Ice Age Giants (2013) s01e02 Episode Script
Land Of The Cave Bear
Two and a half million years ago, life on Planet Earth faced the dawn of a new era.
The Ice Age.
Now, we can go back in time.
Because out of the permafrost, from deep inside caves, and from hostile deserts, the astonishing remains of giant animals are emerging.
How amazing to be one of the first people to see this ancient creature.
The Ice Age was the last time such creatures would walk the Earth.
A lost Eden with mammoths taller than any elephant, cats with seven-inch teeth, and some of the strangest beasts that have ever existed.
I'm fascinated by what the remains of ancient animals can tell us about them, and the world they lived in.
Using new scientific advances, we can reveal how they lived, and why they died out.
Come with me, back to the Ice Age .
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a world ruled by giants! 80,000 years ago, our planet began to cool, heralding the beginning of the last Ice Age.
The Arctic ice sheets expanded.
The impact on everything alive was huge, and sometimes in ways you wouldn't expect.
The largest ice sheet covered half of North America.
But south of the ice, the lands became richer than ever.
Last time, I saw how the Columbian mammoth, the glyptodont, the giant ground sloth, and the sabre-tooth cat all flourished here.
But in the rest of the Northern Hemisphere the story was very different.
These lands had their own cast of giants, magnificent animals that now faced a huge battle for survival.
Here, the impact of the Ice Age was to be especially severe.
I want to find out what chilled Europe to the core and what it took to survive the harshest conditions of the Ice Age.
My first encounter is with a truly ferocious beast.
No other creature has left us such vivid clues about its life and its struggle for survival.
I'm here in the Romanian province of Transylvania, which is the traditional home of Count Dracula, but I'm not looking for vampires.
Here in the Apuseni mountains there's a remarkable cave which has kept a dark secret from the Ice Age for tens of thousands of years.
The cave was discovered by a group of miners, rock-blasting for marble.
This is what they found inside.
Once, these bones would have been assumed to be from unicorns or dragons.
But scientists identified them as Ursus spelaeus - the cave bear - the greatest heavyweight of all Ice Age bears.
Cave bears were even larger than grizzlies.
Analysis of their flat, grinding teeth reveals that they were vegetarian.
They ate mainly berries and alpine plants.
Their remains tell a story from around 40,000 years ago.
Average global temperatures were about six degrees lower than today.
Marius Robu, an Ice Age mammal expert, has spent years piecing together the cave bear's story.
There's bones everywhere.
Are these cave-bear bones? Yes, they belong to cave bears.
How big are these bones, Marius? - Really? - Yeah.
- Yeah.
And what were they doing in here? Were they coming in hereto den? To hibernate? It's quite a difference as well, isn't it? I mean, we've come in It was what, about minus 12 outside? And this must be plus 10.
I wouldn't mind hibernating in here.
But these bones can only mean one thing.
Many hibernating animals never woke up.
And the reason for that is what was happening outside the cave.
Autumn.
A young mother searches for food.
To see the winter through, she and her cub must fatten up.
But this year the high-energy berries she needs are scarcer than ever.
As winter approaches, the bears head for their hibernation cave.
She must choose the perfect spot - warm and safe.
40,000 years later, we're following in their footsteps.
Really? This isn't just water flowing down the side of the cave, then? So many bears passed this way that over thousands of years, they've rubbed the rocks smooth.
This is like looking at ancient steps which have been worn down by people walking up and down them.
This is amazing.
- This isn't just one or two cave bears, this must be generations of them.
- Definitely, yeah.
Massive beasts, pushing their way in to this cave and polishing the walls as they go.
It's hard to believe they came so far in, and through such tight passageways.
There's something very unusual about this place.
Thanks to the constant conditions, the mud on the walls is just as soft as it was all those thousands of years ago.
And 250 metres in, etched into the mud, is something truly extraordinary.
That's just amazing, look at that.
'Scratch marks.
' Marius and his team can only find one explanation - these impressions were made by cave bears during the Ice Age.
I just can't believe that these traces are still there, from tens of thousands of years ago.
The bones are one thing, and it's amazing to have those fossils preserved here, but to have these traces of life, and to They do, they do.
Another hundred metres in, there's a big drop.
Now Marius has told me that this is absolutely worth it, and what's at the bottom of this long drop, that I'm now going to try and negotiate, is very exciting indeed.
OK.
Yeah.
Oh! Goodness me, it's covered in them.
Oh, this is just astounding.
Yeah.
Yeah.
I want to know what became of them.
The trail takes us deeper in.
Oh! My goodness.
It's like looking at a tomb.
These are the remains of the cave bears that left all those scratches in the clay above me, scrabbling to get out.
But they never made it.
Just imagine, dying here in the dark, alone, in desperation, gradually starving to death.
It's not a nice way to go.
It makes me wonder why the bears even took this risk, going so deep inside to hibernate.
It seems they were not always alone.
Deep in another tunnel, there are traces of a different Ice Age giant .
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Panthera spelaea - the cave lion.
Look at that.
That is magnificent.
Superficially, they look quite similar and I can imagine if it was covered in a bit of mud you might have thought it could be a cave bear, butwhen you look at these teeth Wow, look at that.
I mean, huge canines, and meat-slicing molars.
That is wonderful.
Cave lions were 25% larger than African lions.
Chemical tests on their bones reveals that they preferred eating large herbivores, but under pressure would hunt just about anything.
So what was this cave lion doing in the cave? Was he making a den here, in a similar way to the bears? So he's hunting the cave bears? But what a risk for a cave lion to take, coming in to a cave like this knowing that, OK, there might be cubs there that he could take easily, but their mothers are likely to be there as well, and they're big animals with big teeth.
Extraordinary as it may sound, Marius is convinced that a lion fought a bear in this very cave.
The lion's bones were found close to a bear's nest and there are some intriguing marks on the lion's skull.
Right, yeah.
