Painting a picture of the Pleistocene with Alex Taylor

Alex Taylor (pronouns: he/him) is a Field Technician with a consultancy called Eco Logical Australia, working across various different landscapes. His passion however, lies in how the landscape would have looked more than 10,000 years ago during the Pleistocene (often referred to as the Ice Age). Alex is very involved in discussions around Trophic Rewilding and De-extinction and today he paints a picture of the Pleistocene for us and discusses the conservation benefits of controversial research around Pleistocene rewilding.

ALEX’S JOURNEY

Alex has always had an interest and passion for nature. Growing up in rural Yorkshire (England), Alex spent lots of time outdoors exploring the natural world, looking at frogs and toads and even birdwatching with his Dad from a young age.

Despite this, Alex took the long route and veered off the idea of wildlife as a career initially, focusing first on a career in the military and then on a chefs apprenticeship, neither of which he found were for him. And so, Alex packed his backpack and booked a trip to Australia where he met his current partner Kim, and re-connected with his passion for wildlife. The rest is history – Alex returned to study Conservation Biology and Ecology at the University of Plymouth and has been volunteering and working in the industry ever since (whilst making great coffees as a side gig).

Alex is looking to focus his career on studying, conserving and restoring Australia’s small mammal assemblages after their loss and extirpation from most of our landscapes over the past 200 year or so, whilst educating others about their existence, importance for Australia’s ecosystems and the issues caused by feral animals such as cats and foxes.

But what about Pleistocene rewilding? As you’ll discover from reading this post or listening to Alex on the podcast, he is a wealth of knowledge on this subject! Alex encountered the concept of rewilding in 2016 when I he was studying Conservation Biology, where one of his lecturers ran a conservation biology book club, and each month we would read and discuss a book, one of which was Feral by George Monbiot. As he explains,

“I think it’s one of the go-to books that people in Europe think about when they talk about rewilding, and it opened my eyes to how ecosystems have changed… I’d never thought about what was missing – I’d never questioned why a blackthorn has huge thorns, why the biodiversity of Europe was so tied to open land? – and then coming back to Australia, I started reading more and more into it…”

Alex warns us this is a controversial topic, but if you’re ready for it, we’re about to take a deep dive into trophic rewilding and de-extinction – let’s go!

PLEISTOCENE REWILDING: THE BASICS

When we’re talking about rewilding, or bringing animals back into a landscape, the first question is to what point in time? The concept behind Pleistocene rewilding is essentially looking at a baseline where ecosystems hadn’t suffered the late Quaternary events, essentially the extinction of large megafauna during the end of the Pleistocene.

The Pleistocene, also referred to as the Ice Age, is an epoch that ran from around 2 million years ago to around 10,000 years ago at the end of the last glacial period, it was the era that came directly before the one we’re in, the Holocene (although some people would argue we have now entered the Anthropocene!) during which time, most of what we’d consider the ‘modern’ animal and plants, landscapes and ecosystems we are familiar with evolved. An important point to make is that this period wasn’t just ice ages – rather it cycled between glacial and warm periods, similar to the one we live in today!

In general, most of the animals lost around the Pleistocene were the larger species – the megafauna – or the big brothers to many of our remaining species. Many of these animals would have had important functions within their ecosystems including nutrient cycling, habitat creation by trampling, digging or burrowing (yup, South America had giant burrowing ground sloths and armadillos and Australia had giant burrowing wombats, and you thought a mole in your lawn was an issue?!) and impacts from their predatory or browsing/grazing habits.

PICTURING THE PLEISTOCENE

When picturing the Pleistocene, think of a world where every continent was its own Serengeti

Parts of North America would have had herds of mammoths roaming the grasslands. There would have been Mastodons (an elephant relative adapted for browsing tough vegetation), giant ground sloths as big as elephants, herds of wild horses, bison, camels and numerous species of pronghorn, an American Antilocaprid, whose closest living relatives are giraffes and who’s speed evolved to outrun America’s own ‘cheetah’ Miracinonyx, a relative of the modern Mountain Lion. Alongside the cheetah were American lions (Panther atrox), twice as big as the cats we know today, short-faced bears bigger than a Polar bear, Dire Wolves and fearsome sabretooth cats like Smilodon and Homotherium.

So, the kind of ecosystems you would have encountered would have been similar to the famous savannahs of Sub-Saharan Africa today, even surpassing them in terms of their diversity of large animals.

Madagascar, isolated from the rest of the world since the late Cretaceous, had the Elephant Bird, (the largest flightless bird to have ever lived), as well as Dwarf Hippopotamus, Horned Crocodiles, a giant species of the cat-like Fossa and multiple species of Giant Lemurs, some reaching the size of gorillas! This unique fauna survived there well beyond the Pleistocene, until about 1000 years ago, when humans and their livestock arrived on the island.

