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Why are there no wild cows? Think about it. The domestication of the dog didn't lead to the extinction of the wolf. The ancestors of most domesticated mammals - goats, sheep, dogs, cats, pigs - they're still out there. And horses are a whole situation. But most of them are still around. So why not cows? The ancestor of domestic cattle, the aurochs, is extinct. Recently, though. It has the dubious honor of being the first historically documented extinction. It went the way of the dodo in 1627, shortly before the dodo itself in 1662. So the question is: Why was it able to hang on for so long?
But also, paradoxically: Why did it go extinct at all? And also… Is it gone for good? See, there are plans in the works to bring the aurochs back, by piecing together its DNA from modern cattle. This is more than a simple scientific curiosity. And it's more than guilt about being the reason the animal went extinct in the first place. The proponents of this de-extinction program have the future of all of Europe in their sights. They say they need the aurochs to save the continent's entire ecosystem.
It's ambitious. It's controversial. And it's already happening. My name is Michelle Barboza-Ramirez, and I usually host SciShow's sister channel, Eons, where we talk about all things deep time. I'm here today to talk about extinctions … and new beginnings. We're going to take a deep dive into humanity's long relationship with the aurochs. A relationship that might not be over. [♪ INTRO] Ok, first, a quick linguistic note. We're going to be talking about the aurochs, and yes, that word ends with an s in the plural and singular.
The English word aurochs comes from German, and has been used to refer both to the animal we now know as the aurochs, and to the European bison. In older Germanic languages, it was called the ur, which the Romans changed to urus. We're not totally sure what it means, but it might refer to either the color red or to the animal's masculine power. Anyway, that s does belong there. Think of it like the word "ox" but with extra steps. But why are we talking about cows at all? Humanity has an ancient relationship with the aurochs. If you mainly think about cows as the adorably round,
placid critters from the Harvest Moon games, first of all, I love that for you. But second, let me adjust your expectations a little bit. [Wright] Humans have been long fascinated with this animal, I think because of its huge size and its really distinctive horns. That's Lizzie Wright, an archaeozoologist who studies humanity's relationship to cattle. And we have admired their ancestor the aurochs for at least as long as we've had the ability to make art about it. The cave paintings at Lascaux in France, which might be about 17,000 years old, feature beautiful and lifelike renderings of aurochs.
A Proto-Indo-European myth from about 6,000 years ago suggests a cow was present at the creation of the universe. But even as cattle were domesticated, we continued to revere their wild cousins. The Hebrew Bible mentions aurochs when it says, "God, who brings them out of Egypt, is like the horns of a wild ox for them." Julius Caesar described aurochs this way: "Those animals [are] called uri. These are a little below the elephant in size, and of the appearance, color, and shape of a bull.
Their strength and speed are extraordinary; they spare neither man nor wild beast which they have espied. [.] But not even when taken very young can they be rendered familiar to men and tamed. The size, shape, and appearance of their horns differ much from the horns of our oxen." An Anglo-Saxon runic poem from the ninth century CE reads: "The aurochs is fearless and large-horned; a fierce animal - it fights with its horns - the famous marsh walker; it is a brave animal." And even now that aurochs are gone, we still name our sports teams after cows to demonstrate the athletes' prowess.
Think of the Chicago Bulls or the Texas Longhorns. We even pit ourselves against them in feats of strength, as our ancestors have done for generations, at bullfights and rodeos. So the idea I want you to have in your head is that cows mean power. That very association is what doomed the last population of aurochs. But I'm getting ahead of myself. Let's talk about what an aurochs was, and how they're different from the cattle we know today. [Wright] The aurochs was the extinct ancestor of domesticated cattle, and they were similar to domesticated cattle, but they were large. And they had these kind of horns that came out kind of pointing forward like this.
The aurochs, scientific name Bos primigenius, first shows up in the fossil record about 700,000 years ago in what is now Tunisia. And if you want to know what they looked like, you actually can't go wrong looking at those cave paintings. Though it's a bit harder to render the shape of the horns in two dimensions. We know that the bulls were much larger than the female cows, and they were huge. Caesar was probably exaggerating a bit when he said they were the size of an elephant, but some bulls could reach 180 centimeters at the shoulder, or nearly six feet.
