Prehistoric Planet

It's minus 50 degrees…

With one hundred mile an hour winds.

This woolly mammoth is lost in the first blizzard of winter.

And it's brutal.

Alone in these conditions, she won't last long.

And it's not just the cold she's battling.

She's in labor.

This is the worst possible time to give birth.

Her calf isn't moving.

She tries to nudge him into life.

But it's not working.

They're both freezing to death.

It's the herd.

They huddle around mother and baby,

forming a shield to protect them from the storm.

But for the tiny calf, it may be too late.

Morning.

The blizzard has passed.

And echoing off the walls of ice…

Are the sounds of celebration.

The shield held, and the calf is alive.

Covered in thick fur and with a family to protect her,

she's ready to face the coldest temperatures the planet has seen

for more than 50 million years.

This is the Ice Age.

A quarter of our world is frozen…

Covered by sheets of ice two miles thick.

Home to strange creatures never seen before.

Surviving the cold is a struggle.

But the Ice Age makes life challenging in other ways too.

Parched deserts,

vanishing forests…

And windswept plains.

This is Prehistoric Planet: Ice Age.

An arctic fox.

It knows a hidden world where the cold doesn't reach.

A cave system so deep, it stays as warm as a spring afternoon,

no matter what.

It's an underground animal metropolis…

Unique to the Ice Age.

And in the very deepest corners, living in total darkness,

cave bears.

The climate is so harsh, they spend most of their lives underground.

And this mother bear has brought her cubs,

just six months old.

These giants are very well-adapted to the Ice Age.

They can hibernate for up to nine months,

the length of a winter here in the far north.

The cave keeps the family safe from the cold.

But that's not the only danger.

Cave lions.

Giant six-hundred-pound predators.

They're not here to keep warm.

They're here to hunt.

This pair come here year after year.

They have a special strategy.

They're not interested in an arctic fox.

They hunt…

Cave bear cubs.

As the lions close in, outside, there's a change in the weather.

And that's a chance

for one of the strangest Ice Age creatures to venture out.

It might look like a bear…

But this is a huge sloth.

Adapted for life in the far north.

Her shaggy fur is at its thickest at this time of year,

superb at fending off the cold.

But her real Ice Age superpower is taking life slowly.

Because saving energy is vital when it's this cold.

In the Ice Age, families stick together for longer to help each other out.

Her son. A three-year-old male.

And bringing up the rear…

Her daughter.

Just a few months old.

It's her first experience of winter.

A roll around the snow is the perfect way to give their thick, shaggy coats a clean.

But for first-timers, all this snow can be a bit

strange.

That's the idea.

With cleaning out of the way, it's time for lunch.

Getting to the bottom of the valley looks like hard work.

But it doesn't have to be.

Baby sloths hitch a ride on their mothers' backs until they're a year old.

Big brothers use their own backs.

Made it,

with minimum effort, in true sloth style.

The only things on the lunch menu are pine needles.

Not very tasty, but at least there are lots of them.

The trick is to find a spot where you can reach maximum leaves

with minimum effort.

Six-inch claws and powerful arms help them reach the best branches.

For the youngster, this is her first time eating solid food.

Her mother's milk was much easier than this.

Climbing is something only the baby is light enough to try.

Almost there…

Oh, dear.

Trees might be slippery,

but big brothers aren't.

Finally, a mouthful in reach.

In a few more years,

her older brother will leave the family to set off on his own.

For now, thanks to her family,

this young slothling is safe and well.

But for the bear cubs, trouble is heading their way.

To reach their target,

the cave lions must pass the gatekeepers of this underworld.

Cave hyenas.

Each is wary of the other.

Today, neither side is looking for a fight.

Almost a mile deep into the cave, the lions finally reach their target.

They must snatch the cubs in total darkness…

And complete silence.

The bear cubs have picked up a scent.

But so has another bear.

Only one cave lion makes it out.

Mother bear has learnt her lesson.

Now she puts herself in the front line.

In this frozen world, everyone needs a trick to keep safe and warm.

Even the smallest creatures.

This tiny vole works round the clock

to create a labyrinth of tunnels under the snow.

Protection from freezing winds…

And predators.

Woolly rhinos.

Not hunting voles but feeding on plants under the snow.

They can scratch a living through the winter thanks to their four-foot horns.

And the humps on their backs are a fat reserve

that help them survive in hard times.

An elderly female.

At 40 years old, she's losing her vision and is almost blind.

She sticks to safer ground in the middle of the herd…

Alongside its newest arrival.

He may not be able to plow the snow quite yet…

But he can learn from Grandma.

Just one of the advantages of living in a herd.

The oldest and the youngest stay together.

The blind leading the defenseless.

In the low light of winter,