In Europe, the glacial periods were characterized by the true ‘Ice Age’ species of the mammoth steppe grasslands (a vast biome which stretched around the top of the world from northwest Europe to central Canada, characterized by a very cold, dry climate dominated by grasses): Wooly Mammoth, Wooly Rhinoceros, Saiga Antelope, horses, Bison… and of course predators including lions, wolves and scimitar tooth cats.

However, during the most recent warmer interglacial period (the Eemian interglacial), you would have seen a similar fauna in Britain to that of today: Weasels, badgers, hedgehogs and voles scurried in the undergrowth, wild cattle (aurochs) and horses, wild boar and deer roamed the scrub, open woodlands and grasslands. Oak trees emerged from thickets of hawthorn and blackthorn and flocks of cranes made their haunting calls from the wetlands as a beaver smacks its tail on the water before disappearing. But these familiar sights and sounds existed alongside less-familiar ones… like the hulking mass of a hippopotamus crashing through the reeds, the laughing call of a hyena or the deafening trumpets and low grumbles of straight-tusked elephants, a contender for the largest land mammal known to exist, in a climate very similar to todays.

PIECING THE PUZZLE BACK TOGETHER

The picture of the Pleistocene would have looked different, depending on where you were in the world – and piecing these ecosystems back together is easier on some continents than others.

For example, Europe’s pretty lucky as far as potential for rewilding goes. Some of Europe’s megafauna survived until today in the form of domesticated animals: If you’re drinking a latte or enjoying some cheese, you can thank the Aurochs, it survived in the form of cattle and Europe’s wild horses lived on in the form of the horses we are so familiar with. Primitive cattle and hardy ponies like Exmoor ponies have lived feral or semi-wild for thousands of years and in this way, they’ve had a continuous presence in the landscape. So, with agriculture peeling back in remote parts of Europe and people transitioning to cities, it has been a relatively simple process of re-introducing feral horses, wild asses, cattle, deer, water buffalo and bison to restore the processes they perform and preserve the biodiversity linked to those processes.

Predators like lynx have also been reintroduced in some places and wolves have recovered most of their former range in Europe since becoming protected, with packs living only a few kilometers away from the center of Paris! An amazing example of how nature can recover when we allow it. If a future rewilding project wanted to be more ambitious, Europe’s elephants, rhinos, hippos live on in their close relatives in Africa and Asia… Lions were found in southern Europe until the Classical times (maybe beyond), the ancient Greeks knew them from the mountains and the Romans captured them to fight gladiators in the Coliseum.

In a place like Australia this has not been the case, chiefly because of the timescale and drastic changes in ecology since those extinctions and the uniqueness and isolation of Australia and its biota. In Eurasia, Africa, and North America, there was a lot of connectivity between the continents and many species lost to extinction have surviving relatives (like Elephants and Mammoths). Unfortunately, the animals Australia lost during the late Pleistocene extinctions have no large, close relatives left.

There is nothing left that resembles the strange giant short-faced kangaroos (Zygomaturus) or the fearsome Thylacoleo carnifex, a semi-arboreal leopard-sized wombat/koala relative, which had the most derived dentition of any carnivorous mammal in the fossil record and may have hunted by ambushing it’s prey from the trees… Who said drop-bears aren’t real?!

“For example, the Diprotodon, we’re talking about a rhinoceros-sized wombat – there’s nothing like that surviving today and we really don’t know too much about its ecology or how it functioned within the ecosystem.”

Alex believes for this reason, there’s no one-size-fits-all when it comes to Pleistocene rewilding but when looking at modern ecosystems, we can acknowledge that some species that evolved within them are missing – and with that, the processes and ecological functions they performed.

In this way, Pleistocene rewilding can have huge benefits for biodiversity as the introduction and management of a few species such as beavers into Britain’s wetlands, which can restore lost functionality to the ecosystem. As Alex says –

“It’s interesting and it’s contentious. And I’m not saying you should do this everywhere but with the natural world in free-fall, it’s something that should at least be looked at, trialed and studied”

“We’ve lost so much of our wildlife globally so if we can provide a new home for threatened species, let’s say for example, elephants in tropical, South America, which did have elephants until about 9,000 years ago, and they can provide biodiversity benefits for that area then let’s consider that!”

WHAT CAUSED THE EXTINCTION OF OUR MEGAFANA?

The short answer, no one is sure! As Alex says,

“I’m not going to make a definitive statement on whether it was humans who caused these extinctions as we spread around the planet or whether it was climate change or a combination of both… I strongly believe humans were a major factor in a lot of these extinctions, but there are many smart academics who disagree.”