OK, so this has been gnawed.
I know it would have been a formidable predator, but I do find it astounding that he would have faced up to a cave bear.
A cave lion tracks its favourite prey - reindeer.
But each year, there are fewer of them.
High in the mountains, driven by desperation, the cat approaches a cave.
He can smell a meal.
In total darkness, the lion must use its senses of smell and hearing to land a killer blow.
SNARLING AND ROARING It's a harrowing story of animals forced into desperate measures as the Ice Age changed their world.
The puzzling thing, though, is that at this time, the nearest ice sheet was still far to the north.
Could it really have had such a long-range impact? Well, there is a place that shows us how the Ice Age took hold.
It's so incredible to see this.
I've never seen anything like this before.
Now this is just a fragment, a remnant, of that once-gargantuan ice sheet which dominated the Northern Hemisphere, stretching right down into North America and Europe.
This is the Greenland ice sheet.
Like icy fingers radiating outwards from the ice sheet, glaciers stretch out to the sea.
These rivers of ice can move at over 35 metres a day.
And when they meet the ocean, this is what happens.
Icebergs are born.
But this is nothing compared with what happened during the Ice Age.
As the Arctic ice sheet grew, its glaciers spewed out great flotillas of icebergs, many the size of large islands.
They floated out into the Atlantic.
When one large iceberg melts, it releases millions of tons of cold water.
When a thousand icebergs melt, they can disrupt ocean currents.
And that changes the climate right across the world.
Between 50,000 and 30,000 years ago, Europe was rattled by three massive deep freezes - Heinrich events.
It was these intense, savage pulses of cold, produced by Heinrich events, when whole armadas of icebergs were released, which kick-started the Ice Age.
And as the temperature continued to drop, the great polar ice sheet advanced ever southward.
And its influence began to alter the habitats of Europe.
For the cave bears back here in Transylvania, those sudden brutal cold pulses were tough.
The woodland glades which provided the rich vegetation that the cave bears depended on were disappearing in those Arctic conditions and being replaced by much hardier shrubs and grasses, useless for a giant calorie-hungry bear.
Each autumn saw more bears starting their hibernation underweight.
By 30,000 years ago, this was a species teetering on the edge as more and more bears died in hibernation.
Within a few thousand years, the European cave bear was extinct.
Europe's woodland gave way to ever more open landscapes, putting forest species under extreme stress.
But this harsh new world wasn't a total disaster.
It presented a great opportunity for one feisty giant .
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a two-ton eating and fighting machine.
An animal you might have thought would be more at home in the Tropics.
Its remains crop up in the most unlikely of places.
Under the North Sea lies a vast Ice Age plain.
Today, it's a rich fishing ground, and the trawlers' nets often dredge up a lot more than just cod or haddock.
Sometimes, the remains of woolly rhinoceros.
Hundreds of rhino remains have been discovered between Birmingham and Vladivostok.
And just recently, a new specimen, superbly preserved by the permafrost, has been discovered in Siberia.
I'm going to Yakutsk, the coldest city on Earth, to see it.
In winter, temperatures seldom creep above minus 40.
And it's thanks to this unforgiving climate that we can see exactly what a real Ice Age rhino was like.
A 20-year-old female woolly rhino was found in a mine just outside the city.
I can't believe that she died 40,000 years ago! This is an incredibly rare and precious thing - it's the almost complete carcass of a woolly rhino, the most complete that has ever been found.
When you touch it, you expect the skin to give a little under your fingers.
And of course it doesn't - it's still frozen, so it feels like a cold, hard stone.
This is an animal which was perfectly adapted to living on the steppe in Siberia.
She was covered in this woolly, furry coat to keep her warm.
There's a little bit of it still clinging on, on the back feet.
A woolly rhino was about the same size as a modern African rhino.
But it had a double-layered coat of wool to shield it from the brutal cold.
Long hairs formed an outer protective layer, shorter hairs formed a downy thermal layer underneath.
Its ears and tail were smaller than an African rhino's to prevent heat loss in temperatures as low as minus 60.
And her whole body shape, this massive stocky body with short legs, is a very good way of keeping warm in cold climates.
Their most striking feature, the horn, was about twice the size of an African rhino's.
Just the thing for settling territorial disputes.
With two males competing over the same precious territory, it's going to end in a showdown.
The woolly rhinoceros was an impressive creature.
But its very presence reveals something quite odd about the Ice Age in Europe and Siberia.
To fuel its large body, a rhino needs to spend virtually all day eating.
It simply couldn't exist in a place where its food is always getting covered in snow.
And this is the great paradox of the Ice Age.
In the freezing wastes of Europe and Siberia, one thing that was thin on the ground was snow! Temperatures were colder, but with so much of the planet's water locked up as ice, this meant that the climate was also drier.
So under clear blue skies, there was plenty of sun in the summer for grass to grow, and in the winter, hardly any snow to cover it up.
Huge as they were, rhinos weren't the largest eating machines to benefit from these cold, dry plains.
There's one giant without which the Ice Age story would be incomplete.
Winter.
Woolly mammoths make their yearly migration across Siberia.
Over the past hundred years, the Siberian permafrost has yielded some truly amazing specimens.
And this is the most captivating of them all.
This is one of the most famous mammoth finds of recent years.
She's called Lyuba and she's a little baby mammoth, probably just a month old.
She was found in 2007, and she is amazingly well preserved, so that we have her skin, her soft tissues and we even have the contents of her gut.
Specimens like this one reveal that the inside of a woolly mammoth is even more impressive than the outside.
Like the rhino, a woolly mammoth had a double-layered coat of wool to shield it from the brutal cold.
But under the skin coursed antifreeze blood.
Inside the red blood cells, the haemoglobin - the oxygen-carrying component of blood - operated efficiently in sub-zero conditions.
In other words, mammoths actually PREFERRED the cold.