The bulls would also have been dark brown or black, while the females were a lighter reddish color. They would have had powerful builds and cute little curls on the top of their heads. Most importantly, they had very distinctive horns. In contrast to most modern cattle breeds, the horns of aurochs pointed forwards and curved in toward each other. They would have been light in color with darker tips. At their peak, aurochs would have occupied most of Europe, all of North Africa and the Middle East, India, and parts of Asia, possibly extending all the way to China.
That wasn't always the case, since they weren't big fans of the cold. During periods of glaciation, they would have been pushed into refuges in southern Europe. At some point, though, something began to change. Humans didn't necessarily stop hunting them, but they did start keeping them confined for their meat, milk, and leather. This domestication happened twice: once in the Fertile Crescent more than 8,000 years ago, and once only a little more recently in the Indus Valley.
This led to the two kinds of cattle we have today: taurine cattle, the ones that include that cute black and white dairy cow you're probably thinking of, and the humped zebu cattle that originated in India. This development was great for folks who enjoy cheeseburgers. But for the aurochs, it wasn't so hot. [Wright] Wherever farming was adopted, humans had a larger impact on their local landscape than ever before. And so that's also where a massive impact would have been had on the aurochs. This opening up the landscape for growing crops and for livestock grazing, their habitat would have become more restricted.
They would have had less space to roam around. All around the world, aurochs populations began to decline. We know very little about what became of them in Asia. They must have survived in India long enough to be domesticated, but we don't know much more than that. In Africa, very early Egyptian depictions of cattle have horns with the distinct aurochs shape, while later ones point upward. However, fossil evidence seems to suggest that wild aurochs in North Africa didn't make it past 6,000 years ago. In Mesopotamia, they survived into historical times, with aurochs hunts documented in the first millennium BCE.
However, by the start of the medieval period, aurochs were gone everywhere but Europe - central and eastern Europe specifically. The question is why. Although overhunting has been blamed, Wright is skeptical. [Wright] In terms of the overhunting thing, I think it's unlikely to be this primarily. We don't have evidence that they were being hunted in very large numbers, not from archaeological sites anyway. So it would be a bit strange if that was the main reason why they went extinct.
It just seems like hunting pressure wasn't the number one thing. After all, if you need a side of beef, why go hunting for it when there's already one munching grass in your backyard? Instead, it seems to be more related to the indirect pressure of humans and their cows taking up all the best space. [Wright] Their extinction correlates with changes in the landscape related to the introduction of agriculture and other domesticated livestock. In the areas where they survived the longest, and so Central and Eastern Europe, Poland and Germany, primarily, the areas did seem to be those with less human disturbance, and these areas actually became their favoured area from the Neolithic period onwards,
to be honest, and when they became a lot scarcer in Western Europe. The very last group of aurochs - that we know of - was managed in Poland's Jaktorów Forest. And they were managed. The king's men maintained them as his property for the purposes of hunting them for sport. [Wright] In some places, they were maintained in areas so that the elite could go and hunt them on a kind of more staged basis rather than for subsistence. So that's the kind of context in which they go extinct, is where that population was being kept alive so that royals could essentially go and hunt them, more than them just surviving in their favoured bit of forest. In other words, in an ironic twist,
the aurochs only survived for as long as it did because of human management. Not out of compassion for their welfare, but for the prestige of hunting these powerful trophy animals. The very last aurochs bull was killed in 1620. We still have one of his horns. It was taken as a trophy and turned into a hunting horn, and now resides at a museum in Sweden. That horn reveals a secret about the decline of the aurochs. In 2018, a genetic study revealed that he had domestic cattle among his ancestors. It seems that aurochs survived as long as they did in part by interbreeding with cattle. With no remaining males, the species was doomed.
The last remaining cow, the very last aurochs, is believed to have died in 1627. So that's it. The end of the line for the aurochs. We valued it. We admired it. We tamed it. And in the end, we killed it. Story's over. Go home. Unless… No, it can't end like this! There has to be more to the story. And there is. We've talked about what an aurochs looked like and where it lived. But we haven't talked about its ecology - what it ate, what kind of habitat it preferred.
And that's going to be the most important part of our story by far. So important, it could shape the future of an entire continent. But to understand why, we need to stop talking about cows for a minute. Instead, we're going to talk about a very controversial approach to conservation. When an animal goes extinct, it doesn't simply vanish without a trace. The aurochs left a cow-shaped hole in their ecosystem.
