Rewilding

[Fallax]

Environmental changes due to a changing climate. Whenever this has happened throughout Earth's history, there are always species that have gone extinct and it's likely this would've off megafauna species.

But why this last interglacial specifically? Why do we see such a dramatic increase in extinctions here compared to past interglacials?

Another factor to consider is disease. Diseases introduced by dogs accompanying the humans from Eurasia could've passed on diseases onto animals such as Aenocyon dirus and Smilodon fatalis.

I especially think diseases from dogs could've played a part in the demise of these predators due to diseases such as the Canine Distemper Virus being one of the many threats to big cats and social wild canids being in contact with dogs with the diseases

This is still the result of a human introduction...

Did humans play a part? Maybe. But I don't think they were the primary cause of the extinctions and think that putting all the blame on humans is pretty simplistic, to be honest.

Yet you haven't explained how there was such dramatic change in climate in just the latest interglacial to cause such dramatic extinction seen there compared to the previous ones... And also used disease from animals domesticated by humans as a potential reason. Sounds like it was a lot to do with humans to me.

 

[Pantheraman]

@Fallax

It's very well known the climate of the Late Pleistocene was cooler and drier than it is today. Much of northern Eurasia was steppe grasslands, now it's covered in coniferous woodlands, and the Bering land bridge is underwater now due to higher sea levels from melting glaciers. You can't deny that and a rapid enough change in climate would've killed off many megafauna.

And are you forgetting that you're arguing for overkill? The idea that humans killed off the megafauna by overhunting them. The disease idea isn't overkill by humans and that's what I was referring to in the last part of my post.

 

[Fallax]

And are you forgetting that you're arguing for overkill? The idea that humans killed off the megafauna by overhunting them. The disease idea isn't overkill by humans and that's what I was referring to in the last part of my post.

Poor wording on my part, should clarify I mean human causes in general.

I still don't understand where you are coming from with your climate points. Yes, the climate in the late Pleistocene was different but my point is these climactic changes had been happening frequently through the interglacials without the same levels of extinction seen in the last one...

 

[Pantheraman]

Poor wording on my part, should clarify I mean human causes in general.

I still don't understand where you are coming from with your climate points. Yes, the climate in the late Pleistocene was different but my point is these climactic changes had been happening frequently through the interglacials without the same levels of extinction seen in the last one...

My point is that these climatic changes were simply more dramatic than the others.

 

[TeaLovingDave]

My point is that these climatic changes were simply more dramatic than the others.

Except they weren't - during previous interglacial periods conditions were significantly warmer and more humid than they are now (hence the presence of species such as hippopotamus in prehistoric Great Britain!) and therefore the shifting to/from a colder and more arid climate during the subsequent glacial periods represented a bigger shift than the one towards a relatively dry, temperate climate which took place at the end of the last glacial period. The species lost at the end of the Pleistocene and start of the Holocene had survived numerous changes in climatic extremes, and would hence have been expected to cope very well with this lesser change.

 

[Pantheraman]

Except they weren't - during previous interglacial periods conditions were significantly warmer and more humid than they are now (hence the presence of species such as hippopotamus in prehistoric Great Britain!) and therefore the shifting to/from a colder and more arid climate during the subsequent glacial periods represented a bigger shift than the one towards a relatively dry, temperate climate which took place at the end of the last glacial period. The species lost at the end of the Pleistocene and start of the Holocene had survived numerous changes in climatic extremes, and would hence have been expected to cope very well with this lesser change.

So I suppose the massive mammoth steppe being turned into coniferous woodlands due to a warming climate had no part in the megafauna extinction?

Yeah, that makes sense.

Also, I found this too: https://phys.org/news/2022-12-growth-forests-contributed-extinction-large.html

"Herds of megafauna, such as mammoth and bison, have roamed the prehistoric plains in what is today's Central Europe for several tens of thousands of years. As woodland expanded at the end of the last Ice Age, the numbers of these animals declined, and by roughly 11,000 years ago, they had completely vanished from this region. Thus, the growth of forests was the main factor that determined the extinction of such megafauna in Central Europe."

