FAQ

We have preliminary data from Pleistocene Park in Siberia and other sites showing these mechanisms working.  Some of this has been peer reviewed.  However we are making quite bold claims that challenge long established paradigms.  For these claims to be eventually accepted we need a LOT more evidence.  Thus we are creating this experiment in Alaska.  

• • Yes and yes.  Although Jurassic Park is probably not the best representation of how it could go wrong, to start with we are only using animals that already exist on earth, and animals that currently co-exist with humans.   We are approaching this scientifically, taking it one step at a time, and being very transparent about what we are doing.  Our first step is a controlled fenced experiment  with very intensive monitoring - not releasing a bunch of animals into the wild.  

  • Altering the largest terrestrial biom on earth is not something to approach flippantly.   "Should we do it” isn’t just a scientific question.  Our research can make predictions, hopefully accurate, of “if we do this the result will be be that…”  but if and when to do it is a larger social, philosophical, ethical, and for some, spiritual question.  

  • On the other hand the Arctic as we know it is rapidly becoming a thing of the past — transformed dramatically by anthropogenic climate change.   We already changed it and there is no going back.  So now the question is:  does it change with millions of big wooly animals or without them.  

  • Doing nothing is also a choice and also has consequences.  Talking to Terry Chapin about it he told me “At this point we can’t afford not to do these kind of experiments.”   That is where we are right now.  We don’t know enough to make a decision, but doing the research and learning as much as we can as quickly as we can is imperative.  Because climate change isn’t waiting.  If we dilly dally the decision will be made for us.  

We will fence the site with an 8’ tall woven wire game fence designed to contain bison, elk, and anything else.  We will use electric fencing both for temporary interior fences and to discourage animals from challenging the perimeter fence.  

• • Every animal will be radio collared — both for science and to facilitate retrieval in the unlikely even they decide to go on a walk-about.  

  • We will practice “low stress livestock management” techniques.  If both humans and animals are co-trained in low stress, and if we are attentive to the needs of the animals,  it will reduce risk of break outs and facilitate retrieval in the unlikely event of an escape.  

  • If we have to we will hire a helicopter (with a crew very experienced in wildlife work) to help us retrieve animals.  

We are still doing our own research as well as collaborating with state and federal agencies to determine that.   This will likely change but the current rough vision is we will start with about 40 bison calves, 10 horses and 10 yaks.  The following year we hope to add 5-10 musk ox and 5-10 elk and 20 reindeer.  Year 3 we hope to add 10 bactrian camels  and, if it looks like the ecosystem can support it, and we can take care of more animals, then additional elk, musk ox and more bison.  This plan could, and almost certainly will, change dramatically before it’s fully enacted.  

In the long run, as the animals reproduce and push the ecosystem into a higher productivity state,  we (very roughly) estimate our proposed 7000 acre fenced area will support between 200 and 700 large herbivores.  

To address climate change on a meaningful scale:  >10 million.  

• • More than 5 million.  Maybe more than 40 million.  More animals impacting more area will have a bigger effect.  

To have the desired impact on global climate will require tens of millions of bison, elk, musk oxen, caribou, wild horses, and other species roaming the arctic.  For reference the current bison population of planet earth is about half a million.  Most of those in private herds.  However, large herbivores are self replicating and under the right conditions their numbers can grow exponentially.  Canadian Wood Bison released into the wild in the Yukon Territory grew their population at 20% per year until hunting was initiated to hold the population at a pre-determined at a target level.  Exponential growth is hard to fathom but if you start with ~10,000 bison and they grow at 20% per year you end up with 10 million in 40-50 years.  It’s not quite that simple in the real world but it’s theoretically possible — especaly with a little help from motivated human collaborators.  Another research goal is to understand the real world timeframes and growth dynamics of re-introduced large herbivore populations in the arctic 

We aren’t sure, that is why it’s really important to do this experiment.  But some really rough back of the envelope calculations indicate that it could be equivalent to getting 1.5 billion cars off the road (all cars on earth).  

Burps, not farts!  It's true that ruminants burp methane.  Domestic livestock make a significant contribution to climate change this way.  Wild animals, particularly ruminants like bison, also produce methane and several million of them will produce significant amounts.  However, the climate benefits of arctic rewilding far outweigh the methane  -- by orders a magnitude.  Mechanism #4, reducing methane production by soils drying, will in theory make arctic rewilding net methane negative.   That said, it needs more research to verify this.  

