0:33 Intro. [Recording date: January 21, 2020.] Russ Roberts: Today is January 21, 2020, and my guest is author, journalist, and conservationist Isabella Tree. Her latest book, which is the subject of this week's episode is Wilding: The Return of Nature to a British Farm. Isabella, welcome to EconTalk. Isabella Tree: Thank you.

0:52 Russ Roberts: This is a rather extraordinary story and beautifully told. A very personal story about how you and your husband let your 3500-acre farm, which is the Knepp Castle Estate, and Knepp is spelled K-N-E-P-P--the Knepp Castle Estate, which is about 50 miles south of London: you let it go wild. You let it return to nature. And, your book is the story of the expected and unexpected things that happen. But, you began as farmers. So, what went wrong? Why did you decide to give up farming? Isabella Tree: We--it took us 17 years to realize what was wrong with our land. It's basically very, very heavy clay. It's--I think the Inuit are supposed to have dozens of different words for different types of snow, aren't they? And, in the old Sussex dialect, we have 35 different words for mud. That's how much it kind of governs our lives, living on this stuff. So, it's, like, unfathomable courage in the winter when you've had a wet winter like we just had now--you literally can't get heavy machinery onto the land sometimes for six months of the year. So, you can't do any heavy maintenance, any ditch clearance, no maintenance of hedgerows, and you can't sow spring crops. So, you simply cannot compete with farms on much better soils than us, particularly in a globalized market. So, if anything that the longer we did, we tried everything. We did what every good farmer is supposed to do. We intensified; we bought bigger machinery; we experimented with new types of crops. We got different dairy animals in, to, with higher yields of milk. We even diversified into ice cream and yogurt. Haagen-Dazs, the Darth Vader of ice cream manufacturers, came over and blew us out of the water in Europe. But, whatever we tried to do, it was really the soil that we were battling against the whole time. We never turned a profit. And, we realized after 17 years that we were going to have to try and do something else on this land. And we wanted to try something that would work with the land rather than battling against it all the time.

3:10 Russ Roberts: So, what was the initial strategy and what got you started? How did you--why did it ever cross your mind that it would be potentially a good idea to just leave the land alone, more or less? Isabella Tree: I think we had, I think probably our first epiphany. It was very interesting, actually, writing the book, because it made me identify the moments when the penny dropped; and obviously you're on a journey. So, there are different intervals when the penny drops, and you get further and further embroiled in this direction. But, I think the first penny dropped when we had a wonderful--we do have a wonderful 500 year old oak, known as the Knepp Oak, just yards from the house, which was beginning to crack down the middle, and during the war when the Canadian Army was stationed at that, they tied it together with tank chains. And, these were actually beginning to fail. And, we wanted to do the best for this tree, to see if it could, we could save it for another couple of centuries. And, a wonderful man called Ted Green was recommended to us. He's the Custodian of the Royal Oaks at Windsor, in Windsor Great Park. Wonderful man, now in his 80s. And he came to advise us on this tree. And, he said there was nothing essentially wrong with this tree. It would go on for another three or four hundred years. We just gave it a bit of a haircut, helped it stabilize a little bit with a few extra wires. But, what he was really horrified about was, he turned his back and looked into the--what had been wrapped in park, a landscaped park around the house, until the Second World War when all of it was plowed up for the war effort and had been under intensive production ever since. And, all the oak trees in the park which might have been planted by the landscape architect Repton, in the early 19th century could have been even older. Some of them are 300 or more years old, were dying back and looking very stressed. And, I thought--I suppose Charlie and I had noticed it. But, we had sort of thought it must be down to some natural disturbance: maybe a drought, maybe the hurricane in 1997. What Ted pointed too was the soil, and he said, 'You're plowing every year up to the tree trunk. You are turning up its roots. Its whole mycorrhizal fungi, that wonderful network of root systems underneath the soil that bring nutrients and minerals and into these trees--you are doing everything you can, including pouring chemicals, fertilizers, artificial pesticides, herbicides, onto the land every single year. And, this is what is assaulting the trees. You're basically killing their life support systems. And, we'd never thought of it like that. We had sort of considered ourselves to be, you know, nature lovers, stewards of the land. You know, we didn't think we were doing anything wrong. And we suddenly realized that actually we were culpable: that what we were doing to our land had a knock on effect on life. And, it was the first time, I think, we had actually pointed the finger at ourselves. So, it was a very interesting moment and that's when we decided that we could--we found funding to restore the park. We got countryside stewardship funding to restore the Repton Park. And-- Russ Roberts: What did that mean, to restore? Isabella Tree: Well, it meant that we, by then we had stopped farming, in the area. We stopped farming in the area around the house, in the old Repton Park. We, simply--we basically impoverished the soil again. So, we regrew a hay crop for a couple of years and carted it off the land. So, you're basically taking all those artificial nutrients, that surplus fertility that you're pouring on with your nitrates, out of the soil. And, then we reseeded with native grasses and wildflowers. And, that summer after reseeding, we, it was an absolute, we were amazed. We walked out of the house into knee high ox eye daisies and wildflowers. We were kicking up common blue butterflies and the sound of grasshoppers and crickets was deafening. We suddenly realized that we hadn't even heard insects when we were farming. It was a sound we weren't even used to. And, then of course with the resurgence of insects came all the birds. And, suddenly we were surrounded by birdsong. And, it felt like we were living in the middle of the Serengeti. And, then in order to keep the grasses down and to keep the system going, we introduced free roaming fallow deer. And, just seeing wild animals moving around the landscape, not harried, not harassed, not seeing the land under the plow growing maize one year, then barley, then wheat, and sheep. It felt like the land itself was giving this tremendous sigh of relief. And, that was the most relaxing moment of all, this lifting, this burden off ourselves of feeling that actually that we were doing something with the land.