And if this had that kind of effect in Europe, I see no reason it wouldn't have affected North American megafauna.

 

[TeaLovingDave]

The same thing (habitat regression and expansion, with a resulting regression and expansion in the range of steppic megafauna) happened during every preceding interglacial/glacial period cycle, unless you are seriously suggesting that the aforementioned subtropical species such as hippopotamus, hyena and lions were all living in arid treeless steppe, and that the evidence of humid wetlands and mixed woodland throughout interglacial Europe is erroneous? during prior interglacial periods, steppic-specialist species retreated to refugiums in the north and east of Eurasia - such as the modern-day Altai-Sayan region of central Asia, covering areas of Kazakhstan, Mongolia, Russia and China - only to expand once again when glacial periods occurred. Were it not for the impact of man, there is zero reason to suppose that they would not have survived within these refugia into the present day.

Moreover, many of the megafauna species lost in North America and Eurasia since the last glacial maximum (ground sloth, giant elk, various other proboscidean species, aurochs etc) were never steppic species.

This is all a sidenote, of course, to the fact that you have repeatedly made an incorrect claim, repeatedly ignored the attempts by May to request clarification, and then when the claim was explicitly refuted by myself decided to shift the goalposts by both shifting the goalposts (claiming you were talking about a change in habitat and not a "dramatic change in climate" all along) and pulling out a fairly scornful strawman argument to boot

 

[GiratinaIsGod]

So I suppose the massive mammoth steppe being turned into coniferous woodlands due to a warming climate had no part in the megafauna extinction?

Yeah, that makes sense.

Also, I found this too: https://phys.org/news/2022-12-growth-forests-contributed-extinction-large.html

"Herds of megafauna, such as mammoth and bison, have roamed the prehistoric plains in what is today's Central Europe for several tens of thousands of years. As woodland expanded at the end of the last Ice Age, the numbers of these animals declined, and by roughly 11,000 years ago, they had completely vanished from this region. Thus, the growth of forests was the main factor that determined the extinction of such megafauna in Central Europe."

And if this had that kind of effect in Europe, I see no reason it wouldn't have affected North American megafauna.

A main problem with the climatic cold period in the younger dryias being the main corse for the megafaunal extinction is the southern henisphere, espicially south america, in which the cooling was small, with even regional warming. Yet large species die out almost compleatly in the south, while north anerica had more large bodied survivers

 

[Pantheraman]

@TeaLovingDave

Here's a question, why do you and others feel the need to dogpile me? I literally am just saying that while humans probably did have a part in the extinctions, I just don't think they actually killed off the megafauna by hunting them and that climate change was the main driver of the extinctions.

And you know, maybe I wouldn't be scornful if people weren't dogpiling on me on this issue.

 

[TeaLovingDave]

why do you and others feel the need to dogpile me?

I've literally only posted twice so far, and only once before you resorted to that strawman argument - if you think that merely replying to you and addressing inaccurate information is "dogpiling you", I sadly suspect nothing will meet your comfort level barring wholesale, blind agreement. Dismissing any and all dissent as "dogpiling" is merely another attempt to shut down discussion.

But lets put that point aside for now in the name of civil discussion and get to the crux of the matter - given the fact that your initial claim that "these climatic changes were simply more dramatic than the others" is untrue, and that the post-glacial habitat changes (regression of steppic habitat and replacement with temperate woodlands, wetlands etc) which you subsequently cited as the primary factor had *also* occurred during previous interglacial periods with no resulting mass extinction of megafauna, an additional factor must have been in play. When comparing the last interglacial period to the current interglacial period, there* is* one major difference in the biogeographic landscape - the presence of Homo sapiens in Europe, Asia and North America.

