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The polar winter.

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This is the planet
at its most hostile.

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Those that stay here at this time

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must face the harshest conditions
on Earth.

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The High Arctic in late autumn.

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Empty and abandoned to ice and snow.

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Most animals migrated
south weeks ago.

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The few that stay
will face violent winds,

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plunging temperatures
and months of darkness.

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A female polar bear
searches for shelter.

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Other bears are out on
the frozen ocean looking for food,

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but she won't feed again
until next spring.

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Using as little energy as possible,

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she starts to dig a shallow nest.

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The snow here is easy to work.

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It's soft and light.

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A sure sign that soon, plenty more
will accumulate on this slope

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as winter advances.

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And that is what she needs.

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If she has chosen well,

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the Arctic wind will do
much of her work for her.

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Once the snow here is deep enough,

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she will dig down to make a den.

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She'll then lie, waiting for her
cubs to be born as winter sets in.

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The sea ice already covers
twice the area it did in summer.

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Those animals that, a few weeks ago,

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came down here to feed in the sea,
are now locked out.

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But there are windows
in this white desert.

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Gateways to the rich ocean below.

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Most birds have migrated south.

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But in the frozen Bering Sea,

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ducks of one particular species

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are gathering together
in a single, immense flock.

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Spectacled eiders.

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Hundreds of thousands of them.

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With the seas that fed them
throughout the summer

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all but frozen,
this is the eider's last refuge.

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Such patches of open water,

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kept free of ice by strong currents,

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are given a Russian name, polynyas.

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If this polynya stays open
all winter,

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the ducks will have avoided
an exhausting migration.

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It's a gamble and a tremendous risk,

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especially for the spectacled eider,

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for this polynya
holds the world's entire population.

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Surrounded by ice,
these spectacled eiders' survival

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depends on this single,
vulnerable oasis.

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And conditions here
can change very fast.

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A smaller pool.

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Here, common eider ducks
are learning a bitter lesson.

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An early winter storm
has caught them out

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and the ice is closing in.

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The pool is shrinking,
and the ducks are freezing to death.

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These gamblers have lost.

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As the sun's influence continues
to dwindle here in the north,

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the cold pushes south
into Arctic lands.

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Winter brings
a devastatingly-destructive force.

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Frost.

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Ice crystals form
as moisture in the air freezes.

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Inside plants,
the same thing is happening

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to the water in their cells
and their sap.

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With these first frosts,
most plants die.

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Their insides ripped apart
by ice crystals.

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Coniferous trees, however,
like fir and pine,

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can withstand very low temperatures.

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It's these trees that create
the greatest forest on our planet.

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This is the Taiga.

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It encircles the globe and contains
one third of all the trees on earth.

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As winter deepens,
frigid air from the Arctic

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meets warm, moist air
from the south,

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producing particularly heavy snows.

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For the big animals of the forest,

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there's no way of hiding
from the winter.

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But size, for the Bison
of Northern Canada,

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is, in fact, their salvation.

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Big bodies lose less heat

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and can carry more insulation.

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That may be why these bison

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are the largest land animals
in North America.

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And only a large predator
can tackle them.

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Wolves hunt better in packs,

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but there are only two of them here
and the prey they pursue are giants.

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A vast Arctic wilderness
stretches all around.

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In it somewhere, there are bison.

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These deep tracks in the snow
are easy to follow,

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but which way were the bison going?

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They have detected a scent.
The hunt is on.

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Running in the bison's tracks
is easy.

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The snow here is compressed
and firm.

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At this rate,
the wolves will soon catch up.

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They attempt a shortcut.

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The giant bison can plough on
through virgin snow,

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but for the wolves,
deep snow is a hindrance,

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and now they're losing ground.

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The hunters rejoin the bison's
tracks and the contest is on again.

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The bison are the only prey here
in winter.

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The wolves have no option,
they must tackle them.

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But bison are ten times their size.

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In winter, the line between
life and death is so narrow

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that for a wolf, even a small injury
could be fatal.

