DAVID ATTENBOROUGH: At the far south of our planet
lies the most hostile of the Earth's frozen lands.
WIND GUSTS
Antarctica.
Here, temperatures can fall
to below minus 80 degrees Celsius...
..and winds blow up to 200mph.
Its icy centre is almost devoid of life.
But on the edge of Antarctica,
some creatures find a way
not just to survive, but to flourish.
Here are some of the greatest concentrations of life
to be found anywhere on Earth.
The continent of Antarctica
lies at the southern end of the globe.
Twice the size of Australia,
it's the largest, coldest expanse of land on the planet.
To the north of it, however,
across 1,000 miles of ocean,
lie the subantarctic islands,
where conditions are somewhat less hostile to life.
The largest of them is South Georgia.
PENGUINS SQUAWK
Here, a million king penguins live and breed the year round.
PENGUINS SQUAWK
A mother has returned after a month at sea...
..collecting food for her hungry chick.
At ten months old, chicks are the size of a human toddler,
and covered in no more than a downy fleece.
Until they get their waterproof feathers,
they themselves cannot go to sea...
CHICK WHISTLES
..so they have to rely totally on their parents
to bring them food.
Their time together is brief -
just long enough to disgorge her crop of fish and squid.
All too soon,
parents have to return to sea to collect more.
But getting back there
can take several hours.
Hundreds of parents make the commute together.
A beak can be used as an ice-pick
to negotiate the steeper parts of their trek.
This mile-long snow-covered trudge
is unique to this colony,
and has never been seen before.
At last, the sea.
After several days on land,
their feathers need washing to be ready
for the long days of swimming that lie ahead.
But this is a dangerous place to loiter.
Three metres long,
more than three times the size of a king penguin,
these fearsome hunters are usually solitary.
But at this time of the year,
in this bay, there are as many as 30 of them.
If these penguins think that they're safe on land...
..they are mistaken.
PENGUIN SQUAWKS
Any one of these huge seals
can take as many as ten penguins a day.
PENGUINS SQUAWK
Their best chance...
..is to stay with the crowd.
There's safety in numbers.
Made it.
Only to return in a month's time...
..and once again face death head-on.
This is surely one of the greatest challenges
faced by any parent.
1,500 miles off the continent's east coast
lies another of the tiny outposts
that are vital for the survival of Antarctic wildlife.
The Sub-Antarctic Islands of the Antipodes.
In spring, the longer days turn each tiny speck of land
into a potential breeding ground...
..for the Antipodean wandering albatross.
Its wings are three metres across,
amongst the biggest of any bird.
This 14-year-old male
is now mature enough to start selecting a partner.
For the smaller, darker female,
choosing a suitable mate is of equal importance.
After all,
they may stay together for the next 50 years.
To make this crucial decision,
they use one of the most elaborate courtship rituals
of any sea bird.
He begins by sky-pointing.
CALLS
It seems to be working.
CALLS
Next, he attempts a move...
..known as the double head-bob.
SQUAWKING
CLICKING
The finale is the real decider.
Synchronised wing-spreading.
She seems impressed.
But another male appears...
..and shows off...
SCREECHES
..his wings.
The greater the span,
the more attractive he could be.
But the first male won't tolerate
a rival cutting in.
Yet another hopeful joins in the competition.
And another.
This was not supposed to be a dance-off.
She prefers one tango at a time.
It seems that this is not going to be his year after all.
But he's caught the eye of another albatross.
Once again, he begins his courtship display.
SQUAWKING
But this is, in fact, another male.
CLICKING
Regardless, he continues to demonstrate his eligibility.
This could still be the one
with whom he will share the rest of his life.
On the Antipodes Islands, it's becoming increasingly common.
Today, there are three times as many males as females.
Females feed further north than the males,
in waters used by industrial fishing fleets
that catch and drown great numbers of sea birds.
As a result, the female albatross here
is now declining fast.
A same-sex partnership like this
may bring no survival advantage...
..but is apparently preferable to a life alone.
The wealth of life found around Antarctica's lonely islands
is evidence of the richness of the waters that surround them.
The Southern Ocean.
WAVES CRASH
It may appear treacherous.
Its gale-force winds certainly create powerful currents.
But all this stirring has an important effect.
It brings up nutrients from the depths,
helping to create some of the richest seas on Earth.
And this provides food for the largest animal
to have ever lived.
The Antarctic blue whale.
