Interview of Ben Goldfarb ― Resistance Radio

September 23rd, 2018

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(Sound of beavers)

Hi, I’m Derrick Jensen This is Resistance Radio on the Progressive Radio Network. My guest today is Ben Goldfarb. He is an independent environmental journalist and fiction writer. He is the author of Eager: The Surprising, Secret Life of Beavers and Why They Matter (Chelsea Green Publishing), which the Washington Post called “a masterpiece of a treatise on the natural world.” He covers wildlife conservation, marine science, and public lands management, but he’ll tackle any story with an environmental bent (and some without).

So first, thank you for your work, and second, thank you for being on the program.

BG: Thanks for having me, Derrick: I appreciate it.

DJ: So who are beavers?

BG: That’s a great question. Beavers are these extraordinary landscape-scale agents of transformation. They’re rodents and they build dams. We all know that. And those dams, which create ponds and wetlands turn out to be tremendously important for virtually every member of the biological community, from the moose that cool off in them to the amphibians, frogs and salamanders that breed in them, to the juvenile fish that shelter in them, to the waterfowl that nest around them. Beavers turn out to be this essential pillar of so many ecological communities. I think that’s first and foremost who beavers are, is this keystone species responsible for supporting so much other life in North America and Europe.

DJ: So before we go on, let’s talk about their natural range. Not introduced range yet. To where are beavers natural and how many species are there?

BG: There are two species of beaver. There is Castor canadensis, which is the North American beaver, and then there is Castor fiber, which is the Eurasian beaver. They’re very closely related. They can’t interbreed but they are visually indistinguishable for most people. The North American beaver’s historic range was basically northern Mexico to the tundra line, essentially. Every state in the continental United States and nearly the entirety of Canada had beavers. They were incredibly abundant. Over in Europe, again, beavers covered nearly the entirety of the European continent and most of Asia as well. There were beavers as far east as the Korean peninsula, historically, which most people don’t realize. This was once an extraordinarily abundant animal and we’re gradually getting back to that point.

DJ: So, again, before we go to what happened with conquest, can you tell me the average size of a beaver, and how big is a huge one, and also I’ve heard they run in a variety of colors.

BG: A typical adult beaver is probably going to be 50-60 pounds. But 70-pounders are not unusual. I think they are bigger than most people realize. When most people see beavers, they just see a head moving across the water at twilight, with the rest of the body submerged, and you don’t quite realize that these are really some hefty, powerful animals. They weigh as much as many decent-sized domestic dogs.

They do come in a variety of colors. You’ll see beavers who are as light as balsa wood, and as dark as dark chocolate. They definitely come in a range of colors within the general brown spectrum.

DJ: And how long do they normally live and who eats them?

BG: In the wild, 12-15 years would be a pretty old beaver. They’re eaten by all kinds of large carnivores. Wolves love beavers and in some places beavers are actually the majority of wolves’ summertime diet. I think people don’t realize what an important food staple beavers are for wolves in places where beavers and wolves co-occur. Grizzly and black bears both eat beavers. Cougars love beavers. I saw a picture recently of a lynx that had killed a beaver, which was pretty impressive. And as coyotes occupy more and more of the North American land mass, they become a really significant beaver predator as well. One biologist described beavers to me as a fat, slow, smelly package of meat, so there is certainly a lot out there that preys on them.

DJ: Do they sneak up on them when they’re on the shore? I’m guessing that in the pond they’re much more impervious to predators.

