Original subtitles

200 million years ago,

our planet looked very different

from what it does today.

It was entirely covered by sea,

which surrounded one single supercontinent we call Pangea.

And then Pangea began to break up.

Life was cast adrift

on fragments of land.

And these fragments eventually became our seven continents.

We will see how life developed on each continent,

giving rise to the extraordinary and wonderful diversity

that we see today.

We'll venture through the frozen wilderness of Antarctica,

where life thrives against the odds.

And to the riches of South America,

full of the unexpected.

From the wilds of Africa.

To the vast expanses of North America

and the searing heat of Australia.

We'll explore the remote reaches of Asia,

home to rarely seen creatures.

And Europe, a world transformed by humanity.

And we'll discover how this may be

the most critical moment for life on Earth

since the continents formed.

We are changing the world so rapidly,

that wildlife is now facing some of its greatest challenges yet.

Never has it been a more important time

to reveal the precious diversity of life

on our seven continents.

This is Seven Worlds, One Planet.

Of all the continents,

one was first sighted by humans just 200 years ago.

And only now

are we beginning to understand

what it takes to survive here.

It's the most hostile of them all.

98% of mainland Antarctica,

an area one-and-a-half times the size of the United States,

is covered in ice

on which virtually nothing can live.

So life is dependent on the ocean that surrounds it.

But even the ocean freezes.

Only one mammal can live this far south.

The Weddell seal.

She has to keep her breathing hole open

by grinding back the ice with her teeth.

Out here on the sea ice,

all these seals are far from the predators of the open ocean.

So, this is the safest place for her to give birth.

Leaving the warmth of the womb and landing on ice

is the sharpest drop in temperature any animal ever faces.

But her pup can't swim for the first ten days of its life.

It's trapped here

out on the ice.

She shields her pup from the wind.

Although in spring, temperatures can drop

to minus 40 degrees Celsius,

and blizzards can rage for days.

Three days on, and the storm is still raging.

She now faces the hardest of decisions.

Does she stay with her pup?

Or shelter in the water?

Now, her pup's best chance of survival

is for the storm to pass quickly.

Some pups didn't make it.

An answer.

If this pup now joins its mother in the water,

it will be safe

from any future storm.

It's minus two degrees Celsius,

but being in water is warmer

than lying on the ice

in the howling wind.

Its chances of surviving here are now extremely good.

Only a few hardy animals can live all year round as far south as this.

Further from the pole,

on the fringes of the continent,

lie islands that are free of sea ice.

Here, there are other challenges.

St Andrews Bay on South Georgia

is packed with half a million king penguins.

In spring, the chicks are left for days,

while their parents are away

collecting food for them.

There is a simple arrangement.

The chicks must stay exactly where their parents left them

to be sure of being found again.

But this chick has decided to look around.

There is a lot to be investigated.

But it must not stray too far

from its meeting place.

This parent has returned

with food in its crop.

But its chick isn't where it left it.

It's hard to stay put

when there's so much to play with.

Elephant seals are here, too.

Very mysterious.

Finding it in the crowd of youngsters

is not going to be easy.

They must recognise each other by their calls.

But to hear these in such a noisy colony,

then they must be within 15 metres of each other.

Reunited.

St Andrews Beach is one of the most crowded on the planet,

and so holding a territory here is a constant battle.

This bull elephant seal holds

the mating rights to 60 females.

For two months, he's guarded this stretch of beach.

Unable to feed,

he's losing ten kilos a day,

and he's exhausted.

But other bulls are lying around,

waiting their chance.

Blubber, 15 centimetres thick,

is protection against the cold,

but not from the impact

of a four-tonne opponent.

He holds his ground

and forces the intruder

back out to sea.

Life in the Antarctic is harsh indeed.

But all these creatures come here

because the Southern Ocean

is one of the richest on Earth.

When, 30 million years ago,

the continent broke away

from South America and drifted south,

currents began to swirl right around it.

They are now the strongest

of any currents on the planet.

They sweep up nutrients from the depths,

and so create one of the richest feeding grounds

in all the world's oceans.

And some of the creatures

that come here to feast

do so in a most sophisticated way.

Humpback whales.

It's summer, and they've come here

for a banquet.

The cold waters contain

great shoals of krill.

It's estimated that there are 400 trillion of them

and that their combined weight is greater than that of any other

animal species on the planet.

To collect them, the humpbacks blow curtains of bubbles,

which the krill won't cross.

The whales then rise, spiralling inwards, to concentrate the swarm.

Summer in Antarctica is a time of plenty,

when most humpbacks are able to put on the reserves they need

for the whole year.

But the wildlife in these waters faces an uncertain future.

The Southern Ocean is warming.

90% of the world's ice lies in Antarctica

and, in some parts, the rate at which it's melting

is doubling every decade.

Sea levels are rising.

But there is a more immediate threat.

The warming of the coldest region on Earth is having a profound effect

on global weather patterns.

And this change in the climate is already being felt right here.

This grey-headed albatross chick is four weeks old.

