DAVID ATTENBOROUGH: In winter, at the top of the planet
lies an icy wilderness...
..not of land but of frozen water.
The Arctic Ocean.
Its surface forms an almost solid platform
that is bigger than the whole of the United States.
WIND HOWLS
Its presence and condition
dominates the lives of all the many and varied animals
that live both on it...
..and beneath it.
In the coming months, the sun's warmth
will melt much of it and expose the rich waters beneath.
CRACKING
To survive here, life must adapt to this world
that alternates between ice and water.
CRACKING
After three months of winter darkness,
the sun rises across Arctic Norway.
A newly emerged polar bear mother
encourages her cubs to take their first tentative steps
on the sea ice.
Cubs will stay with their mothers for two years,
learning the skills needed to survive out here.
BEAR CALLS
But thereafter, they will be on their own.
Further out on the sea ice...
GRUNTS
..this young female bear, less than six years old,
is already fully independent.
She's superbly adapted to life
on the frozen ocean,
protected from the cold by thick, insulating fat
and a double layer of fur.
This time of year is the best time for feeding.
The ringed seals on which she depends
feed on fish
and are swimming 40 metres beneath her.
But after ten minutes down there,
they must return to the few gaps in the ice
to take a breath and rest.
She has acute hearing
and one of the most sensitive noses in nature.
She can detect a seal's lair beneath two metres
of snow and ice.
Timing is everything.
Only one in ten attempts is successful.
So for a young bear, each meal is very important.
But a male has picked up the scent of the kill.
Large males pose a real threat...
..and could inflict fatal injuries in a fight.
But she stands her ground.
Remarkably, rather than fight...
GROWLING
..they start to play.
And then,
they set off to explore together.
Well fed and still young,
these two seem to be forming a friendship.
She shows off the swimming skills
that enable her to move with ease between water and ice.
GROWLING
She's behind you!
Dancing on ice...
..apparently, just for the joy of it.
After three hours together, they part company...
GRUNTS
..and return once again to their solitary lives.
GRUNTS
Polar bears thrive at this time of year
thanks to the huge platform of sea ice on which they can hunt.
The Arctic Ocean lies
across the top of the northern hemisphere
and over the North Pole itself...
..and is surrounded by three continents -
Europe, North America and Asia.
In winter, the sea ice extends
across an area of over five million square miles.
But off the coast of Arctic Russia,
a tiny pocket of water has been kept open...
..by the continuous stirring of 30 trapped beluga whales.
These four-metre-long Arctic whales are superbly adapted
for hunting far beneath the surface of the sea ice.
WHALES CALL
Nonetheless, being mammals,
they must return to the surface to breathe
every 15 minutes or so.
But this cold spell is exceptionally severe.
And there's not another breathing hole within 20 miles.
Nearby fish and squid disappeared long ago.
These emaciated whales have been imprisoned by the ice
for five months, and they're now starving.
Their only chance of escape will come
when there is a change in the season.
As spring finally reaches the north of the planet,
air temperatures creep above freezing.
CRACKING
The impenetrable ice ceiling begins to fracture.
Small, life-saving channels open up...
..bringing freedom.
But spring is a dangerous time for beluga.
As tides and currents pull ice apart,
the beluga find themselves
in a labyrinth of shifting ice floes
that could close their breathing holes
at any point and so drown them.
WHALES CALL
Using their sophisticated sonar,
they try to find a way through the icy maze...
..and eventually reach a patch of open water.
They're not the only whales here.
Narwhal,
the unicorns of the sea, are closely related to beluga.
In a rarely seen encounter,
these two kinds of whales appear to socialise.
Who knows what's going on between them?
But soon, they set off together
through the shifting fields of ice...
..a journey of up to 1,000 miles...
WHALE CALLS
..before they reach ice-free waters,
where they can rear their young.
As the spring sunshine strengthens,
the broken pack ice off the coast of Greenland
becomes a nursery.
A harp seal pup.
Born just a week ago.
He has little fat.
His thick fur
is his only protection from the Arctic chill.
In between dozes, he waits for his mother to return.
MOTHER GRUNTS
She has only one pup a year...
PUP SQUEALS
..and will produce milk for only 12 days,
one of the shortest nursing periods in nature.
That is just long enough
for him to develop a thick layer of blubber...