8:46 Russ Roberts: And, what did you expect to happen at that point, if you can cast your mind back to that? Obviously, we're going to talk about some of the things that happened that you didn't expect. We just, a much longer list, I would guess. But, what did you expect was going to happen when you planted those native grass seeds and introduced those deer? Was there a plan, in some sense? Isabella Tree: Well, I think that was the first moment--we knew we were trying to restore a Repton landscape, which is Humphrey Repton, you know, was quite a sort of managed[?] landscape architect. So, we weren't trying to do anything typically different to him. But, suddenly feeling that life was resurging, in this way, made us bolder, I think. And, it made us think, 'Well, we could actually roll out a project for nature, across the whole estate.' And perhaps outside the landscaped area of the Repton Park, we could do something a bit wilder, a bit more experimental. And, that's when we met this amazing Dutch ecologist, Frans Vera, whose work--he just published a book called Grazing Ecology and Forest History in 2000, which was the year that we sold our farm machinery and our dairy herds, and we actually gave up farming. And, I think because we were then out of that sort of terrifying tunnel vision of trying to make a farming system work, we were much freer in our heads to think of options. And, what Frans Vera was saying really sounded exciting to us, because he was saying that in all our imaginings of what our landscapes used to look like, we tend to forget the zoology. We forget the big animals, the megafauna that would have been here, driving the creation of habitat before us. We forget about things like aurochs--the ancestor of the domesticated cow. We forget about tarpan, the original horse; about bison, the European bison; about elk, which you call moose. We forget about reindeer, red deer, wild boar, beavers by the million--all these animals would have been shaping our landscape in Europe. And, we've forgotten about them because we hunted most of them to extinction, or at least we excluded them from our agricultural landscapes, from our river systems. And, they only exist in very small numbers in kind of remote areas. But, if you put them back into your landscape--figuratively speaking--what you suddenly get are really big dynamic processes, natural processes, that are disturbing the soil, adding urine and dung, even their carcasses to the soil, a huge nutrient cycle that starts to kick off, you're then adding processes that connect with vegetation. So, disturbance with scrub, with plants, even as far as ring barking and getting rid of trees. So, you have a huge impact on the environment that is very dynamic. And, that is rocket fuel for biodiversity. So, what Frans is saying is that if you want to recover biodiversity--and we've seen that catastrophic collapses, and I think in Britain just across the board, we've lost 60% of our biodiversity since 1970--you want to recover those losses. He's indicating the way to do that is to allow these animals, or proxies of them if you haven't got the originals, to free-roam around the landscape and kickstart that dynamism again. And, so that's what we thought we'd try and do--to try an experiment, to see if we could get really dynamic nature back in our landscape by releasing some free-roaming animals on our land.

12:48 Russ Roberts: And, we'll talk about that in a minute. But, it's going to be, as you say, the closest you could get to megafauna in a 3500-acre area 50 miles south of London. But, I want you to talk about a tension that you discuss in the book between what you describe as, quote, "closed canopy woodland," which we would, I think, call a forest; and "open grazing grassland." And, I think there's a natural tendency to think as she mentioned in the book that, 'Well, forests are natural; and we think of letting things return to nature, we'd get a forest.' There'd be some trees, there'd be some birds in it. And, maybe some squirrels or squirrel-like small creatures, but there's a very, very big difference between that and the open grazing grassland, which is, as you said, more like the Serengeti, more like what, in America we would call a prairie. It's a very different landscape. And you started with--I don't know what you would call it--a manicured landscape, a farmed landscape and you started letting it go, and introducing the animals. And, then it changed. So, talk about first that tension between those two types of ecosystems sort of, I would call a forest and prairie; and then how you experienced that: what you did to introduce those species into the land and how it changed. Isabella Tree: Yes, I mean, this was something that I find so interesting. This word 'forest,' and we have this idea very much in Europe that before human impact, every area in temperate zone Europe that could grow trees would have been covered in trees. In Britain, we have a sort of a legend that a squirrel could have run from John o'Groats in Scotland all the way to Land's End in Cornwall without touching the ground. And, so, this idea of this [?] of primal, verdant, unfathomable forest has become almost a sort of a metaphor for a sort of untouched, pristine state of nature. Russ Roberts: It's a n Eden myth. Isabella Tree: An Eden myth. Yes, that we now--I think it's really important to understand how it works because obviously, we have to have an idea of what we want to recover in terms of nature conservation. And, really, if we look at what we had here in the past, it wasn't closed canopy forest. It would have been much more open: it would have been like a wood pasture more like. And interestingly, the word forest originally doesn't mean close canopy woodland at all. It comes from the Latin 'fora,' [sp.? foras?--Econlib Ed.] which means outside. So, it was really the area outside the cultivated land. So, where you had all these free roaming wild animals , in Germany they called it the 'wilds'--the 'wild'--and that's the word that actually our Sussex 'weald' comes from. We're on low-weald clay. So, it would have been a much more open landscape forest. A forest actually meant a land where you have deer, and in Scotland now, you have deer forests where there aren't--there isn't a single tree on it. So, it's very important, I think, to recognize that the word 'forest' is--we've changed that. And, we consider it --often, we even call a plantation a forest. And it's very species-poor, very undynamic, very static. We have very few bird species in Europe that actually live exclusively in closed canopy woodland. Where you find most of the biodiversity and the floral complexity is where you have glades or clearings, where you have areas that are managed for coppice or the margins around the woods. You don't find that much life deep inside closed canopy woodland. Russ Roberts: Explain what coppice is. Isabella Tree: Coppice is when you cut a tree so that it grows again. This amazing ability that trees have to regrow their shoots. And, centuries ago we would coppice for charcoal. So you have these thinner tall shoots that come out from the base stump, and you can keep coppicing in a rotation every few years. Russ Roberts: In American English we call it pruning. Isabella Tree: Yeah, I guess so. And, there's also pollarding, which is when you do the system higher up. And, of course, what we're doing in, in essence is imitating the grazing and browsing animals. The reason that trees bounce back when they have their limbs cut off, is because they would have been browsed and broken and trashed by animals like bison, red deer, and in the distant past by things like straight-tusk elephant. So, what we're doing is just mimicking nature all the time. And, I think it's very important to have that notion in our heads of these free roaming animals disturbing the landscape and keeping it open and moving the habitats on. So, essentially, you would have had trees in the landscape, many of which are light-demanding species, which again, can't regenerate naturally in closed canopy conditions. But, you would have had thorny scrub, you would have had water meadows, bogs, heaths, all shifting and kaleidoscopic and moving. Russ Roberts: Talk about scrub. I think scrub is, we would call--it's called scrub in America sometimes. It is also, it would include things like bushes, weeds especially. Correct? What we call weeds. Isabella Tree: My new year's resolution is never to use the word 'weed' ever again. At least not to refer to that. So, native wallflowers, maybe. Russ Roberts: We had Rory Sutherland on the program. He said a weed is a flower without a marketing budget. So, it's very convenient. I think that's a very sympathetic to your view.