Climate change is often put forwards as the sole driver for many of these extinction events but this doesn’t always seem to make sense when looking at why these extinctions are so focused on just the larger animals – with extreme climate events, you’d expect to see a much wider diversity of species lost.

Furthermore, none of these events occurred at the same time globally. Alex explained that in reverse order, 800-1000 years ago, the Moa disappeared from New Zealand, in South America, the extinctions occurred 9000 years ago, in North America, 12,000 years ago, in Europe 30,000 years ago and Australia, 30-40,000 years ago.

“We can see from archeological evidence, cave art and paleo sites that humans were hunting these animals, but there is also evidence that efforts to create conservation areas for megafauna as people realized they were becoming scarce”

These timings don’t always correlate with any major climatic shifts or events, but rather, each of them happens after the arrival of modern humans. Cave art and paleo sites around the word indicate humans were hunting a wide variety of species from South America to Australia, from Europe to New Zealand.

Populations of many of these animals survived for thousands of years longer than their relatives on offshore islands too, something you wouldn’t expect to see if a climatic event was severe enough to cause concurrent extinctions from Alaska to southern Mexico

ARE WE INHERANTLY DESTRUCTIVE?

I don’t know about you but hearing this, I certainly feel a level of guilt as the story has a similar tone to what we experience in the natural world today. Alex doesn’t agree (phew!) –

“A lot of people try and use the extinction of megafauna as a way to condone racist views against indigenous populations which I hate – as it was nothing like that, we were just surviving!”

“There’s an idea, the eternal frontier, and I think that’s probably what people thought they had as they spread across the world into new landscapes with plentiful resources and no competition.”

How could we possibly make a dint in the abundance of diverse life forms we were discovering?

Alex explains that over generations, as humans began to establish in these new landscapes, it is very likely that slow-breeding, large (and naïve!) animals felt the pressure of hunting attrition and habitat loss with changing fire regimes and the subsequent changes in ecology, vegetation and hydrology.

“So, I don’t think it’s a case of that we’re inherently destructive because we know we’re not – in the very sense that we’re trying to restore things as well. When we’re made aware of the situation, most people will try and address that imbalance – historically through until today.”

And following each of these extinctions, an ecological equilibrium was reached between Indigenous peoples and their environment that they lived in and supported, and that supported them.

“There’s a lot we can learn from looking into extinctions – although people don’t like to think that we are capable of wiping out entire species, I mean, up until the 1800s, there was no concept of extinction – nobody thought animals could go extinct. When we found fossils or other evidence, we simply assumed it was still alive somewhere else”

Climatic change has caused some of the largest mass extinctions in the history of our planet (and could do so again!), but it could be a convenient alibi when looking back at the events that ended the Pleistocene megafauna.

HOPE FOR THE FUTURE
Rewilding is becoming more and more utilized as a conservation strategy for protecting threatened species and restoring damaged ecosystems. With so many examples of successful rewilding projects taking place across the globe, perhaps it’s time to start turning our attention towards some of the more ambitious project proposals to reintroduce Pleistocene functionality back into damaged landscapes in the form of modern descendants or relatives of the species that would have been present in these environments.

If we could only turn back time! Unfortunately we can’t, ecosystems are dynamic and moving forwards, you can’t go back, that shouldn’t be our goal… but we can acknowledge that the plants and animals we see today evolved in a different context to our modern one until very recently, then use the past as a template whilst looking towards modern science and indigenous knowledge to help us preserve, enhance and restore what we have left and maybe help our own species from going the same way as the mammoths!

When we asked Alex to design any Pleistocene rewilding project he would most like to experience, his response was a large fenced area on the southern prairies of North America and reinstating an approximation of the fauna that would have been present 11-12,000 years earlier.

“This is me being very ambitious and it would certainly be quite spectacular! Currently, north America’s fauna here is a shadow of the 22 genera known to be lost at the end of the Pleistocene from this landscape. For me, it would be cool to introduce the Asian Elephant, camels and the cherry on top, lions (yes, Europe and north America had lions until very recently!)”

“Although these modern relatives are different species, seeing how they could interact with a modern prairie ecosystem would be so interesting in terms of reducing weed transmission and monitoring their impact on the existing smaller species within the system.”

Why not? You can dream right!

KEEP IN TOUCH

Want to hear more from Alex? Tune into the podcast to listen to our conversation.

You can follow Alex (and his dogs) on Instagram @wild_about_wildlife_ and if you’re interested in diving deeper, you can join the Facebook group that Alex has played a big part in administering and supporting, Trophic Rewilding and De-extinction

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