- [host, Joe Hanson] They make their living by flipping homes,
except once they've built or repaired a dwelling
and they move on,
they leave the whole community better off
for having occupied it.
Of course,
I'm referring to the beaver.
Our relationship with the beaver is,
well, it's complicated.
But 400 or so years
after humans skinned them to near extinction
in the name of headwear,
more and more scientists
are starting to ask the question,
could beaver be the ally we've been waiting for
when it comes to saving the environment?
Beaver thrived in the United States and Canada
for centuries.
It's estimated that as many as 400 million of them
lived on the continent.
That breaks down to between 5 and 30 beaver
for every kilometer of stream or river
on the continent.
But as colonization took hold in the 16th century,
trappers began to hunt them in earnest
for their pelts and scent glands.
Then, one of the most ridiculous
and regrettable fashion trends in human history
nearly wiped them off the continent,
the beaver hat.
Yeah, seriously.
Today, there are an estimated 10 to 15 million beaver left
in North America.
In the meantime,
people had started farming on former beaver land
and they didn't want the beaver back.
Their solution?
Beaver relocation.
It's called translocation
and it has a long-standing roots in this country.
In the 1940s,
the Idaho Fish and Game Department
made this film.
- [Film Narrator] Into the drop box,
nearly ready for that flight
back into the mountain.
The plane makes a careful approach,
ready for the drop,
now into the air,
and down they swing.
- [Joe] Yeah, that is real.
They say hindsight is 2020,
but someone had to think
this was not a great vision
at the time, right?
This is filmmaker, Sarah Koenigsberg,
and that is her very good dog, Willow.
Sarah made the film,
The Beaver Believers,
a documentary about folks trying to save the beaver
in part through translocation.
But what many scientists have found out
in the ensuing years
is that moving beaver doesn't guarantee
that they'll stay where we put them.
And if they're released in an area
that's too degraded,
they might not have the food and water depth
that they need to survive.
- [Sarah] It's not as simple as just picking up some beaver
from somewhere where they're having a conflict with humans
and then just plopping them down.
In some cases,
that's still appropriate and successful,
but the thinking has really evolved
to recognize there are all these other areas
where we humans can help them out
so that they can move on their own.
In the years following The Beaver Believers,
I got fully sucked into the beaver microcosm
and it's quite literally taken over my entire life.
- [Joe] And that's what's brought us here
to Central Oregon,
just outside of the Painted Hills
where Dr. Chris Jordan and a team of scientists
have created a kind of revolutionary beaver laboratory.
- [Chris] We started working in Bridge Creek
to make it more productive for fish.
- [Joe] And Dr. Jordan learned early on
in his work on Bridge Creek,
that where there were beaver,
there were fish,
specifically the salmon and trout
they were working to protect.
But why?
Though they're the second largest rodent in the world
behind the capybara,
beaver have a lot of natural predators.
In the West,
that means coyotes, wolves,
bears, and mountain lions,
to name a few.
- [Chris] The way they escape
from those terrestrial predators
is by being in water that's deep enough
that they can hide.
If they're in a smaller stream,
they need to make the deeper water.
And this is where the dams come in.
They block the flowing water to make it deeper.
- [Joe] And in doing so,
they change the amount
and the quality of water available
in a stream system.
The small ponds that they build
to escape predation
are nurseries for juvenile fish.
Watching beaver gave the team a new idea
for how people can restore river ecosystems.
- [Chris] And we call it low-tech process-based restoration.
And the low-tech comes from mimicking a beaver,
no machinery.
We're enabling the natural systems
to recover and rebuild themselves.
- [Joe] Instead of telling nature what to do,
Dr. Jordan and his team
are asking nature to guide them.
And if the environment needs fixing
in order to put a stream
where it wants to go,
then they'll repair the land.
And that repair gives you some appreciation
for just how hard industrious, little beaver work.
These are human-built beaver dam analogs.
- [Chris] So, these simple actions
were meant to directly mimic the structures beaver built.
They were meant to trigger erosion and deposition processes.
- [Joe] Sometimes the beaver
give the humans' work
a beaver seal of approval,
like this one, right here,
a beaver dam analog
that's become a real beaver dam.
- Oh, look, right here.
All this is fresh mud and fresh veg.
We're seeing more and more species
that we care about
really struggle
due to habitat loss
and beaver make habitat for all these other animals.
Something like 80% of all wildlife species
depend on the kind of habitat that beaver create.
- [Joe] Beaver are mostly nocturnal.
They're also crepuscular,
meaning they do work at twilight.
Basically they're staying out of the light
to avoid their predators.
- [Sarah] So, if you go down to the confluence
of the John Day River and Bridge Creek,
it's just a very simple channel,
it's curving along.
But if you start moving up
through the restoration reaches,
you kind of get a snapshot,
step by step by step
of the river returning to
that beaver-dominated, really healthy and robust state.
- [Chris] The question remains,
did we just get lucky?
Or is this actually an exportable, generalizable approach?
And so,
we've tried it elsewhere
and it works there too.
- [Emily] You can read about them
written in trapper journals.
They're like, oh yeah,
beavers totally fight fires.
That's great.
And then you go looking for the science on it
and there's nothing there.
- [Joe] This is Dr. Emily Fairfax.
She's an ecohydrologist and remote sensing scientist.
Dr. Fairfax studies what happens to beaver landscapes
during major disturbances
like fires and droughts.
She's pretty good at stop-motion too.
Here's a film she made
to show how beaver complexes fair in wildfires.
- [Emily] By building its dam,
and then expanding that dam,
and then digging these little canals out
into the landscape,
beavers are creating these really broad swaths of landscape
that can resist all sorts of different disturbances.
So, when you have really similar streams
with and without beavers,
the streams without beavers
burned three times more intensely
than the streams that do have beavers.
- [Joe] To do her research,
Dr. Fairfax looks at aerial images of rivers
from different years
to see how healthy the vegetation is,
and then looks for differences between areas
with and without beaver.
- [Emily] Beaver complexes stay very green.
What we have seen
is that these beaver complexes,
they're storing so much water in the pond
and in the canals,
and in the soil,
that even when the droughts are going on
for two or three or four years,
there's enough water to keep the plants green.
It's like an underground irrigation system
for the whole zone.
- [Chris] Beaver should be our national climate action plan
because connected floodplains store water,
store carbon,
improve water quality,
improve the resilience to wildfire,
and what beaver do
play an enormous role
in controlling the dynamics
of those systems.
So, yeah,
it sounds really trite to give
a national climate action plan to some rodents.
But if we don't do that directly,
we should at least be trying to mimic what they do.
- [Emily] There's a lot of work that needs to be done
for climate change.
Things are changing very quickly.
And even with all the money in the world,
it's a hard problem to tackle.
So, why not let the beavers help us?
- [Sarah] You're not gonna find restoration practitioners
who will literally work 24/7,
365 days a year.
Beaver just do it.
They'll help us,
but we've screwed things up so badly
that now they can't quite do it on their own,
without us kind of setting the stage
for them a little bit
through restoration actions.
- [Joe] And before you go,
we want to invite you
to participate in PBS Digital Studios
Annual Audience Survey.
Your feedback really helps us understand
what our audience is interested in
so we can give you more of it.
You even get to vote on potential new shows.
There's a link down in the description below.
If you have a few minutes,
we'd love your input.
Thanks.
♪