19:18 Russ Roberts: But, anyway, so this landscape would have all this diversity rather than just trees. Talk about what you introduced into the land in terms of fauna. Isabella Tree: Yes, so for the first few years we allowed this vegetation scrub, this vegetation to scrub up and kind of to pulse, so that you're getting your thorny scrub back into the landscape. So, things like brambles, hawthorn, blackthorn, dog rose, gorse, even. Russ Roberts: Thistle. Isabella Tree: Thistle, absolutely. So, all this scrub coming back into the landscape, and once that's really established, then we began to introduce our free-roaming animals. And, because we don't have the aurochs anymore--we hunted to extinction several centuries ago--we can use its descendants, which are domesticated cattle. So, we have Old English Longhorn, which is a very hardy breed, that we've chosen instead. And, the theory really is to choose old breeds because we intended not to interfere, or to interfere as little as possible. So, no supplementary feeding; they wouldn't be given any shelter. I mean, there are actually a few barns out there, but they never use them. And, essentially, to let them to their own devices. We used, we introduced exmoor ponies to stand in for the tarpan--the original horse. The exmoor is a very hardy breed of horse. They've got wonderful sort of adaptions to living in very cold climates. They have something called 'toad eye' which has this amazing eyelid, which can come down and protect the eyes from driving snow and hailstones. Wonderful, very wild, sturdy little horse. And, then we had, because we're not allowed to introduce wild boar, we were using Tamworth pigs, which are a wonderful sort of proxy for the boar. They're big ginger pigs; again, they're very closely related to European swine. So, they've got quite long legs, long snouts, so they're very good at rootling. They can run as fast as a horse for short distances. Amazing animals. And, then we introduced fallow deer and red deer as well. And, again, the idea is that all these animals have different mouthpieces, different ways of browsing and grazing, different vegetation preferences, and completely different ways of disturbing the land. Russ Roberts: Give us a rough idea of how many of each you started with. Isabella Tree: Very small to begin with. So, we allowed the herds to build up very gradually. So, we introduced, I don't know, it's probably about 20 English Longhorn to begin with. We now, over the three different sections of the rewilding project, probably have about 400 head. Again with the ponies, we introduced about six in the beginning, and we have now a herd of about 30. So-- Russ Roberts: And, the pigs? Isabella Tree: probably very small numbers to begin with. Russ Roberts: The pigs? Isabella Tree: Pigs. We started off with six, and we thought--well actually two sows and eight piglets; sorry, so 10. But, we thought we would be able to have a herd of about 70 or 80 and make this wonderful jamón. But, I'm afraid pigs create much more of a disturbance than we'd anticipated. So, we still have relatively few pigs in the system. We probably have about six females and they will have a litter of maybe six piglets every year. So, the numbers fluctuate. But, really the vegetation complexity and biodiversity depends on having this very diverse number of megafauna out there, the very, the different species that are doing different things. Russ Roberts: And, it's important to let listeners know because it wouldn't otherwise cross their mind: The reason you just sort of mentioned casually, you couldn't introduce wild boar and you wanted to. There, part of the reason is that your land is semipublic. There are paths running through it, there's--people can ride horses through it. They can walk through it. They walk their dogs through it. There's roads that I think go through it as well. And, so there were some limits on what you could introduce; and in particular, there are no predators. Isabella Tree: That's right. I mean, the question about the wild boar is a really mad, anomalous, kind of weird British thing. It's categorized as a dangerous wild animal, even though it was present until about 400 years ago in our landscape. And, there are now feral populations that have escaped from wild boar farms back in the countryside, colonizing. So, you've got this weird thing where you can't introduce a wild boar, but if it gets onto your land of its own accord, then it's no more notifiable than a fox or a badger. So, we're in this weird system where we're just hoping that the scent of our delightful Tamworth sows will entice some wild boar from about 10 miles away and they'll break down the fence and get in, and we'll have be able to have wild boar. But, we would certainly love to have bison, for example. And, again, we have a job on our hands to convince the government and the great British public that that would be fine. In Europ,e where they're much more adventurous and kind of perhaps less insular than we are, bison are proving to be a real keystone species in all these huge rewilding projects in Europe. And, there's even one rewilding project in the Netherlands which is only about 800 acres or so in size, just a few miles from Amsterdam, where bison are quite happy to tolerate footpath walkers. And there's even another reserve where they've been able to climatize bison to dog walkers. So, it's perfectly possible to live with these wild animals again. We've just got to get used to how to do it. I think is as much about training people as it is about training the animals themselves.

25:49 Russ Roberts: Yeah. We talked with Pete Geddes of the American Prairie Reserve about their extraordinary efforts in the western United States. But, that's a very desolate area, relatively--not--'desolate' is too strong, but it's relatively unpopulated. You're in a somewhat populated area, and of course you have neighbors who saw what was happening to your land. And you described in the book--it's both comic and tragic--their reaction to this, to seeing your land go from being a very manicured farm land, at least manicured on the surface. As you point out, what was going on below the surface was not nearly as attractive, but what at least looked good, to something that was more like, I don't know, a teenager's bedroom or my bedroom sometimes, when I don't--or my office right now. Chaotic, unplanned, unmanicured, unmanaged. So, you did introduce these animals, but you sort of let them run wild; and you let the vegetation do whatever it was going to do. They didn't like it so much. Talk about the reaction you got from the great British public. Isabella Tree: Yes. I mean, it's understandable. I think because we are, as you say, used to very manicured landscape. And, it's, you know, the picture postcard of the British countryside is linear edges. It's tightly managed hedges. It's isolated woodland. There's no scrub in[?] as a tool. Your rivers are canalized. It's very micromanaged. And, if you're used to looking over your head at this sort of landscape and suddenly you see a riot of thistles and ragwort and thorny scrub popping up, you're going to be outraged. So, we had letters of saying that, to Charlie, my husband, saying that his grandparents--which is who we inherited the estate from--would be rolling in their graves and we'd turned something beautiful into an abomination. We were accused of being lazy, irresponsible, unpatriotic even, because we weren't producing food from our land any more. Very much that 'dig for victory' kind of ethos from the Second World War still persists, I think, in Britain. And, we did have to kind of really steel ourselves to continue a lot of the time in the early days. But, then eventually, I think--first of all, our headline species started coming back. Suddenly, some of the rarest species in Britain started popping up on our land. Birds like the nightingale, and the turtle dove, which is supposed to be going extinct from Britain in the next 10 to 15 years. Its numbers have declined from 125,000 pairs when I was growing up in the 1960s to less than 3000 now. And, suddenly, we were finding turtle doves breeding on Knepp in this amazing thorny scrub that was coming back. So, I think suddenly, perceptions began to change. People began to realize that there was sort of method in our madness. And, when they were walking the footpaths--and we probably have about 20 miles of footpaths on our land--you know, people began to hear the birdsong. And, slowly, I think that aesthetic began to change. Because it is an aesthetic that we've kind of grown up with. It's conditioning that makes us think that the land is good to look at when it's micromanaged. A lot of it is about letting go in ourselves and our own perceptions of what is beautiful. And, we even had a letter, which was so lovely, last year from one of the women who had written to us, the one who had said that we turned this beautiful landscape into an abomination. And, she apologized. And this was 15 years on. And, she said, 'You know, I wrote this letter in anger. And, I now realize I was too quick to do that. And, now I realize that your land is still beautiful, but just beautiful in a very, very different way.' So, I think a lot of what we have to learn to do, I think, if we're going to start managing our land in a different way, and doing it in a way that is wilder and to encourage biodiversity--and, we haven't even talked about all the other things that can come from this sort of system as well, like carbon sequestration and soil restoration, and flood mitigation and air purification, and water purification. All these other things that come together when you restore land. I think it all really boils down to changing our own mindset about what we feel happy living with and looking at.