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It's crucial they select
the right target.

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This one is very big.

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Good decision.

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This is smaller, a yearling.

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Even though it's young,
it's none the less heavier

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than both wolves combined
and it is extremely powerful.

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The male wolf backs off.

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Perhaps he's frightened of injury.

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But the female is more determined,
or more desperate.

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Having given so much already,
she must make the kill.

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This is a battle of life and death
for them both.

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The bison has no strength left.

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The battle is over.

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Winter deepens.
The snow continues to accumulate,

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smothering the forest.

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Some trees are loaded with
three tonnes of snow.

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It shuts out what little light
there is at these latitudes,

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and that shortens the growing season
still further

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and limits how far north
trees are able to grow.

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So, snow influences
both the shapes of the trees

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and the extent of this forest.

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And it affects the animals, too.

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SQUAWK!

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It helps to have friends

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if you want to find food
at this time of the year.

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Wolverines and ravens,
a match made in the Taiga.

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It's the hardest time of the year
to find food.

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But the wolverine knows
that a raven's call

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is as good as a dinner bell.

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And the raven has just recruited
the best can opener in the forest.

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The moose carcass is frozen solid,

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but the wolverine
has immensely powerful jaws,

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well able to deal with frozen food.

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The raven's bill
is more suited to leftovers.

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The raven has to be patient.

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A wolverine's appetite is legendary.

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According to folklore,
it can eat more at one sitting

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than any other creature
in the forest,

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hence its other name, the glutton.

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What the wolverine can't eat now,

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it stores in the deep freeze.

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It will bury these food parcels
across the forest,

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planning ahead for leaner times.

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For a few, the snow is an ally.

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Voles stay active throughout
the winter beneath the snow,

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despite the freezing temperatures
above.

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Travelling along tiny corridors,

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they move from pocket to pocket
of perfectly refrigerated food.

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Snow is a great insulator,

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so down here,
the temperature never falls

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more than a degree or so below zero.

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And that's warm enough
for a vole to thrive,

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even if it lacks
the stature of a bison.

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In some years, vole numbers boom,

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and then they are forced to break
cover to search for more food.

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The great grey owl is a silent
and very skilful hunter,

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but deep snow
can be beyond its reach.

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But such snow is no barrier
to one predator.

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The least weasel.

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A tiny hunter,
and the vole's nemesis.

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Its body is exactly the same width
as a vole's,

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so there's nowhere a vole can go
that the weasel can't follow.

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INSTRUMENTAL

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The weasel's long, slender shape

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is perfect for hunting in tunnels,

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but the worst possible shape
for staying warm.

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So they need a special way
of doing that.

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She plucks the fur from its body
tuft by tuft.

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And now she puts it all together
to make a cosy blanket

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under which to sleep
in her den below the snow.

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Midwinter in the northern forests.

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The sun is so low
that it's twilight at midday.

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Further north in the high Arctic,

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the sun has been below the horizon
for months

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and it'll be several more
before it appears again.

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The male polar bear spends winter
out on the frozen ocean.

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Few creatures can endure
these conditions.

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If he's lucky,
he will find a carcass

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that could provide a little food,

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possibly that of a fox
or another polar bear.

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But otherwise,
he must live on his reserves.

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This is the time to scrape by,
to wait.

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But on lee-side slopes,
beneath the snow,

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new lives are beginning.

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The cubs are born blind and tiny.

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An early birth is easier
on the mother, who is barely awake.

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Despite her sleepiness,

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her instinct to nurse
is overwhelming.

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The cub's clucking calls

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stimulate her to produce milk.

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And what milk!

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It's nine times richer than our own

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and enables her to double
their weight every few weeks.

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It's over two months

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since the autumn snows
first arrived.

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00:25:52,120 --> 00:25:55,120
In two more months,
polar bear families

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will emerge onto the snowy slopes

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all around the Arctic.

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But for now, they lie protected

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within their icy cocoons.

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00:26:28,600 --> 00:26:31,080
A hundred miles above the earth,

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the Aurora lights up the sky.

