‘I think we are learning that we need to reset our relationship to the natural world’

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The right side of this image is a black-and-white headshot photo of Leila Philip; the left side reads "PAWcast: Leila Philip ’86 on How Beavers Shaped America."

Once, beavers ruled North America. Their habit of rearranging streams into ponds filled the landscape with spongy wetlands teaming with life. But with the arrival of European colonists came the fur trade, and beavers were hunted nearly to extinction. On the latest PAWcast, College of the Holy Cross professor Leila Philip ’86 discussed the extensive research she conducted for her new book, Beaverland: How One Weird Rodent Made America, and how learning to live again with beavers could be key to restoring land in North America and fighting the effects of climate change.    


Liz Daugherty: Only one creature, other than humans, substantially engineers the landscape around it, the beaver. Many millions of these furry dam builders once busily trapped water in ponds across North America, keeping the landscape lush and fertile, until colonists in the 1600s discovered the lucrative fur trade. In her new book, titled Beaverland: How One Weird Rodent Made America, Leila Philip ’86, an English and environmental studies professor at the College of the Holy Cross, who lives near a beaver pond in Connecticut, traces the Native Americans who viewed beavers as sacred, and the colonial capitalists who nearly drove the beaver to extinction. Today, reintroduction efforts have brought the beaver back, along with hopes that they can help with ecological restoration and climate change mitigation. But can humans, with our concrete buildings and flood insurance policies, really coexist with beavers? 

So Leila, thank you so much for coming on the PAWcast.

Leila Philip: Thank you so much, I’m really thrilled to be here. 

LD: So, let’s start with what is it about the American beaver that got you interested in writing this book? 

LP: I’ve always been interested in the way humans interface with the natural world, and one day I witnessed beavers making a pond near my house, in my adopted home of Woodstock, Connecticut. And it was literally one of the most incredible things I’d ever seen, and that was the start. Just watching beavers do what they do, make a dam, build their pond, create so much water suddenly where there was none. And then I started learning about beavers, and soon learned the ways in which beavers literally shaped our country, the first foundations of wealth came from beaver fur, our first multimillionaire, John Jacob Astor, started out trading beaver pelts in Manhattan, and the beaver was on the first seal of New York City. Our first corporations, both in the United States and Canada, were about fur. 

And it wasn’t just that beaver revved up the engines of capitalism here, and started our first economies. When I really started to study beavers, I began to see how they literally, literally shaped our continent, the land, our watersheds, and our geology were influenced by beavers over millennia. So, North America was and is beaver land, although colonization and 300 years of development really dried out those wetlands, to the extent that we’re facing a lot of environmental problems much more intensively now, because of the loss of that water, and I’ll get to that in a minute. 

But what I came to realize writing this book, and researching about beavers, is that this weird rodent really has a huge new role to play, helping us fight what really is the greatest crisis of our generation, which is climate change. And on one hand, watching the beavers make that pond was magic, because it wasn’t just watching them make the pond, the whole area was soon teeming with life, and it showed me how resilient the natural world is. And I think we need stories of hope and resiliency to help us face our collective future. Beavers are one of the greatest conservation comeback stories of the 20th century, so that’s sort of all backstory as to why I got started and became so excited about working on this book, and would spend so many years researching beavers, because it’s an incredibly timely story for our time.  

LD: Can you describe a little bit how beavers shaped the land? Because I think it’s helpful to understand how the land became what it was when the colonists arrived here, to understand what they did to it. 

LP: Yeah, well it’s, you know, it’s a big story, but I’ll try to just give you the short version. So basically, a beaver will come to a creek or a stream, and build a dam across it, so that water will swell out, so soon that creek or that stream has a growing, swelling pond coming out from it. And then, they’ll move downstream a little bit, and they’ll do that again. So instead of one long line of water, you soon have what looks like a line of water with almost like beads on a chain. So seen from above, a river system with beavers on it is just this extraordinary series of lines and pods of water. 

And then, the beavers build, dig out canals into the woods and the meadows on either side, because they need transportation. So, they further press that water into the land. And it’s not just the water you can see, but underneath those, the visible water, you have a whole invisible, almost like, imagine a sponge under there. So every wetland is a big sponge of water being held under the ground. So that in times of drought, there’s a reservoir of water there that can be drawn upon, so that river system doesn’t dry out. Or, if there’s an extreme rain event, and you have flooding, instead of that water running through that creek, and stream, and river system, and just ripping through and all that water going down into the ocean, taking with it topsoil, and carving out the land, the water is slowed down and sinks into those sponges. 

