How are Wolves Good For Their Ecosystem?

You might have heard that wolves are very good for their ecosystem. But have you thought why?

Ecosystems are insanely complex, but as far as we can understand, wolves have a very positive impact on their surrounding environment. The most breathtaking example is the change they caused in Yellowstone National park.

A little back story

First, let us begin with the term "Trophic Cascade". Trophic Cascade occurs when the animal on the top of the food chain, controls the abundance of the animals which are lower in the food chain. Here is an example: Imagine a grassland full of deer herds and no natural predators. Since there is no external cause of death, the herd is left to grow at an immense speed. This might initially seem harmless. But in time their numbers grow so large that they start consuming more grass than the grass can replenish itself. As there is less grass to feed on, the herd starts to starve and eventually ends up having much fewer members than the herd initially had, if not eradicated. So, you can see the problem here. With the top of the food chain gone, the ones at the bottom initially blossom until they bring their own demise.

The same case was present in Yellowstone National Park. Before humans re-introduced the wolves in 1995 they had been absent for almost 70 years.

Here is how wolves changed the park

Obviously when they arrived, they started hunting the deer. However, this wasn’t the major factor in controlling the deer population and changing the park. The major factor was that, the wolves changed the behavior of the deer. The deer had to stay away from certain areas to avoid getting hunted. Those areas now free from deer started to flourish again. In just 6 years some vegetation’s height quintupled. These areas started to become forests of Willow, Aspen and Cottonwood.

As the trees were growing, various bird species as well as beavers started to come back. Beavers are great for the ecosystem because they build dams which are habitats for other species like: ducks, fish, reptiles and many more.

Wolves also got rid of coyotes which brought back: rabbits, fox and mice. Which brought hawks, bald eagles and badgers.

As you can see when wolves returned, they didn’t just control the deer population they rejuvenated the whole ecosystem. But here is something more interesting…

They changed the behavior of the river!

That’s right. They didn’t just cause ecological changes, they also caused geographical as well. The returning vegetation and forests prevented a lot of the erosion. With less erosion the rivers were more predictable and they didn’t flood so much. With calmer waters, new meanders started to form as well as new ponds and pools.

In summary, the re-introduction of wolves into Yellowstone National Park surprised everyone. Scientists expected some positive effect on the ecosystem, but they never imagined something on this scale. As you can see wolves are not just awesome because they are “cool”, but they are genuinely beneficial for the environment. Now that we have a better understanding of their effect on the ecosystem we should do more to protect them.

As always, Thank you for reading.

Here you can see the effects they had visually!

Yellowstone before and after Wolves