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00:26:44,320 --> 00:26:47,200
After travelling millions of miles
across space,

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solar winds, attracted by
the magnetic pull of the poles,

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00:26:51,200 --> 00:26:53,440
collide with the earth's atmosphere.

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00:26:55,680 --> 00:26:58,320
Trillions of charged particles

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00:26:58,320 --> 00:27:00,360
dance across the sky.

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00:27:08,080 --> 00:27:12,040
Above the Arctic,
the Aurora Borealis -

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the Northern Lights.

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00:27:14,240 --> 00:27:18,000
In the south,
it's the Aurora Australis -

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00:27:18,000 --> 00:27:19,480
the Southern lights,

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that bring light
to Antarctica's long winter.

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00:27:31,160 --> 00:27:35,120
These spectacular lightshows
are only a tease.

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00:27:35,120 --> 00:27:37,120
Solar energy maybe,

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00:27:37,120 --> 00:27:40,160
but no warmth
that will help the emperor penguins.

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00:27:53,280 --> 00:27:56,040
The Arctic winter is brutally cold,

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00:27:56,040 --> 00:27:57,840
but in Antarctica,

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the darkest months
are even more savage.

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00:28:16,720 --> 00:28:20,160
The male penguins
have not eaten for months,

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00:28:20,160 --> 00:28:23,480
and have only each other
for protection from the gales.

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00:28:33,800 --> 00:28:36,560
Each has been entrusted
with a single precious egg

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00:28:36,560 --> 00:28:39,320
balanced on the top of its feet.

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00:28:39,320 --> 00:28:42,840
If the egg were to drop onto
the ice, even for a moment,

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the chick inside would die

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and all this
would count for nothing.

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00:28:55,720 --> 00:28:58,360
The emperors are not entirely alone.

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00:29:03,480 --> 00:29:05,280
The Weddell seal.

228
00:29:05,280 --> 00:29:08,480
The only mammal to remain here
throughout the winter.

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00:29:15,000 --> 00:29:16,880
They must have breathing holes,

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and so have to constantly
scrape away the ice

231
00:29:19,680 --> 00:29:21,320
that threatens to close them,

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00:29:21,320 --> 00:29:23,560
rasping away fresh build-ups

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00:29:23,560 --> 00:29:25,960
with special wide-gaped jaws.

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00:29:31,160 --> 00:29:35,720
Beneath the ice, they are beyond the
reach of the bitter winter winds.

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00:29:39,720 --> 00:29:42,800
The sea is -2 degrees centigrade.

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00:29:42,800 --> 00:29:46,280
A warm bath, compared to
the conditions overhead.

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00:29:58,520 --> 00:30:03,560
The roof of ice insulates this world
from the wild fluctuations above.

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00:30:05,400 --> 00:30:08,160
The temperature down here
has barely changed

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00:30:08,160 --> 00:30:10,880
for 25 million years.

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00:30:19,280 --> 00:30:23,080
Of course,
animals must still be hardy.

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00:30:23,080 --> 00:30:27,280
These borchgrevinki fish
have antifreeze in their blood,

242
00:30:27,280 --> 00:30:30,760
so they are untroubled
swimming among the ice crystals.

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00:30:36,280 --> 00:30:39,240
Many animals here
are remarkably long-lived,

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00:30:39,240 --> 00:30:41,960
perhaps because the conditions
are so stable.

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00:30:43,200 --> 00:30:46,200
Some sponges could be
a thousand years old

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00:30:46,200 --> 00:30:48,240
and large enough
for a human to hide in.

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00:30:50,840 --> 00:30:52,920
There could hardly be
a greater contrast

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00:30:52,920 --> 00:30:56,640
to the bleak, windswept world
just above.

249
00:31:29,640 --> 00:31:32,960
But there is a constant danger here.

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00:31:38,240 --> 00:31:42,600
Swirling patterns in the water
reveal its presence.

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00:31:44,240 --> 00:31:46,560
They are made by brine.

