Beavers: Pest or Ecological Powerhouse?

When Europeans reached what would become the United States, they encountered an environment that was largely shaped by beavers. At the time, beavers were considered a pest species because of their penchant for “chaos.” In fact, they were hunted to extinction in Great Britain at roughly this time. Beavers pull down trees, causing streams to flood, which can be a nuisance if you’re trying to work the land. From the 1500s, Beaver populations gradually diminished in the United States partly due to their nuisance status, but also due to high demand for fur hats and coats. 

Now, however, scientists are starting to understand the importance of beavers to the environment. They are considered keystone species, meaning that beavers can support an entire biological community, and their removal can contribute to ecosystem collapse. 

Ecological Importance of Beavers

“To acknowledge that beaver[s] create environments that store water and help sustain other creatures is insufficient. Beaver[s] are nothing less than continent-scale forces of nature and in part responsible for sculpting the land upon which Americans built their communities.”

- Ben Goldfarb in Eager: The Surprising Secret Life of Beaver, 2018

Beavers are often referred to as nature’s engineers because they continuously build dams and lodges, which in turn create new wetlands, ponds, and lakes. The resulting habitats support insects, fish, amphibians, moose, waterfowl, etc. They also have profound effects on the environment. Beaver dams and lodges alleviate flooding of areas downstream, and these new ecosystems reduce water pollution, boost fish and amphibian populations, store carbon, and mitigate against the spread of wildfires.

Beavers were reintroduced to Absaroka-Beartooth Wilderness Area near Yellowstone starting in 1986. The results of their reintroduction were increased ecological productivity. Before beavers reintroduction, willows were lacking in number and variety, but due to the damn building habits of beavers, willows were able to thrive. The dams allowed willow habitats to remain wet, keeping their roots wet and allowing them to thrive. Beaver activity can cause the reduction of water pollution by agricultural runoff. Pollutants get filtered out through their dams and resulting wetlands. 

New research is showing that areas across the U.S. where beavers have altered the environment stay green during wildfires. This research suggests that beaver reintroduction can have positive effects on the mitigation of wildfires, particularly in increasingly wildfire-prone regions of the U.S., like the west. The implications of the profound positive effects that beavers can have on the environment have seen a growing movement of people and groups who are trying to make beaver reintroduction a priority. This is particularly true for Native groups here. 

Efforts to Reestablish Beavers in the US

While the importance of beavers ecologically is only growing in recognition and efforts to reintroduce them into different environments have been supported by ecologists, scientists, gubernatorial candidates, and the like, it’s Native American tribes who have been at the vanguard of this effort. There is a growing movement here called the “Beaver Believer” movement, which advocates for beaver reintroduction as a means to ecological restoration. 

Tribes in the U.S. have long known and understood the ecological symmetry and underpinnings of their environments. Many tribal cultures depend on a healthy ecosystem and, thus, see the importance of beavers as land managers. Many of the benefits of beaver reintroduction will directly support these tribes by increasing fish populations and protecting their forests from wildfires. Not only that, but their efforts support change in our broader culture and society by encouraging governments to change anti-beaver policies and encouraging landowners to have a more open mind. 

While some landowners are for good reason skeptical of beaver reintroduction efforts, there have now been numerous studies and devices made to help alleviate some of the problems that beavers can have on properties. For example, a British beaver reintroduction study found that some farms upstream from where beavers built their dams started to have flooding problems that impacted their crops. Luckily, with active beaver management, you can mitigate against some of these potential pitfalls. For example, you can place beaver deceivers in dams to prevent flooding. Beaver deceivers are pipes that carry water through beaver dams without the beavers realizing, thus lowering water levels. 

While there are potential pitfalls of beaver reintroduction, there are many ways to mitigate against their negative effects, and the beneficial impacts of beavers far outweigh the costs. It’s important that we support efforts to help these important creatures thrive once again in our natural world. Their cultural and ecological significance is far too important to overlook, and they can have a significant impact on our ability to mitigate against and adapt to climate change. 

Photo Credit: National Park Service

What You Can Do

Let’s take a quick look at how we as individuals and communities can help support beaver reintroduction efforts. 

State laws across the West classify beavers as a nuisance and allow the trapping and killing of beavers on private property, so it’s important that we support legislation that changes these notions. It’s also important to get the word out on different ways to handle “nuisance” beavers on private property instead of just killing them and/ or destroying their dams. If you own a lot of land and encounter beavers on your property, consider letting them be if you can or look into alternative ways to dealing with their effects. 

Even though beaver reintroduction is not possible everywhere, we can still mimic their benefits on the environment in more urbanized areas. Consider supporting projects that introduce man-made beaver dams into local environments, as these can have profound impacts on water quality and aquatic ecosystems. So, in general, if you encounter chances in your personal life to support beavers, take the chance. Also, try and educate your family and friends - who knows, maybe one day we will all be able to reap the benefits of clean water and more fish!