But the real mystery of both woolly mammoths and rhinos isn't how they survived appalling cold, but what these giants found to eat.
These were animals that needed up to 200 kilos of food a day.
And this was nothing like the Serengeti, or the jungles of Borneo where elephants live today.
How could a freezing Ice Age environment provide enough food for these mighty giants? 30,000 years ago, mammoths ranged over a vast area.
Thanks to lower sea levels, Britain was joined to Europe, and Siberia to Alaska, north of America's great ice sheet, which meant mammoths could have walked an unbroken belt all the way from Britain to the Canadian Yukon.
Today, it's in this far-flung corner of the mammoths' world - the Yukon - that their lost habitat is uniquely well preserved.
Mammoth remains were first identified in the Yukon when they were discovered by miners of the Klondike gold rush.
A century on, and things are a bit more organised.
The territory now has its own official palaeontologist.
What we have here is a woolly mammoth molar.
This is a typical iconic Ice Age fossil that's found from the Yukon, Alaska, Siberia, all over the north.
The grinding surface on the top of a woolly mammoth tooth is very indicative of a large grazer, something that eats a lot of grass.
But sometimes with the palaeontological record, you have to look beneath that.
You have to look at some of the smaller guys that lived here, too.
They can actually provide us with a lot more information in terms of the whole ecosystem, and how it functioned, how it was structured during the Ice Age.
When you look out on these valleys here, this is a mammoth playground.
This is a huge, huge Serengeti of large mammals during the Ice Ages.
Today, in the search for gold, the ground, still frozen since the Ice Age, is broken up with high-pressure hoses .
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giving Grant a brief chance to hunt for clues left behind by one very special Ice Age character.
Well, we're always looking for these bales of grass heaps.
These look like little hay bales.
But it's just grassy material.
When we see that in the outcrop we know we're dealing with squirrel nests.
These are the traces of an Ice Age animal, one that is still with us today - arctic ground squirrels.
These endearing rodents once lived under the feet of mammoths.
Today, they still thrive in the Yukon alongside a couple of other Ice Age survivors.
The reason that the ground squirrel is so useful to Grant is that it's one of nature's collectors.
In the brief summer, the race is on for this male ground squirrel.
Before he settles down to hibernate, he must eat enough to double his bodyweight, collect plants for his bedding, and make a cache of seeds, ready for when he wakes up in the spring.
When winter finally arrives, he goes underground to hibernate.
This is the most dangerous time of year.
There's no guarantee that he'll survive the winter.
Back in the Ice Age, death in hibernation was common.
Thousands of years later, the frozen remains of ground squirrels along with what they collected, are an Ice Age time capsule.
I think we have a dead squirrel in this nest.
Oh, yeah, for sure.
Oh, wow.
Look at that.
Wow.
We've got ourselves a whole Arctic ground squirrel skeleton in this nest.
This guy died during the Ice Age and never made it through hibernation.
Very interesting.
Within a few feet of space, there's three squirrel nests, this is literally a colony of ground squirrels here during the Ice Age.
This is a great one.
There's some really nice seeds preserved in here.
The plant remains in the ground squirrel nests hold the secret to the woolly mammoth's success.
I'm seeing here a number of plant species that we typically find in Arctic ground squirrel nests.
There's a number of buttercups and poppy seeds, things like wild rye grass, some bluegrass, and these are all the types of plant species that really love cold settings, so places like mountain tops, and ridge tops, grassland environments.
It's not just grass, but a wide variety of species, creating a robust and productive habitat - plenty for mammoths and rhinos to feast on.
It's not a good place today to be a mammoth in the north because there's essentially nothing to eat, but if we go back where there's grass everywhere and small flowers, very few trees and very few shrubs, it's a feeding frenzy for grazing mammals, and if you can imagine that sort of grassland environment spread all the way from northern Canada, here in the Yukon, all the way to England.
This lost grassland is known as the Mammoth steppe .
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a source of food for mammoths and woolly rhinos that wrapped round half the world.
Autumn on the European steppe.
Mammoths mingle with a huge herd of bison making their way to winter grazing grounds in France.
A cave lion waits to pick off the weak and the old.
But there's only one predator that is a real threat to the mammoth, and it makes the lion look like, well, a pussycat.
This Ice Age creature was a giant of its kind, and it preyed on giants.
Science has probed it more than any other Ice Age species, right down to its genetic makeup.
Supremely successful hunters and scavengers, intelligent, with a huge geographic range, one of the largest apes - our very own cousins, Neanderthals.
Neanderthals, with their long, low heads, pronounced brow ridges and stocky frames, were better adapted to the cold and had already survived several Ice Ages.
But, for Neanderthals, this Ice Age was to prove more challenging than any that had gone before.
In one site, on the edge of Europe, there is compelling evidence that in their struggle to survive, Neanderthals turned to the biggest beasts of the steppes.
It's a cave - La Cotte de Saint-Brelade, on Jersey.
Matt Pope of University College London wants to show me what it looked like 30,000 years ago.
We're getting a perspective here that Neanderthals would have had approaching it from the bay.
This would have all been dry land, and you can see, it absolutely dominates this bay and it would have dominated the skyline out there on the hunting grounds on the plains surrounding this site.
And these cliffs, which have always been a feature of the Jersey coast for the past several hundred thousand years, would have just been rising up of this relatively flat, open landscape.
Excavations spanning nearly a century have revealed that generation upon generation of Neanderthals used this cave.
Now this has got to be one of the most famous Neanderthal sites anywhere in the British Isles, so what types of animal bones have been found here? Well, bone preserves fairly poorly at the site, but it's dominated by abundant amounts of mammoth and rhinoceros bone, and we know this isn't just a natural accumulation of animal bone because on the bones are clear marks from stone tools.
And we know exactly what those tools those were.
This is a hand axe, or a bi-face.