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00:31:46,560 --> 00:31:48,960
Super-concentrated salt water.

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00:31:48,960 --> 00:31:50,960
It's a warning.

254
00:31:55,000 --> 00:31:57,520
New sea ice forming above

255
00:31:57,520 --> 00:32:00,880
leaves behind brine
that is so extremely salty,

256
00:32:00,880 --> 00:32:02,800
it sinks rapidly.

257
00:32:08,320 --> 00:32:12,560
As it descends, the sea water
around it freezes instantly

258
00:32:12,560 --> 00:32:15,640
and forms a sheath of ice,
a brinicle,

259
00:32:15,640 --> 00:32:18,520
that grows downwards
towards the seafloor.

260
00:32:28,120 --> 00:32:33,040
Winter is reaching down
from the cold world above.

261
00:32:46,480 --> 00:32:47,920
As it touches the seafloor,

262
00:32:47,920 --> 00:32:50,720
it kills whatever living thing
it contacts

263
00:32:50,720 --> 00:32:54,000
by encasing it in a tomb of ice.

264
00:33:20,600 --> 00:33:23,440
Even in the relative warmth
of the water,

265
00:33:23,440 --> 00:33:25,280
the lethal cold of winter

266
00:33:25,280 --> 00:33:27,400
threatens life on the seafloor.

267
00:33:37,440 --> 00:33:42,760
Another more constant attack
rises from below.

268
00:33:42,760 --> 00:33:45,400
Pressure in the depths
keeps water liquid,

269
00:33:45,400 --> 00:33:48,600
even though its temperature
is far from freezing.

270
00:33:51,600 --> 00:33:55,600
Currents bring up this colder water,
but it turns to ice,

271
00:33:55,600 --> 00:33:58,720
covering everything
that can't move away from it.

272
00:34:21,040 --> 00:34:24,360
And then, the ice,
being lighter than water,

273
00:34:24,360 --> 00:34:28,640
begins to float,
lifting away anything attached.

274
00:34:49,480 --> 00:34:53,200
Even some of the faster-moving
animals are caught.

275
00:35:08,520 --> 00:35:11,520
So the ice cleanses the seafloor

276
00:35:11,520 --> 00:35:13,920
and strews the ceiling above

277
00:35:13,920 --> 00:35:16,360
with remnants of life from below.

278
00:35:27,560 --> 00:35:30,680
A sign that winter is nearly over.

279
00:35:33,200 --> 00:35:36,080
The songs of male Weddell seals

280
00:35:36,080 --> 00:35:38,480
challenging their rivals to battle.

281
00:35:45,200 --> 00:35:48,840
The male seal's calls
can be heard over 15 miles away.

282
00:36:00,880 --> 00:36:03,880
He aims to control
the best breathing holes

283
00:36:03,880 --> 00:36:06,960
for they will determine
his mating rights in spring.

284
00:36:14,680 --> 00:36:17,920
His calls create powerful
shockwaves in the water.

285
00:36:19,240 --> 00:36:20,680
They are threats.

286
00:36:31,120 --> 00:36:34,160
This hole has already been claimed,

287
00:36:34,160 --> 00:36:36,640
and the owner will not surrender it
willingly.

288
00:36:47,160 --> 00:36:49,200
No change this time.

289
00:36:49,200 --> 00:36:53,280
The challenger will need to find
a hole with a weaker owner.

290
00:37:01,600 --> 00:37:04,920
The battles continue
until the females arrive,

291
00:37:04,920 --> 00:37:07,600
and that time is now close.

292
00:37:34,720 --> 00:37:37,600
The sun returns to Antarctica.

293
00:37:40,440 --> 00:37:42,840
The longest night on earth has ended

294
00:37:42,840 --> 00:37:45,680
and winter begins
to give way to spring.

295
00:38:16,160 --> 00:38:18,560
Female emperor penguins.

296
00:38:18,560 --> 00:38:20,520
After four months feeding at sea,

297
00:38:20,520 --> 00:38:23,400
they are returning sleek and fat.

