Science Vs - I’ll Be Dammed: Beavers Fighting Climate Change

Episode Date: May 4, 2023

Today, we give a dam about beavers. These busy rodents don’t just chill and go with the flow — it turns out their grabby paws are actually helping hands in the fight against climate change. We dive into how this works with ecologists Dr. Emily Fairfax and Dr. Ben Dittbrenner.  Find our transcript here: https://bit.ly/ScienceVsBeavers In this episode, we cover: (00:00) Intro: How beavers “beaver away” (02:22) Chapter One: How beavers can help  (06:18) Chapter Two: Can we move beavers for the better?  This episode was produced by Disha Bhagat, with help from Michelle Dang, Meryl Horn, Rose Rimler and R.E. Natowicz. We’re edited by Blythe Terrell. Wendy Zukerman is our Executive Producer. Gimlet’s managing director is Nicole Beemsterboer. Fact checking by Eva Dasher. Mix and sound design by Catherine Anderson. Music written by Bumi Hidaka, Emma Munger, and Bobby Lord. Science Vs is a Spotify Original Podcast and a Gimlet production. Follow Science Vs on Spotify, and if you want to get notifications every time we put out a new episode, tap the bell icon in your app. Learn more about your ad choices. Visit podcastchoices.com/adchoices

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Join me every Wednesday for Pioneers of AI. And don't forget to subscribe wherever you tune in. Hi, I'm Michelle Dang, and you're listening to Science Versus from Gimlet. I'm filling in for Wendy today, and we've got a bit of cutting-edge science for you to gnaw on. We're going to talk about a surprising new soldier

in the battle against climate change. It's the beaver. And government nerds are so excited about their potential, they're pouring millions of dollars into beavering up the U.S. Okay, to tell us about this beaver thing, we wanted to talk to Emily Fairfax. She's an assistant professor at California State University, Channel Islands. Originally an engineer, which she didn't really like, Emily fell into her love of beavers by accident. I was sitting on the couch feeling mopey and a

documentary came on called Leave It to Beavers. I was so hooked. I didn't know beavers did this much. I'm like, I need to know more about beavers. And so I quit my job and went to grad school to study beavers and I've not looked back. Right off the bat, Emily told us beavers are freaking adorable. And we have to agree here. They kind of look like lovely fat squirrels with big buck teeth and a tennis racket for a tail. Is there a reason that they're so chunky and blobby? That's a great question. There are reasons they're so chunky and blobby because they spend so much time in cold water. And that thick fur, their sort of fat bodies, make them very good at living in the water, being in the

water, and being like on their A-game when they're in the water. Yeah, beavers love the water. They're pretty awkward on land, but in the water, they're majestic. This is actually why they do their signature beaver thing, build dams. You see, when a beaver shows up at a stream, they get straight to business, stacking up sticks and rocks and mud. They do this to slow down the water in the stream, so it collects into a nice pool that they can swim and live in. But that's not all these dams are doing. Over the past decade or so, scientists have realized that they can also be a big help during droughts. Like those pools, they don't just keep beavers cool.

They keep plants hydrated too. Even if it hasn't rained in months and months and things are starting to get pretty crispy out in the landscape, there's plenty of water stored for those plants to drink. and so they can stay green and they can stay lush. This happens because water from those beaver ponds seeps into the soil. This can keep things very wet, even during a drought. These damp conditions help keep plants green and can even create wetlands rich with all sorts of life. So beavers are basically little pudgy gardeners brightening up their backyard. We have to try so hard to maintain greenery,

but the beavers are really just doing this really easily. Yeah, well, easily. Oh, yes. They work pretty hard. Once Emily realized that beavers were good for droughts, she got thinking about other disasters, like wildfires. Emily thought, maybe these soppy, wet beaver ponds could stop a fire in its tracks. And we know it sounds a bit nutso, like a little beaver firefighter. But she decided to find out.