It's a large symmetrical tool, but where they really come into their own is where they become an incredible meat knife, where just using a rotational hand grip, which kind of picks up the tissue, it picks up meat, and then it slices through.
So having with you a very portable, very useable butchery knife is a survival tool in itself.
That makes sense, especially when we think about earlier ancestors who'd have competed with all sorts of formidable predators, to be able to cut a carcass up, to be able to take pieces of meat away quickly.
A tool as simple as this extends any kind of human range.
It's a technology that extends the abilities of our basic anatomy.
Before the Neanderthals could butcher a mammoth, they had to kill one.
So how did they hunt these five-tonne behemoths? An early theory was that they chased mammoths over the edge of the cliff here.
But Matt thinks this an unlikely strategy.
LOUD TRUMPETING He's got another theory, based on the shape of the landscape here.
During Neanderthal occupation, with sea levels far lower than today, the cave was at the head of a narrow gorge, a dead end.
If you bring a small herd of mammoth within that dead-end valley, you stand a good chance of being able to isolate individuals, isolate a group of them and kill them through a different way, using technology and the Neanderthals' robust physique to kill them at close quarters.
A woolly mammoth, searching for water, follows the path of the gorge.
He has no idea that he's walked straight into a trap.
But despite their prowess as hunters, Neanderthals were a species threatened with extinction.
In the north, the great ice sheet was growing, locking up more and more water.
The land began to dry out, and across Eurasia, deserts formed.
Their dust was scooped up by strong winds and blown westward.
In the cave in Jersey, above the Neanderthal remains, archaeologists discovered a thick layer of this dust.
Around 35,000 years ago, the Neanderthals' cave was suffocated by it.
Shortly afterwards, Neanderthals disappeared from Jersey.
Their species now clung on in just a few refuges around the Mediterranean.
As the ice sheet neared its greatest extent, there was one final mighty glacial pulse.
It sent armadas of icebergs out into the North Atlantic.
As they melted, the ocean cooled.
This time, the continent was plunged into the coldest period of this last Ice Age.
Average global temperature plunged to 12 degrees below that of today.
By now, Neanderthals had become yet another Ice Age species to go extinct.
The climate was partly to blame.
But it's also very likely that it had something to do with the arrival of some new immigrants.
Our own species, homo sapiens, began colonising Europe just 20,000 years before the peak of the last Ice Age.
Our ancestors didn't have the physical adaptations of Neanderthals and they weren't proven Ice Age survivors.
So how come our ancestors survived while the Neanderthals died out? During the Ice Age, modern humans spread right across Europe and Asia, right up to the coast of the Arctic Ocean.
But as the last glacial maximum approached and conditions worsened, they sought refuge in the south.
Even there, though, the climate was harsh, but they found ways of surviving.
Using the natural resources available to them, they eked out a living in the challenging environment of central Europe and southern Siberia.
Evidence of their survival skills has been found here, in the town of Zaraysk, on the banks of the Osyotr River, in Russia.
A mediaeval fortress now stands on this spot, but excavations show that humans were making their home here 20,000 years ago.
And there are clues as to how they survived the Ice Age.
Those ancient hunter-gatherers used whatever material they could lay their hands on, and there was one material in particular that was to be found in great abundance across swathes of Europe and Asia at the time, and that was the remains of woolly mammoths - their bones and their tusks.
Sergey Lev leads the project.
Trees were scarce during the Ice Age, and mammoth bones, teeth and tusks offered an alternative fuel.
200,000 artefacts have already been found here, some of which suggest an ingenuity not known in Neanderthals.
This is a really beautiful example of something that would have been used probably for piercing or for drilling.
Some kind of material, probably quite hard material, and we can tell just from the lovely slender shape and the fact that there's all this wear around the top, they've shaped it very carefully to begin with and then we have additional wear on top of that.
- So that's been used to drill through something? - It could be ivory.
- You think it's for ivory working? - Yeah, it could be ivory.
- Yeah.
The archaeologists have discovered some really ingenious uses for mammoth remains.
Tusks were driven into the ground to form a frame.
Sergey believes that traces of organic material suggest that hides were stretched over the top, to form a roof.
These semi-subterranean pit dwellings are some of the very first houses ever built.
Our ancestors had been using Ice Age giants to survive.
The technology used by these people, surviving in extreme conditions, during the peak of the last Ice Age, is a fantastic example of the ingenuity and adaptability of our species.
But it wasn't just about building shelters and making stone tools.
The archaeologists here at Zaraysk have uncovered some truly beautiful and enigmatic objects.
Many of them speak to us of the close relationship that our ancestors had with the Ice Age giants, whose world they shared.
This bison, carved from mammoth ivory, represents an animal that must have been key to the survival of the people who lived here during the Ice Age.
It takes time and effort to carve something this beautifully, and I would love to know what it meant to the person who made it and to his or her community.
Was it an object of great ritual significance? An object that was perhaps revered? Was it something used to teach children about the animals that they would hunt when they grew up? There are some things that we will never know.
But how wonderful to have this intimate connection to those Ice Age hunters.
For our ancestors, these animals were sources of food, clothing, and building materials.
They may even have worshipped them.
These images of lions, bison, woolly rhino, woolly mammoths and cave bears are from Chauvet cave in southern France.
Animals which, along with our own species, battled against the Ice Age.
Right across the Northern Hemisphere, in Eurasia and North America, the temperatures plummeted to the lowest they'd been for thousands of years.
The changing climate and environment put large numbers of species under enormous pressure, driving many to the brink of extinction.
But many species survived through the peak of the last Ice Age, and what's really surprising is that it wasn't those years, those millennia of intense cold, that finally finished them off - it was what happened next as the world began to warm up and the great ice sheets of the north started to melt.
Join me next time as I revisit the Ice Age landscapes of the Northern Hemisphere.
I'll discover what it took to survive the Ice Age .
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and find out why so few of the megafauna are still with us today.