298
00:38:54,320 --> 00:38:57,480
Penguins, it seems,
can fly after all.

299
00:39:00,560 --> 00:39:03,680
But a winter at sea has left them
a little out of practice.

300
00:39:56,640 --> 00:39:58,640
There is no time to waste.

301
00:39:58,640 --> 00:40:01,440
Far away, the males are waiting.

302
00:40:12,040 --> 00:40:15,400
While the females were gone,
the sea ice grew,

303
00:40:15,400 --> 00:40:19,040
and it's now twice the distance
from its edge back to their colony.

304
00:40:26,640 --> 00:40:31,040
70 miles away, the males
are in desperate need of help.

305
00:40:34,120 --> 00:40:37,040
Despite doing all they can
to conserve their energy,

306
00:40:37,040 --> 00:40:40,360
many are close to dying
from starvation.

307
00:40:53,160 --> 00:40:55,360
SQUAWK!

308
00:41:02,160 --> 00:41:04,720
SQUAWK!

309
00:41:09,600 --> 00:41:11,640
SQUAWKING

310
00:41:31,760 --> 00:41:35,680
Reunited after three months apart.

311
00:41:46,000 --> 00:41:48,040
The reward for her return?

312
00:41:48,040 --> 00:41:50,440
A first glimpse of her chick.

313
00:41:56,280 --> 00:42:00,040
The reunion made,
it's time for the handover.

314
00:42:05,280 --> 00:42:08,080
The father finds it hard to let go.

315
00:42:10,600 --> 00:42:14,200
Some gentle persuasion is needed.

316
00:42:16,640 --> 00:42:19,880
He has endured the most appalling
conditions on earth

317
00:42:19,880 --> 00:42:22,320
to ensure the survival of his chick,

318
00:42:22,320 --> 00:42:24,760
and the bond is strong.

319
00:42:26,720 --> 00:42:28,640
The exchange must be quick,

320
00:42:28,640 --> 00:42:32,960
as the tiny chick, unprotected,
could freeze to death in seconds.

321
00:42:44,320 --> 00:42:47,520
A task that began in autumn
has been completed.

322
00:42:47,520 --> 00:42:50,520
Despite the huge odds against it,

323
00:42:50,520 --> 00:42:53,200
the precious chick
has survived the winter

324
00:42:53,200 --> 00:42:56,840
and is now with its mother.
And she has food.

325
00:43:07,000 --> 00:43:09,440
The chick's first fresh meal.

326
00:43:11,680 --> 00:43:13,920
Her mission is complete.

327
00:43:17,560 --> 00:43:19,120
But for other mothers,

328
00:43:19,120 --> 00:43:22,320
the journey ends in disappointment.

329
00:43:25,080 --> 00:43:28,560
Their chicks have not survived.

330
00:43:31,800 --> 00:43:35,280
The females' need to nurture
remains strong.

331
00:43:35,280 --> 00:43:37,480
Any chick that strays from
its parent

332
00:43:37,480 --> 00:43:39,920
is at grave risk of being kidnapped.

333
00:44:16,920 --> 00:44:21,640
The chaos may be a consequence
of frustrated parental urge,

334
00:44:21,640 --> 00:44:23,680
but the outcome can be tragic.

335
00:44:40,760 --> 00:44:43,800
For those emperor penguins
that survive,

336
00:44:43,800 --> 00:44:46,320
the worst is over for this year.

337
00:44:51,760 --> 00:44:54,880
There will soon be
abundant food for everyone.

338
00:45:04,440 --> 00:45:08,920
The emperors have taken on
the polar winter and won.

339
00:45:08,920 --> 00:45:10,920
The gamble has paid off.

340
00:45:12,120 --> 00:45:14,560
All other animals escaped,

341
00:45:14,560 --> 00:45:17,600
only they remained
to raise their young.

342
00:45:17,600 --> 00:45:20,880
And now, it is they
who will now benefit most

343
00:45:20,880 --> 00:45:23,320
from the rich southern spring.