Research by members of our team as well as other scientists suggests that the modern arctic can support animal densities roughly equivalent to the modern African Serengeti.  This idea is still subject to ongoing debate.  The argument is that animals impact ecosystems in ways that increase ecosystem productivity.  In simple terms they: 1) cause physical disturbance by trampling and eating plants.  This breaks woody vegetation and favors fast growing grazing adapted grasses and forbs.  And 2) animals rapidly cycle nutrients.  They eat a plant, digest it, and return the nitrogen, phosphorus, and potassium to the soil in a mater of hours -- where it can be used by a plant again.  By trampling and rapidly cycling nutrients animals shape an ecosystem that produces more food for animals.  More food allows more animals which allows more trampling and nutrient cycling.  Research by Zimov et al (2014) estimates ice age animal densities based on animal remains in permafrost.  They conclude that in parts of Siberia during the Ice Age there where 11 tons of herbavor biomas per km2.  

• • No, we are way past the point of easy solutions to climate change.  At this point we are going to have to rapidly decarbonize, compromise our consumptive lifestyles, blanket pristine desert ecosystems with solar panels, build machines that suck carbon from the air, let a bunch of big wooly animals loose the the arctic, and some other crazy stuff.  And climate change is still going to profoundly suck.  Especially if you are poor and live somewhere hot and did very little to contribute to the problem in the first place but suffer the worst of the consequences.  But climate change will be much much worse if we don’t do all those things.  The apocalypse is a gradient not a binary.  We are aiming for bad as opposed to god awful.  To put 1.5 billion cars off the road in different terms:  it is roughly equivalent to making the United States (no longer the world’s biggest emitter) carbon neutral.  That would be huge.  But it’s still only about 15% of the overall problem.  

  • It’s not all doom and gloom.  Rewilding the Arctic is fun.  Riding a bike is also way more fun than sitting in a car.  We would all probably be happier and a lot healthier if we compromised our consumptive lifestyles a bit.  

• • Did you skip the above rant about consumptive lifestyles?  

  • If AKDF&G will let us we would love to bring bactrian camels. Camelids also evolved in the Americas and there were camels (different species, now extinct, but related and functionally very similar) in Alaska during the ice age.  Bactrian camels thrive in Mongolia, Tibet, and parts of Siberia — places that see similar low temperatures to interior Alaska (although being farther south the winters are shorter) 

  • Summer of 2021 Nikita Zimov brought 10 1 year old bactrian camels to Pleistocene Park in Siberia.  They all survived their first winter outdoors well north of the arctic circle and actually gained weight faster than a herd of bison that arrived the same summer.  Nikita fed them but he is convinced they would have survived even without supplementary feed.  Super tough animals.  

  • Camels will eat anything — like a combination between a horse and a moose (and maybe a bit of goat) they will graze but they are equally happy browsing on willow.  In fact they eat it with gusto!  This is super ecologically important because in a rapidly warming arctic willow is taking over previously open landscapes with harmful consequences for biodiversity, albedo, and carbon cycle.  

  • Camels are super cute!  Nikitas camels like to snuggle.  So they are kind of like a cross between a horse, a moose, a goat, and a golden retriever.  

  • If you come visit our experiment in Alaska maybe you will tour around the site on camel back.  That would be fun right?  Still sound bat doodoo?  

• • We have started this conversation.  It will be ongoing for a very long time.  Building a large scale fenced research site will allow peoples to visit and see for themselves the kind of changes re-introduced animals have on the landscape.  Data gathered from and models parameterized with this data will allow us to begin predicting the impacts introduced animals will have over larger parts of Alaska.  Both the ability to see first hand, and the scientific results, will inform decisions about how to move forward.  We have specifically reached out to the closest communities:  he municipality of Healy and the tribal government of Nenana to collaborate going forward.  As the project advances we will engage more and more Alaskans.  

We do not plan on introducing any exotic predators to Alaska.  Wolves and grizzly bears are abundant in Alaska and along with their smaller cousins will make up the predator guild.  Initially we will do our best to keep predators away from the young and naive we bring.  But as they mature and can fend for them selves we will allow natural processes, like predation, to run their corse.  It wouldn’t be a representative experiment if we didn’t.  

As long as animals are inside a fence, and are still developing the skills and knowledge to survive on their own we have an obligation to care for them.   This includes suplementary feed as needed and vetrinary care.   This is a fine line. We want to gain insight on natural processes, and hungry animals are a natural process, but it would be both unethical and counter productive if we just let them starve. 

