The way of the beaver

Strategies for survival of the world's second-biggest rodent

Beavers have some things to teach us about strategy.

No really. When a big slow rodent survives a nasty world, we should take note.

Those from the US and Canada are passingly aware of the fact that beavers were, a couple centuries ago, hunted to near extinction. Estimates are there were about 100 million beavers in North America before the Europeans came, and Ben Goldfarb’s excellent book, Eager, recounts that number dropped to about one hundred thousand at the turn of the twentieth century.

But they came back, more than a hundredfold—today there are approximately 15 million beavers in North America. Goldfarb calls them “one of our most triumphant wildlife success stories.”

What fascinated me in reading about castor canadensis (the North American beaver) is the why and the how.

Why = survival.

How requires a bit more description.

Here’s Goldfarb riffing on buildings the beavers have built:

“The primary reasons are the same ones that first drove humans to build domiciles of their own: safety from predators, shelter from the elements, and food storage. On land, beavers—North America’s biggest rodent, and the world’s second largest, after South American capybaras—are ungainly and vulnerable, and their pear-shaped bodies make delectable meals for black bears, cougars, coyotes, and wolves. Yet beavers are as balletic in water as they are clumsy out of it. They can hold their breath for up to fifteen minutes, and their underwater gymnastics are powered by webbed hind feet. Transparent eyelids allow them to see below the surface, while a second set of fur-lined lips close behind their teeth, permitting them to chew and drag wood without drowning. Building dams expands the extent of the beavers’ watery domains, submerges lodge entrances to repel predators, and gives them a place to stash their food caches.”

There’s three things, at least three things, worth drawing out of this wonderful paragraph.

First, it’s what beavers do. They’ve developed practices that enable their survival. They build with mud and sticks and logs and there’s even a case of one using a prosthetic leg and whatever else they can to make an underwater-access-only castle. Well before we humans started building moats, the beaver built moats. (Heck, humans likely got the tip from a beaver.) Beavers figured out a way of doing things to succeed, spread that knowledge widely over a long period of time, and used it to survive and grow and thrive.

Second, it’s what beavers are. Long-air-lungs, super-underwater eyes and lips, and teeth optimized for their practices. And that fur! Through generations and generations and generations, they’ve cultivated bodies capable of living and working in environments that protect them from predation. It’s slow hard work to get there, but over hundreds and thousands of years, beavers have bred themselves into this super-defender.

They changed the game. Now that humans aren’t hunting them to near-extinction, think of the modern predator-prey relationship. Put a beaver on land and it gets eaten in nanoseconds by the next wolf that comes along. But force that wolf into the water and the beaver escapes easily.

So that’s what beavers did. They simply moved the field of play onto a surface and location that benefitted their long-term survival. By sticking close to the intersection between land and pond, they made it so they derived gains from both while reducing the risk of dying-off.

What’s our takeaway? I mean, we’re not beavers worried about wolves, of course. But we can note that for beavers to develop a strategy for survival took a great amount of time, a great amount of effort, there was an enormous setback when an outside variable came into the picture.

But those big slow rodents survived. And I love them for it.