So far, it has been sheltered from the gales by its parents,

who take turns to collect food for it out at sea.

It is the only chick that they will have in two years.

The delicate touching of beaks strengthens their bond.

But these tender moments cannot last forever.

As a chick grows, so does its appetite.

So one parent has to leave to find food before the other returns.

Parting is a big step and they take time over it.

For the first time in its life, this chick is alone.

The Antarctic is the windiest continent,

and in recent years, climate change has brought storms

that are more frequent and even more powerful.

Winds now regularly reach 70mph.

But the albatross chicks must try to stay on their nests.

Surviving the storm is one thing...

..but now, off the nest in these freezing temperatures,

this chick has just hours to live.

The brutal conditions have taken their toll.

Some chicks have already succumbed to exposure.

The bond is so strong, it can be hard for a father to let go.

The albatross population here has more than halved

in the last 15 years.

These albatross are facing extinction.

They simply cannot keep pace with the changes

affecting their world.

More parents are returning to the colony.

Something is not right.

The nest should not be empty.

The chick is actually right below its parent,

but because it's not on the nest, the parent doesn't recognise it.

And doesn't help it.

Strangely, perhaps, these albatross do not recognise their chicks

by sight, sound or smell.

They identify them by finding them on the nest.

So, these violent storms have created a problem

that the albatross are not equipped to solve.

If it is to survive, the chick will have to get back on the nest

by itself.

The chick has made it.

The bond is re-established immediately

and its parent, once again, provides the warmth that the chick

so desperately needs.

It's safe... for now.

Nowhere in Antarctica is survival easy.

Gentoo penguins travel up to 50 miles every day

to find food.

And they're now returning to their chicks.

They are the fastest penguin in the sea

and can swim at 22mph.

But other animals can swim much faster.

Orca.

This penguin must rely on its agility.

With four orcas chasing it, the penguin stood little chance.

Most gentoo parents do make it back to the colony.

Today, it's been a good hunt for krill.

Perhaps too good.

The chicks grow and it seems that the Mohawk style

is back in fashion.

It's just a phase.

He'll grow out of it.

He'll soon lose these remaining down feathers and be ready to leave

the colony and collect food for himself.

But doing so is becoming harder because of climate change.

Glaciers in the region are now calving faster

than they have done since records began.

And this brash ice now fills the bays.

It's autumn.

The chicks have lost their down feathers and they're hungry.

They must go to sea for the first time.

But now there's a risk of being crushed between blocks of ice.

They have to get to the distant icebergs...

..and so reach the open ocean that lies beyond.

And that is easier said than done.

A leopard seal...

..their main predator.

It's a giant, three metres long.

These icy conditions help it to hunt.

The penguins can neither walk nor swim.

They have no way of telling where the seal will strike.

These are easy pickings.

For some, it's time to retreat.

But now, it's back to square one.

There's no alternative but to run the gauntlet once again.

The seal seems to be toying with this penguin.

But safety is in sight.

The ice floe is near the open ocean.

But this penguin is exhausted.

Perhaps it's not worth it, after all.

Winter is coming.

Antarctica now undergoes a major transformation.

Every day, 40,000 more square miles of sea freeze over.

By the end of winter, the continent has doubled in size.

This is by far the largest desert in the world.

But the frozen surface of the sea hides a great secret.

It may be hostile above the ice, but below it,

conditions are so stable that life over millennia

has had time to diversify.

Creatures here grow to a great size.

Predatory nemertean worms are three metres long.

These dramas only become visible when speeded up.

We're only just beginning to discover the details of the lives

of such strange creatures.

Nudibranchs are hermaphrodites.

Each individual possesses both male and female reproductive organs.

So, to mate, one nudibranch just needs to find

another nudibranch.

And any one will do.

But nonetheless, this is a challenge when their tiny eyes can barely see.

Some do get lucky.

They're fertilising each other and both will produce young.

When it's hard to find a partner, it pays not to have to worry

about your gender.

Sea anemones may look like plants, but, actually, are animals

and feed by catching edible particles that drift within reach

of their tentacles.

But being rooted to the sea floor makes them vulnerable to predators.

An ocean-going jellyfish, a metre or so across, searching for food.

The jellyfish senses prey.

But it's the sea anemones that have made the catch

and they've grabbed a monster.

A rare feast for these stationary predators.

They devour their catch over the next four days.

Life here under the ice has remained unchanged for millennia.

But in the last 200 years, much of Antarctica's wildlife

has had to face new predators...

..human beings.

We devised new hunting techniques and used them so mercilessly

that we almost exterminated the great whales.

These whaling stations on South Georgia were at the centre

of this industry.

More than one-and-a-half million whales were slaughtered

in Antarctic waters.

The blubber was stripped from their massive bodies

and boiled down in vats to make margarine and soap.

And the largest animal ever recorded,

a 33-metre blue whale, perhaps over 100 years old,

was butchered on this ramp in just two hours.

This reckless slaughter marked a new low in our relationship

with the natural world.