As such, there are three options:

1) This was indeed the additional factor in play which led to megafaunal mass extinctions.
2) There was no additional factor in play, and the megafaunal extinctions were caused by the same changes in climate/habitat which these species had survived unscathed numerous times previously - in which case the question is how you would explain this?
3) Another undiscovered factor was in play - in which case the question is, what do you think this could have been, given the fact your original suggestion (that the change in climate between glacial and interglacial was more dramatic this time) is incorrect?

 

[Pantheraman]

@TeaLovingDave

And to quote from the article I posted earlier.

"While archaeologists are more likely to cite Paul Martin’s earlier works of overkill - which focused primarily on North America and human movements through the continent - ecologists are more likely to cite his later works in which the model is global. On top of that, the researchers found, ecological papers were more likely to use Martin’s hypothetical scenario as evidence for the argument that humans wiped out megafauna rather than as a reference to the idea.

What’s wrong with this paper trail is that many of Martin’s untested assumptions - that megafauna were naive to invading humans, and that human dispersal across the world explains the distribution of modern megafauna - are often stated as facts. This isn’t helped by an interdisciplinary communication breakdown, as Nagaoka and colleagues call it out. Some of this is as simple as where experts publish. Critics of the overkill hypothesis, or those who see humans as one of several pressures leading to Pleistocene extinction, often publish in archaeological journals or those concerned with the latter part of the Cenozoic. Papers supporting the overkill hypothesis, however, are often published in broader scientific journals and have gotten plenty of additional publicity as being citations for debates over Pleistocene rewilding and de-extinction, thus more likely to be taken as a sign of consensus by ecologists when no such consensus exists."

I think this entire discussion proves this. We aren't actual ecologists but we're more interested in ecology than archaeology.

And when I mean dogpiling, I mean the fact that more than one person comes after me on this.

 

[Chlidonias]

And when I mean dogpiling, I mean the fact that more than one person comes after me on this.

If you say things that people are going to question, or indeed when you say things that are either factually wrong or which you preface by saying "you can't deny that...", then the result is that people are either going to question it or refute it. That's not "dogpiling", it is discussion or debate.

Also, given that you only just found out about Paul Martin and the origin of the Overkill Hypothesis a few days ago (see previous page), some of your posts do seem like you should be doing a bit more reading.

 

[Pantheraman]

@Chlidonias
"Also, given that you only just found out about Paul Martin and the origin of the Overkill Hypothesis a few days ago (see previous page), some of your posts do seem like you should be doing a bit more reading."

I literally was just speculating a little on parts of it. Like the canine disease idea. But I guess that isn't okay, but it's perfectly fine for "fantasy rewilders" to speculate on Pleistocene rewilding.

I get criticized for information I thought was right but turned out to be wrong. Fair enough. Yet when a pleistocene rewilder does the exact same thing, criticizing those ideas is wrong because "they don't know any better".

I apparently didn't know better here on some details I got wrong, but I still got criticized for it.

 

[Chlidonias]

@Chlidonias
"Also, given that you only just found out about Paul Martin and the origin of the Overkill Hypothesis a few days ago (see previous page), some of your posts do seem like you should be doing a bit more reading."

I literally was just speculating a little on parts of it. Like the canine disease idea. But I guess that isn't okay, but it's perfectly fine for "fantasy rewilders" to speculate on Pleistocene rewilding.

I get criticized for information I thought was right but turned out to be wrong. Fair enough. Yet when a pleistocene rewilder does the exact same thing, criticizing those ideas is wrong because "they don't know any better".

I apparently didn't know better here on some details I got wrong, but I still got criticized for it.

If you are presenting your posts as being factual - as you have been doing over the last two pages - it is not "speculating a little". If you don't know the basis for hypotheses then it is better to read a lot more so that you understand the background before presenting arguments for or against. That doesn't mean reading fantasy rewilding posts on Reddit or where-ever, it means reading actual source material. I understand that you may not be able to get access to Martin's books, but there are many scientific papers available for free on the internet.