It's been a mystery for over a hundred years, but new discoveries tell a surprising story of what finally killed off the Ice Age giants.
The Ice Age.
Now, we can go back in time.
Because out of the permafrost, from deep inside caves, and from hostile deserts, the astonishing remains of giant animals are emerging.
How amazing to be one of the first people to see this ancient creature.
The Ice Age was the last time such creatures would walk the Earth.
A lost Eden with mammoths taller than any elephant, cats with seven-inch teeth, and some of the strangest beasts that have ever existed.
I'm fascinated by what the remains of ancient animals can tell us about them, and the world they lived in.
Using new scientific advances, we can reveal how they lived, and why they died out.
Come with me, back to the Ice Age .
.
a world ruled by giants! 80,000 years ago, our planet began to cool, heralding the beginning of the last Ice Age.
The Arctic ice sheets expanded.
The impact on everything alive was huge, and sometimes in ways you wouldn't expect.
The largest ice sheet covered half of North America.
But south of the ice, the lands became richer than ever.
Last time, I saw how the Columbian mammoth, the glyptodont, the giant ground sloth, and the sabre-tooth cat all flourished here.
But in the rest of the Northern Hemisphere the story was very different.
These lands had their own cast of giants, magnificent animals that now faced a huge battle for survival.
Here, the impact of the Ice Age was to be especially severe.
I want to find out what chilled Europe to the core and what it took to survive the harshest conditions of the Ice Age.
My first encounter is with a truly ferocious beast.
No other creature has left us such vivid clues about its life and its struggle for survival.
I'm here in the Romanian province of Transylvania, which is the traditional home of Count Dracula, but I'm not looking for vampires.
Here in the Apuseni mountains there's a remarkable cave which has kept a dark secret from the Ice Age for tens of thousands of years.
The cave was discovered by a group of miners, rock-blasting for marble.
This is what they found inside.
Once, these bones would have been assumed to be from unicorns or dragons.
But scientists identified them as Ursus spelaeus - the cave bear - the greatest heavyweight of all Ice Age bears.
Cave bears were even larger than grizzlies.
Analysis of their flat, grinding teeth reveals that they were vegetarian.
They ate mainly berries and alpine plants.
Their remains tell a story from around 40,000 years ago.
Average global temperatures were about six degrees lower than today.
Marius Robu, an Ice Age mammal expert, has spent years piecing together the cave bear's story.
There's bones everywhere.
Are these cave-bear bones? Yes, they belong to cave bears.
How big are these bones, Marius? - Really? - Yeah.
- Yeah.
And what were they doing in here? Were they coming in hereto den? To hibernate? It's quite a difference as well, isn't it? I mean, we've come in It was what, about minus 12 outside? And this must be plus 10.
I wouldn't mind hibernating in here.
But these bones can only mean one thing.
Many hibernating animals never woke up.
And the reason for that is what was happening outside the cave.
Autumn.
A young mother searches for food.
To see the winter through, she and her cub must fatten up.
But this year the high-energy berries she needs are scarcer than ever.
As winter approaches, the bears head for their hibernation cave.
She must choose the perfect spot - warm and safe.
40,000 years later, we're following in their footsteps.
Really? This isn't just water flowing down the side of the cave, then? So many bears passed this way that over thousands of years, they've rubbed the rocks smooth.
This is like looking at ancient steps which have been worn down by people walking up and down them.
This is amazing.
- This isn't just one or two cave bears, this must be generations of them.
- Definitely, yeah.
Massive beasts, pushing their way in to this cave and polishing the walls as they go.
It's hard to believe they came so far in, and through such tight passageways.
There's something very unusual about this place.
Thanks to the constant conditions, the mud on the walls is just as soft as it was all those thousands of years ago.
And 250 metres in, etched into the mud, is something truly extraordinary.
That's just amazing, look at that.
'Scratch marks.
' Marius and his team can only find one explanation - these impressions were made by cave bears during the Ice Age.
I just can't believe that these traces are still there, from tens of thousands of years ago.
The bones are one thing, and it's amazing to have those fossils preserved here, but to have these traces of life, and to They do, they do.
Another hundred metres in, there's a big drop.
Now Marius has told me that this is absolutely worth it, and what's at the bottom of this long drop, that I'm now going to try and negotiate, is very exciting indeed.
OK.
Yeah.
Oh! Goodness me, it's covered in them.
Oh, this is just astounding.
Yeah.
Yeah.
I want to know what became of them.
The trail takes us deeper in.
Oh! My goodness.
It's like looking at a tomb.
These are the remains of the cave bears that left all those scratches in the clay above me, scrabbling to get out.
But they never made it.
Just imagine, dying here in the dark, alone, in desperation, gradually starving to death.
It's not a nice way to go.
It makes me wonder why the bears even took this risk, going so deep inside to hibernate.
It seems they were not always alone.
Deep in another tunnel, there are traces of a different Ice Age giant .
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Panthera spelaea - the cave lion.
Look at that.
That is magnificent.
Superficially, they look quite similar and I can imagine if it was covered in a bit of mud you might have thought it could be a cave bear, butwhen you look at these teeth Wow, look at that.
I mean, huge canines, and meat-slicing molars.
That is wonderful.
Cave lions were 25% larger than African lions.
Chemical tests on their bones reveals that they preferred eating large herbivores, but under pressure would hunt just about anything.
So what was this cave lion doing in the cave? Was he making a den here, in a similar way to the bears? So he's hunting the cave bears? But what a risk for a cave lion to take, coming in to a cave like this knowing that, OK, there might be cubs there that he could take easily, but their mothers are likely to be there as well, and they're big animals with big teeth.
Extraordinary as it may sound, Marius is convinced that a lion fought a bear in this very cave.
The lion's bones were found close to a bear's nest and there are some intriguing marks on the lion's skull.
Right, yeah.
OK, so this has been gnawed.