BG: That’s a really good question. There’s a Ph.D. student named Tom Gable who’s studying this right now. How do predators, especially wolves, kill beavers? He actually shot some amazing footage. He came across this wolf that was standing in the middle of a logging road around Voyageurs National Park in Minnesota. The wolf was staring intently at a stream. 15 minutes or so went by, and suddenly the wolf lunged into the stream and came back onto the road with a beaver in its jaws, and then kind of dropped the beaver on the road, still alive, and the two animals faced off for a few minutes and finally the wolf killed the beaver. So that was a pretty cool example. Clearly the wolf had staked out this stream, knew that beavers were moving back and forth across it, set up this patient ambush, and nabbed one. You’ll also hear about bears that actually tear into beaver lodges. Predators have all kinds of interesting strategies for hunting these guys. They are challenging prey in some respects because they build these dams to create these ponds and wetlands so that they can be safe. The pond is a pretty good stronghold. They’re not always the easiest animal to hunt. But predators clearly have evolved all kinds of strategies for eating these delectable rodents.

DJ: One last question before we go to what happened when Europeans came to this continent, which is: something I’ve always wondered is how is it that concrete dams harm anadromous fish – we don’t need to make that case, because it’s so obvious – but beaver dams – how do anadromous fish deal with beaver dams?

BG: It’s a good question. Certainly there are fish biologists out there who dislike beavers. There are programs out there that involve destroying beaver dams and even killing beavers, to promote anadromous fish passage. To me, that’s ridiculous. We know beaver dams aren’t impermeable like concrete dams. There’s plenty of water moving through a beaver dam and fish are often capable of wriggling through the dam itself, through the woody framework of the dam. I know scientists who have actually observed that in action. Fish are capable of jumping certain beaver dams. That’s definitely been documented. And then they can also swim around beaver dams. Oftentimes in a beaver stream you’ll have this kind of multi-threaded, multi-channeled stream where maybe one channel is impounded by a beaver dam but there are other side channels that circumnavigate it. It’s true that at very low water beaver dams can pose temporary barriers to fish passage, but ultimately fish are able to surmount these things without too much trouble. There was one study in Oregon that documented steelhead passing more than 200 beaver dams, individual steelhead crossing a couple hundred beaver dams. So they clearly figure out ways around them. In fact, we know quite conclusively that beaver dams and the fantastic ponds, wetlands, side channels, backwaters that they create are incredible juvenile salmon habitat. Beaver occupancy and salmon production have been very closely linked. We know that beavers are great for fish. So yeah, there’s definitely a lot of fish-related beaver opposition out there, but increasingly agencies like the National Oceanic and Atmospheric Administration are adopting or promoting beaver restoration as a tool for salmon recovery, because they create such great salmon habitat.

DJ: Yeah, the opposition seems frankly kind of absurd to me. They evolved together and they’ve been getting along for hundreds of thousands, if not millions, of years.

BG: Yeah. The bumper sticker I really like says “Beavers taught salmon to jump,” which I think kind of captures the co-evolutionary relationship there.

DJ: Oh, I like that.

I know I’ve said this a half dozen times, but one more question before we go to the conquest, which is: what would be an example – there’s a salmon-bearing stream 30 yards from where I’m sitting. And it has beaver on it further down, and I’m always sort of day-dreaming that they’re going to move their way up. So the first question is what are the smallest streams that beavers ever live on? This stream is maybe five feet wide and two feet deep. And then also what is the larger – it doesn’t have to be the world record, but the larger end of beaver dams. How big are beaver dams from tiniest to largest?

BG: That’s a good question. The largest beaver dam ever recorded is in Alberta, and that’s a half mile long or so and is visible from space. So these things can be pretty massive. But more typically, a beaver colony will build a primary dam and then a number of secondary dams. And that primary dam, which sort of does the bulk of the water storage work, is typically, you’ll often see, a couple hundred feet even is kind of a large primary dam. As for the smallest, it sounds to me like your stream is suitable. Their amazing talent, of course, is that they’re almost capable of creating water seemingly from nothing. I’ve heard and seen so many stories of beavers taking these pathetic little seasonal trickles, you know, and by slowing water down and backing it up and prolonging the residency time of the water, they take these pitiful little streams and turn them into kind of robust perennial flows. So I think that beavers would be okay on your stream. More important, really, than the volume of water is the gradient of the stream. If you’ve got a very steep stream that water is really rushing down in the spring, it’s going to be hard for them to build a lasting dam there. So more important than the volume of the flow is the power of the flow, because dams do wash out and if the stream is too steep, beavers won’t be happy there.