Just as some advice also, debates on this forum are about peoples' position - not against the person themselves. If you take offence at what people say about what you post (e.g. calling it "dogpiling"), you aren't doing yourself any favours.

Yet when a pleistocene rewilder does the exact same thing, criticizing those ideas is wrong because "they don't know any better".

You appear to be quoting what I said on page 12 (this post: https://www.zoochat.com/community/threads/rewilding.356904/page-12#post-1444859). yes? Either you didn't understand that post or you are misrepresenting it. I didn't say that they shouldn't be criticised, what I said was in direct response to your line "But the reason I criticize these people is that they honestly should know better". Stupid ideas should always be criticised. Ill-thought ideas should be criticised. Good ideas should be criticised if need be. But here you appear to be equating Pleistocene rewilding ideas and Pleistocene extinction ideas - those are two completely separate things.

 

[Pantheraman]

My new take on what killed North America's megafauna.

Alright, let me try this again.

In the seemingly never-ending debate of what killed the megafauna of North America, there are two main competing hypotheses. One is the so-called overkill hypothesis, the idea that humans killed all of the megafauna by overhunting them. The second hypothesis is a changing climate, the idea that the megafauna weren't able to adapt to a changing climate.

Many simply take one side, Some say it was a mix of both. I however say it was a combination of abrupt climate change and overkill. Let me explain.

The oldest evidence of humans in North America comes from the White Sands area in New Mexico in the form of footprints that have been dated to be between 21,000-23,000 years old. (check here: https://www.pbs.org/wgbh/nova/article/human-ice-age-footprints-white-sands-national-park/)

This to me says that humans and megafauna coexisted in North America for thousands of years, and the hunted megafauna adapted to the presence of humans. So in my opinion, something had to disrupt this relationship to allow the humans to kill off their prey. Around 12,800-12,900 years ago, the earth's climate returned to near-glacial levels after a warming period, something the megafauna would've adapted to. But then this period ended abruptly around 11,600 years ago.

The more abrupt a change in climate is, the harder it is for species, especially larger ones with slower reproduction rates, to adapt and populations decline as a result. Leaving behind the individuals of the species better suited to the changes to pass on their genes. And this I think is where overkill came into play. The smaller a population is, the easier it is for humans to kill off the population, which is one reason many recently extinct animals happen to be island dwellers. And these ancient people had an easier time wiping out the megafauna.

So I do not think humans caused the extinctions on their own, but that the Younger Dryas made it easier for them to do it.

 

[DesertRhino150]

An experimental trial introduction of field crickets to Cornwall has been a success, and may pave the way for a full reintroduction to the county, where the crickets became extinct in 1906.

In April 2022, scientists released 70 field crickets collected from Spain onto a meadow on a Cornish organic farm. The population has since increased to around 1,000 individuals. The crickets were sourced from Spain because the only British population, in Sussex, is too small and fragile to have individuals removed. It is thought that this field in Cornwall may now have more field crickets than present in the whole of the rest of the UK.

Field crickets were once a common feature in southern Britain, but agricultural changes combined with a poor dispersal ability (owing to their flightlessness) means they have become one of Britain's rarest insects. The next important milestone for this population is seeing if they can survive the winter.

More information can be found in the link below:
Field cricket introduction experiment in Cornish meadow

 

[Swampy]

Odd they say about seeing if they survive the winter- presumably, if the release was in 2022, they've already survived 1 winter?