I know it would have been a formidable predator, but I do find it astounding that he would have faced up to a cave bear.
A cave lion tracks its favourite prey - reindeer.
But each year, there are fewer of them.
High in the mountains, driven by desperation, the cat approaches a cave.
He can smell a meal.
In total darkness, the lion must use its senses of smell and hearing to land a killer blow.
SNARLING AND ROARING It's a harrowing story of animals forced into desperate measures as the Ice Age changed their world.
The puzzling thing, though, is that at this time, the nearest ice sheet was still far to the north.
Could it really have had such a long-range impact? Well, there is a place that shows us how the Ice Age took hold.
It's so incredible to see this.
I've never seen anything like this before.
Now this is just a fragment, a remnant, of that once-gargantuan ice sheet which dominated the Northern Hemisphere, stretching right down into North America and Europe.
This is the Greenland ice sheet.
Like icy fingers radiating outwards from the ice sheet, glaciers stretch out to the sea.
These rivers of ice can move at over 35 metres a day.
And when they meet the ocean, this is what happens.
Icebergs are born.
But this is nothing compared with what happened during the Ice Age.
As the Arctic ice sheet grew, its glaciers spewed out great flotillas of icebergs, many the size of large islands.
They floated out into the Atlantic.
When one large iceberg melts, it releases millions of tons of cold water.
When a thousand icebergs melt, they can disrupt ocean currents.
And that changes the climate right across the world.
Between 50,000 and 30,000 years ago, Europe was rattled by three massive deep freezes - Heinrich events.
It was these intense, savage pulses of cold, produced by Heinrich events, when whole armadas of icebergs were released, which kick-started the Ice Age.
And as the temperature continued to drop, the great polar ice sheet advanced ever southward.
And its influence began to alter the habitats of Europe.
For the cave bears back here in Transylvania, those sudden brutal cold pulses were tough.
The woodland glades which provided the rich vegetation that the cave bears depended on were disappearing in those Arctic conditions and being replaced by much hardier shrubs and grasses, useless for a giant calorie-hungry bear.
Each autumn saw more bears starting their hibernation underweight.
By 30,000 years ago, this was a species teetering on the edge as more and more bears died in hibernation.
Within a few thousand years, the European cave bear was extinct.
Europe's woodland gave way to ever more open landscapes, putting forest species under extreme stress.
But this harsh new world wasn't a total disaster.
It presented a great opportunity for one feisty giant .
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a two-ton eating and fighting machine.
An animal you might have thought would be more at home in the Tropics.
Its remains crop up in the most unlikely of places.
Under the North Sea lies a vast Ice Age plain.
Today, it's a rich fishing ground, and the trawlers' nets often dredge up a lot more than just cod or haddock.
Sometimes, the remains of woolly rhinoceros.
Hundreds of rhino remains have been discovered between Birmingham and Vladivostok.
And just recently, a new specimen, superbly preserved by the permafrost, has been discovered in Siberia.
I'm going to Yakutsk, the coldest city on Earth, to see it.
In winter, temperatures seldom creep above minus 40.
And it's thanks to this unforgiving climate that we can see exactly what a real Ice Age rhino was like.
A 20-year-old female woolly rhino was found in a mine just outside the city.
I can't believe that she died 40,000 years ago! This is an incredibly rare and precious thing - it's the almost complete carcass of a woolly rhino, the most complete that has ever been found.
When you touch it, you expect the skin to give a little under your fingers.
And of course it doesn't - it's still frozen, so it feels like a cold, hard stone.
This is an animal which was perfectly adapted to living on the steppe in Siberia.
She was covered in this woolly, furry coat to keep her warm.
There's a little bit of it still clinging on, on the back feet.
A woolly rhino was about the same size as a modern African rhino.
But it had a double-layered coat of wool to shield it from the brutal cold.
Long hairs formed an outer protective layer, shorter hairs formed a downy thermal layer underneath.
Its ears and tail were smaller than an African rhino's to prevent heat loss in temperatures as low as minus 60.
And her whole body shape, this massive stocky body with short legs, is a very good way of keeping warm in cold climates.
Their most striking feature, the horn, was about twice the size of an African rhino's.
Just the thing for settling territorial disputes.
With two males competing over the same precious territory, it's going to end in a showdown.
The woolly rhinoceros was an impressive creature.
But its very presence reveals something quite odd about the Ice Age in Europe and Siberia.
To fuel its large body, a rhino needs to spend virtually all day eating.
It simply couldn't exist in a place where its food is always getting covered in snow.
And this is the great paradox of the Ice Age.
In the freezing wastes of Europe and Siberia, one thing that was thin on the ground was snow! Temperatures were colder, but with so much of the planet's water locked up as ice, this meant that the climate was also drier.
So under clear blue skies, there was plenty of sun in the summer for grass to grow, and in the winter, hardly any snow to cover it up.
Huge as they were, rhinos weren't the largest eating machines to benefit from these cold, dry plains.
There's one giant without which the Ice Age story would be incomplete.
Winter.
Woolly mammoths make their yearly migration across Siberia.
Over the past hundred years, the Siberian permafrost has yielded some truly amazing specimens.
And this is the most captivating of them all.
This is one of the most famous mammoth finds of recent years.
She's called Lyuba and she's a little baby mammoth, probably just a month old.
She was found in 2007, and she is amazingly well preserved, so that we have her skin, her soft tissues and we even have the contents of her gut.
Specimens like this one reveal that the inside of a woolly mammoth is even more impressive than the outside.
Like the rhino, a woolly mammoth had a double-layered coat of wool to shield it from the brutal cold.
But under the skin coursed antifreeze blood.
Inside the red blood cells, the haemoglobin - the oxygen-carrying component of blood - operated efficiently in sub-zero conditions.
In other words, mammoths actually PREFERRED the cold.
But the real mystery of both woolly mammoths and rhinos isn't how they survived appalling cold, but what these giants found to eat.