• • This is a really important question and one we struggle with a lot.  Again, it’s a fine line.  I’m not prepared to do what Frans Vera did and let animals starve to death inside a fence because “starvation is a part of nature too”.  No disrespect for Vera, he isn’t wrong.   Oosvaderplatsen is incredible and a lot of bravery and determination for him to make that happen.  I just can’t bring myself to do it.  I think in the context of our project it would be politically counter productive and I think we have some options that Vera did not — namely predators, both human and non human.  We aren’t going to bring our bison the flakiest butter croissants every morning with their lattes.  They may get hungry enough to chew the back off some spruce trees in the middle of winter — that would be a really good outcome actually to see the impact they would have in the wild.  But we will bring them some hay or pellets if there is a real danger they won’t make it, for example in a freak rain on snow icing event (more common these days).  We asked Terry Chapin about this.  His response was (paraphrased) “If you want to know how ecosystems impact animals the you shouldn’t feed them, but if you want to know animals impact ecosystems, and you want to get results sooner rather than later, then you probably should.”  (Feeding them strategically  so that they survive stochastic adverse events means you will have more animals having a bigger impact the rest of the time).  

  • The fence and the food means that our experiment won’t be a perfect analog of nature.  Our goal is to get it good enough, balancing competing priorities, to get results that we have faith in.  Then replicate.  

• • The list is still not settled.  Bison are key.  Most likely plains bison or plains x wood.  Other candidate species are: musk ox, elk, horses,  reindeer/caribou, yaks, and bactrian camels.  Each of these species has complications and we may not be able to include all of them in the experiment.  

This is a risk we take very seriously and are doing everything possible to avoid.  Alaska Department of Fish and Game, The State Vet, The USDA, USFWS, and other agencies are also working hard to minimize this risk.  These agencies require rigorous quarantine and testing on any “livestock” entering Alaska.  Out of an abundence of caution we may not be able to include some of the species on our candidate list.  

• • Our plan is to bring one year old bison.  Transportation at this age is less stressful and less risky for both bison and humans.  Experienced bison ranchers strongly recommend starting with young bison so both the bison and the people who will be care taking them develop a relationship from scratch — both between humans and bison and between bison and the environment.  Other species, particularly elk and muskoxen,  we may not get to be choosy.  

• • We argue that it’s not that simple.  Horses evolved in North America before spreading westward across the Bearing land bridge to Asia, Europe, and Africa.  There is DNA evidence from the Yukon that horses persisted in Alaska/The Yukon until 3000 years ago — long after the end of the ice age and a blink of evolutionary and geological time.  Feral horses and donkeys can in come cases be destructive to native wildlife and plant communities, especaly in the absence of any effective predators. As wolves repopulate more of the US West it will be interesting to see how that impacts the ecological dynamics of horses.  In Alaska we hypothesize that horses will play an important and complementary ecological role alongside other herbivores like bison.  Although they both will focus on grasses if available the utilize different parts of the plant, consume it differently, and digest it differently.  Understanding the functional role horses will play in a diverse ecosystem that includes several other large herbivores as well as predators is another important research focus.   

No.  Our long term vision is wild animals living self determined lives on public lands.    Lots fencing would despoil one of the few remaining totally unfenced places in the US, would be an ecological disaster, and 8 foot game fencing is crazy expensive so it’s just not financially possible.  Fencing is a necessary evil to run a controlled experiment.  There may be additional fenced plots in other locations to validate and replicate our findings, but the goal is wild and free.  

• • Sorry, rhetorical question, but that is crazy cool right?  

In rural Alaska humans are not somehow separate from nature — taking only pictures and leaving only footprints.  Humans have been very active participants in Alaskan ecosystems for over 12,000 years (maybe much longer).  And they will be in future ecosystems as well.  

• • The majority of the arctic and permafrost regions are in Siberia — not Alaska and Canada.  If this were scaled only in Alaska/Canada it would be a significant impact and totally worth it.  But if it scales in Siberia the impact will be several times larger.  Due to the war in Ukraine, American and European researchers can no longer work in Russia.  This is a huge problem because the majority of thawing permafrost carbon emissions are coming from Siberia and with out doing research there we have no way of understanding the scale of the problem much less mitigating it.  For now we are thinking about Siberia and hoping that, ideally sooner rather than later, this war ends and the geopolitical situation resolves itself in a way that rewards collaboration on solving the worlds big problems rather than adding to them.  