So you have basically a river system with all these sponges all throughout it. And on top of that, those wetlands serve as giant coffee filters, if you will. So that water is not just slowed down, but as it is slowed down, it’s being filtered of sediment and pollutants. So today, for example, and I write about this in the book, down in the Chesapeake, for example, not just the Chesapeake, but that’s one really dramatic area where they are finding that not only can beavers be harnessed to create very valuable water storage that costs millions of dollars to build, but they are cleaning the water that’s going into the Chesapeake. The Chesapeake Bay is one of the, it’s one of the largest, I think it is the largest watershed in the Atlantic, and it is really in trouble. So all of the six states that contribute water to the Chesapeake are under real pressure to do more to clean the water that goes into the Chesapeake, because the pollution rates are so high. 

So a beaver-altered stream that creates a beaver wetland has a filtering system in it that’s capturing nitrogen, and phosphorous, and sediment, and they’re measuring this, so they are actually finding that beavers are being harnessed and doing what’s called nature-based restoration. And that’s just one example of the kind of environmental good that beavers do. But I sort of jumped ahead into, you know, their future, but I — have I explained for you how they function in the river system?

LD: I think so. In the book, you describe how this landscape in North America, full of beavers, full of these wetlands, and how much life there was. And then compare that to what we have today, right? Controlled rivers, right, that run very fast, and aren’t allowed to spread out, because we’ve built our cities around them, just this very different landscape. 

LP: Yeah. Well, you know, and we can’t undo all of our infrastructure, obviously. You know, just to go back to what you said about life, the biodiversity that beaver ponds bring, and beaver wetlands bring, is pretty dramatic. So a teaspoon of water from a wetland is just teeming with millions of microorganisms, and they have measured beaver-altered streams and compared them to, you know, streams without beavers, and just like 15 times more plankton and microbial life is living in these beaver-altered wetlands and streams. So, you know, that’s from the ground up, that’s the life you cannot see. And then there’s all the animals that come to a beaver area. 

And just to go back to the book, that was the thing that I witnessed at my local beaver pond that was so remarkable, because the beavers made this pond, and what was this kind of quiet, swampy place that I walked by and didn’t pay any attention to was suddenly like a hullabaloo of wildlife — otters, and raccoons, and all kinds of animals were there, within it seemed like six months, it was just crowded with wildlife. So, they bring a lot of biodiversity that we can see, and we can’t see. 

But you know, to go back to your point about where beavers can be and where beavers can’t be, I think there is a lot of places where beavers can coexist with humans if we can accept a little less control. You know, we can’t undo roads and things like that, but I think people are finding, and I write about this in the book, it is exciting, the possibilities for harnessing what beavers can do. Because we can manage the water levels in beaver ponds through things like pond levelers, they — or flow devices, it’s basically you put a permanent hole in the dam, so that instead of overspilling its banks and flooding a road, you manage the level in the pond. So the beavers are fine with it, and then you can have beavers there, and you don’t have your flooded road. 

Beavers will dam a culvert. From a beaver’s point of view, a culvert is just this crazy hole that humans have left in their own dam. They think of a road as some kind of a dam if it’s near a road. So they’ll try to fill it forever and ever, they’re never going to stop. That’s why they’ve been considered a pest, but there are things called beaver deceivers, and culvert blocking devices that have been designed by people who’ve studied beavers that really work, and beavers back off, and they don’t block the culverts, and they can live nearby, and the roads aren’t flooded, things like that. So you know, there are, as you point out, really big problems with our river system, which has been highly degraded. Beavers can’t fix all of that, but they can sure help, and we’d be a lot better off to think about them as millions of highly trained engineers throughout North America, ready to work for free, than as, you know, pests we need to trap and get rid of. 

LD: Like, you can spend millions of dollars on trying to engineer a landscape to solve all kinds of problems that beavers can kind of do for free. 

LP: The study of what beavers can do has become increasingly sophisticated, and again I have a lot of fun writing about this in the book, but there’s like one project in Milwaukee, and it was funded in part by the Milwaukee municipal sewage department. And they have a tremendous problem with floodwater out there, and they, this study discovered that if they could repopulate, and this is available areas of the watershed, so this is places where there are no roads, where there are no people, this is places where beavers could live. If they put beavers in there and let them do what they do, create their wetlands, within 25 years those beavers could create enough wetlands to store 1.7 trillion gallons of water a year. That has an economic value of $3.3 billion annually. That’s a lot of savings, and that’s not even factoring in the savings of all the flood damage that the beavers would save, which they calculate to be about 20 percent, and there are thousands of bridges, and culverts, and roads that would be better preserved if those beavers were in the landscape. 