A hole that had previously interacted with predators, with plants, with the flow of energy through the entire food web. That loss of energy flow can be profound. Big herbivores like aurochs eat a lot of plants. They also trample, and wallow, and poop. Their daily lives change the shape of their habitat, sometimes in massive ways. If big cows trample and eat all the seedlings, a forest will never grow. To understand how the loss of the aurochs affected the landscape, we first need to know what that landscape was. So, remember the poem that called the aurochs a "marsh walker"? And that forest in Poland, Jaktorów, was pretty swampy.
From the historical information like this, you might infer that aurochs preferred to live in wetlands. However, scientists now doubt that conclusion. [Wright] I think it's a bit misleading to look at that last population of aurochs in Poland as an example of, you know, that's the kind of habitat that they would have wanted to live in. That was a kind of marshy area with some deciduous woodland and the kind of wild isolation of this environment is often cited as the reason that they survived there. Wright is not the only person who thinks so, which brings me to our next guest.
[Goderie] Well, that's the story of domesticating the animal and then pushing the animals back into forests, back into marshes. They can survive there, but it's not the optimal habitat. The optimal habitat is drier grassland, the mix of drier grassland and open forests, et cetera. That's Ronald Goderie, an ecologist and director of the Grazelands Rewilding Foundation, and we'll come back to him later. The point is that aurochs probably preferred open grasslands, maybe mixed with forests, but were pushed into more marginal habitats by human activities.
Open grassland, mixed with forests. There's a problem with that conclusion, though. See, for a long time, there was a broad consensus that for most of its history, Europe was heavily forested with a dense canopy, until humans cut the trees down. There's plenty of historical evidence to support this notion. Let's ask our friends the Romans again. Caesar wrote frequently about how much trouble the dense forests gave him in his campaign against the Gauls. And other writers, like Tacitus, also described dense forests and marshes. That makes it seem like at least by 2,000 years ago, Europe was a forest.
Other lines of evidence support a forested Europe as well. But in recent years, that consensus has been challenged. [Goderie] And it must have been what I always say, a kind of cooler version of what we now still know of, what Africa looks like. A mix of woodlands, but also open areas, savannah and steppe-like. And not so much a closed, the European landscape was not so much a closed forest before we had a big influence on the landscape. And there's quite some circumstantial evidence that it must have been this way, because we've still got a lot of species that are adapted to open landscapes. So how would they have survived in the evolutionary sense without open landscapes?
There must have been open landscapes. Goderie also cites other evidence, like plants that are adapted to regrowing after being trampled by herbivores. In general, there's a growing movement of people who support the idea that Europe was not a closed-in forest, but a park-like mix of forests and grasslands. And the reason that closed forest never grew was because herbivores like the aurochs ate or trampled the seedlings. [Wright] They were grazers and maintaining open habitats that support a wide range of plants and animals, and thus increasing biodiversity. So they would have been part of a process where kind of a rich mosaic of open landscapes was maintained.
But they would have been doing it alongside other large herbivores as well, red deer, bison and some others. The idea is that some trees would establish themselves eventually, in areas defended by thorny plants that those animals didn't want to eat. So patches of forest would grow up, only to eventually die to fire and disease, maintaining mixed open landscapes that could support more biodiversity than closed forest alone. Now, where am I going with this? Well, a lot of European land has been converted to farms. But a lot of that farmland has subsequently been abandoned. And people would like to restore it to its natural state.
But to do that, they need to know what the natural state was: dense forest or mixed grassland. And if it was grassland, it's because big grazing animals maintained it that way. No grazers, no grassland. Maybe you can guess the conclusion some people reached: What if… grazing animals again? Then… grassland? This is going to take a second to explain. So, stick with me. This approach to conservation is called rewilding. Rewilding seeks to restore the function of ecosystems.
Now, that doesn't necessarily mean reverting them to a pristine state from the past, but rather, putting all the parts back together to create a functional whole. Usually, what they mean is putting big animals back where they belong. Rewilding is often described as being "top-down." Some conservation strategies are "bottom-up," focusing on how things like climate or vegetation affect the ecosystem. Rewilding instead proposes that big animals, especially carnivores but also big herbivores, have such profound effects
on their environment that replacing them will have ripple effects all the way down. In this example, you'd be replacing large grazing animals to support the return of a mixed forest-grass landscape. Rewilding was originally proposed around "the three Cs": cores, corridors, and carnivores. Meaning core wilderness areas connected by corridors that animals could travel along, all managed from the top by the presence of carnivores. Rewilding also tends to envision limited human management, at least once things reach a stable state. It calls for rebuilding functioning nature, and then leaving it the heck alone.