  • We are in communication with the Zimovs.   Pleistocene Park is still active.  In fact it is currently expanding.  They will likely spearhead any scaling on that side of the world.  In the mean time they, like us, are doing the research necessary to understand if and how this will work.  

• • They are still operating although without any direct involvement of foreign scientists.  It’s pretty tenuous but they are extremely stubborn people.  Nikita currently has some Russian funding which he is using to expand the fenced area, bring more animals, and hire a team of Russian scientists gather data in the Park.  There are a lot of challenges.  Because of sanctions Nikita can’t get some of the equipment he needs — like gas analyzers.  Also because of sanctions the airplanes that fly from Yakutsk to Cherski may not have enough spare parts to keep operating by next summer.  

  • Some of us communicate regularly with Nikita.  We intend to harmonize data gathering protocols between the Alaskan experiment and Pleistocene Park.  If both experiments are able to advance the results will be much more robust than just one.  In Alaska we will have access to high tech equipment and much easier logistics (our site is on a paved highway an hour from an international airport.)  Nikita’s experiment has been running for 30 years already and hooves are currently on the ground.  Data from two sites, on two continents, ours in the boreal at the southern edge of the permafrost zone, Nikita’s in the taiga-tundra transition zone well north of the arctic circle, will be idea.  

  • If/when direct collaboration becomes possible again, and if Siberian Pleistocene Park manages to persist and develop between now and then Nikita will be in a key position to begin scaling in Siberia and we will be in an excellent position to facilitate that — with a strong corpus of published research supporting the approach, with technical knowhow developed on our end, and by loading up ship after ship with bison and sending them over to Siberia.  

  • Pleistocene Park has an occasionally updated website here: and social media feeds you can follow here, here, and here.  

  • If you have the time and desire there is no reason not to send Nikita an email or DM offering unsolicited advice on what he should do with his park.  He used to find it really annoying but now he might find it encouraging that people still care.  His email is Nzimov@mail.ru  

• • No, there is more to it than that.  First of all pushing the “launch” button is not our decision to make.  Even if we wanted to we simply don’t have the power to unilaterally do that in Alaska.   99% of Alaska is either owned by Native Corporations, public land owned by the state, or public land owned by the federal government.  Those decisions will be made by land owners, land managers, government, agencies like ADF&G, indigenous people, rural residents, the people of Alaska… Russia is a different matter.  It’s possible that Nikita could find himself in a position of unilaterally pushing the launch button over there.  

  • There is no “launch button”.  Exponential growth can move almost imperceptibly slow until it starts moving crazy fast.  If full implementation were to happen the slow ramp up would look like more of the same with steady iterative advance: release some animals in a new site, take care of them while they adapt, and continue doing research to understand the ecological impacts.  If there are unintended consequences it will be small enough scale that it will be strait forward to make adjustments or reverse corse if needed.  

• • We don’t have any cloned mammoths and we aren’t releasing any as of yet non- exastant wooly packaderms into the wild.  A bio-tech company called Colossal is genetically modifying the asian elephant genome to have some of the key qualities of a mammoth — like wooly-ness.  They are also inspired by the work of Sergey Zimov and the potential ecological and climate benefits that de-extincting mammoths might have.  

  • Nobody has offered AFEI any “arctic elephants” (yet) and our official position on the subject is “mammoth-agnostic”.  (I did however witness and film a conversation between George Church, the Harvard geneticist who developed the idea, and Sergey Zimov, where Church, sitting on the bow of a rusty river barge drifting down the Kolima river in Siberia, offers Zimov his first born baby mammoth.  You can see it in the award winning documentary Pleistocene Park, now streaming on Vice Media’s “The Short List” documentary series.)  

  • We are in contact with Colossal.  The research we do on the ecological impacts of large herbivores will provide key insight that will help them (and public lands managers) better understand the ecological role of mammoths and make decisions about if, how, when, where to introduce them.  

  • My current understanding is that Colossal is +- 5 years from creating a first baby mammoth.  But mammoths are social creatures so they will need to create several.  And they have a life cycle equivalent to a humans, so you probably would not want to send them off till the arctic until they are at least teenagers.  The optimistic scenario for a herd of teenage mammoths coming to Alaska is 2040-ish.