So, I think people are starting to put numbers to this, and similarly down in the Chesapeake, there’s one moment in the book where I’m standing with this environmental restoration professional, and his codename is “The Beaver Whisperer,” because he works a lot with beavers, he’s really an interesting man, he has a very successful company. And he’s a person who I think worked in a field for a number of years and then one day had a paradigm shift and said you know, we really need to reset our relationship to the natural world, and we could — we need to learn from it, and we can even save money if we do. And so I was standing with him out by a beaver pond, and he pointed to this beaver pond we’d just hiked around and through, it was about 10 acres, and he said, you know, that beaver pond, which the beavers did for free, would cost a million dollars for him to build. He builds them all over the Chesapeake watershed for people. So that’s a lot of money for a pond that beavers, six to eight beavers have built for free. 

So anyway, pretty compelling, I think! 

LD: It gets back to that question that you were just talking about of our relationship with the natural world, like we’re envisioning a world where beavers are allowed to construct their ponds and dams, and we let them do it, and also keep an eye on it through, like you said, the pond levelers, and kind of working with them on the landscape, because of course we can only control nature so much. Humans have had a long experience, like sort of like, there’s a long history there of our relationship with beavers, right? Like the Native Americans had one type of relationship, the colonists had a completely different type of relationship, right? And it’s changed over time. 

LP: Well, you know this is why I start the book with the Great Beaver story, because I think we, you know, we have a lot to learn from bodies of indigenous ecological knowledge that are here, and have been here all along. So the Great Beaver story is one of the oldest stories of the continent, about a Great Beaver flooding the Connecticut River Valley. It’s also, there are versions of it all up and down the Eastern Seaboard, and across to the Great Lakes. And there is a lot of writing and thinking about beavers throughout North America that varies, depending on the indigenous peoples that lived in different regions, because of course there were, you know, hundreds of different cultures throughout this country, there’s no one monolithic Native American anything. 

But that story is an environmental parable about learning from the natural world, about not hoarding, excessively hoarding natural resources, and it’s really interesting. And I think we are learning that we need to reset our relationship to the natural world, because our attempts to control the natural world just aren’t serving us. You know, you can’t extract forever and ever, we are facing the limit of that, we are seeing the consequences of that. The very thing that built this country, the extraction of natural resources is the building block of empire, but you can’t just keep extracting and expect them not to give out. 

And you know, in part that was, for me, the purpose of telling the story of John Jacob Astor, who was in many ways just brilliant, and he took the beaver trade to a whole nother level, and you know, I write about that. But at the end of the day, it was so efficient that he set up this global network to transport and market the beaver, and then the beaver gave way, they trapped them out. Now he didn’t care, because by that point he’d moved onto something else, but the point is there, you can’t just extract away and not face the consequences of that, and we’re facing that now. 

But I think, you know, I think we’re also facing new ways of thinking about it, where we’re at a revolution in all kinds of information and new ways of thinking about animal behavior, and the way we think about the forest, think about the incredible advances we have made recently in understanding the animal world, understanding the way the forest works, the forest soil, the river system, it’s pretty exciting. 

LD: If I may switch gears for just a moment, I’m curious about your Princeton experience, we are of course your alumni magazine, and —

LP: Yes! 

LD: — can you talk at all about how your experience at Princeton may have, I don’t know, helped you at all with this book? Which is a very interesting way that you’ve woven together so many different things, yeah? 

LP: I was incredibly lucky, because as a freshman, I was able to study with an amazing teacher and mentor, John McPhee, and I took his famous writing seminar. And it was just incredible to week after week just study from a writer who was that good, and such a wonderful teacher. And I think what he taught all of us was that, you know, to be a writer, you needed to just be interested in something, and just really care. So, his passion for the written word, and for learning about things, I think it really influenced all of us, it really influenced me. It was just, I think, one example of the kind of things that were possible at Princeton, to have exposure to people working at such high levels who were still interested in really sharing that with undergraduates. It was so exciting. I just remember feeling on fire when I was at Princeton. And then, you know, you walk around campus and you think oh, there are all these incredibly smart people, (laughs) you know, and that’s a good experience, to be challenged like that.

