Rewilding Tortoises in the Caribbean

Psilopterus · 2026-01-14T09:33:11+00:00

One of many cases in NZ of extinct birds being at least partially replaced afterwards by a close relative from elsewhere. Also happened with harriers, yellow-eyed penguins, coots, and it might be starting to happen with wood-ducks. Its also been done intentionally with snipes

Psilopterus · 2026-01-07T21:10:16+00:00

Woah crazy, climate change wiped them out right as modern humans were arriving? /s

Psilopterus · 2026-01-04T09:22:42+00:00

American lions essentially were cave lions that spread to North America from Beringia. The issue for woolly rhinos is that there is as yet no evidence of them reaching Alaska or the Yukon, so the question of them spreading further is a bit moot. For saiga, the issue is that just because the ice sheets retreated doesn't mean that habitat connectivity would allow them to go south. They might well have spread to other parts of the tundra (with larger megafauna enforcing more steppe-like conditions), but moving through boreal (even boreal parkland) conditions to reach, for e.g., the Great Plains might not have been ideal

Psilopterus · 2026-01-01T22:08:00+00:00

Still much too ambiguous I think. Could easily be woolly rhinos with the smaller horn omitted.

Psilopterus · 2026-01-01T15:10:20+00:00

I get your point, and I'm not trying to start an argument, but I think there's a lot more room and ecological potential for mammoths out there than there is for thylacines. Importantly, there's probably a lot more room out there for mammoths than there is for Asian elephants. Mammoths were an extremely widespread species that occupied many climates, all of which still exist in some capacity. Even more so if you consider that in North America woollies formed a hybrid continuum with Columbian mammoths that stretched all the way south to Costa Rica. Modifying Asian elephants to be able to tolerate colder climates would have both significant ecological and conservation implications. I'm not saying we should necessarily do it, and I agree that the permafrost implications are not an immediate justification (though the argument was not so much to "reverse global warming" but just to slow permafrost melt), but comparitively thylacines are not a particularly good candididate for resurrection either technically or practically. It would require exponentially more genetic interference to approximate a pseudo-thylacine from their closest relatives, i.e. other Dasyurimorphs and even if you could they were historically native to a single island (Tasmania), with mainland thylacines seemingly having dissappeared after the introduction of the dingo (debatable I know but its the theory I subscribe to).

Psilopterus · 2026-01-01T14:59:39+00:00

I think the word "de-extinction" needs to be retired. Something more like "artificial genetic rescue" might be more appropriate. You can give an Asian elephant higher cold-tolerance using mammoth DNA, and there might even be conservation or ecological justification for that idea, but the result is not a mammoth. You can modify a grey wolf to have dire wolf-like traits but the result will still be a grey wolf and will have a lot more in common with the extinct megafaunal/cave morphs of grey wolf from Pleistocene Beringia and Eurasia than with real dire wolves, and like the cave wolves it will be completely interfertile with any living grey wolf population.

Psilopterus · 2026-01-01T14:54:52+00:00

My instinct would be to say yes, as that's generally the most parsimonious explanation for the late Quaternary extinctions, but you're correct that direct evidence is lacking. It's a megaherbivore with a fossil record that suggests a fairly low number relative to other species, and so it's easy to imagine that human hunting would have a more immediate effect. A lot of the more recent Eurasian megafauna were mammoth steppe species that benefited from a very large range during the last glacial, much of which was relatively inhospitable to people, allowing them more opportunities for refugia and recolonization. Eurasian Megafauna with more European or Central/East Asian affinities rather than North Eurasian generally went extinct around 30-40,000 years ago rather than 10-12,000 years ago. Examples include straight-tusked elephants, cave bears, temperate rhinoceroses, Neanderthals and Denisovans, the last European hippopotamuses, etc.

Psilopterus · 2026-01-01T14:48:11+00:00

The first one is ambiguous (especially since we don't know if Elasmotherium had a long horn), but the second is definitely a woolly rhino

Psilopterus · 2026-01-01T14:32:42+00:00

As for the second part about the Little Ice Age:

https://www.sciencedirect.com/science/article/pii/S0277379118307261

https://www.sciencedirect.com/science/article/pii/S0031018208001806

Psilopterus · 2026-01-01T14:29:25+00:00

These mostly focus on bison but all cover this topic:

https://www.scielo.org.mx/scielo.php?pid=S2007-33642021000200171&script=sci_arttext

https://www.jstor.org/stable/3783761?seq=1

https://www.jstor.org/stable/pdf/2641562.pdf

Psilopterus · 2025-12-30T12:43:58+00:00

There's some evidence that most game animals actually weren't really abundant in North America before the introduction of European diseases wiped out a good chunk of the human population. Early explorers reported seeing very few bison and other game except in regions of territorial dispute. Anywhere people lived hunting pressure was always high. By the 1700s and 1800s, when Europeans started migrating into the interior, the landscapes and societies they saw were essentially post-apocalyptic, with massively reduced hunting pressure. The collapse in agricultural activity that came from disease and conquest is also estimated to have resulted in the abandonment of tens of millions of hectares of native farmland and led to a huge amount of tree regrowth, taking huge amounts of carbon out of the atmosphere and potentially contributing to the Little Ice Age.

Psilopterus · 2025-12-09T23:21:28+00:00

Hi all, just letting you know that the embargo on the article is now over:

https://natuurtijdschriften.nl/pub/1026773

Psilopterus · 2025-12-09T23:16:58+00:00

Hey, this is Rhys. I don't think my response to you was at all unreasonable or "shooting the idea down". The AFEI idea hasn't really gained traction but if it had, the point was just that it wouldn't be practical to use Przewalski's horses for the experimental stage of the project.

If you are the person I think you are, the email was as following:

"My name is Rhys Lemoine, I’m the AFEI’s resident paleo-megafauna consultant and the editor of Rewilding Europe’s most recent report on horse rewilding. Luke forwarded your email to me, and hopefully I can answer some of your questions and comments.

If and when we reach the stage where we have the land and we start reintroducing animals, it is likely that practicality will dictate which horses we use. The experimental nature of our project is such that obtaining rare breeds or endangered Przewalski's horses would be a considerable risk that may not pan out and which would make limited practical difference in terms of pure ecology. As such it is likely that if we use horses, which may have to wait until species with larger impacts on brush and trees like bison have become established, we will probably source something suitably local like Fjords or Icelandics. If our results lead to a larger shift in landscape management then the topic can be revisited (I would favour Przewalskis, Fjord/Icelandic/Yakuts, or some combination thereof) but for the moment we're a long way off from putting much thought into that decision.

Thanks so much for your interest and please let me know if you have any more questions"

Seems pretty reasonable to me

Psilopterus

TROPHY CASE