..thanks to his mother's milk, which is 50% fat.
And his mother stays alongside
while he learns
an important survival skill
for any seal...
CALLS
MOTHER GRUNTS
..how to swim.
He may not be keen to take the plunge.
The saltwater is minus two degrees Celsius, after all.
Pups start with a doggy paddle.
Mum stays reassuringly close.
Still developing his insulating blubber,
a pup is at risk of hypothermia
so needs to rest
and warm up.
Each day,
he puts on another two kilos...
..and practises swimming
for just a little longer.
Since birth, this pup has tripled in weight,
and he's now at ease in this curious other world.
12 days gone by.
A mother's work is done.
In producing milk, she's lost a third of her body weight.
Now she must return to her feeding grounds.
CALLS OUT
She will never see her pup again.
The next four weeks he spends alone,
sticking close to the ice platform...
..surviving on his fat reserves
as his downy fleece is replaced by a sleek coat
more suited to swimming.
But temperatures in the Arctic are now
rising faster than ever before...
..creating storms that break up the ice floes
earlier each spring.
Harp seal pups are being tipped into freezing waters
before they're ready to endure long periods at sea.
In some pupping areas, almost none survive.
As spring turns to summer,
life on the sea ice suddenly begins to proliferate.
The daylight increases,
and algae that had remained dormant
within the ice all winter
begin to bloom.
This upside-down meadow is now cropped
by plankton.
For a little skeleton shrimp
living at the bottom of a towering forest of kelp,
the best way to get a share of the food...
..is to climb.
If you're only two centimetres long...
..this is like scaling a skyscraper.
And yet it's not alone.
Hundreds of fellow shrimps
are attempting the same ascent.
A new mother
has parked her brood halfway up.
And she's not about to give way.
This one is a determined commuter.
But the mother's drive to protect her young
is now causing a traffic jam.
At last...
many have made it to the topmost branches
of this underwater forest.
And it's been well worth the effort.
The prize...
is a plankton feast...
..raining down from above.
By midsummer, Arctic waters are filled
with food...
..making them into one of the richest of all oceans...
..feeding billions of microscopic mouths
as well as...
..the biggest mouth on the planet.
The bowhead whale.
Its four-metre-long baleen plates
enable it to sieve out
up to six tonnes of plankton a day.
And it grows swiftly into an 18-metre, 100-tonne giant.
In summer, the bowheads are so well fed
they head for an annual get-together.
After a year of wear and tear,
their skin needs reconditioning.
WHALES CALL
This is a whale health spa.
Rocks and sand in the shallows are used like pumice stones
with which to rub off dead skin and parasites.
Such places can become very popular.
This bay, off the coast of Russia,
attracts an immense gathering of over 50 bowheads.
They are the longest-lived of all mammals.
Some are 200 years old
and have been coming here for many decades.
Suddenly...
their peace is shattered.
Killer whales have arrived from the south...
..nine metres long,
weighing nine tonnes...
..and renowned for their exceptional intelligence.
This particular pack specialises in hunting
bowhead whales.
The bowheads retreat into the shallows...
..where it will be harder
for killer whales to launch an attack.
But the killers can swim
much faster than the bowheads.
The group tries to close ranks.
But the killers attempt to separate them.
They look for individual signs
of weakness.
In the shallows, the bowheads lash out...
..with their seven-metre-wide tails.
But in the confusion,
some run aground.
Others try to reach deeper water.
This youngster, half the size of an adult,
is extremely vulnerable.
The killer whales
take turns to ram into its sides...
..cracking its ribs so that it struggles to breathe.
Then they push the youngster down until, finally...
..it drowns.
The battle is over.
It lasted an hour.
Yet now the killer whales eat only one part of their prey...
..the young bowhead's soft, fatty tongue.
Today, more and more bowheads
are falling prey to killer whales
as the warming climate
causes the protective barrier of sea ice
to melt earlier each year.
By midsummer, millions of migratory sea birds,
having flown thousands of miles to get here,
are feeding in the Arctic's rich waters.
BIRDS CALL
Over a million
crested auklets, no bigger than puffins,
now descend on Alaska's Saint Lawrence Island
and are preparing to breed.
To win a mate, a male must try
to stand out from the crowd.
And auditions are already under way.
CHEEPING
Males and females, unusually, look very similar,
each adorned with an Elvis-like crest.
