Why We Need Beavers

One of my permaculture teachers would say he only does three types of work: Human work, Salmon work, and Beaver work.

Human work is all about causing disturbances, like fires or construction projects, that stimulate the environment to renew and adapt.

Salmon work entails carrying vital nutrients upstream to feed the forests, as the salmon do when they return to their birthplaces to spawn and decompose into the soil.

Beaver work is about reshaping waterways to slow the flow of energy downstream, letting life flourish in swirling wetlands far better than it could in roaring rapids.

What do the three species have in common?

We're all keystone species, whose presence is integral to the functioning of our entire ecosystem. The name comes from a keystone at the top of a stone archway, without which both sides would collapse into each other.

I love this concept of keystone species, because it lets us focus on one creature while acknowledging its inseparable part within the whole. Just as that archway wouldn’t hold up without the keystone in the center, our environments tend to experience disastrous ecological cascades when we remove a keystone species.

Unfortunately, that’s exactly what’s happened with Beavers, which is why my permaculture teacher can’t just leave the Beaver work to the Beavers.

Across North America, beaver populations used to number as high as 200 million. From the 17^th through 19^th centuries, they were nearly hunted out of existence. Instead of their vital role in the ecosystem, they were valued first and foremost for their coarse fur, used to make beaver hats and other clothes, and castoreum oil, used to mark their territory and (by humans) make perfumes.

The fur trade was so aggressive it had to keep moving west as beaver populations dwindled. Before the famous 1849 Gold Rush, the California Fur Rush catalyzed some of the earliest European settlements in California.

What makes beavers so crucial to their environment? Namely, their building habits.

As ecosystem engineers, they build dams by chewing down and piling up trees, branches, twigs, grass, mud, and rocks along waterways. Contrary to what you might assume (I know I did), Beavers don’t live in dams, but in lodges within the artificial ponds the dams form.

Instead, the dam serves to create a deepwater refuge where they can hide out from their common predators like coyotes, cougars, wolves, and eagles.

These Beaver-designed riparian zones provide valuable habitat for other species sharing their environment, including aquatic plants, insects, underwater invertebrates, juvenile salmon, fish, migratory birds, and large game. They also improve water quality reduce soil erosion, selectively prune forests, moderate flooding impacts, provide fire breaks, and sequester carbon from the atmosphere.

Overall, the effect of Beaver’s ecosystem engineering is a big boost in biodiversity throughout the territory they occupy. For humans, Beaver ponds lend themselves to valuable hunting grounds for indigenous tribes and early colonists alike. The silt and sediment that accumulated in Beaver ponds also created fertile bottomlands for farming.

Alas, all these positive effects don’t persist when Beavers aren’t present.

Thankfully, now that their ecological significance is widely recognized and hats made from their fur are out of style, Beaver populations are making a comeback.

That's so 19th century.

From the brink of extinction, protection efforts have revived North American Beaver populations to the level of 10 to 15 million. That’s still only a fraction of what they once were, leaving a gigantic unfilled niche in our ecosystems to compensate for.

Still, not all humans are happy about Beaver’s return. Many landowners still consider them pests for chewing down trees and blocking culverts they use to channel water around roads and structures.

Historically, many tried to relocate or exterminate the bothersome Beavers, but this rarely works—as, like the Salmon, they seem to remember their way home and would resettle the same spot within a couple years. As an alternative, some modern-day Beaver believers have developed and distributed the more humane and effective solution of flow devices, or Beaver deceivers, that regulate the water levels of dams while keeping culverts clear.

If I may editorialize a bit, it’s far more important to keep streams healthy than keep landowners happy. (Have you tried to keep a person happy? We’re pretty impossible, truth be told.) So, in response to the ecological cascade caused by Beaver’s absence, a growing field of stream restoration called low-tech process-based restoration (LTBPR) aims to reverse the changes with methods mimicking beaver activity.

Long-term, the hope is to lay the foundation for Beavers to return and resume their labor-intensive work of waterway management, now fallen on our people’s bipedal shoulders.

There’s a grand karmic justice to this situation. Through our greed for beavers as fashion statements and status symbols, Humans nearly eradicated them from this land. Because of the environmental cascade that followed, we now find ourselves taking on more work to fill the niche they’ve left in their absence.

We Beavers and Humans have a lot in common. We’re both ecosystem engineers, with dexterous forepaws and unparalleled abilities to reshape the world around us to suit our needs. But we Humans still have a lot to learn from Beavers.

Right now, we’re surrounded by evidence of the negative effects we can have on our environments. We’ve made the world more convenient for some of us, but at the expense of other natural resources, plants, animals, and people who fall on the lower end of our socioeconomic hierarchies.

We are still a keystone species, but because of our greed and poor listening skills, we’re by and large using our power to ill effects. We can still turn that around, to go from the most harmful element of our environment to the one of the most helpful, as we’ve been throughout most of our evolution.

Many permaculture practitioners make good models for this, but they do so only by humbling their egos to learn from others who retain close connection with the land and waters. That includes the indigenous knowledge that hasn’t already been lost to cultural and ecological genocide, of both human and other animals.

Take Beaver (not actually; just as an example). To maintain their holding dams, they listen and react immediately to the sound of running water, like first responders patching up a structural defect (stat!) with more branches and mud.

All that diligence pays off, even beyond what we’re capable of. The largest known beaver dam in northern Alberta spans 850 meters, more than twice the width of the Hoover Dam. Maybe we can compensate for that, but we can’t compete with it.

To conclude, here’s a poem based on my first in-person encounter with a Big Mama Beaver.

Enjoy.

Mama Beaver

Mama Beaver bathes by the riverside to the sunset of a summer's day, tail between her legs, poplar tree between her teeth. Without the will and a pause, the water would never get her clean. The homes of debris she builds let life breed at every branch of the stream. The oil of her fur reflects what's lost and passed on in the great Ball juggling horizons too fiery to keep both eyes on. Before dinner, she sits, a breath of stillness to hold for peace beneath the divine violence, removed from the current, renewed by being out of her element.