DJ: Well I hope they make it up, then, because I live on a coastal plain, so the gradient’s very low.

BG: That sounds like good habitat to me.

DJ: So let’s get to conquest. Something that both breaks my heart and I think is one of the most important things to do is to recognize who was here before. In Northern California, for example, prior to conquest, you would routinely see, if you were by a river, every fifteen minutes you’d probably see a grizzly bear. And we know about the flocks of passenger pigeons so large they’d darkened the sky for days at a time. The flocks of Eskimo curlews. I was reading not very long ago about down by Houston very early European explorers would see a single pack of wolves that would number several hundred.

BG: Wow!

DG: We can tell these stories for everywhere. So can you tell some stories about abundance/range/ubiquity of beavers?

BG: Absolutely. Of course we don’t know exactly how many beavers were in North America prior to colonization. The best estimate we have is up to 400 million. By 1900 they were down to 100,000 after trapping, so that gives you some numeric sense of how dramatic the destruction was. But you’re right. You read these incredible trappers’ and explorers’ accounts of what the land looked like. It’s just incredible to me how dramatically beavers influenced this continent historically. When Lewis and Clark went up the Missouri in Montana they saw beaver dams in every single tributary as far as the eye could see, to the base of the mountains. There were places where they couldn’t even use their canoes in some of these valleys because beavers had so thoroughly dammed and ponded that they had to walk along the ridge lines, the influence of beavers was so great. And that was in 1805. By 1843, John James Audubon went up the Missouri Basin to the exact same area and he didn’t see a beaver for 2000 miles. He was looking for beavers to paint and he couldn’t find one. So in just 38 years we went from having dams in every single tributary as far as you could see, to this animal being completely eliminated from this vast watershed, which is pretty incredible.

Elsewhere, you read about explorers crossing the state of Indiana and not finding a dry place to camp for 100 miles because beavers had so thoroughly ponded and marshed the entire place. There are so many of these stories. So, to me, it’s one of the really tragic things in a lot of ways, about reporting this book and researching the historic influence of these animals, just realizing how much we lost and how much important habitat we lost too. We know that wetlands are so critical to sustaining life on this continent, and we lost hundreds of millions of acres of beaver-built wetlands. We just lost so much open water and wet meadows and just incredibly lush ground.

I don’t think we really think about beaver trapping in the same terms as we think about the deforestation of the northeast, or the busting of the midwestern prairie, or placer mining in California. But I think we should think about beaver trapping in that way, as sort of this early, seminal environmental catastrophe that must have been so devastating for so many species that are intensely reliant on these fantastic beaver-built habitats.

DJ: What year was the nadir of this, and what was the lowest number, about, that we know?

BG: Probably around 1900 the beaver populations bottomed out at around 100,000. And, again, these are very ballpark estimates. Beavers were certainly wiped out of nearly the entirety of the lower 48. There were still some beavers out west, but they were totally gone from the northeast, southeast and most of the midwest, California. There were a handful of pockets of beavers in kind of the Rocky Mountains and the northwest, and Canada still had some, but there’s no question that well over 99% of North America’s beavers were killed during the fur trade.

DJ: And what are the numbers now? What has happened since?

BG: A lot of these population estimates are just shots in the dark, but you know, the ones that I’ve seen are maybe 15,000,000 or so beavers in North America. So it all depends on what your historical baseline is. From one perspective, we went from 100,000 barely over a century ago to 15,000,000. That’s one of the world’s greatest wildlife recovery stories. Beavers are this incredible success. But of course if you brought in your lens to 1491, we’re still at a very small percentage of historical beaver occupancy. People often ask me if beavers are endangered, and to me, the answer is “No, there are plenty of beavers in North America.” I’m sure most listeners have seen a beaver at some point. But it’s all about how abundant we want this animal to be. If we want to reap all the benefits beavers are capable of providing us, we have a long way to go in getting back to what a really beneficial beaver population might be.