But it's the size of the crest that matters.
And this male's headgear seems to be
no more than adequate.
BIRD SCREECHES
A position on the ground is also important.
One large male wants this particular perch.
And having got it, he breaks into song.
WHOOPING CALL
He now releases a potent tangerine scent
from the back of his neck.
And a mob of fans go wild.
This male, however,
seems to have nothing to offer.
But a gaggle of groupies
can be a dangerous distraction.
An Arctic fox.
BIRDS CALL
It's found an egg.
With the stage cleared,
the highest perch
has become vacant.
This is a moment to shine.
BIRD SCREECHES
His display doesn't go unnoticed.
And his tangerine perfume attracts an admirer.
And not just one.
Now it's down to the females to impress him.
In auklet society, both sexes
have a say when it comes to choosing a mate.
At the height of summer, with 24 hours of sunlight a day,
over half the sea ice melts away.
BIRDS CALL
The beaches of Svalbard
provide safe places to haul out for one of
the Arctic's special residents.
Walruses.
They forage for shellfish for up to 17 hours at a stretch.
Now...
GRUNTS
..it's time for a rest.
Each adult male weighs more than a tonne.
And heaving oneself over the sand...
..without the support of water
is very hard work.
This male has a particular
sunbathing spot in mind...
..right in the middle
of the 50-strong huddle.
GRUNTING
A prod helps in parting the crowd.
Almost in.
At last, he can settle down for a snooze...
..swaddled on all sides
by the bodies of his neighbours.
GRUNTING
But it's not a peaceful spot.
LOUD GRUNTING
Sleep isn't easy when a fidgety bedfellow
decides that he has an itch
that needs scratching.
This is the time to moult,
to get rid of one's old fur with all its parasites
and expose the healthy new coat beneath.
BUBBLING
These days, Svalbard's summer temperatures
can soar to 22 degrees Celsius.
Flushing red by bringing blood close to the skin
helps them to keep cool.
But some overheating is unavoidable...
..especially for a big male.
Enough is enough.
Getting up here...
was a slog.
But this male has found a better way of getting down.
Let gravity do the work.
Now, that is cool!
Ahhh!
Everyone is doing it. It saves both time and energy.
But walruses will need all the tricks they can find.
The Arctic is warming,
and these cold-loving animals are facing
a precarious future.
For millennia, the Arctic Ocean has frozen over in the winter
and then gradually melted
throughout the spring and summer.
But in the last 40 years,
the extent of the summer sea ice has declined by 50%.
Some predict that it will be ice-free as early as 2035.
This profound change...
..is already having an impact
on the Arctic Ocean's highly specialised wildlife.
With less summer sea ice from which to hunt seals,
some polar bears are now travelling up to 400 miles...
swimming continuously for up to ten days
in search of land.
Wrangel Island, off Arctic Russia...
..the only land for almost 100 miles.
Each summer, more and more polar bears come ashore here.
This newly arrived mother
needs to find food for her family...
CALLS OUT
..but knows not to approach other adult bears.
A full-grown male
can kill and eat a cub
and will do so if other food is in short supply.
There are over 1,000 bears on this one island.
It's the greatest concentration of polar bears
on the planet.
But there is food to be had on these remote shores.
A walrus colony...
..2,000 strong.
The walruses panic.
And there are casualties.
GROWLS
Fights break out.
This is no place for a young family.
The mother calls her cubs away.
They must search elsewhere.
Grass is a poor meal for a growing cub.
And starvation in summer is a real threat.
But this opportunity to feed...
..is one she cannot afford to ignore.
It's time to gamble.
Her cubs follow her.
MOTHER GROWLS
She urges them to stay back.
CUBS CALL OUT
The males are twice her size.
But, preoccupied with feeding,
they tolerate her presence.
The distress calls of her cubs, however...
CUB CALLS OUT
..attract unwelcome attention.
Their mother rushes to shield them with her body.
But she seems torn between guarding her family
and feeding herself.
Cubs left by themselves
are easy prey for a hungry male bear.
But now her maternal instincts take over.
Faced with a mother's fury...
the dominant male backs down.
Having fought her way in...
..her cubs can now feed for the first time in weeks.
Polar bears were once
the supreme hunters on the sea ice.