30:28 Russ Roberts: Talk about some of the species that have come there and the numbers of them, and particularly the butterflies, the owls, the bats, the dung beetle. I was just--I feel like it's teeming with life, your land. I don't know if it's--you may have romanticized that a bit, but it's certainly more teeming than it was when you were farming. Isabella Tree: I think what's happened here has astonished not just us, but all the specialists--the scientists who've been monitoring and helping us survey what's been happening over the years. I mean it is just astonishing. If you walk out into the scrub on a spring morning, the sound of birds is so strong you can actually feel it vibrating in your stomach. We have now all five U.K. species of owl. We have 13 out of the 17 breeding species of U.K. bat. Including two bats, the Bechstein's and Barbastelle bat that is so rare, they're rare even in Europe. And, of course they're flooding in because they are seeing, not just the habitat--and we leave dead wood, which is obviously wonderful for bats--but also the insect populations are just rocketing. We've now got one of the rarest species of butterfly in Britain, the Purple Emperor. We're by far the biggest colony of Purple Emperor butterflies in Britain. And, as you say, dung beetles: I mean the lowly dung beetle, which I probably hadn't given a second thought to before. And, of course we never had them because-- Russ Roberts: Maybe not a first thought, Isabella. Isabella Tree: Not even a first thought. Russ Roberts: No. Isabella Tree: When we were farming, of course, we were putting ivermectins[?]--you know, wormers--into our cows, and antibiotics all the time. So, their dung was full of the kind of chemicals that will kill a dung beetles stone dead. But now, of course we're in a completely organic system, and we're beginning to understand how crucial dung beetles are as a keystone species. They actually, they're pulling the dung back into the soil to replenish it. It's one of the quickest ways of kick-starting natural processes under the soil is this, this thing that the beetles do, is pulling down the dung into the soil. My husband's turned into a bit of a dung beetle fetishist, it turns out. And he's--I couldn't understand what he was doing last year. He was following the cattle around with his mobile phone, and every time one of them did a cow pat, he would dropped his stomach next to cow pat. And, I couldn't work out what he was doing. But he was timing how long it took the dung beetles to find the cow pat. And I think the record was under 60 seconds. And, that was kind of fine until he started bringing the cow pat into the kitchen and continuing his experiments on the kitchen table. And, there were unspeakable things in the freezer for a while. But, at the end of a summer he had identified 23 different species of dung beetle in a single cow pat. And, including one dung beetle, the violet door beetle, which is so rare hasn't been seen in Sussex for 50 years. So, these creatures are clinging on somewhere in the landscape to little shreds of habitat. And, as soon as the opportunity is available to them, they colonize and find us, and then the populations explode. It's a miracle really. Russ Roberts: And, it's not--I mean, 3500 acres sounds like a large area. Because it's 3500, which is a number over five or 10. But, it's only about five square miles, if Google is correct in telling me. So, it's not the size of, say, Yellowstone National Park. It's a very modest area that you have created unintentionally. And, I say that explicitly. You did not have the intention of having 23 dung beetles on your soil. I want to read an excerpt because it will resonate with many themes in this program. Quote: It was becoming clear to Charlie and me that had we set out with the intention of creating the perfect habitat for purple emperors [--Russ: which is a butterfly--] we would never have achieved the numbers that have spontaneously emerged through rewilding. The phenomenon is an example of what we are learning to refer to as 'emergent properties.' An emergent property is a property which a complex system has, but which the individual constituents of that system do not have, like the cells of the heart which, on their own, do not have the property of pumping blood but which together create a higher level aggregate--a complex organ--that does. At Knepp, previously missing or dormant components were coming together, striking up extraordinary and unexpected outcomes. In effect, two plus two was making five--or more; and this imposed on us as midwives of the system acceptance and humility about our role. There may well be other factors involved in the success of purple emperors at Knepp that we have not yet identified, perhaps may never identify--a preference for certain types of animal dung, minerals or sap-runs, temperatures, moisture or some other tiny cog in the wheel, or a fortuitous combination of any number of things. What seems imperative is that we take care not to fall into the trap of assuming, as conservationists have so often in the past, that a couple of specifics--some tall trees and a massive amount of sallows--is basically all the purple emperor needs. This is tantamount to asserting that the individual cell of a heart is the property of pumping blood--an assumption known as the 'fallacy of division.' The purple emperor butterfly, with its complicated life cycle involving numerous stages, requiring different conditions over the course of almost a year, beats its wings to the tune of the entire symphony orchestra that has conjured it into being. That's very beautiful. And, by the way, the nature writing in this book is just spectacular. It makes you want to step outside. Certainly if you live where you do, not so much where I am, outside Washington, D.C., but certainly to get to a slightly wilder spot than my suburban neighborhood. But that idea, that we do not fully understand the complex connection between the different parts of the land is something that really rings clearly throughout the book, and it resonates with again, as I said, many themes on this program about emergent order. We often talk about it in the economic sphere, but certainly in the natural sphere. It's really an incredibly beautiful thing. Isabella Tree: I think it is a very difficult thing, though, I think, for human beings to sit on their hands and do nothing and to allow nature to express itself. I think it's--we've learned to micromanage so much that we find the thought of unpredictability very nerve-wracking. And, again, I think that's something we need to identify and change in ourselves somehow: that, to actually feel sort of joy in the unexpected rather than fear. And, to trust that nature has had millions of years of R&D [research and development], that it knows how to regulate; that it can--it has amazing abilities to rebound and to sort out systems and to control monocultures. That, I think that trust in nature is something that we've sort of lost in this role that we've imposed on ourselves as sort of playing God in the countryside.