DJ: So let’s go back to the collapse of beaver populations. Were the primary causes the physical trapping, or was it also putting in dams, draining swamps, or was that sort of a synergistic effort?

BG: I think the primary cause was trapping. Beavers were mostly trapped for their underfur, which trappers often called “beaver wool,” which is felted into hats. Hats were all the rage in Europe for a few centuries there, and beaver hats were a very hot commodity. It was certainly the direct trapping of these animals that wiped them out. You’re right that the draining of wetlands for agriculture and development eliminated lots of beaver habitat and made it hard for them to recover. I think another really big impact was grazing, the introduction of domestic livestock. Beavers of course require riparian or streamside vegetation, for food and to build their dams and lodges. When you’ve got herds of thousands of cattle grazing unchecked in a stream bed, eating all of that vegetation, it becomes basically impossible for beavers to establish. I think, as you say, it was kind of a synergistic effort where the primary and original cause of the collapse was the direct trapping. But then the draining of these wetlands and destruction of all this riparian forage that was eaten by domestic cattle made it hard for beavers to recover in many places.

DJ: So I mentioned before, I believe, that I grew up in the West; grew up in Colorado and then lived in Nevada and North Idaho, and now it’s northern California. The places I’ve lived have been rural west, which means they’re very strongly anti-nature for the most part. One of the complaints I would hear nature-haters throw out against beavers is “They kill trees. They kill lots of trees. They’ll just kill a forest.” So can you respond to the notion that beavers are evil forest destroyers, expressed by the guy holding a chainsaw?

BG: Right, right. Exactly. You definitely hear that a lot. To that I would respond that beavers, yes they are cutting down trees. There’s no way of getting around that. But they’re also producing new trees. Beavers are almost like rotational farmers in a lot of ways. They cut down trees, they build these dams, they raise not only the level of the pond, but they’re also raising the water tables. When you look at a beaver pond, of course there’s all of the visible surface water, but there’s also lots of water being forced into the ground and spread out on the floodplain and being stored in aquifers. There’s incredible groundwater recharge that you get thanks to beavers, which basically acts as this incredible force of irrigation that is actually stimulating the growth of new willow, aspen, cottonwood, elsewhere in the beaver complex. So, again, they’re sort of like rotational farmers. They’ll build this complex and they’ll cut down willows on one side of the pond and that will be their forage for a year or two, or whatever, but meanwhile by raising water tables, they’re creating conditions for the growth of all these riparian trees on the other side of their complex.

So yes, they’re cutting down trees, but they’re also creating the conditions in which new trees can flourish. It’s this wonderful long-term cycle that they perpetuate.

DJ: So what are the causes of the increase from 100,000 to, I think you said 15,000,000?

BG: Yeah.

DJ: Is it simply fashion, that hats went out of style?

BG: That was part of what saved beavers, I think, originally. Fur was replaced by cheap silk from China. That kind of became the hat style, with these silk top hats rather than beaver hats. But more recently there’s just been a lot of beaver conservation, reintroduction. There are many stories, many examples of these beaver populations being reintroduced and just taking off. In New York, for example, the northeast was completely de-beavered by 1900. There were basically no beavers left in New England, or the entire northeast. And in 1904 some New York State biologists reintroduced around 20 beavers. Some they got from Yellowstone, some were Canadian beavers. They dumped 20 beavers into the Adirondacks in upstate New York in 1904, and by 1915 there were 15,000 beavers. So there was this incredible dramatic increase that was caused by; trapping, in that case, was banned; but we’d also wiped out beaver predators at that point. There were no more wolves left in New York, so that probably helped their populations grow really quickly. And we also eased up on logging around then too, so there was a greater food resource for them.