It's not as simple as tossing an animal into an environment and asking it to sort things out for us, but it's a little bit like that. Although I should probably note there's a lot of discussion in the field of what rewilding really is, and what it should do. I've only sketched out the broad strokes. Indeed, some rewilding approaches and strategies can get downright kooky. Imagine driving down the freeway in North America and seeing a cheetah or an elephant out your window. That's the vision proposed by Pleistocene rewilding. Some restoration efforts in North America try to reset things back to right before the year 1492, when some guy named Chris set off with a couple of boats.
The people who proposed Pleistocene rewilding say: That ain't good enough. After all, humans were managing the environment in North America long before that. Just not European humans. Instead, Pleistocene rewilding says: A lot of big animals went extinct beginning with the end of the Pleistocene epoch, right around 13,000 years ago. Even though that seems like a long time to us, in evolutionary time that is a blip. That means the animals and plants we have today evolved alongside those extinct animals.
They're supposed to be here. They should be present in the ecosystem, providing all of the functionality that carnivores and big herbivores normally would. And so, what do you do? You introduce the closest equivalents. If you can't make your own woolly mammoths, store bought is fine! Throw in some lions and cheetahs to replace the extinct North American lions or saber-toothed cats, maybe a camel or two, and you've got your very own Pleistocene menagerie. Now of course, this is the point where I should note that no one is actually serious about doing this.
Well… almost no one. And even the people discussing this strategy can see obvious flaws, like the need to keep large and potentially dangerous animals contained, or the fact that African elephants would have a rough time surviving winter in the Rocky Mountains. Rather, this is a thought experiment. An inquiry into what North America would look like with its ecosystem fully intact, the way it was thousands of years ago.
Now, the conclusion of that thought experiment is that we can't truly turn back the clock. But we should be willing to entertain radical strategies to try to ensure the future. Which brings me to the kinder, gentler cousin of Pleistocene rewilding: trophic rewilding. It's still focused on restoring the flow of energy through food webs - that's what trophic means - but with slightly fewer elephants. The goal of trophic rewilding isn't exactly to restore an ecosystem to what it was like in the past. After all, things change, and especially with climate change going on, it's more important to promote biodiversity and the capacity for biodiversity.
It's pretty open-ended, but that's kind of the point. Humans aren't deciding what the final state is. They're just giving it the ability to get better. And unlike Pleistocene rewilding, this one has been tried in quite a few places. Some initiatives have introduced non-native species, but in less dramatic fashion than the Pleistocene approach. Think tortoises, not elephants and lions. Other times, a species has been returned to its native range where it had been absent, or domesticated animals are used in place of their wild equivalents. And we're going to get into both of those.
The first one is a place in the Netherlands called Oostvardersplassen. Oostvardersplassen, or OVP for short, began in 1968 when a section of land was reclaimed from Lake IJssel in the Netherlands. A 6,000 hectare slice of this reclaimed land was left undeveloped and was eventually converted into a nature reserve. The area proved irresistible to rare native birds and quickly became a flourishing pocket of nature tucked in amongst otherwise developed areas. An ecologist named Frans Vera saw an opportunity to test the hypothesis that Europe had once been grassy, not forested.
And in the rewilding fashion, he decided to use large herbivores to prove his point. He introduced horses and cattle to take the place of extinct wild horses and aurochs. The horses he used were Konik horses, a breed that at the time was thought to resemble the extinct wild horse called the tarpan. The cattle were… well, he chose a very specific kind of cattle for a very specific reason. But we're going to come back to those. And at first, this was a screaming success.
It's fair to say we learned a lot about how herbivores can maintain open landscapes from OVP. For example, one paper from 2014 shows how the establishment of woody species first increased at OVP, then decreased as herbivore populations grew. And a 2015 study likewise suggests herbivores prevent trees from establishing, well, a little too well, and that two of rewilding's three C's - corridors and carnivores - might help the trees get a toehold. But in 2018, everything came crashing down. There had been public outcries for many years over the treatment of the animals in the reserve. The place was totally fenced in, and during harsh winters the animals had no way to leave for literal greener pastures. And human management?