38:06 Russ Roberts: And, in another book, called Feral, which is about the rewilding going on throughout the United Kingdom and in Europe as well, which by George Monbiot, he has a very negative view of sheep. He understands--what I liked about his book, among other things is that he understands that sheep farmers are going to disagree with him and that they have a life and a set of expectations that may not be the same as his, and he's tolerant of their differences with himself. But, he basically says that we've come to believe that a sheep-dominated landscape like Scotland's, and other places that are fundamentally denuded of vegetation and browsed down to the soil, it is somehow natural; and we're neglecting the fact that that is not natural. So, explain to me--one of the puzzles I had read of your book is that sheep are not natural. But, deer, which in some settings also act like sheep: they basically destroy everything green, if you have enough of them. So, you're in a setting where one might have thought that you've simply replace sheep with deer and oxen or Longhorns and ponies--they're all grazing away. Why is your landscape so vibrant? And, why has it not been reduced to the more sterile species-free world of say, a sheep pasture? Isabella Tree: Yeah, I love George's descriptions of the sheep-wrecked landscape. I think sheep are a slightly different question because they are not originally from Northern Europe. So, they're from Mesopotamia. So, they've been in Britain for several thousand years. But, our vegetation hasn't evolved with them in the same way. I don't go as far as George: I would say that there's probably a very good role for sheep in rewilded landscapes. It's all a question, as with any herbivore, with the numbers. So at net, we're very careful about the stocking density. So, if you can sort of imagine that there's two basic natural processes in action out there in the wild. One is vegetation succession. So, that's the growth of plants coming up, that sort of movement, if you like, into scrub and then eventually closed canopy woodland. And, then the other is your large herbivores, to animals out there that are grazing and browsing, interrupting that process. There's two forces that battle with each other. And, so what you want really is neither force to kind of get away too much. You don't want too many animals because then you'll get an over-grazed system, something that we're very familiar with. We were driving up through California and seeing your wonderful sort of oak, wood pasture, but super over-grazed underneath by cattle. That's very much the systems we have here. We're used to seeing huge numbers of sheep over-grazing and red deer in Scotland grazing everything out of the landscape. So, you don't want too many animals. And, you don't want too few because then you have your scrub turning into closed-canopy woodland, which is, again, very static and species poor. You want that interaction to be able to go on together. And, it's that which creates all the messy margins that stimulates biodiversity. So, of course, in the past, you would have had huge migrations of animals moving through the landscape from one place to another, allowing areas to recover as they were left behind. So, at Knepp we don't have that, obviously. We've got a small enclosed, relatively small enclosed area, that we keep the stocking levels of animals very, very low. So, we're culling animals all the time, really, and that produces 75 tons of meat off the project. And, we're also very aware that we don't have predators as you say, we're not Yellowstone. We haven't--a wolf needs, I can't remember how many hundreds of square miles of territory wolves need, but it's huge. And, the same with the lynx, which would be our other large predator. So, that's not viable, particularly in the Southeast of England in the busy-ness[?] of conurbation. But, when--predators don't actually, or they're not responsible for huge numbers--they're not actually responsible for population control, as such. I think if you look at somewhere like the Serengeti where you've got huge numbers of predators, they only account for about 10% of mortality rate in those herds of herbivores. But what they do, is they push them on. So the herbivores bunch up and they move--they live in a landscape of fear. And, that certainly has an impact on allowing vegetation to be released from the pressure of herbivores. So, again, that's the system that we don't have here. So, another reason for keeping the animal numbers very low. And, we want to make sure that they can come through even the harshest winter. We don't get many frozen winters anymore down in the south of England with snow like we used to in my youth. But, we want the animals to be able to come through a long winter--especially if it's been very wet with not much grass--in really good shape, and that's another reason for keeping the numbers low.

44:06 Russ Roberts: So, I just wonder--we talk on here occasionally about the challenges of creating a prairie. They're not that different than the challenges of creating a vibrant economy. We sort of know what it looks like when it's done. A prairie has certain set of species in America, at least. A grassland will have a certain set of species, a certain dominance of some, lack of dominance of others. And, similarly, with the economy, we know a successful economy has got property rights, it has freely moving prices, it has competition. Just starting with those doesn't work as well as I think most economists would have thought. And, similarly just trying to mimic a prairie, it's not so effective. It--the analogy I like is cake. If you make a cake, you'll know what the ingredients are. But, if you don't know the right order and the amounts, you don't get a cake. You get a mess. And, a mess that's not edible. A prairie can be a mess, but it has a vibrance and a dynamism, as you point out. Now, in America, my understanding is in many ecosystems fire plays a crucial role, but I assume there's not a lot of fire now. And, I wonder if someone who took a Knepp-like area in a different part of England and tried to do what you did, it might not come out--well, I'm very confident--it wouldn't have come out the way yours did. They could have gotten a different succession of plants and animals, flora and fauna. So, what are your thoughts on that? Isabella Tree: Well, I think the question of fire is a very, very interesting one. And, of course, it's so much on our minds. Now we're thinking about this, the terrible fires in California and now this sort of furnace in Australia. And, I think we can, if we look back into the role of megafauna, it can be very instructive because in temperate-zone Europe, I think fire wouldn't have played such a huge role because we have very few trees with ignitable sap. And, even in the driest of summers, if you try and light a bonfire outside, it generally doesn't work unless you put some petrol or something in that too. But, I think that the role of herbivores often, particularly in brittle landscapes, is to take out that dry vegetation that's actually stuff that can very quickly ignite. I was talking to a friend , a regenerative farmer in Australia, just this week, and he said in areas of Australia where aboriginal friends of his, had their land, they haven't caught fire because they culturally burn. And what has been erupting with such drama recently is areas where there aren't the herbivores anymore to take out the thatch and also there's no system of control burning. But I think also, landscapes can undergo a kind of catastrophic shift into a landscape where burning is part of the natural process. And, I think that happened, for example, in Australia, and I wouldn't be surprised at all if it didn't have hadn't happened in America, too, where the extinction of megafauna--we think of the dozens and dozens of huge species in America, including a whole suite of camels--that's where the camel came from, and horses--all those species that were wiped out after human arrival. And particularly in Australia, where they lost all their megafauna that were larger than a grazing kangaroo--and, some of them were giant--had a massive impact on the environment, because suddenly you knock out all those big grazers and browsers. And you have all this ignitable vegetation in a landscape that very quickly can combust. And, if you, like in Australia, only now have grazers rather than browsers, that's a huge shift to a situation where you're now prone to fire. And, then you get fires happening, which then take out your more temperate trees, and you get trees that are actually--can withstand or even need fire--and shift to a different kind of fire-tolerant vegetation. Russ Roberts: We made it [?]. Isabella Tree: And that again starts desiccating it even further. So, the question, I think, is: would introducing some of these megafauna back into a landscape again, could that actually start regenerating soils? Could that start getting rid of some of this dry, thatchly[?] vegetation? Could it in a way kickstart more moist microclimates in areas again? I mean, I think it's an interesting dynamic that we're only just beginning to consider.