It's more than 30 metres long...
..but it's rarely been filmed before.
Only the Southern Ocean
can provide the four tonnes of food
that the biggest of all blue whales needs every day.
This ocean giant was almost hunted to extinction,
but thanks to an international ban
on commercial whaling,
its numbers are now increasing.
The closer the seas are to mainland Antarctica...
..the colder they become...
..until, a few hundred miles offshore,
the ocean's surface freezes solid.
It forms a cover of sea ice
that is twice the size of Europe
and encircles the entire continent.
This is a stronghold
for one of Antarctica's most remarkable inhabitants.
It uses its teeth
to prevent its breathing holes from freezing over.
The Weddell seal.
The most southerly breeding mammal on the planet.
GRUNTS
This ten-day-old pup
is still entirely dependent on his mother.
Out on the ice,
it may be safe from marine predators...
..but within its first two weeks,
it will have to venture into the underwater world
upon which its future depends.
This is the coldest water on Earth.
So it's not surprising
that a pup needs some encouragement.
It's time to leave the safety of the breathing hole.
To catch fish and then safely return,
this pup must learn how to find his way
through the maze of underwater ice caverns.
But after just eight minutes...
..his mother signals that it's time to head back.
She can hold her breath for an hour and a half.
But he is already starting to tire
and is running out of air.
On their way back to their breathing hole,
they hear a sound as loud as a fighter jet.
STEADY THUMPING
It is the call of a half-tonne male Weddell seal
announcing that he's on the lookout for a mate.
She, however, is still producing milk for her pup,
and so isn't sexually receptive.
But he doesn't stop trying.
THUMPING
To repel his advances,
she leaves her pup's side.
But the pup isn't strong enough
to haul himself out without his mother's help.
PUP WAILS
She tries to fight off the adult male.
She's wounded him so seriously
that he is unlikely to be back any time soon.
SQUEAKS
A gentle nudge from Mother
is all an exhausted pup needs
to make it to the safety of the sea ice.
Mothers stay with their pups for six weeks,
by which time they're strong enough to fend for themselves.
PUP WHINES
As spring arrives, the sea ice retreats,
and in a few places, Antarctica's coast
is exposed to the open sea.
And that attracts all kinds of animals.
Having spent the winter at sea,
chinstrap penguins can now come ashore to breed.
Soon, the coast becomes extremely crowded.
But there are ways to maintain social distance.
SPLATTING
Oh, dear.
The chicks, until they're eight weeks old,
depend on their parents for food
and, critically, warmth.
Meltwater is a particular problem.
The chicks' feathers are not yet waterproof.
Getting wet could be fatal.
A father's duty is to keep his chicks high and dry...
..using the only building material available.
Stones.
And suitable ones are precious.
So it's vital to hold on to every one.
But while backs are turned...
..collections are readily plundered by neighbours.
With thieves like these around...
..that stone has just become even more valuable.
SQUAWKS
What's lacking in skill...
..is made up for with persistence.
But a parent's labours could be in vain.
CHICK CHEEPS
Summer temperatures have now been recorded
as high as 18 degrees Celsius.
As a result, the penguins' carefully constructed platforms
are now being flooded.
There is more meltwater than ever before...
..and the ground is becoming a quagmire.
Downy feathers,
which are excellent insulation from the cold when dry,
are no defence when wet.
Hypothermia sets in.
Over the last 50 years,
the number of chinstraps here has dropped by half.
Antarctica is losing
the very element that defines it.
Ice.
That is now diminishing
six times faster than it once did.
Neumayer Glacier on South Georgia
has lost nearly six miles of ice in just 20 years.
Parts of Antarctica are warming faster than anywhere else
in the southern hemisphere.
And that is having a serious effect
on the animals that live on its coast,
such as the Weddell seal.
With less sea ice available,
many are now hauling out on land.
That's not just a problem for them...
..but also for the predators
that specialise in hunting them...
..one particular group of Antarctic killer whales,
100 or so animals strong.
Killer whales are among the most intelligent
of all nonhuman predators.
And they're now working out how to tackle prey
that isn't a Weddell seal.
An Adelie penguin, resting on the ice.
SQUAWKS
A mere snack for an adult killer whale...
..but it gives this group of six-year-olds
a chance to practise one of their particularly ingenious
hunting techniques.
Wave-washing.
PENGUIN SQUAWKS
A skill that takes at least 15 years to perfect.
