern2 Source:

When the wolves moved into the park, they of course began to hunt deer once again.

Because deer were hugely overpopulated, they were grazing too much and killing a lot of the local vegetation. But what the park rangers didn’t expect is that the wolves’ hunting would have an effect on deer behavior in general. After they became aware of the threat of getting hunted by wolves, they started to avoid parts of the park where they could get trapped most easily—which only makes sense, after all.

Still, that subtle change had yet another unintended effect.

swiggle1 dot pattern2 Source:

Because the deer were staying out of the valleys and gorges, those areas saw huge explosions in their plant life.

Everything regenerated, trees grew taller and all was abundant. After there were trees growing in all kinds of areas where there weren’t before, a bunch of birds also started to move into those areas. That brought in other animals as well including beavers, who eat trees and dam rivers, creating new areas for other smaller animals like rodents, which in turn brought in hawks, and so on.

Although the flurry of animals moving in changed, nobody expected all of that activity to change the activity of the park’s rivers.

swiggle1 dot pattern2 Source:

Because of the explosion of plant life, the park’s soil conditions changed.

The river banks began to firm up, meaning that there were fewer collapses and thus less runoff and diversion. As a result, the flow of the rivers became calmer and steadier in some areas. There was also less soil erosion in various areas as well, all of which strengthened the habitats for different animals. The most incredible thing about all of this is that it was all the result of just a handful of wolves.

And as it turns out, there’s a scientific name for this kind of phenomenon.

swiggle1 dot pattern2 Source:

The case of wolves in Yellowstone in 1995 is a perfect example of what scientists call a trophic cascade.

A trophic cascade is an indirect series of interactions in an ecosystem starting from the top, whereby the entire food web beneath it is changed. Needless to say, this is an important scientific discovery! Although on one hand this is simply an interesting story about a natural park, it also has huge implications for human life on Earth as well.

swiggle1 dot pattern2 Source:

While we tend to think of ourselves as isolated from the rest of the world, the truth is that all things on our planet are closely interconnected. What we do has tons of effects on other creatures around us—and on the planet itself.

swiggle1 dot pattern2 Source:

In all, this is a pretty incredible story—check out the full video below:

Please SHARE this with your friends and family.

Sources: We Love Animals, Wikipedia, Yellowstone Park (1, 2)