Southern right whales were hit the hardest.

They were so trusting and inquisitive

that they swam right up to the whalers' boats.

And the whalers called them right whales

because they were the right whales to hunt.

Mothers with calves were targeted first.

To give birth, females came to the same sheltered bays

and would not leave their calves alone at the surface.

In just decades, a population of 35,000

was so reduced that only 35 of the females survived.

But times have changed.

A ban on the commercial hunting of whales, introduced in 1986,

has stopped all but Japan, Norway and Iceland.

Our relationship to these remarkable creatures

has undergone a huge shift.

Scientists are now learning a great deal about these whales.

But we still don't know how long they live.

It's thought that some individuals alive today

were around at the time of the mass slaughter.

Yet these 60-tonne whales remain gentle

and inquisitive around humans.

By putting a stop to commercial hunting,

this population of whales has now grown to over 2,000.

The recovery of life in Antarctic waters may have a significance

that extends far beyond the reaches of the continent

and will affect us all.

Just off the coast of Elephant Island,

we have recently witnessed what might be

the greatest feeding spectacle on Earth.

On the horizon, over 150 whales have gathered

to feast on krill.

This is the largest congregation of great whales ever filmed.

These are mostly fin whales, up to 26 metres long.

Humpback whales are dwarfed in comparison.

Thousands of animals from all over Antarctic waters

are making their way here.

These seas are, once again, beginning to brim with life.

And scientists have discovered that the Southern Ocean,

and the life within it, soaks up more than twice as much

carbon from the atmosphere as the Amazon rainforest.

By protecting Antarctica, we don't just protect the life here...

..we are helping to restore the natural balance

of the entire planet.

St Andrews Bay provides one of the most spectacular sights

in the whole of the Antarctic.

But to get there, the team will have to cross

the roughest seas in the world, and nerves are starting to show.

The wind is picking up already!

It'll take ten days at sea to reach this remote location.

And it's not long before they start to feel a bit green.

There's some big waves coming now.

With these conditions lasting days, all who can take shifts at the helm.

And you get given a talk, to say if you fall in the water here,

there's nothing anyone can do - they can't save you.

It's so cold, you'll die in under a couple of minutes.

Wow!

Below deck, Rolf hasn't yet found his sea legs.

For me, this is like punishment or prisoner-ship or whatever.

I mean, I can't understand at all how people do this voluntarily,

people dream of being on a boat or sailing or anything.

Look at that.

I mean, look how much the boat is moving.

I feel like in a washing machine.

The island of South Georgia finally appears.

It's a relief to step onto solid land.

Yeah, the seasickness is already forgotten, to be honest!

But it's all forgotten.

It's just out of this world.

It's so wonderful that these places still exist.

They will spend the next three weeks in St Andrews Bay.

Rolf is here to film the king penguins in this enormous colony.

And Mark must capture the elephant seals' intense mating season.

On such a crowded beach, fights can break out anywhere.

Males are up to six metres long and they are pumped

full of testosterone.

The bulls take little notice of the crew and will stop at nothing.

Oh, my God!

That went from nothing to being nearly steam-rollered

by four huge males.

Beyond the chaos of the beach, Rolf has king penguins in front of him,

and, thankfully, he's smiling again.

I would really call them the gentleman penguins

because they are very polite, they're charming,

they have humour.

There's so many funny, lovely moments.

I absolutely adore these penguins for that!

But as weeks go by, the reality of living amongst penguins

comes to the fore.

Every morning, I think, "Wow, it's stinky!"

But then I realise, these smells come out of my shoes

and it's myself.

Back on the beach, the team is using a stabilised camera rig.

They can now react faster to fights.

So far in the shoot, we've seen a lot of quick fights,

but we haven't seen some extended fights,

where you see one bull paired

equally against another bull.

These sights are rare.

The team will need to be at the ready.

Mark, Mark, Mark!

Let's get running.

Oh, hello!

These are two huge, evenly matched boys.

I know.

Wow, I never thought we'd be this close to it. I know, nor did I.

This is really tense, we've just got to watch out.

We got there.

I never thought I'd see it that close

and be able to move around it, as this kind of

aggressive ballet is happening.

And it does make you quite tense.

The shoot is going well, but the crew are noticing worrying signs.

It's a really hot day today.

30 years ago, the front of that glacier

was right down on the beach.

It's retreated a huge amount.

I don't really know what climate change is going to mean

for all the wildlife that's living here.

Parts of the Antarctic are warming five times faster

than the rest of the world.

If this trend continues, it will threaten the very existence

of these polar creatures.

On the last day of filming, the team can't help but reflect

on the future of the wildlife here.

For me, it's emotional because I know this might have been

a once-in-a-lifetime experience.

I will definitely take big memories with me and I will be sad.

It's a really special place, you know? So...

I don't know.

I just hope we can keep these places.

And protect them.

Next time...

..the largest continent on Earth.

A world of extremes...

..where rarely seen animals roam the land...

..Asia.