344
00:45:31,640 --> 00:45:37,160
Another arrival is the certain
confirmation that spring is here.

345
00:45:37,160 --> 00:45:40,800
The Adelies, having spent winter
at sea, have come back,

346
00:45:40,800 --> 00:45:45,320
but they have not even mated yet,
let alone laid their eggs.

347
00:45:53,400 --> 00:45:56,840
Now, at last,
the male emperors can return

348
00:45:56,840 --> 00:45:59,120
to where they are most at home.

349
00:46:14,880 --> 00:46:17,960
One season ends and another begins.

350
00:46:19,400 --> 00:46:22,240
The penguins will soon
be joined by migrants

351
00:46:22,240 --> 00:46:27,320
and the far south will bustle
with life for a few frantic months.

352
00:46:37,280 --> 00:46:41,840
But there are only a special few,
north and south,

353
00:46:41,840 --> 00:46:43,800
who can survive winter

354
00:46:43,800 --> 00:46:47,000
at the farthest ends of our planet.

355
00:47:19,920 --> 00:47:25,440
Next time, Frozen Planet is with
the people of the polar regions.

356
00:47:27,000 --> 00:47:29,200
From traditional ways of survival...

357
00:47:30,480 --> 00:47:33,800
..to the very frontiers of science.

358
00:47:55,320 --> 00:47:58,280
More than any other season
in the poles, winter

359
00:47:58,280 --> 00:48:02,080
was to pose the greatest challenge
to the Frozen Planet crew.

360
00:48:02,080 --> 00:48:05,840
The team endured winds
of over 100 miles an hour

361
00:48:05,840 --> 00:48:09,120
and temperatures as low as
-50 degrees centigrade.

362
00:48:10,440 --> 00:48:12,920
Their boats were trapped in sea ice
for days,

363
00:48:12,920 --> 00:48:15,960
while bears trapped others indoors.

364
00:48:20,680 --> 00:48:23,000
Some of the coldest conditions
experienced

365
00:48:23,000 --> 00:48:26,120
were near the Arctic circle
in Northern Canada.

366
00:48:26,120 --> 00:48:30,600
In winter, temperatures drop
to -40 degrees, and stayed there.

367
00:48:32,480 --> 00:48:35,600
On the edge of the vast
Taiga forest,

368
00:48:35,600 --> 00:48:38,160
the team hoped to film
one of the most remarkable

369
00:48:38,160 --> 00:48:40,560
predator-prey relationships
on the planet.

370
00:48:42,520 --> 00:48:45,640
What they experienced was the
struggle against the elements.

371
00:48:45,640 --> 00:48:48,640
What they witnessed
was a more profound struggle

372
00:48:48,640 --> 00:48:51,320
for life and death.

373
00:49:01,240 --> 00:49:02,880
Wood Buffalo National Park

374
00:49:02,880 --> 00:49:05,720
covers 28,000 square miles.

375
00:49:05,720 --> 00:49:07,800
The size of Denmark.

376
00:49:07,800 --> 00:49:10,400
One of the few cameramen
to have filmed wolves

377
00:49:10,400 --> 00:49:13,240
and bison here is Jeff Turner.

378
00:49:13,240 --> 00:49:15,280
I first tried to film bison
and wolves

379
00:49:15,280 --> 00:49:17,920
in this national park 15 years ago.

380
00:49:17,920 --> 00:49:19,840
And getting around on the ground

381
00:49:19,840 --> 00:49:22,400
is incredibly difficult
at any time of the year,

382
00:49:22,400 --> 00:49:24,520
but in the winter, it's tough.

383
00:49:24,520 --> 00:49:27,400
We quickly realised the only way
we'd get anything here

384
00:49:27,400 --> 00:49:29,880
was we had to get up in the air.

385
00:49:29,880 --> 00:49:31,960
The Frozen Planet team
had never attempted

386
00:49:31,960 --> 00:49:34,400
aerial filming
in such low temperatures.