First, the killer whales assess the size and position
of a possible victim.
They must then calculate the speed needed...
..for an attack.
SQUAWKS
But they're too late.
Even though a co-ordinated flick of their tails
creates a reasonable wave...
..it's nothing without precision timing.
GRUNTS
With fewer of their favourite prey of Weddell seals
resting on ice floes,
killer whales now have no choice
but to target new prey.
Crabeater seals.
Numbering 15 million,
they're the most abundant marine mammal on Earth.
SEAL GROWLS
But they are a far more dangerous target...
..than a Weddell seal.
Stronger...
..and more inclined to fight back.
But each member of this pod
needs to eat a seal a day.
So the pressure is on to feed.
They're led by a matriarch
who knows exactly what to do.
Living 100 years or more,
she has plenty of hunting experience to draw upon.
GROWLS
With the ice floe having broken in two,
the seals have become more vulnerable.
The matriarch now pushes the ice floe into open water
to give their next wave maximum impact.
This requires teamwork and precision.
She makes her final calculations.
This seal has only one way
of escaping death.
Unlike the less muscular Weddell seal,
the crabeater has the strength
to hurl itself out of the water...
..just in time.
For the killer whales,
it has been a significant waste of energy.
Their need to eat is now greater than ever.
A leopard seal.
By far the most ferocious of all Antarctica's seals.
Dare this pod tackle him?
He's a three-metre adult,
an aggressive hunter in his own right.
Unused to being targeted by killer whales...
..the leopard seal makes the mistake
of leaving the safety of the ice floe.
The killer whales approach the seal with utmost caution.
Keeping away from its powerful teeth,
they seize it by its tail...
..and try to drown it.
The hungry youngsters get to feed first.
But tackling less-familiar prey is risky,
and starvation is a real danger for these killer whales.
Only time will tell
whether these skilful hunters can adjust quickly enough
to survive in this changing world.
Beyond Antarctica's rich coastal fringes
lies a vast frozen interior.
This is certainly one of the most inhospitable places
for life on Earth.
Its icecap, three miles thick in places,
holds almost two-thirds of the Earth's fresh water.
The accumulation of snowfalls over millions of years
has bedded vast mountain ranges longer than the Himalayas.
All that can be seen of them is the tips of their peaks.
Smoking vents standing 20 metres tall
hint at the volcanicity that lies beneath the ice sheet.
The recent discovery
of more than 20 previously unknown volcanoes
reveals that Antarctica is
one of the most volcanic places on Earth.
Almost 4,000 metres high,
Mount Erebus is one of just seven volcanoes on Earth
with a permanent lava lake.
Less than 1% of this frozen interior
is free of ice.
But isolated outcrops of rock
offer sanctuaries for one of the few animals
willing to brave temperatures of minus 30 degrees Celsius.
The snow petrel.
They fly 100 miles inland
in order to breed away from predators.
This male gets to work clearing a shallow scrape,
which he will then line with feathers
to give his chick a little protection
from the bitter cold.
But crevices are in short supply... SQUAWKING
..and rivals are ever ready to fight for them.
SQUAWKS
SQUAWKING
When aerial combat fails,
snow petrels deploy another weapon.
Vomit.
It could be lethal.
If the putrid stomach oil freezes,
his flight feathers could stick together.
Fortunately, he knows how to clean them...
..with a snow bath.
Now to get on with the task of breeding.
CHIRPING
From here to the South Pole, 1,000 miles further inland...
WIND HOWLS
..conditions become even more hostile for life.
Winds driving over the East Antarctic Ice Sheet
can reach speeds of up to 200mph.
As these gale-force winds descend from the ice sheet,
they pick up both speed and warmth.
They create the most arid conditions on Earth.
These aren't snowdrifts.
They're sand dunes.
Some of these so-called dry valleys
have not felt rain in over a million years.
Carved by the wind,
strange monuments up to four metres tall
stand on the desolate valley floor.
The only life form...
..a mummified crabeater seal
that mysteriously strayed here,
possibly thousands of years ago.
But if you look hard enough...
..life can be found in Antarctica's interior.
Hidden in the mountains of eastern Antarctica,
Lake Untersee.
A little over ten years ago,
scientists dived beneath its frozen surface...
..and made a discovery that would change our perception
of the possibility of alien life.
Lying on its lakebed
are living structures found nowhere else on Earth.
Giant stromatolites.
Standing half a metre tall...