Now, each summer, more and more of them
have to come to land in search of food.
Whether the ice bear survives into the next century
depends on what happens to the sea ice on which they rely.
As with all of the Arctic Ocean's remarkable wildlife,
it's how the climate changes over the coming years
that will determine their future.
In today's unpredictable and changing Arctic,
filming its wildlife is an ever-increasing challenge...
..none more so than trying to capture the brief time
that a mother harp seal spends
preparing her pup for life at sea.
To find the seal's pupping grounds,
the crew have sailed to a remote area of the Arctic
off the east coast of Greenland.
But here, they quickly discover
that its usually solid platform of sea ice
has broken up into thousands of floes.
It's a surprising sight even for veteran captain
Bjorne Kvernmo.
And with the sea ice so fractured,
there's no sign of any wildlife.
We've been at sea for well over a week now.
We still haven't filmed a thing.
With mother and pup together for just 12 days, it's a race
to find the dense pack ice
on which the breeding seals give birth.
The team head a further 100 miles up the Greenland coast,
to an area no film crew
has ventured into before.
Their gamble pays off.
SQUEAL
Our first harp seal, baby!
From the smaller, more manoeuvrable tender,
cameraman Jamie McPherson
hopes to record the precious time
mother and pup spend together
on the ice.
WHISPERS: I've been filming
probably one of the cutest animals in the world.
And there was suckling,
which is really cool, because it's really funny,
because the baby goes from one nipple to the other nipple
and just goes backwards and forwards.
WHISPERS: That's one of the sweetest things I've ever seen!
Utterly adorable!
With mum now calling it into the water,
this pup may be ready for its very first swim.
PUP CALLS OUT
It's the cue for underwater cameraman
Hugh Miller.
We're going to try something different
and actually get into the water with the seals.
We're definitely in new territory here.
To film this rare moment underwater,
Hugh will need to get a lot closer,
without disturbing them.
But with Arctic waters at minus two degrees Celsius,
even with a protective thermal dry suit,
Hugh only has an hour before he risks developing hypothermia.
It's now a matter of waiting for the pup to take the plunge.
The guys have now been in for about...
..20 minutes.
I can guarantee you they'll be freezing cold.
Hugh's body temperature is getting dangerously low.
HUGH: Conditions have been...
really hard.
The cold just...
It's been very, very difficult! LAUGHS
DAVID: With less than a week to go
before this mother is likely to leave her pup forever,
Jamie continues to capture their intimate interactions...
..while Hugh is yet to film a single shot.
To make matters worse,
temperatures fall to
minus 30 degrees centigrade.
And as the wind direction changes,
the floes are forced closer together.
Pack ice has just come in from all around us.
It could flip the boat,
and that would be the end of the shoot.
Hemmed in by blocks
weighing several tonnes, the small skiffs
are at risk of getting crushed.
They radio for help.
But as the mother ship approaches, she shunts
even more ice their way.
So, we've got these big chunks of ice either side of us
and they've got to go somewhere, so...
With help three days away, the crew
can't afford any mistakes.
In the nick of time, a lifeline.
Safely aboard!
That was a bit full-on!
By the next day, the pack ice has drifted apart.
And not a moment too soon.
RACHEL: Awww!
JAMIE WHISPERS: We just saw it go for its first swim.
It was amazing.
It just sort of flops about on the surface. It was very cool.
With the pup finally in the water, Hugh seizes his chance.
But what will the pup make of this curious sea creature?
This pup is playing with - playing with! - the camera.
I can see Hugh's smile from here.
HUGH: Oh, lovely. Wow!
That was great!
Yeah, we saw. That was great!
HUGH: So nice.
Just as Hugh gets his reward,
the Arctic conditions take a turn for the worse.
WIND HOWLS
We've been getting some amazing stuff,
but now the wind's picked up, so we're trying to get out.
With a storm brewing,
not even the mother ship is safe among the ice floes.
The crew have no choice but to leave the seals behind.
It would roll in on a storm?
And they drown?
Today, the combination of reduced Arctic sea ice
and heavy storms
is leading to more and more tragedies like this.
Unless this trend is reversed,
the future for much of the Arctic's unique wildlife
hangs in the balance.
Next time...
..we explore the unpredictable world
of frozen peaks...
..to discover the surprising animals
..that live life...
..on the edge.
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.