So it was a combination of things. Deliberate reintroduction combined with predator elimination, somewhat ironically. And, as you said, trapping became less of a way of life, I think. Trapping was such a vital early economic industry throughout North America, and gradually as both fashions and social mores changed, as conservation ethics developed there were more restrictions or limitations on trapping and that also helped beavers recover.

DJ: I’ve interviewed a wolf person and also a grizzly bear person, and I asked each one of them “What are the mechanics by which…” I hate that word, but what are the means by which these creatures expand their range? And wolves, as you know, will just strike out. You can have a wolf in Idaho and all of a sudden you’ve got one in northern California because he or she decided to move. And grizzly bears, it turns out, expand their territory pretty slowly. A daughter will take up range near her mother, and so it might take five generations to go 100 miles, for permanent range. Males can spread around. So where I’m leading with this is how…obviously if they went from 20 up to 15,000 in 11 years, (a) they have a lot of babies, and (b) can you talk about their means of natural reinhabitation?

BG: That’s a good question. So to answer that question you need to know a little bit about beaver family structure. A typical beaver colony, a family, is a mating pair, which is a generally monogamous male and female, who mate for life, and then you’ll typically get three successive years of offspring all cohabitating in a lodge. So you’ll have the newborn kits, who are born in the spring, and you’ve got the one-year-olds, and then you’ve got the two-year-olds. And some time during their second year the two-year-olds will disperse, strike out and look for new territory, just like that juvenile grizzly bear. And in looking for new suitable territory, they can go a really long way. I’ve heard accounts of beavers traveling over 200 linear stream miles. And that’s probably pretty unusual. I’m sure it’s very unusual. But they’re capable of dispersing great distances in search of habitat, especially when the habitat’s not great. In places where the habitat is really good, where there’s lots of food, lots of water, not too many predators, they can live in pretty close proximity to each other. You’ll get a colony or two every half mile of stream. But in places, especially the arid West, where the habitat is not as good, they can disperse many miles in search of new terrain. So I think it’s really that colony structure where the offspring all cooperate in the dam and lodge construction until their second year, until they’re ready to strike off on their own. That’s kind of the mechanism that allows for pretty rapid colonization.

DJ: It sounds to me like you’re saying that when they want to find new territory, the preference is to swim up or downstream or up or downriver.

BG: Yes. They will occasionally cross overland, but that’s definitely not their preference. They definitely stick to the watercourses.

DJ: Well, that was my next question. How do they reinhabit – that must be terribly scary and terribly dangerous for them to inhabit a new watershed. Say one watershed is completely filled up with beavers, and then you have a ridge line, and then you have another whole river system. That’s got to be a really brave little beaver to go walking across the land.

BG: That’s definitely true, especially during that two-year-old dispersal season. You see lots of beaver roadkill because we built roads through all of these wetlands and that’s a really big source of beaver mortality as well. So you’re right. It’s a very dangerous journey, and that’s certainly the most perilous time in a beaver’s life, I think, is being a dispersing two-year-old.

But actually what’s interesting is I’ve been learning and reading and going out and seeing more and more of these estuary beaver colonies in Washington. I live in Spokane and last week I was out in the Seattle area looking at some beavers that had successfully built dams and lodges in tidal salt marshes, which was pretty interesting. I think that they do more ocean swimming than we give them credit for. So that’s a method of dispersal, too. Instead of having to cross over a ridge line and swim out to the ocean, you know, hang a right and look for the next river mouth. They’re definitely using salt water as well to recolonize some of these river systems.

DJ: So maybe listeners won’t care, but I lived in Spokane, Washington for ten years, and how are beavers around Spokane and northern Idaho?

BG: I think in the immediate Spokane area they’re doing pretty well. There are definitely lots, you can go down to the Spokane River. I saw a beaver in the Spokane River last week. They’re certainly abundant down there. There’s a nonprofit here called the Lands Council, which has done a lot of beaver relocation in the area, and has definitely gotten some colonies up and running in eastern Washington. Northern Idaho, that’s a good question. I’m not quite sure. There’s definitely – Idaho is kind of a different political climate. There’s certainly lots of beaver animosity and lots of trapping there, I think, compared to Washington. So I’m not sure what their status is in northern Idaho. Probably not great, but around Spokane I think they’re doing pretty O.K.