..their existence down here
provides an extraordinary insight
into how life on our planet might have evolved.
These living structures have been built
over thousands of years
by arguably the most important microorganism on Earth.
Cyanobacteria.
The very first living organisms to have produced oxygen.
Without them, Earth would have remained uninhabitable
for higher life forms.
If the building blocks for life can be found here,
in the most hostile place on Earth...
..surely life could exist
in the ice-covered lakes of distant planets.
Whilst filming in the extremes
of Antarctica, capturing the remarkable behaviour
of wave-washing killer whales was to prove
the crew's greatest challenge yet.
The team set off from the Falkland Islands
on board the Golden Fleece,
which will be their home for the next month and a half.
It's under the command
of Antarctic explorer Dion Poncet.
What's the weather like for the crossing?
The first day is good.
And then...
..nothing bad... that we can see...yet...
To reach Antarctica, they must first cross the Drake Passage -
650 miles of the world's roughest ocean.
Confined to his bunk, executive producer Mark Brownlow
has yet to find his sea legs.
Destroyed.
Fourth day at sea.
Sick.
On arrival at the peninsula,
their search begins, guided by Leigh Hickmott,
a whale scientist who is part of a 14-year study
on the only killer whales in the world
known to wave-wash.
We now have a greater understanding,
perhaps, of how small the population is, actually,
of these killer whales.
The parent population is about 50 animals,
so really not very many at all.
With so few of these highly specialised killer whales
patrolling an area more than half the size of Wales,
they head to where they were last sighted.
After three days of round-the-clock surveillance,
the team finally catch a glimpse.
Found our first killer whales.
There's the one we want! Whoo!
Good start.
To get shots low to the water,
they launch a gyro-stabilised camera system in a small boat
that's only half the length of the killer whales.
Stay still.
That's so cool!
Definitely feel like we've just been checked out.
It's quite intimidating.
In a filming first,
camera operator Bertie Gregory
launches the drone to capture a new perspective
on this hunting technique.
We've got four, five killer whales, spy-hopping.
Some are moving away! They might get ready for a wave.
There's the first wave!
That's the breaking wave that's broken the pack in half.
The seal's in the water!
Seal's in the water! He could be in trouble here.
They could just kill the seal cleanly,
but they are using the seal to teach their young how to hunt.
It's really hard to watch.
The team's ground-breaking footage
is also providing valuable scientific data,
contributing to the long-term study
of these highly specialised killer whales.
Animal B-17 - she was first photographed back in 2009.
So here she is.
This is a photograph taken during Frozen Planet I.
If we look on the right,
here's a picture that we took during our cruise.
She's certainly the matriarch of her particular group.
We're seeing how she's teaching her offspring
to become this very efficient killer.
But after such a promising start,
conditions take a turn for the worse.
The thing that's changed
enormously here is the weather.
In the past, the peninsula was famous for
perfect calm, still,
bright sunshine, clear skies.
And...
..doesn't happen so much.
And warmer weather here means less sea ice, which could
have consequences for the killer whales'
preferred prey of Weddell seals.
There's a cruel irony, really,
that we've today found the largest group of Weddell seals,
but they're on the beach. They're not on pack ice.
And that's potentially because the Antarctic Peninsula
is one of the most rapidly warming places on the planet.
The team film the killer whales
switching to hunt crabeater seals...
...but then, something remarkable happens.
They approach one of Antarctica's
most formidable predators, the leopard seal.
This is absolutely incredible,
because that's really not considered a key prey for them.
Ooh, he's chosen a bad piece.
The ice has split into four...
..and he's chosen the smallest quarter.
It's phenomenal.
It's the first time a killer whale
hunting a leopard seal has been captured on camera.
As extraordinary as that is,
it's a sobering indication of the challenges ahead
for these killer whales.
I don't think it's too much to say
that we are facing a climate emergency.
There's a real chance that,
as we lose this pack-ice environment,
that this predator, that has one of the most complex
foraging strategies on the planet,
is going to be potentially lost.
And that's a tragedy that I,
in my lifetime, don't want to see,
and for our children, most certainly,
we can't allow to happen.
Next time, we journey to the frozen lands of the north.
A world of snowbound forests and vast open tundra.
Where seasonal extremes
push animals to their limit.
The Open University has produced a poster
exploring how animals adapt to life in the world's coldest environments.
To order your free copy, please call...
..or go to...
..and follow the links to the Open University.