Emily set up this study looking at satellite images. She focused on areas with streams that had been through wildfires in the western U.S. and looked at spots that had beaver ponds and spots without. She pulled out pictures from one year before the fire and of the aftermath of the fire. Emily then measured how green these areas were, up to 30 meters or about three school buses out from the water's edge. And what she found was that when beavers were around, things stayed greener. It had this protective effect, a bubble around the dam that's basically fire resistant. The fire couldn't get in. It was just too wet to burn.

The dirt is wet. You step and it makes a squishy sound. There's pond everywhere. Like the leaves are legitimately wet. They're so healthy. And so anywhere you have that really dense moisture, that's going to be sort of your fireproof zone. Yeah, a simple dam holding out in the middle of a raging wildfire.

Pretty amazing. And Emily has visited the Beavers after a fire blazed through the area and says it can be emotional. There's a very visceral experience of driving through a recent wildfire's burn scar and just seeing the effects of a fire that burned too hot and too intensely, images of death all around you. And then you get to the beaver pond and it's the opposite. It's like, that's life. Suddenly you're in this bright green oasis. And every time I'm like, I'm tearing up a little bit. I'm like, oh my gosh, they made

it. Emily says these beaver bubbles can be this safe zone for wildlife when everything around it is up in flames. There's fish swimming around, there's open water, there's beavers, there's frogs, there's herons. It's just booming with life. And you look around in the pond and you're like, wow, this is an amazing, healthy landscape. This is remarkable that this is still here, given the intensity of the fire that surrounded it. And like, that's just beavers being beavers. Emily and other scientists are hoping that if you have more of these beaver bubbles, they could act like speed bumps to a fast spreading fire, giving us more time before the fire gets out of control. But if we want more beaver ponds, we need more beavers.

And while we're sort of shooting ourselves in the foot there, because we actually kill a lot of beavers. Back in the day, around colonization, it was mainly for their fur. But now, it's mostly because a lot of people see beavers as pests. Because sometimes they wreak havoc on people's land, like ruining trees, causing floods, messing up farms. So when this happens, the beaver might get removed and killed. The U.S. Department of Agriculture found that in 2021, there were over 24,000 beavers killed across the country. Now, though, some people are stepping in to save these beavers and to harness their power. The idea is that we might be able to move these nuisance beavers instead of killing them,

and put them in new spots that are dry and struggling. Ecologist Ben Dittbrenner did a study to see if this can work. He's also a beaver believer. They're just really curious and interesting creatures that kind of just tug at your heartstrings from the second you see them. Ben is an associate professor from Northeastern University. He worked with the Tulalip tribes in Washington state to move beavers from one spot to another and to measure the difference it made on the environment. And Ben says all this beaver moving starts out a bit weird. Yeah, I frequently think about it like an alien abduction. You know, like, we capture these creatures in the night,

we bring them back to their mothership into a really strange environment, we probe them, we violate them in ways that they never imagined would be possible. Okay, let's break this down, starting with that probing business. Well, to get beavers to stick around in a new home, researchers have found that you have more luck if you keep a beaver family together. And if you've got a single beaver, Ben's team figured you could find them a little beaver friend. A special friend, you know? So Ben and the team need to do some beaver matchmaking.

Which means they need to find out the beaver's sex. And it turns out that's more complicated than you might think. So they don't have any external anything. They have a cloaca, which is like what birds have. And I just call it the everything hole. So it's one hole for everything. One hole to pee, to poop, to mate, and to spray their scent. In that hole, there are special glands that ooze this liquid, which is the telltale sign to figuring out a beaver's sex. But how? Okay, so Ben told me they first put the beaver into something that kind of looks like a pastry bag with two ends, one small and one big. The beaver's nose goes at the small opening and the butt is at the bigger one. And the beaver is squirming away. Somebody's wrestling and

wrangling it so it stays upside down. Another person will palpate the abdomen. And if you do it, if you feel their abdomen, you can actually feel the gland inside. It kind of feels like an oblong golf ball, kind of. And so if you palpate just right and you kind of keep moving your fingers down along their abdomen, if you do it right, you can actually pop the gland out of the cloaca. Oh, okay. Which is awesome. And once that happens, at this point, if you're a sane human being, you feel like you're really violating the beaver's personal space in a major way because you really, really are. But this is all in the name of science, so

whatever. And then, so that gland pops out and then you milk it. And so you just like very gently just kind of palpate it. And the beaver juice will come out. And for sex determination, if the liquid is a whitish color and smells like bad cheese, that is a female beaver. And if it's a brownish color and it smells like motor oil, that is a male beaver. It's actually surprisingly accurate. Yep, a pretty wild ride to go on just to figure out the sex. And it's probably even wilder for the beaver. But back to Ben's study, now the team sets up the singles so they can mingle.