DJ: So we’ve talked about beavers in streams. Do beavers ever live in rivers and not make a dam? They just make a hole in the side of the river and eat whatever is growing there?

BG: Yes, definitely. And I’ve seen beavers in the Grand Canyon where they’re certainly not building a dam. The Bureau of Reclamation down there is the only dam-building entity in the Canyon. The point of the dam is to create sufficient water depths so that they’re safe, and of course if that water depth exists without having to dam, that’s their preference. They certainly build lots of dams, but they don’t necessarily want to build dams. That’s what they do when they have to. They’re very efficient animals. People often talk about – “busy as a beaver” is such a cliché. But I think that “efficient as a beaver” in some ways makes more sense. They’re not busy for the sake of business. They’re certainly capable of taking it easy when the water depth is adequate. So yeah. In addition to the classic beaver lodge, an island lodge that most people picture as a beaver home; they’re certainly very happy, they just tunnel into the banks and create bank burrows, essentially.

DJ: I’m going to jump back to a subject. When we’re talking about the two-year-olds leaving home – let’s say a river or a stream is pretty full and one of the youngsters is going to leave. Are they pretty territorial in terms of; will they kick somebody out as they’re walking through? Do they fight with them or do they just not let them in? How do they maintain territories?

BG: They definitely do fight. If you were to live-trap an older beaver you’d often see him or her covered in scars from battle with other beavers. They’re definitely territorial and they will fight if necessary. The two-year-olds, the subadults, are typically smaller, so I think they try to avoid picking fights with the occupants of an established territory.

DJ: I think you said they live like 15 years. Failing somebody else coming in, will this family territory more or less be passed down for generations? Can the same family often live in the same place for a long time?

BG: That’s a good question, Derrick. I think that certainly you see lots of habitats continuously occupied for many, many years. I lived previously in Northampton, Massachusetts, and there was a beaver colony there at a place called Lake Fitzgerald. There was this giant lodge, very prominent, with active human-habituated beavers that you often saw out and about in the evening. And I heard from a local scientist that that lodge had been continuously occupied since the 1950’s. Whether there’s a direct genetic lineage there, whether it’s inhabited by successive generations of offspring, I’m not sure about. I imagine that probably happens to some extent. But there’s no question that good beaver habitat can be continuously occupied by some beaver or another for decades or even centuries.

DJ: Is their culture passed on? By which I’m asking are their techniques of dam building that can be passed on generation to generation, or is it, and I’m not saying this pejoratively, is it purely instinctual?

BG: That’s a really good question. I think the answer is that it’s both, which is probably not a surprising answer. The experiment that’s always cited when people talk about dam building being instinctual is there’s this behavioral scientist named Lars Wilsson who, in the 1960’s, performed this experiment where he basically put young beavers, beavers that had never, that weren’t raised by their parents, that had never seen dam building before. He put those young beavers in a concrete-walled room with no water in it and played the sound of running water through a speaker in the floor. And he gave the beavers sticks, and the beavers immediately dammed the speaker that was playing the sound of running water in this concrete room. That indicates that, yes, certainly the dam-building behavior is deeply hardwired in beavers.

DJ: I just have to mention that that’s really sadistic.

BG: It’s very, very cruel. Yeah. It wasn’t a kind experiment. But it was a sort of illuminating one. People often say “clearly these animals are just automatons, there’s no learning happening here.” But counter to that, I highly recommend a book called “Lily Pond” by a naturalist named Hope Ryden who observed beavers for many years. She documented very clearly, and this has also been observed by many other beaver scientists, that dam and lodge-building is an incredibly collaborative, interactive exercise in the beaver colony, and that young beavers, the kits, are quite clearly following their parents, imitating their parents, learning techniques of dam and lodge construction and of food acquisition, of tree felling. They’re very complex behaviors and it’s clear to anybody who’s ever observed beavers closely that the kits are gaining a lot from their couple of years in the company of their parents.