LD: Well if he taught you how to write a book that brings, that pulls together your passion for something, that I think comes through very clearly in here, because you are really interested in the beaver.

LP: Yeah, yeah, and I think, you know, I feel very passionate about the topic, because I do think we’re just at a very interesting moment in our history, and beavers have a lot to teach us. You know, when I drive by a messy swamp by the road now, I used to just look at it as a place that maybe should be tidied up, you know? Honestly. And now I see it as this lifegiving area, teeming with biodiversity, and I imagine the huge reservoir of water that’s there under that messy muck, and I think, that’s going to keep us alive when the next drought comes, or you know, a forest fire hits. And you know, beavers showed me that. So, I think we have a lot to learn from the natural world, and I also think that stories of hope and resiliency are there, and there’s a lot of nuts and bolts, concrete things we can do, so the fact that beavers are a kind of, you know, I think they’re our secret weapon against climate crisis, in a way, in North America, because they’re right here. All we have to do is let them do what they do, and we can gain a lot of resiliency, and that in and of itself should give us hope, because if there are beavers, there might be something else. 

You know, I wrote this book during the pandemic, and surrounded by loss and change, and I think we’re not very good at thinking about loss, and how that’s part of the picture. But if we’re going to live into a moment of accelerated climate change, which we are, we have to find ways to adapt to change. The only constant in nature is change, and beavers are all about that, that’s why I call them the kind of Shiva of the natural world. You know, they take down some trees, and they make a pond, so trees are destroyed, a pond grows. It’s this constant movement, and we’re pretty much hardwired not to like change as humans, it seems to me, and we also need to learn from the natural world to think about loss, what we consider loss, in different ways. Especially of environments. Because if we try to hang onto the environment like it’s an old master painting that we want to save, you know, I think we’re going to be doomed, because there’s just too much going on, and it’s happening too fast. 

LD: So this has been so great. Is there anything we haven’t touched on that you’d like to mention? 

LP: Oh yeah, thank you. I think I just wanted to mention about the Great Beaver story that I start the book with, in the prologue, and just very quickly, the Great Beaver story is this, really it’s one of the oldest stories in North America, and it is, it basically tells the forming of the Connecticut River Valley, and I’ll tell the short version of it. 

A beaver floods the Connecticut River, and to the extent that the humans are almost flooded out, and they go to the Creator and beg him to do something, and he has to discipline the Great Beaver, and the Great Beaver is chased by the Creator all up and down the Eastern Seaboard, and during that great fight, where the club comes down of the great Creator, mountains come up, and cliffs, and valleys, so it’s one of those wonderful stories that explains the topography of an area, as well as serving as a parable about, it’s an environmental parable about the misbehavior of the beaver. And it’s kind of a brilliantly subversive story, because of course any listener knows that it’s not really the beaver that is the one who’s misbehaving, or who has flaws, it’s really about the human possibility and potential for hoarding resources. So the beaver takes too much water, and has to be disciplined, and chased away. And this story is all up and down the Eastern Seaboard, in Algonquin culture, through into the Great Lakes. 

And so, I started the book with this because I wanted to point out to readers that while I spend a lot of time in the book writing about Colonial history, there’s this long history in North America that goes back millennia, which is of course the history of the Indigenous peoples here. But also because by the end of writing this book, I really came to feel that one of the things that studying the beaver and looking at the beaver could teach us is right here in this story, which is that in this story, which is this parable of kind of the creation and destruction of the American paradise, we can’t forget our interconnectedness to others. The beaver forgets his obligation to the humans, and that’s why he has to be disciplined. But if we remember our interconnectedness to others, I think we will be able to reset our relationship to the natural world, we will find solutions, and climate change resiliency options, like the North American beaver, this weird rodent that’s out there in the woods throughout North America, as a kind of highly trained climate change engineer, ready to help us.

So I just wanted to end on that note, because that to me is, I guess, part of why I spent so many years writing this book, and felt so passionate about getting it out now, in this moment, when we’re facing such a difficult time in our history. Thank you.

LD: Thank you so much for taking the time to talk to me. 

PAWcast is a monthly interview podcast produced by the Princeton Alumni Weekly. If you enjoyed this episode, please subscribe. You can find us on Apple Podcasts, Google Podcasts, Spotify, and Soundcloud. You can read transcripts of every episode on our website, paw.princeton.edu. Music for this podcast is licensed from Universal Production Music.