It was minimal, merely culling animals who got too weak. There was no supplemental food, and shelter was only added later. As a result, during harsh winters, hundreds or thousands of cattle, deer, and horses could die. And the public hated it. They didn't see a self-regulating wilderness at work. What they saw was downright animal cruelty. Eventually, the pressure proved too much and the rewilding experiment at OVP was shut down, and the area is now a game reserve. And there does seem to be agreement in the literature that OVP was mismanaged, however, that doesn't mean OVP proves the concept of rewilding itself is invalid.
Mostly because it… kinda did rewilding wrong? I mean, the definition of rewilding has changed over time, but as a starting point let's look at how the three C's worked at OVP anyway. Cores: The "cores" proposed by rewilding should be as big as possible, and at 6,000 hectares, OVP just isn't very big. Corridors: The animals literally had nowhere to go. There was supposed to be a corridor connecting OVP to the outside, but it was never completed. And Carnivores: There weren't any of those either! If carnivores had been keeping herbivore populations in check in the first place,
maybe they wouldn't have crashed so badly. Now, combine that with the management decisions that led to the culling or starvation of thousands of animals, and yeah, this is more of an administrative problem than a science problem. The science could still work, and other reserves based on OVP do exist. But researchers warn that we risk a repeat of history, and that a fourth C - compassion - should guide our approach to animal welfare. Thanks for watching SciShow! You help our non-profit bring more educational videos to more people every time you watch, comment, share, and tell people about a SciShow video. And now you can get something beautiful too.
We made a very nice t-shirt to go along with this wild story about wild cows. So you can support SciShow and our work spreading aurochs knowledge, and other knowledge, while you liven up your wardrobe. The original art designed by our very own Elliott Zheng was inspired by the Lascaux cave paintings. And you can get it cave colored or vintage white to fit whatever vibe you're feeling. The shirts are on sale now at Complexly.store/aurochs. And it's spelled differently than how it's pronounced It's at Complexly.store/a-u-r-o-c-h-s.
See you there! So that's the very mixed success of OVP. But what happens when a native predator is reintroduced to its historic range? Now some of you, like me, might have been thinking, "Where's the bit where they get to the wolves in Yellowstone?". Well, this is the bit where we get to the wolves in Yellowstone. If you're familiar with this project, you might know it as a huge success. As the story goes, elk populations were out of control in Yellowstone, but wolves cut them down to size. And of course, carnivores being one of the three C's, reintroducing a top carnivore and inducing changes in the food web is absolutely textbook rewilding-
[MacNulty] In the- In the context of Yellowstone, the wolf reintroduction in Yellowstone, that actually came before the whole concept of rewilding was even coined. The reason why wolves were reintroduced to Yellowstone and to central Idaho back in the mid 1990s was because the wolf, the northern Rocky Mountain wolf population was a listed entity under the Endangered Species Act. It was motivated purely by the legal requirements of the Endangered Species Act. …Oh. Huh. That's Dan MacNulty, a professor of ecology at Utah State University and kind of the guy you want to talk to about this stuff.
Not only was the wolf reintroduction in Yellowstone National Park not a rewilding exercise, but the managers actually worried that the wolves would kill too many of the elk and have a negative economic impact on local hunters. But even though rewilding wasn't the motivation, wolf reintroduction still provides an opportunity to test another of rewilding's hypotheses: that of the trophic cascade. Recall that the word "trophic" refers to the movement of energy through food webs. So a trophic cascade is when you make a change at the top of the food web, and that change cascades all the way down.
[MacNulty] It's the idea that a predator has indirect effects on the resource that a prey uses. So if we're talking about carnivores, herbivores, and plants, a trophic cascade is an indirect effect of the carnivore on the plant that the herbivore eats. Here's what's supposed to happen: The wolves introduce pressure on herbivores, mostly elk, who were putting too much pressure on plants like aspen and willow. If wolves eat the elk, or even just scare them away from where plants are growing, they ease the pressure on those plants and the plants can recover. And this does appear to have happened. But the extent of it is unclear.
[MacNulty] And so that's one of the questions that's being debated still, quarter century later. And then we're also debating the strength of that cascade. it shows up in some places. Some plants in some places are recovering. But not all plants in all places, and the question is why and we really don't have a rock solid answer to that question. Let me give you an example. In 2025, a paper came out called "The strength of the Yellowstone trophic cascade after wolf reintroduction."