I think about it like language, maybe, in humans, or other species too. Of course, the desire to speak is really innate in us. You don’t actually learn English unless you spend a lot of time in the company of a lot of other English speakers. And I think that beavers are similar. There’s a deeply hardwired impulse to dam but the finer points of that construction are acquired through the transmission of intergenerational knowledge.

DJ: So we have about ten minutes left and this isn’t the official wind down question yet, but a sort of starting to wind down question. I’m sure you’ve seen that video of what happened when wolves reinhabited Yellowstone and how there was a cascading effect of ecological enhancement. They drove the elk out of the riparian zones, which allowed the trees to come back, which allowed the trout to come back, which also allowed the songbirds to come back. The elk aren’t quite so happy but everybody else is very happy.

So can you walk us through a 10 to 20 to 30 year period of a stream that’s been hammered, and a couple of beavers walk in, and then tell us about who – we could tell the same story about prairie dogs, of course, or burrowing owls, or rattlesnakes. So tell us what happens and how the land and water, the beings, plants and animals, come alive. Walk us through that process.

BG: Sure. I’m glad you brought Yellowstone up, because to me, Yellowstone is actually; yes it’s an amazing wolf story but it’s also an amazing beaver story. That Yellowstone was once an incredible, especially the northern range where a lot of the trophic cascade is happening – that was once an incredible complex of beaver ponds and wetlands. That was such a lush, spectacular place and when predators were eliminated and elk ran wild and ate all of that stream-side willow and aspen and cottonwood, beavers really collapsed in the park. And now, partly because wolves are returning and thinning those elk herds a little bit, beavers have been somewhat able to re-establish in the northern part of the park and are recreating some of that wet, lush habitat. So to me, I think the Yellowstone story is an amazing story that indicates how important beavers and wolves together are, right? You need beavers to create this wonderful pond and wetland habitat, and in many cases you need wolves or other predators to create the conditions in which beavers can return. You get two keystone species interacting in a really interesting way.

Anyway, to return to your original question about what happens when beavers move in: what’s really cool about beavers to me is the amazing cycle that happens. Initially they build this dam, of course, and they create this big deep pond. The first beneficiaries there are fish. That’s fantastic habitat, especially for rearing young salmon, trout and other species. As the water spreads out and the water tables rise you’ll get trees that die in the periphery of the beaver pond, and those turn into snags and become fantastic habitat for woodpeckers, who create holes that are then occupied by fishers and flying squirrels and other creatures.

Gradually, over time, what happens is those beaver ponds tend to fill in.

DJ: Wait. Can you bring insects in too, please?

BG: Of course. We know that these beaver ponds are fantastic habitat for aquatic insects as well. It’s been shown by scientists repeatedly, many times, that you get amazing production. And the reason for that of course is that you’re broadening the pond, you’re removing – beavers are removing these trees so you’re opening up the canopy. You’re getting all of this sunlight hitting the surface of the pond. This leads to this huge growth in primary production, right? All of this photosynthesis is happening now because you’ve permitted light to strike the pond. So you’re producing lots of aquatic vegetation and that leads to this boom in aquatic insects, which also feeds songbirds. Beaver ponds are fantastic places for songbirds to inhabit, because they’re these really wonderful kind of edge habitats where you can perch in a pond-side tree and fly out into the middle of the pond to snatch a mayfly or what have you. And they’re great bat habitat for the same reason. People don’t really think about the beaver/bat connection but bats do really well around beaver ponds.