Remember, they're trying to pair up the beavers so they'll be more likely to stick around in their new spot. Though they weren't too sure how well the mingling would work. But every single beaver that we paired up with another one, they were totally okay with the other beaver. You can make a business out of this now as a 100% success rate matchmaking. And once beavers find a mate, they're usually partners for life. So then it was on to the final step of the study, moving these beavers to a new home, particularly a spot where they could do some good.

In this study, they moved 22 beaver families to a new spot. Unfortunately, most of them either weren't interested in building or simply hightailed it out of there. But five families stuck around and started beavering away. Within a day or two, they started building dams and really creating habitat. And that was the exciting stuff. It was really great to see what we were hoping for happen, happen, and then happen so quickly. After those dams went up, Ben's team could start to see what was happening to the environment. And they found something surprising. These dams don't just make things more wet, which, again, can help with droughts and wildfires. Ben found that they changed the water in the stream itself by making it cooler.

They were decreasing the stream temperature downstream of beaver dams by about two and a half degrees. We were really surprised to see that in this system, that they were having a pretty substantial cooling effect. That's two and a half degrees Celsius, which may not sound like much, but keeping streams cool, especially as we're dealing with climate change, can be great for some fish. Like, one study on trout found that beaver dams almost doubled the amount of juvenile trout. So how does this work? This happens because even when water closer to the surface gets warm,

beaver ponds can have these deep pockets where the water is cooler. And that cooler water can spread downstream. Ben's study also found that all this damming helps to add more groundwater below the pond, which makes sense because the water is seeping everywhere. To sum it up, beavers and their dams are doing some incredible things in our waterways. So forget streaming music.

We should be streaming beavers. Of course, they aren't the be-all end-all solution here. All this beaver sexing and relocation is tough work. But lots of people are getting on this beaver bandwagon. Doing stuff like building beaver starter homes to try to draw them to areas that need help. In fact, the U.S. government has started using beavers to try to restore habitats. And California recently put $3 million into beaver projects.

As beavers start entering the mainstream, Emily is pretty excited about it. Because fire and drought and climate change is very grim, it feels like there's another set of paws out there in the fight against climate change. Your friendly neighborhood Spider-Man, except this is like your friendly neighborhood beaver where it's just going out there

and making the good changes day after day. That's Science Versus. Hello? Hey, Disha. Hi, Michelle. How's it going? Going well. How about you? I love beavers so much now.

I just have a new appreciation for them after all this. Me too. Me too. So how many citations this week? We have 67 citations. And if people want to find these citations, where should they go? They can find them by going to our show notes and following the link to the transcript. What else do we have for the people if they're intrigued about beavers now? Yeah, we've got some really cute pictures that Emily and Ben, our beaver believers, shared with us. So check those out on our Instagram at science underscore BS. And everybody, sadly, this is our goodbye to Disha. She's been our fantastic intern for the past six months, but is moving on to greater things.

So we just want to say thank you so much, Disha. Thank you. It's been great. And I'm so happy to end up with Beavers as a fellow Canadian myself. Yes. Thank you for blessing us with these Beavers. Happy to do so. This episode was produced by Disha Pugut, with help from me, Michelle Dang, along with Meryl Horn, Rose Rimler, and Ari Natovich. We're edited by Blythe Terrell.

Wendy Zuckerman is our executive producer. Fact-checking by Eva Dasher. Mix and sound design by Katherine Anderson. Music written by Bumi Hidaka, Emma Munger, and Bobby Lord. Thanks for listening.