This paper claimed to find a 1500% increase in the crown volume of willow trees - a way of measuring their recovery. MacNulty and others dogpiled on this paper for exaggerating its findings, claiming flawed methodology and conflicts with other published literature. I mean, according to a different paper from 2024, the effect of the trophic cascade on willow trees is actually fairly minor. In other words, this is an active, even ferocious debate. And it concerns two related questions: How much has elk predation by wolves affected the vegetation? But also, to what extent is the decline of elk actually the wolves' doing? After all, there are other carnivores in Yellowstone.
[MacNulty] The expectation though is that wolves have that power to restore vegetation. But what we're seeing in Yellowstone is like, well, the bit of change that we are seeing can't be attributable all to wolves. Other players are involved like these other predators. And we're trying to work out what the contributions of all those other predators are. That's probably one of the biggest myths we've I think been reasonably successful at challenging over the last, say, 10 years or so is that this isn't just a wolf system, folks. This is a cougar system, you know mountain lions.
It's a grizzly bear system. It's a black bear system. Maybe it shouldn't surprise anybody to learn that food webs are complicated. And the thing is, there's more than just food webs making up a given ecosystem. A trophic cascade can only do so much. [MacNulty] This is kind of humbling to say this, but based on the measurements we've made, the total land area covered by Aspen in Northern Yellowstone National Park, has actually shrunk since wolf reintroduction. And overall, that the study area is predicted and has been shown to become more warm over the last 30 years, warmer, drier, less hospitable to a plant like an Aspen. So it's this notion that, you know, wolves can't fight climate change, right?
I mean, that's really something that's on us as human beings to deal with. You know, wolves are not the ecological silver bullet if you're looking to, you know, bring back your aspen forest or bring back your willow forest. You need to do other things in order to bring that back. Once again, none of this totally invalidates the hypotheses proposed by trophic rewilding. There is more than likely some sort of trophic cascade in Yellowstone. And I think having wolves there, as opposed to not having wolves there, is a good thing for biodiversity!
But what this story does tell us is there is a lot we need to pay attention to beyond introducing an animal to a system and hoping it will clean up our messes. And before we move on, I want to point to one or two other slight problems with rewilding. One is the risk of human-animal conflict. Rewilding seeks to create relatively autonomous landscapes with large carnivores operating in a natural state. But people have always feared wolves for a reason. Safety is an important concern with any rewilding project. Also, every project has to account for different stakeholders, not all of whom are going to be crazy about turning large animals loose in their backyards.
[Wright] Another thing around rewilding is that it doesn't take place in a political vacuum. You know, it needs backers, it needs support, both politically and financially. And there are people for and against it. For example, in Britain, this issue with the lynx is because sheep farmers don't want to lose their sheep, essentially. But at the same time, we have a massive red deer issue and they have to go out and like physically cull them because there's too many. So it would be good to have a carnivore around to do some of that work for us. But the farming lobby is very strong. So you always have to have in mind that there's all of these different players in the process.
There are also just some straight up issues with the idea that large herbivores always naturally maintain grasslands. African forest elephants, for example, live in - you will never guess - forests, in places like the Ivory Coast. Even rewilding advocates say they'd like more evidence. Still, it's pretty clear at least that herbivores do shape the landscape around them. [MacNulty] Yeah, herbivores have a tremendous ecological effect. There's all kinds of examples of this from Africa with things like elephants, et cetera, hippo, massive effects on the environment. And the aurochs, well, it is gone.
See, I told you we'd come back to cows. Let's go ahead and say we're at least willing to test the hypotheses of trophic rewilding. That we're willing to see what aurochs used to do for the environment, and what they would do if they were still around. People have tried to use domestic cattle in their place, at OVP as well as elsewhere. But what if we didn't have to compromise? What if we could bring the aurochs back? Back from the dead, and back to its rightful place in the ecosystem, where it could - theoretically - restore the wilderness of Europe?
Let's talk de-extinction. So, you know how I said we were gonna come back to the cattle used at OVP? As it turns out, those cattle represent an attempt from the first half of the twentieth century to de-extinct the aurochs. It's not a very good attempt, and… Ok look, the number of Nazis in a story about cows should be zero. Unfortunately, the number of Nazis in this story about cows is more than zero, and in fact, it is two. It's not gonna be that heavy, but if you'd rather just skip it, we'll provide a timestamp on the screen that you can jump ahead to.