 

[Haliaeetus]

On 27th July 2013, 13 young Ural Owls that hatched in French zoos have been transferred in a Bavarian centre in the purpose of a future reintroduction in Rheinland-Pfalz (in the extreme West of Germany, near the French border !).
Parc Animalier de Sainte-Croix on Instagram: "́ ’ ̀ Sainte-Croix participe au Programme d’Élevage Européen (EEP) des Chouettes de l’Oural afin de les réintroduire dans la forêt du Haut-Palatinat, en Allemagne. Le 27 juillet dernier, 13 chouettes nées dans des structures zoologiques françaises dont 3 nées à Sainte-Croix ont pris la route direction la Bavière ! L’objectif est d’établir une petite population stable et de la relier à une autre petite population isolée actuelle du parc national de la forêt bavaroise. Dans le Haut-Palatinat où elle avait disparu, la chouette de l’Oural joue un rôle primordial dans l’équilibre des écosystèmes. En tant que prédateur, elle va consommer diverses espèces, assurant ainsi son rôle de régulateur naturel des populations. Cette année est particulièrement importante car Sainte-Croix coordonne le tout nouvel EEP de cette espèce, soutenu par l’ ́ (). Ce projet est rendu possible grâce à la collaboration de plusieurs structures zoologiques, environnementales et en partenariat avec l’ ( ̈ & ̈) qui se charge du relâcher les chouettes en Bavière. Le Parc Animalier de Sainte-Croix à travers son - ́ et le Siane, transporteur français d’animaux ont notamment financé ce transfert. Les chouettes sont désormais dans une volière d’acclimatation où elles vont pouvoir entrer et sortir afin d’explorer et regagner progressivement leur habitat naturel ! Depuis 2020, c’est 7 chouettes de l’Oural nées à Sainte-Croix qui ont été réintroduites à l’état sauvage en Bavière."

 

[Jana]

On 27th July 2013, 13 young Ural Owls that hatched in French zoos have been transferred in a Bavarian centre in the purpose of a future reintroduction in Rheinland-Pfalz (in the extreme West of Germany, near the French border !).
Parc Animalier de Sainte-Croix on Instagram: "́ ’ ̀ Sainte-Croix participe au Programme d’Élevage Européen (EEP) des Chouettes de l’Oural afin de les réintroduire dans la forêt du Haut-Palatinat, en Allemagne. Le 27 juillet dernier, 13 chouettes nées dans des structures zoologiques françaises dont 3 nées à Sainte-Croix ont pris la route direction la Bavière ! L’objectif est d’établir une petite population stable et de la relier à une autre petite population isolée actuelle du parc national de la forêt bavaroise. Dans le Haut-Palatinat où elle avait disparu, la chouette de l’Oural joue un rôle primordial dans l’équilibre des écosystèmes. En tant que prédateur, elle va consommer diverses espèces, assurant ainsi son rôle de régulateur naturel des populations. Cette année est particulièrement importante car Sainte-Croix coordonne le tout nouvel EEP de cette espèce, soutenu par l’ ́ (). Ce projet est rendu possible grâce à la collaboration de plusieurs structures zoologiques, environnementales et en partenariat avec l’ ( ̈ & ̈) qui se charge du relâcher les chouettes en Bavière. Le Parc Animalier de Sainte-Croix à travers son - ́ et le Siane, transporteur français d’animaux ont notamment financé ce transfert. Les chouettes sont désormais dans une volière d’acclimatation où elles vont pouvoir entrer et sortir afin d’explorer et regagner progressivement leur habitat naturel ! Depuis 2020, c’est 7 chouettes de l’Oural nées à Sainte-Croix qui ont été réintroduites à l’état sauvage en Bavière."

Ahm, I think this is a slight misscommunication. Ural owls from Sainte-Croix will be rewilded in northern Bavaria in area called Naturpark Steinwald in Oberpfalz. That is nice forested area near westenmost tip of Czech republic, not far from city Bayreuth. (I know about it because part of this project is also hanging of nest boxes in nearby forests including on Czech side of border).

 

[Haliaeetus]

Ahm, I think this is a slight misscommunication. Ural owls from Sainte-Croix will be rewilded in northern Bavaria in area called Naturpark Steinwald in Oberpfalz. That is nice forested area near westenmost tip of Czech republic, not far from city Bayreuth. (I know about it because part of this project is also hanging of nest boxes in nearby forests including on Czech side of border).

Thanks for this geographical correction.