49:19 Russ Roberts: Well, I think the challenge--I'm curious how you think about this--is, we've wax poetic as do in the book, and I tried to a little bit in commenting on the book about the virtues of leaving things alone, and leaving things to nature and taking your hands off the steering wheel and giving up control. Things that I personally find very challenging, but I systemically find deeply rewarding. And, yet, you have to cull because you don't have those predators: you have to intervene. You do have to manage the herds of those animals on your land. And, so, 1. Talk about the psychology that for you emotionally have that sort of, it's a, I would call it a, sort of a, you have to give up your principles to some extent, because you have a fixed area of land and you're trying to make it wild, but it can't exactly be wild in 2020, an hour south of London. That's number one. And then 2. Talk about what you've done to try to make lemonade out of those lemons. The use of, the selling of meat. Which, incidentally, the American prairie reserve has a similar flavor, pardon the word, where what they do is they reward farmers who allow animals to pass through their land. And, they give a badge of approval to the beef that's grown on that property, on those properties, where effectively those cattle-raisers have allowed a land bridge for these larger and wilder creatures. So, farms that cooperate with this prairie project in the western part of the United States, get honored with this badge of approval, which then makes customers happy when they're eating it, because they know they're contributing, in some sense, to a wilder environment, not just eating a grazed animal that was raised for food. But, in your case, you're actually selling the meat directly to folks. So, tell us how, first reflect on the psychology of that, because that must be --I assume that's somewhat challenging. And two, talk about how you've done the best you could with it. Isabella Tree: Well, I think the way to look at it is that you have --rewilding isn't just to say--there isn't a formula for it. We're all on a journey, in a sense. So, the ultimate goal might be to be somewhere like Yellowstone, but actually even Yellowstone probably isn't enough-- Russ Roberts: Oh, it's not-- Isabella Tree: Y2Y-- Russ Roberts: It's not so wild-- Isabella Tree: We want to connect that with the Yukon. You know, we want continental connectivity. And so, if you're looking at a tiny area like Knepp or even our miniature nature reserves--we've got nature reserves in the United Kingdom that are one acre big, protecting a particular species of orchid--I think you have to look at that on a spectrum. So, when you get to Yellowstone you don't need any human intervention at all. When you're an acre looking after one particular orchid, you need masses of management to micromanage to protect that orchid. But when you're at Knepp somewhere wafting about in the middle, you can be as hands-off as you can possibly dare. And, our main intervention, as you say, is controlling the number of animals. And that's specifically because we don't want to see them starve. You could actually let them starve. You would lose your scrub and your vegetation for a bit--the population would collapse. And, then eventually the scrub would come back and the population would rise again. That's what would happen in the Serengeti, or even in enclosed areas like Ngorongoro Crater. But, what we do then is we make a virtue out of that sort of sensibility, if you like, that we don't want to let animals starve. And, we cull them. So, that's now a very important income stream for us. It brings in about £200,000 [British pounds] a year, and that's very low input. So, of course, the profit is very high. And, we hope to be able to encourage more profit from that as we begin to sell direct to our consumers. And, there's increasingly, I think, an interest in buying ethical meat, eating less and no industrially, grain-fed feedlot meat, but really thinking about where our meat comes from. So, it's an income stream for us. And, I think it's something that other rewilding projects can also imitate. And, I think we also now have an ecotourism business, which again, has brought in income. So, we are now looking at being a sustainable business. Whereas before when we were intensively farming, we definitely weren't. So, it's a model, I think that can be rolled out. I think ecotourism is definitely on the rise. The more urban we become, the more--there's a sort of hunger and need to get out into wild spaces. I think we know how much it affects us, not just physically, but also mentally if we disconnect ourselves from nature. So I think all these things are really interesting. And, I think that the American prairie project is--it's an astonishing model and it's huge. But, I think it's all about connectivity. Ultimately we would like to be able to connect with other landowners around us, perhaps even as far as the sea, 20 miles away. And, as soon as you have that connectivity, you can let your animals roam even further. You can take your hands further off the steering wheel. You could perhaps actually let your, some of the populations go for a bit. So, the larger you can become, the more connected you can become; then, the further up that graph towards Yellowstone, you can go.

