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 Pangaea.
And then Pangaea 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 to 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.
(SEAL GRUNTS)
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.
(PUP MEWLS)
But her pup can't swim for the first ten days of its life.
It's trapped here, out on the ice.
(WIND GUSTS)
(PUP MEWLS)
She shields her pup from the wind.
Although it's 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?
(MEWLS)
Or shelter in the water?
Now her pup's best chance of survival is for the storm to pass quickly.
(WIND HOWLS)
Some pups didn't make it.
(YOWLS)
(MEWLS)
An answer.
(YOWLS)
(MEWLS)
If this pup now joins its mother in the water,
it will be safe from any future storm.
It's minus 2 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.
(CAWING)
Here there are other challenges.
Saint Andrews Bay on South Georgia
is packed with half a million king penguins.
In spring, the chicks are left for days
whilst 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.
(CHEEPS)
But this chick has decided to look around.
There is a lot to be investigated.
(CHEEPING)
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.
(GRUNTING)
Elephant seals are here too.
Very mysterious.
(SEAL GRUNTS)
(GRUNTING)
Finding it in the crowd of youngsters is not going to be easy.
They must recognise each other by their calls.
(CAWING AND CHEEPING)
(CHEEPS)
But to hear these in such a noisy colony
they must be within 15 metres of each other.
(CAWS)
(CHEEPS)
(CAWS)
(CHEEPS)
Reunited.
Saint 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.
(GRUNTS QUIETLY)
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.
(GRUNTS)
(PENGUINS CAW)
(GRUNTS)
(GRUNTING)
Blubber 15cm 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.
(SQUAWKING)
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.
(CHEEPS)
A delicate touching of beaks strengthens their bond.
But these tender moments cannot last for ever.
As a chick grows, so does its appetite,
so one parent has to leave to find food before the other returns.
(CHEEPS)
Parting is a big step,
and they take time over it.
(CHEEPS)
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.
(WIND GUSTS)
Winds now regularly reach 70mph.
But the albatross chicks must try to stay on their nests.
(CHEEPS)
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...
(CHEEPS)
...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.
(CAWS)
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.
(HOOTS)
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.
(RUMBLING)
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 there's now 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.
(CAWING)
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.
(GRUNTS)
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.
(CAWS)
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.
(PENGUIN CAWS)
(SEAL GRUNTS)
(PENGUIN CAWS)
(SEAL GROWLS)
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.
(WIND HOWLS)
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 nemertine 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 anyone 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.
(BELL TOLLS)
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.
(CREAKING)
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.
(HOOTS)
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.
DAVID ATTENBOROUGH: Saint 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.
No, 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!
(RETCHES)
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. 1 mean, how much the boat is moving,
1 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 Saint Andrews Bay.
Rolf is here to film the king penguins in this enormous colony.
And Mark must capture the elephant seals' intense mating season.
(SEAL GRUNTS)
On such a crowded beach, fights can break out anywhere.
(GRUNTS)
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.
(GRUNTS)
Beyond the chaos of the beach,
Rolf has king penguins in front of him,
and, thankfully, he's smiling again.
1 would really call them the gentlemen penguins
because they are very polite, they are charming, they have humour -
there are so many funny, lovely moments.
1 absolutely adore the penguins for that.
But as weeks go by,
the reality of living amongst penguins comes to the fore.
Every morning 1 think, "Wow, it's-it's stinky,”
but then 1 realise these smells come out of my suit
and it's myself!
Urgh.
Back on the beach, the team Is using a stabilised camera rig.
They can now react faster to fights.
So far on this 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 fights are rare.
The team will need to be at the ready.
- Mark, Mark, Mark. - Let's get running.
Ooh, hello.
- These are two huge, evenly matched boys. - I know.
Wow, 1 never thought we'd be this close 10 them.
1 know. Nor did 1.
This is really tense. We've just got to watch out.
Got there.
1 never thought I'd see it that close
and be able to move around it as this kind of aggressive ballet is happening.
(SEAL GRUNTS)
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.
1 will definitely take big memories with me and 1 will be sad.
It's a really special place, you know, SO...
1 don't know.
(PENGUINS CALL)
1 just hope we can keep these places...
...and protect them.
(SOBS QUIETLY)
Next time...
...the largest continent on Earth.
A world of extremes...
...where rarely seen animals roam the land.
Asia.