I’m glad you brought up the insects. They’re a critical link in the chain. So what happens gradually over time is either the beavers will exhaust their food supply and move on, or the pond will fill in with sediment and gradually over time the pond, either the dam will breach or the pond will just fill in. And when that happens, you get the growth of this entirely new plant community. Lots of sedges, for example, that will grow in these wet meadows that replace the open water from the initial pond. And when that happens, that becomes fantastic foraging sites for ungulates; for elk, deer, moose. Black bears show up to eat all of the plants, the berries and the roots that are taking hold in these wet meadows. That’s a completely different kind of habitat and a really important one.

Those wet meadows are really vital for amphibians as well. It can be hard for tadpoles and frog eggs to survive in a fish-occupied beaver pond, but as those ponds fill in and become less fish habitat, they become really great amphibian habitat. So there’s this fantastic cycle that happens as the initial beaver pond becomes a wetland and a wet meadow and then gradually the forest canopy closes in again, and then conditions are right for the next beaver family to arrive. And that process can take years or it can take decades, or centuries. But I think that’s one of the really amazing things about beaver-occupied sites, the way that they kind of transition from one habitat state to another over the course of very long time periods.

DJ: So I have two wind-down questions. One of them is what do you want people to take away from your book and from this interview? Your book is fantastic, by the way. Again, it’s called Eager: The Surprising, Secret Life of Beavers and Why They Matter. Fantastic book. And the second is: if people are already in love with beavers, what can they do to help them?

BG: Good question. To me, the big message of the book is humility. Humans are such fanatical micromanagers of nature. We’re so enamored of our godlike engineering prowess. To me, the lesson that beavers teach us is that there are other species out there that are not only capable of engineering, but they do it in a way that is so much more beneficial for other life than the way we do it. Earlier you compared human-built concrete dams and the fact that they’re huge anadromous fish barriers, with beaver dams, which are permeable for anadromous fish. So we’re sort of doing the same thing, yet we have vastly different impacts on the environment.

One of my favorite quotes from the book is from an engineer and beaverologist named Joe Wheaton down in Utah. Joe’s mantra is “Let the rodent do the work.”

http://beaver.joewheaton.org

Instead of fanatically micromanaging nature, we can encourage this rodent that is capable of storing water, improving water quality, creating habitat for other creatures, providing firebreaks that dampen the landscape against wildfire, slowing down floods. Beavers provide all of these incredibly valuable services that we spend billions of dollars trying to replicate. And they do it ingeniously and for free in a way that’s beneficial to other life, rather than inimical to it. So to me, the lesson is let the rodent do the work and let’s be humble in the face of other species.

As for what individuals can do for beavers; first of all, if you live in a place that has beavers – for all my love of beavers, I’m not naive about how challenging beavers can be to coexist with. Your rural western folks complain that they cut down trees, they flood people’s property, they wash out roads, they clog up culverts, they damage irrigation ditches. They do all of this stuff that can be at times tricky to coexist with. But there are lots of techniques for coexistence. One of the solutions that I highlight in the book is a thing called a flow device. You often hear it called a “beaver deceiver” and it’s basically this pipe and fence system that you can install that kind of regulates the height of the beaver pond, so you can say “Okay, I like having these beavers here, I appreciate all the good they do, but I don’t want my property underwater,” and you can install one of these flow device contraptions to manage the problem non-lethally.

So I think there are lots of opportunities to solve these beaver/human conflicts in a way that’s beneficial for both parties. If you live in a town where beavers clogging culverts and flooding roads is an issue, talk to your town roads department or the state DOT manager or whoever, the person who controls infrastructure in your town is, about looking into these flow devices or beaver deceivers, these contraptions that can help manage those problems without having to resort to trapping.

There’s a really great nonprofit out there called the Beaver Institute, which is run by a guy named Mike Callahan, one of the leading champions of beaver coexistence.

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That has lots of resources on it about how you can install these things and live harmoniously with these really extraordinary animals.

DJ: Well thank you so much for your work, and thank you for being on the program. And I would like to thank listeners for listening. My guest today has been Ben Goldfarb. This is Derrick Jensen for Resistance Radio on the Progressive Radio Network.

Filed in Interviews by Derrick Jensen