55:26 Russ Roberts: Well, I just want to put a footnote on that, which is that: I'm afraid you're idealizing Yellowstone a bit. I mean, it's a beautiful, magnificent place. But, until, as you know, until about maybe 25 years ago, they had exterminated all the wolves from the park. But they didn't cull. So, the elk population got rather large, which eventually killed off the beavers because there was no vegetation on the sides of streams and very little vegetation. At least on the sides of streams. The willows were destroyed. It's a rather extraordinary thing that when they--I've written about this because it's a beautiful example, again, of unintended consequences. When they reintroduced wolves, the beaver came back. Which, because they were able to reduce the pressure of the elk population and the elk herds on the riparian--the stream--areas and other vegetation. The other part of Yellowstone I think is very relevant is that Yellowstone for a long time did not tolerate--probably still doesn't--fire very well. Meaning the managers of Yellowstone. So they would put out a lot of fires partly sometimes for fear it would spread to inhabited areas nearby. But, because there was a zero--what was close to a zero tolerance of fire--that thatch that we were talking about earlier built up, and then there came a fire they couldn't put out. So, the horrible enormous fires of Yellowstone. Isabella Tree: I've never seen that-- Russ Roberts: Comes from mismanagement and not allowing the smaller fires to work. And, so even Yellowstone, which we're romanticizing a bit here is not anything close to a-- Isabella Tree: No, I mean, absolutely. Yeah. And, I think that the apex predator trophic cascade that you talk about with the wolf is an astonishing one. And, it just shows that we, even in areas that vast, you need the full suite of predators and herbivores for the whole thing to function. And, again, the problem with the fires was that it was too hands on. It was not allowing fires to happen that ultimately caused the big problem of a massive take-all fire. So, yes, it's interesting. Russ Roberts: I made the analogy to the financial sector as well that if we have zero tolerance for bank failure, there comes a set of failures that require a bailout that's both socially and economically disastrous, with all the decisions that get made along the way. We would have been--you know, people say to me, 'So, you would have bailed out the banks?' Well, I don't know if I'd have bailed out the banks or not. I don't envy the decisions that people made in 2008, when faced with that crisis. But the seeds for that conflagration, that financial conflagration, were sown, in my view decades before, with all the small fires that they refused to let burn. And, so as a result, people took riskier and riskier, made riskier-- Isabella Tree: Yeah. So, interesting-- Russ Roberts: and riskier decisions. As that I think there's a useful analogy there.

58:42 Russ Roberts: I don't want to leave this untouched. It's not the easiest topic for some of the squeamish in my audience. But, you are also--you have to cull your ponies--they're called 'ponies,' but they're not. How much does an Exmoor pony weigh, and how much, by the way, does a Longhorn weigh, and how much does a Tamworth pig weigh? Roughly. Isabella Tree: Oh, gosh. You're asking me something I really couldn't tell you. Russ Roberts: No, but they're big. Isabella Tree: They're big. They're very big. Russ Roberts: They're not tiny. Isabella Tree: We don't we don't cull our ponies yet. We would like to in the future. Because, it's very difficult to have a viable natural herd, if there is no market for them. What do you do when your population is so large that you feel it's beginning to impact on the rewilding project? And, you know, we feel that we can, our capacity is probably about 30 ponies. At the moment we can take the ponies to other rewilding projects that are beginning to start up. And, there is a movement now, which is wonderful to see happening in the United Kingdom from people who've visited Netherland, seen how successful it can be. But, there will come a time when those populations will still grow. And, what do we do then? At one point, when we had no market for our ponies, we had to castrate them. And, that's deeply distressing, not only for the ponies but also for the men doing the castrating. And, it costs £200 [pounds[ to tranquilize the ponies. There's the vet's bill. Or, you could sell the live animal for the market, and you would probably get about £40 [pounds] for it. Again, you would have to tranquilize it and get it off to market, about five- or six-hour journey from here--where it would probably be sold for meat, for France. So-- Russ Roberts: Because eats France horse, right? Isabella Tree: Yes. Russ Roberts: But, England, no? Isabella Tree: Quite a few countries. England, no. We've had a sort of taboo about it, for many, many years. I'm sure we would have eaten horse in the past because, you know, before the Second World War, we would have had millions of horses out there on farmed landscape. And what would you do, when you had a horse was beyond its life and you didn't want to go on supporting it for another five or six years beyond its working life? I'm sure people would have eaten their horses. It's become a big taboo. But, when you've got a wild herd of exmoors--and exmoor ponies are still rarer than the giant panda--you need to keep that dynamism going in that herd. It's very, very sad when you see them just floating around castrated males. They're just eating. There's no dynamism in the herd structure any more. You don't see the colts play-fighting. You don't see lovely foals being born. And, of course, they're probably prone to laminitis, because they are just doing nothing else but eat. Russ Roberts: That's a hoof disease, right? Isabella Tree: Yeah. So, it really is having to be pragmatic about how you get natural-functioning herds in a landscape again. If we want to see these animals in our landscape, and we don't want to see them starve, and we want to look after their welfare, then you do have to, I think, appreciate that, you need to be able to cull them at certain periods. And, if you cull them then I think it--you also need to eat the meat, because horse meat is just as good as beef, and we should just be honest about it, rather than trying to hide it away. In the New Forest, they have New Forest Ponies--another breed of pony. And, again, they're sort of secreted away. And when the population gets too large, and again, they get transported off to France--often live animals. Which is pretty harmful to the animal. So, I would feel much happier about being honest and selling conservation-grade pony meet than pretending that there isn't a problem, castrating. Russ Roberts: This is, of course, recorded, but I think I can hear the shrieks and screams of my audience at the thought of that. But we're going to assume they're okay. It's, I guess I should have had a trigger-warning about pony meat.

