A Beaver Post
The mandatory beaver post that my brain was asking about
Have you ever felt like something is chasing you?
For me, it’s beavers.
For the past few months, beavers keep finding me. Not literally, even tho they live pretty close by my house. It’s more like a constant presence.
The first time I actively thought about beavers, it was while reading an article from the Guardian. Someone forwarded me this story, and honestly it was pretty funny: a bunch of extremely frustrated beavers found themselves planning, implementing and inaugurating a new dam while human engineers were figuring out permits. The funniest part of this story is that the dam was build exactly where the human engineers had planned to. It’s like they knew.
“Well, I would be fast as well if I hadn’t bureaucracy to worry about!“
That’s what I thought, before going back to my life.
The next one was more subtle. While scrolling through article suggestions on a rainy morning while sipping my coffee (honestly, I have no recollection if it was a morning, if it was rainy or even if I was drinking coffee, but that’s just storytelling), I saw another article about beavers being released in the UK.
I don’t know why it got my attention. It might be because I often read about reintroduction programs in Europe. Most of the time I am skeptical about them (don’t read me wrong, I am all for reintroductions! But I am wary of humans-centered environments, and humans when they are not used to share their space with wildlife), and I always want to know more.
I read about beavers reintroduced in Dorset, Cornwall, and Biggleswade (I had to google maps all of them), in areas were beavers hadn’t been around for the past 400 years.
Maybe the people in the UK needed some construction work done? After noticing the exceptional emotional intelligence of Czech beavers, that just knew where the dam was needed and worked for free in half the time, the UK might have thought to give that a try.
The third and last story is the most suspicious.
It happened last week. I was feeling a bit under the weather, with my head almost literally drowning from a nasty nose congestion, when my husband came to my office to tell me a funny story about beavers.
“Beavers” I said. My eyes were reduced to small cracks, driven by suspicion and the beginning of a feverish beaver-induced paranoia.
Apparently, in the Ukrainian-Belarusian/Russian border, beavers build a good number of dams that flooded the land. And nobody complained or removed them, either because no one is there anyway, or because (once again) flooding the area was actually a good idea, since tanks can’t go through swamps.
And additionally, why complain when the whole security perimeter is done fast, and for free?
Despite the curious coincidence, now I was hooked about beavers. It was just a question of time before I dragged myself into a rabbit hole (beaver’s dam?) of research articles.
What’s in a dam?
The first question I asked myself is: what are the beavers doing, exactly?
Let’s take a beaver. This lady and her life partner get dropped into a river they’ve never seen. To take the UK example, The Eurasian beaver (Castor fiber) had been absent for a while, hunted to extinction. This means that these two are essentially arriving in a landscape that has forgotten them entirely.
You’d expect them to build, that’s what beavers do. But first, they need to check the place. On one hand, you’d never build a house next to very annoying neighbours, and beavers are highly territorial: before anything gets constructed, they need to figure out if this place is worth staying. On the other hand, beaver are also extremely picky, and quite specific about what they need. They like their river calm, wide, and lazy, with a lot of room for flooding on either sides (maybe they need to be the very annoying neighbours). These can be found, for example, in valleys or lowlands, or anywhere the landscape flattens out.
Geomorphologically, these are called floodplain: a flat strip of land alongside a river that floods periodically. The obvious opposite would be a mountain torrent -- too fast and narrow. And can you imagine the loudness?
Once our honeymoon couple found the perfect floodplain, they need enough depth so that the entrance to their nest is under water. This will keep predators out (unless a fox or a wolf learn to dive and snorkel, evolution can be that crazy).
Did you know? A group of beaver is called a family!
A single beaver family can transform a stream into an entire wetland ecosystem within months, and can use the dam for a long time. The family unit at any given time consists of the breeding pair, the kits born that year, and the yearlings from the previous year. So at peak you might have two adults, a litter of new kits, and one or two teenagers still hanging around, and mostly helping as free babysitters. After a while tho, Mama Beaver shoo away the oldest kits with loving intolerance. She would like some quiet every now and then.
So the kits disperse. Each one leaves, finds a new river, builds a new dam.
And that’s the weird part: what seems like a simple animal doing a simple thing is actually something much bigger. The river they arrived in is not the same river anymore. And neither are the rivers downstream, or upstream, where the kits will go.
It’s called niche construction, and it’s not that common.
When scientists land on a topic, and need to make it difficult
While reading about beavers, I kept landing on the same two topics: niche construction, and ecosystem engineer. Sometimes they were used interchangeably, and I did not understand either. So, like a fox hunting a beaver, I snorkeled into the topic.
What’s the difference between being a niche constructor and an ecosystem engineer?
An ecosystem engineer is any organism that physically changes the habitat around it, in a way that affects other species. The beaver floods a valley? Now there’s a wetland where there wasn’t one. Fish move in. Birds nest there. Amphibians appear. Humans shake their fists in anger.
The beaver didn’t plan any of that, but it happened because of what the beaver egoistically built.
It’s not the only example, there are many animals that can be defined as ecosystem engineers. My dad would be furious if he knew (”Everybody is an engineer nowadays!” while shaking fists in anger).
Niche construction is a similar principle, but from a different lens: it comes from evolutionary biology rather than ecology. Evolution is often thought as a one-way street: the environment changes, and animals adapt to it. If they don’t, they are goners (remember the fox and the snorkel? Who knows, maybe one day.)
Niche construction says that organisms don’t just adapt to their environment, they also modify it in ways that change the selection pressures acting on themselves and other species. It’s evolution being a two-way street. The environment shapes the organism, but the organism also shapes the environment, which then shapes future evolution.
So the phenomenon is the same, but one definition is about ecology, the other about evolution.
So what?
This whole experiment into beaver territory started, quite frankly, as a series of coincidental conversations, and articles.
It felt like this beaver idea was chasing me, so the compulsion to know more just could not go away on its own. I keep seeing them everywhere and I just want to know what the heck they are doing. So I had to figuratively follow the beavers down the dam(n).
What I find the most remarkable is that beavers aren’t trying to engineer anything. They definitely are not trying to impress anyone.
Beavers are just doing what beavers do. Find a river, build a dam, reproduce, and repeat. Whatever happens on the side, whatever other animals they influence with their engineering, that’s not their problem.
Articles link
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/ecosystem-engineers
https://www.semafor.com/article/01/13/2023/beavers-are-helping-ukraine-in-its-defense-against-russia
I laughed (and learned new things), as always!
My own personal reconnection point with beavers was the recent Pixar movie Hoppers. I wasn't thinking of watching it... until I ended up in a metro station completely covered in ads (the station was MehringDAMM, and I love puns, so they really got me there), and I got a 2-for-1 cinema ticket discount I could use for it.
Not the best movie I’ve ever seen, but still worth a watch. And I appreciated that Pixar brought in a real beaver scientist (Emily Fairfax) to ensure real-world accuracy 💪