Ok. It's time to talk about the brothers Heinz and Lutz Heck. The two of them each started a breeding program where they chose domestic cattle and bred them to try and produce something that would recapture their view of what the aurochs had once been. They did it separately from each other, which is weird, but I guess we shouldn't assume that just because they're brothers, they'd also be research collaborators. [Wright] So, my understanding of it is that the original motivation was pre-war, it was pre-Nazi Party, and they wanted to show people what the aurochs looked like and essentially create a spectacle for the public. And then of course the Nazi party came along
and one of the brothers was quite good mates with Hermann Göring, and helped him in this vision to recreate the kind of Nazi ideology around ancient, pure German landscapes and with all of these large animals roaming around to be hunted. In addition to their garbage politics, though, their science was… iffy. Let's call it iffy. [Wright] One of the things that they've been criticized for is that there's not a clear, they weren't very clear about why they were choosing the species- the breeds of cattle that they chose. And there wasn't really any sensible scientific reason that they gave as to why they chose these specific breeds. And that's an understatement.
Seriously, for this piece we read a book called "Retracing the Aurochs" by Cis van Vuure. It's out of print, but if you can get your hands on it, he spends like 40 pages just dragging these two losers for their bad science and it's pretty funny. Here's the short version. Their criteria for what an aurochs was, and therefore the goals of their respective breeding programs, appear to have been partially made up. They didn't even agree with each other on what their cow should look like. They chose breeds to cross with one another, but they didn't provide much of a rationale for why they picked those ones over others.
And then they didn't even take good notes on who got bred with whom! Folks, as a wise man once said, the only difference between screwing around and science is writing it down! What that means is that we don't even really know what went into the Heck brothers' cows. We kind of just know they're cows. Lutz's cattle don't seem to have survived WWII, but Heinz's did. In fact, they survive to this very day. They're at OVP, among other places, and they're now known as Heck cattle.
They were chosen for OVP because of their supposed resemblance to aurochs. But that resemblance is dubious at best. There have been more credible attempts at de-extinction in recent years. And that's why we wanted to talk to Goderie. He's the guy. He's that guy! [Goderie] When you're in the Netherlands and you see one of our herds, you might get the feeling, especially if you're not very specialized in cattle breeds, that you're back in time. You see herds high on the legs, large horns, performing natural behavior. Yeah, those animals really look like Aurochs already.
They might be a bit higher on the legs still. Maybe the horn shape is not exactly yet what Aurochs was, but then again, we don't want, and we aren't able even, to copy exactly what Aurochs was, because too much has gone lost. But we use Aurochs as a reference, you might say, to breed the best Aurochs-like population that's well adapted for the wild circumstances that European rewilding landscapes ask. Goderie is responsible for the Tauros Programme: a breeding project designed to reproduce, as best as possible, the appearance, ecology, and behavior of the aurochs… for real this time.
Strictly speaking, because this is a breeding project using cattle, the animals it produces are also cattle, but they're cattle designed to reproduce the aurochs as closely as possible. [Goderie] We chose a name that's similar, but not aurochs, because there must have been maybe a million of those animals, if not more. And of course, the domestication process went through a very narrow bottleneck. So you lost that much information that-no, well-the chance that you will really get a copy of aurochs are zero, at least on the techniques we use. So that's why we call it Tauros.
Do you remember how I told you the last aurochs bull had some cow DNA? Well, the reverse is also true. Wild aurochs DNA snuck into our domestic cows, especially early on in domestication. There are relatively ancient cattle breeds kicking around Europe that have changed fairly little since their domestication. What this means is that the aurochs may be extinct, but their genes still exist. And if you can identify those genes out there in the wild, you can use an approach called back-breeding, where you breed together individuals to maximize
the concentration of those genes, until you have something that has an awful lot of aurochs DNA. In theory, anyway. At the time, in the mid-2010s, Goderie and his team had only a single aurochs genome to work with. They compared this genome to around 50 modern cattle breeds, and picked out ten of them with the most similarity to that one genome. But if we really wanted to rebuild the aurochs, with those special horns and all the other characteristics, we'd need to know what all those genes do. [Goderie] We would really like to know where, for example, the genes for big horns, or for a kind of coat color, or for specific adaptation and behavior to
wild landscapes are located, and that's still not very well known. For all kinds of commercial breeds and commercial traits it is known that we know quite good. If you want to have a cow that produces, say 15,000 kilo of milk a year, we know exactly where those genes are located and the fat content, et cetera, But we don't know this for the traits that were very characteristic for aurochs. Unlike some prominent de-exctinction efforts, these Tauros animals are not genetically engineered. The team used genetic tools to identify portions of ancestral aurochs DNA, but not to put them into the cows. That's being done by back-breeding.