These were animals that needed up to 200 kilos of food a day.
And this was nothing like the Serengeti, or the jungles of Borneo where elephants live today.
How could a freezing Ice Age environment provide enough food for these mighty giants? 30,000 years ago, mammoths ranged over a vast area.
Thanks to lower sea levels, Britain was joined to Europe, and Siberia to Alaska, north of America's great ice sheet, which meant mammoths could have walked an unbroken belt all the way from Britain to the Canadian Yukon.
Today, it's in this far-flung corner of the mammoths' world - the Yukon - that their lost habitat is uniquely well preserved.
Mammoth remains were first identified in the Yukon when they were discovered by miners of the Klondike gold rush.
A century on, and things are a bit more organised.
The territory now has its own official palaeontologist.
What we have here is a woolly mammoth molar.
This is a typical iconic Ice Age fossil that's found from the Yukon, Alaska, Siberia, all over the north.
The grinding surface on the top of a woolly mammoth tooth is very indicative of a large grazer, something that eats a lot of grass.
But sometimes with the palaeontological record, you have to look beneath that.
You have to look at some of the smaller guys that lived here, too.
They can actually provide us with a lot more information in terms of the whole ecosystem, and how it functioned, how it was structured during the Ice Age.
When you look out on these valleys here, this is a mammoth playground.
This is a huge, huge Serengeti of large mammals during the Ice Ages.
Today, in the search for gold, the ground, still frozen since the Ice Age, is broken up with high-pressure hoses .
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giving Grant a brief chance to hunt for clues left behind by one very special Ice Age character.
Well, we're always looking for these bales of grass heaps.
These look like little hay bales.
But it's just grassy material.
When we see that in the outcrop we know we're dealing with squirrel nests.
These are the traces of an Ice Age animal, one that is still with us today - arctic ground squirrels.
These endearing rodents once lived under the feet of mammoths.
Today, they still thrive in the Yukon alongside a couple of other Ice Age survivors.
The reason that the ground squirrel is so useful to Grant is that it's one of nature's collectors.
In the brief summer, the race is on for this male ground squirrel.
Before he settles down to hibernate, he must eat enough to double his bodyweight, collect plants for his bedding, and make a cache of seeds, ready for when he wakes up in the spring.
When winter finally arrives, he goes underground to hibernate.
This is the most dangerous time of year.
There's no guarantee that he'll survive the winter.
Back in the Ice Age, death in hibernation was common.
Thousands of years later, the frozen remains of ground squirrels along with what they collected, are an Ice Age time capsule.
I think we have a dead squirrel in this nest.
Oh, yeah, for sure.
Oh, wow.
Look at that.
Wow.
We've got ourselves a whole Arctic ground squirrel skeleton in this nest.
This guy died during the Ice Age and never made it through hibernation.
Very interesting.
Within a few feet of space, there's three squirrel nests, this is literally a colony of ground squirrels here during the Ice Age.
This is a great one.
There's some really nice seeds preserved in here.
The plant remains in the ground squirrel nests hold the secret to the woolly mammoth's success.
I'm seeing here a number of plant species that we typically find in Arctic ground squirrel nests.
There's a number of buttercups and poppy seeds, things like wild rye grass, some bluegrass, and these are all the types of plant species that really love cold settings, so places like mountain tops, and ridge tops, grassland environments.
It's not just grass, but a wide variety of species, creating a robust and productive habitat - plenty for mammoths and rhinos to feast on.
It's not a good place today to be a mammoth in the north because there's essentially nothing to eat, but if we go back where there's grass everywhere and small flowers, very few trees and very few shrubs, it's a feeding frenzy for grazing mammals, and if you can imagine that sort of grassland environment spread all the way from northern Canada, here in the Yukon, all the way to England.
This lost grassland is known as the Mammoth steppe .
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a source of food for mammoths and woolly rhinos that wrapped round half the world.
Autumn on the European steppe.
Mammoths mingle with a huge herd of bison making their way to winter grazing grounds in France.
A cave lion waits to pick off the weak and the old.
But there's only one predator that is a real threat to the mammoth, and it makes the lion look like, well, a pussycat.
This Ice Age creature was a giant of its kind, and it preyed on giants.
Science has probed it more than any other Ice Age species, right down to its genetic makeup.
Supremely successful hunters and scavengers, intelligent, with a huge geographic range, one of the largest apes - our very own cousins, Neanderthals.
Neanderthals, with their long, low heads, pronounced brow ridges and stocky frames, were better adapted to the cold and had already survived several Ice Ages.
But, for Neanderthals, this Ice Age was to prove more challenging than any that had gone before.
In one site, on the edge of Europe, there is compelling evidence that in their struggle to survive, Neanderthals turned to the biggest beasts of the steppes.
It's a cave - La Cotte de Saint-Brelade, on Jersey.
Matt Pope of University College London wants to show me what it looked like 30,000 years ago.
We're getting a perspective here that Neanderthals would have had approaching it from the bay.
This would have all been dry land, and you can see, it absolutely dominates this bay and it would have dominated the skyline out there on the hunting grounds on the plains surrounding this site.
And these cliffs, which have always been a feature of the Jersey coast for the past several hundred thousand years, would have just been rising up of this relatively flat, open landscape.
Excavations spanning nearly a century have revealed that generation upon generation of Neanderthals used this cave.
Now this has got to be one of the most famous Neanderthal sites anywhere in the British Isles, so what types of animal bones have been found here? Well, bone preserves fairly poorly at the site, but it's dominated by abundant amounts of mammoth and rhinoceros bone, and we know this isn't just a natural accumulation of animal bone because on the bones are clear marks from stone tools.
And we know exactly what those tools those were.
This is a hand axe, or a bi-face.
It's a large symmetrical tool, but where they really come into their own is where they become an incredible meat knife, where just using a rotational hand grip, which kind of picks up the tissue, it picks up meat, and then it slices through.