1:03:18 Russ Roberts: But, talk for a minute about the financial side of this, which is: You got a grant from a local conservationist--a government source. And, the main thing you needed that money for initially was you had to tear up a bunch of fences. And, then you had to put up a bunch of fences in different places. You had to essentially ring your land, which is a lot of money. I'm curious if, with the benefit of hindsight, and now aware of the revenue you're getting from meat as well as tourism--there's glamping and tours on your land; and, I have to confess having looked at your website, I wanted to go; I'm disappointed we didn't do this live on site but such is life--whether you think you could have made a go of that without that government money? Is the amount of money coming in, potentially enough to change that calculus? And, then the other thing I want you to mention is that: The European Union for a long time has been subsidizing farming, which is a sort of reverse--I don't know what the opposite of wilding is 'dliw-ing' or something--that's 'wild' backwards. But, they have paid people to ruin their land to some extent. So, talk about the financial side of it. Isabella Tree: Yes, I mean, I think to kickstart the whole rewilding project, we certainly needed that seed money, the funding. And we still do get agri-environment money from the EU [European Union] for what we do. It's called a 'high level stewardship grant.' And, so we get money for having, you know, reestablished natural systems on our land. And, we hope pros[post?] Brexit, and it looks like the government is going this way, that we will still continue to get money for what we do. Because, we're providing what are called ecosystem services, services for the public good. I mentioned them earlier, but, you know, carbon sequestration being a huge one. Solar restoration. We're mitigating against floods so that properties downstream from us don't flood any more, because our soil and our vegetation is holding onto water in the floods. We're cleaning the air. We're cleaning water: So, water that pours onto Knepp from surrounding land is very heavy with nitrates, or it's flooding onto us from polluted roads and towns. But, once it's been through that filtration system of our soil and vegetation, the water actually standing on that is of the highest possible quality. So, we're doing all these services for the public good that I think the government for the first time are going to recognize. They're actually going to be encouraging farmers for the first time to manage their land responsibly and sustainably. And, this is something that the EU has not been doing. What it's been subsidizing people, up until now, is to grow mainly arable crops on their land, irrespective of whether that land is suitable for it, and irrespective of the damage that's caused to the land in growing those crops. So, farmers have been protected largely from the penalties given to other businesses if they pollute. Pot[?] farmers have been getting away with murder, basically. From the amount of chemicals that can be used on the land, destroying the soils and plowing and destroying the water sources. So, I think it's going to be very interesting, both the incentives that are going to be coming online in Britain for incentivizing farmers to manage their land much more responsibly. But, also I think for the first time the Polluter-Pays Principle is going to be leveled at farmers. And, that is going to be a complete game changer. And, I hope that will influence Europe eventually too, which still spends 43% of its entire budget on farming subsidies. So, I think it's a very interesting opportunity for farmers moving into sustainable regenerative farming, but also for marginal land like ours to be turned over to rewilding because it's providing all these public goods. Russ Roberts: Yeah, I think it'll be interesting to see if the connectivity or at least yearning for--whether it'll actually happen is a hard question, of course. But, of course, if there were 1000 Knepps scattered around England, you're glamping and Safari wouldn't be as interesting. You'd have more competition. Right now, you'd have, you're in great situation where you have this wonderful wildlife park, near London, but far enough away certainly emotionally and spiritually that people can experience something they wouldn't otherwise be able to experience. Isabella Tree: Yeah, but I genuinely think that this is the tip of the iceberg. I think there is a real hunger and passion out there now for connecting with nature. And, you know, you see this--one of the first introductions of beavers into this country for 500 years is on a river appropriately called the Otter in Devon. And, there's--a farmer's in the headwaters of that river, have quite a small farm--I can't remember it's a couple of hundred acres. But they are now making a healthy income stream from working as a sort of Bed and Breakfast. And, they've converted a couple of barns so that people can go and stay, because they're wanting to see just a pair of beavers. As soon as you have an osprey introduced, you have hundreds of thousands of people going, paying to go and sit in a bird hide to look at ospreys or white-tailed seagulls. So, I think this can really--and it's not just one species. I think it's just that ability to go on a break for a couple of nights and just be surrounded by life. It's what your wonderful biologist E.O. Wilson calls biophilia. It's that innate desire in all of us to connect with living things and to feel ourselves surrounded by humming, strumming, buzzing life.

1:09:47 Russ Roberts: So, I had the privilege of going to Yellowstone--oh, I don't know, a decade and half--a couple decades ago, 20 or so years ago. And, I came upon a herd of--I was hiking and I came upon an elk herd, and it was it was really majestic. And, I wasn't aware of it that time or thinking about the fact that it was actually a somewhat destructive force. And, that the river I was also enjoying seeing wouldn't have been visible if the elk herd had been smaller, because there would have been hundreds and hundreds of small trees sprouting on its banks. And, it would have had a totally different look. But it had a certain landscaped, manicured look. And, before I forget, I want to mention the play Arcadia by Tom Stoppard, which deals with some of these issues about manicuring and landscaping versus letting things go their own way. And, what we think of is what England looks like . And it's just an incredible thing. But, back to Yellowstone. So, I'm in this park and I don't realize there aren't any wolves there. And, later when found that out, one of the reasons I think, that wolves disappeared is that people are afraid of them. They certainly have mythological, primal fear of that predator. Elk are really safe. And, so to some extent, I would, I have argued that Yellowstone at that time before they reintroduced wolves, I think in the 1990s --wolves, Yellowstone was Disney-fied. It was, it looked like wild nature, but to some extent had been pruned and culled in its own way through the elimination of the wolf. Certainly the bear, in that ecosystem is kept relentlessly far from humans--partly because humans don't know how to interact with bears, they leave out their food, and that's not good for them. It's not good for us. But, it's a challenging problem. I think we messed it up there. We're trying to get back to a better mix. I want to close to allow you to talk about what England could look like, if you had your way. There'd be beaver there'd be wild boar. Maybe there'll be some lynx. Maybe there'd be a lion or two. Now some of these things, or 50[?]--some of these things can't exist because of highways. But we could create what you talk about--green bridges--ways, and they've done this in America, ways for animals to migrate safely. What would be your ideal and what would it take for the public to tolerate nature, red in tooth and claw? Which I think is part of the challenge that Yellowstone failed at? And is getting better at and I think England faces a similar challenge. Isabella Tree: Well, interestingly, I think in Europe, they are beginning to show how humans can live with predators again. I think in Europe, which is half the size of North America and much more densely populated and has a history of management. So, our national parks have people living in them, unlike most of yours. We now in Europe have double the amount of wolves that you have in America. We have 10 times as many brown bears. Our brown bears are, you know, the original. You got your Grizzlies from us. So, your Grizzly is a subspecies of our European brown bear. And, we've got 10 times as many species, as many numbers of bears in Europe. We've also got lynx now living in 29 European countries. So, in Germany alone, there are now 60 packs of wolves. And, that's from, grown from one pack in the year 2000. So, people are beginning to show how they can actually live alongside predators again. I think in the United Kingdom, we're a long way off that. We are so kind of control freaky and nervous about anything. But, what I'd like to see is our landscape eventually become much wilder. I think areas that are under agriculture will be still intensive food production, but there will be regenerative agriculture. And, so they'll be much more in tune with nature, and threading throughout the whole landscape, you'll have rewilded areas. So, hotspots like Knepp, which are producing these amazing species, connected together with wildlife corridors that will be running through your agricultural lands. So, you can have stepping stones. You can have rejuvenated water systems, because thankfully the beaver will now be back in Britain to stay and we've just had a license to release to two pairs of beavers at Knepp, which we're very, very excited by. So, we'll suddenly have much more connectivity, much more diversity and much more prey species back in our landscape. Much more resilience, I think, for populations of wildlife to be able to respond to climate change and pollution. And, so then perhaps in 50 years or so my grandchildren, great grandchildren will be able to make that decision about, so: Is it time now? Is there enough habitat connected? Is there a big enough landscape? Are there enough prey species for us to now consider introducing the wolf and the lynx again?