At most, they're using techniques like artificial insemination to speed things along. We asked Goderie how close he thinks he is to the genuine article, and how close he thinks he can get. [Goderie] Well, I think we go for 99.X%, because as I already mentioned, genetically spoken, well, there's hardly any difference even between maybe a dairy cow and a former aurochs. But of course, the way the animal looks, the way the animal behaves, that's a completely different story. And that's where we try to get us as close as can be with the knowledge we have. And of course, the reason he's doing this is because the aurochs should be great at engineering the environment around it.
[Goderie] Yeah, that has to do with the fact that the European landscape, of course, has dramatically changed the last centuries, but now again it's changed dramatically. Large areas of Europe are being left by farmers. So that would mean that a lot of biodiversity linked to those open landscapes, you would lose this biodiversity. Natural grazing is one of the forces that can change this. Oh, yeah. It's rewilding. And while there's a robust debate to be had about the ethics of de-extinction, Tauros cattle are already out there - in several places in the Netherlands and across Europe.
They're not running around in the wild, mind you. European law requires them to be managed as captive cattle, complete with ear tags. They're in protected conservation areas, and Goderie's team works together with whoever manages that particular nature reserve to accomplish their goals. When we asked why ordinary domesticated cattle weren't good enough, Goderie matter-of-factly told us that they needed to be able to defend themselves from wolves. He's picturing spaces not just with herbivores, but with totally rewilded assemblages of carnivores and everybody else.
Gang's all here. It's a daring, long-term vision that's already in progress. [Goderie] And because those landscapes are wild landscapes, including big predators, wolves, bears, you would need animals that are completely self-defended, self-reliable. So that's why we think that you need an animal that should come as close as can be to what aurochs once was because, well, it co-evolved with all the big predators, including lions and tigers and then you name it. Now… are these really aurochs? Even Goderie says we just don't have access to enough DNA to put the whole thing back together. But at the same time, if they're filling the same ecological niche, performing the same behaviors,
shaping the landscape around them in the same way… how much does it matter? It's rewilding at its finest: Restoring a functional piece to the ecosystem, without worrying so much about whether it's the same as the old piece used to be. As long as it works, that's the goal. Goderie seems very confident that these Tauros cattle are the way forward. They'll munch, trample, and poop their way to a wilder Europe. He sees nowhere to go but up. [Goderie] We aim at scaling up. We need to scale up in terms of landscapes and herds and in the end, in connecting the landscape so that even migrating patterns might be possible again.
And that's easily said, but not easily done, because of course every square meter in Europe has an owner and to be able to get this going is not so easy. Not everyone is as convinced. Do we really need this one specific animal - this one admittedly charismatic, majestic animal, when others might do? [Wright] There is a bit of a question mark over whether it's worth bringing back the aurochs because there are these other breeds that are doing quite a similar job, as part of a wider network, a wider ecosystem,
and the loss of this one specific large herbivore could potentially be compensated by other things. And are we bringing back these animals. Is it really going to make a difference? Is it worth the resource that we're putting in essentially? The motivations behind what the Heck brothers were doing wouldn't cut it today. And the biodiversity and rewilding argument is a lot stronger in my view, of course. But there is something about the Aurochs where there's always a bit of a feeling that people are just really excited about this big cow.
I have to admit… I am! I am excited about the big cow. But we're asking the big cow to do a lot. And it's just a cow, you know? Rewilding seeks self-regulating natural spaces with limited human involvement. And look, humans have made a mess. It makes a lot of sense to picture a state of nature where we undo all the stuff we've done, from soda bottles littering the ground to microplastics in the water to carbon in the atmosphere. But if you look at it differently… if we leave humans out of the equation… we're actually leaving the most powerful tool we have on the table.
[MacNulty] Human beings have vast potential to be ecosystem service providers to all the animals and plants on our planet if we put our minds to it. So I'd say that the most powerful species by far, we all know this, are humans. To me, what-I see untapped potential for humans to work together with these reintroduced species whether it's an auroch or a wolf or what have you, it's sort of a team effort to make ecological restoration happen. So… we can work together with the big cow. The cow can do what the cow does… and we can do what we can do. We and the aurochs were together for thousands of years.
It might be nice to be reunited. [♪ OUTRO]