So having with you a very portable, very useable butchery knife is a survival tool in itself.
That makes sense, especially when we think about earlier ancestors who'd have competed with all sorts of formidable predators, to be able to cut a carcass up, to be able to take pieces of meat away quickly.
A tool as simple as this extends any kind of human range.
It's a technology that extends the abilities of our basic anatomy.
Before the Neanderthals could butcher a mammoth, they had to kill one.
So how did they hunt these five-tonne behemoths? An early theory was that they chased mammoths over the edge of the cliff here.
But Matt thinks this an unlikely strategy.
LOUD TRUMPETING He's got another theory, based on the shape of the landscape here.
During Neanderthal occupation, with sea levels far lower than today, the cave was at the head of a narrow gorge, a dead end.
If you bring a small herd of mammoth within that dead-end valley, you stand a good chance of being able to isolate individuals, isolate a group of them and kill them through a different way, using technology and the Neanderthals' robust physique to kill them at close quarters.
A woolly mammoth, searching for water, follows the path of the gorge.
He has no idea that he's walked straight into a trap.
But despite their prowess as hunters, Neanderthals were a species threatened with extinction.
In the north, the great ice sheet was growing, locking up more and more water.
The land began to dry out, and across Eurasia, deserts formed.
Their dust was scooped up by strong winds and blown westward.
In the cave in Jersey, above the Neanderthal remains, archaeologists discovered a thick layer of this dust.
Around 35,000 years ago, the Neanderthals' cave was suffocated by it.
Shortly afterwards, Neanderthals disappeared from Jersey.
Their species now clung on in just a few refuges around the Mediterranean.
As the ice sheet neared its greatest extent, there was one final mighty glacial pulse.
It sent armadas of icebergs out into the North Atlantic.
As they melted, the ocean cooled.
This time, the continent was plunged into the coldest period of this last Ice Age.
Average global temperature plunged to 12 degrees below that of today.
By now, Neanderthals had become yet another Ice Age species to go extinct.
The climate was partly to blame.
But it's also very likely that it had something to do with the arrival of some new immigrants.
Our own species, homo sapiens, began colonising Europe just 20,000 years before the peak of the last Ice Age.
Our ancestors didn't have the physical adaptations of Neanderthals and they weren't proven Ice Age survivors.
So how come our ancestors survived while the Neanderthals died out? During the Ice Age, modern humans spread right across Europe and Asia, right up to the coast of the Arctic Ocean.
But as the last glacial maximum approached and conditions worsened, they sought refuge in the south.
Even there, though, the climate was harsh, but they found ways of surviving.
Using the natural resources available to them, they eked out a living in the challenging environment of central Europe and southern Siberia.
Evidence of their survival skills has been found here, in the town of Zaraysk, on the banks of the Osyotr River, in Russia.
A mediaeval fortress now stands on this spot, but excavations show that humans were making their home here 20,000 years ago.
And there are clues as to how they survived the Ice Age.
Those ancient hunter-gatherers used whatever material they could lay their hands on, and there was one material in particular that was to be found in great abundance across swathes of Europe and Asia at the time, and that was the remains of woolly mammoths - their bones and their tusks.
Sergey Lev leads the project.
Trees were scarce during the Ice Age, and mammoth bones, teeth and tusks offered an alternative fuel.
200,000 artefacts have already been found here, some of which suggest an ingenuity not known in Neanderthals.
This is a really beautiful example of something that would have been used probably for piercing or for drilling.
Some kind of material, probably quite hard material, and we can tell just from the lovely slender shape and the fact that there's all this wear around the top, they've shaped it very carefully to begin with and then we have additional wear on top of that.
- So that's been used to drill through something? - It could be ivory.
- You think it's for ivory working? - Yeah, it could be ivory.
- Yeah.
The archaeologists have discovered some really ingenious uses for mammoth remains.
Tusks were driven into the ground to form a frame.
Sergey believes that traces of organic material suggest that hides were stretched over the top, to form a roof.
These semi-subterranean pit dwellings are some of the very first houses ever built.
Our ancestors had been using Ice Age giants to survive.
The technology used by these people, surviving in extreme conditions, during the peak of the last Ice Age, is a fantastic example of the ingenuity and adaptability of our species.
But it wasn't just about building shelters and making stone tools.
The archaeologists here at Zaraysk have uncovered some truly beautiful and enigmatic objects.
Many of them speak to us of the close relationship that our ancestors had with the Ice Age giants, whose world they shared.
This bison, carved from mammoth ivory, represents an animal that must have been key to the survival of the people who lived here during the Ice Age.
It takes time and effort to carve something this beautifully, and I would love to know what it meant to the person who made it and to his or her community.
Was it an object of great ritual significance? An object that was perhaps revered? Was it something used to teach children about the animals that they would hunt when they grew up? There are some things that we will never know.
But how wonderful to have this intimate connection to those Ice Age hunters.
For our ancestors, these animals were sources of food, clothing, and building materials.
They may even have worshipped them.
These images of lions, bison, woolly rhino, woolly mammoths and cave bears are from Chauvet cave in southern France.
Animals which, along with our own species, battled against the Ice Age.
Right across the Northern Hemisphere, in Eurasia and North America, the temperatures plummeted to the lowest they'd been for thousands of years.
The changing climate and environment put large numbers of species under enormous pressure, driving many to the brink of extinction.
But many species survived through the peak of the last Ice Age, and what's really surprising is that it wasn't those years, those millennia of intense cold, that finally finished them off - it was what happened next as the world began to warm up and the great ice sheets of the north started to melt.
Join me next time as I revisit the Ice Age landscapes of the Northern Hemisphere.
I'll discover what it took to survive the Ice Age .
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and find out why so few of the megafauna are still with us today.
It's been a mystery for over a hundred years, but new discoveries tell a surprising story of what finally killed off the Ice Age giants.