387
00:49:36,560 --> 00:49:39,640
The first challenge for director
Chadden Hunter

388
00:49:39,640 --> 00:49:42,800
was protecting
the sensitive aerial camera.

389
00:49:42,800 --> 00:49:46,880
At -40, electrical cables
short-circuit like fireworks.

390
00:49:46,880 --> 00:49:50,000
Oh! Ooo!

391
00:49:50,000 --> 00:49:53,440
How cold can you fly this chopper?
Minus 40.

392
00:49:53,440 --> 00:49:55,880
Aerial cameraman Michael Kelem

393
00:49:55,880 --> 00:49:57,560
comes from sunny California

394
00:49:57,560 --> 00:49:59,920
and has never experienced
temperatures so low.

395
00:49:59,920 --> 00:50:02,880
What kind of temperatures
can you operate down to?

396
00:50:02,880 --> 00:50:06,880
Me? Usually about 70-degrees
Fahrenheit in LA-kind of weather.

397
00:50:06,880 --> 00:50:09,120
Yeah?
I'm only rated for Santa Monica.

398
00:50:10,320 --> 00:50:14,880
Operating delicate controls
while wearing gloves is not easy.

399
00:50:14,880 --> 00:50:18,440
A computer and joystick are needed
to control the aerial camera

400
00:50:18,440 --> 00:50:21,120
attached to the outside
of the helicopter.

401
00:50:21,120 --> 00:50:24,320
It's actually warmed up to -38.'
Michael would have to choose

402
00:50:24,320 --> 00:50:27,440
between dexterity or warmth.

403
00:50:27,440 --> 00:50:28,840
INDISTINCT RADIO

404
00:50:28,840 --> 00:50:30,880
With their camera
mounted on the nose,

405
00:50:30,880 --> 00:50:33,720
the aerial team could now fly
hundreds of miles

406
00:50:33,720 --> 00:50:35,280
in search of the animals.

407
00:50:36,720 --> 00:50:38,800
Jeff, meanwhile, is still on foot,

408
00:50:38,800 --> 00:50:41,240
scouting the other side
of the national park.

409
00:50:41,240 --> 00:50:43,840
'I wonder what Jeff's getting
on the ground?'

410
00:50:43,840 --> 00:50:45,760
Oh, man, it's cold!

411
00:50:45,760 --> 00:50:47,920
With the wind today, it's about -37,

412
00:50:47,920 --> 00:50:51,280
so...we've got to keep
these heaters in here.

413
00:50:51,280 --> 00:50:53,880
Keep the camera running
at these temperatures.

414
00:50:53,880 --> 00:50:56,480
From 3,000 feet up,

415
00:50:56,480 --> 00:51:00,160
Chadden catches a glimpse of the
elusive wolf pack. Yeah. Come in.

416
00:51:00,160 --> 00:51:03,240
'I can see wolves.
I can see wolves near buffalo.'

417
00:51:03,240 --> 00:51:05,800
10, 15. There's a big pack. 'Wow!'

418
00:51:05,800 --> 00:51:07,400
We've got a big pack of wolves here.

419
00:51:07,400 --> 00:51:10,040
The wolf pack turns out to number

420
00:51:10,040 --> 00:51:12,880
an extraordinary 25 individuals.

421
00:51:12,880 --> 00:51:14,640
One of the largest ever filmed.

422
00:51:14,640 --> 00:51:17,520
'There's two more
walking in from the left.'

423
00:51:17,520 --> 00:51:19,800
It looks like they're already
on the hunt.

424
00:51:19,800 --> 00:51:21,400
The helicopter allows the team

425
00:51:21,400 --> 00:51:24,560
to shadow the wolf pack
without disturbing them.

426
00:51:24,560 --> 00:51:28,120
So, let's go back into that nice
slow circle, move around them.

427
00:51:29,400 --> 00:51:31,440
'They look pretty determined.'

428
00:51:31,440 --> 00:51:35,640
The pack are moving in on their
prey, and the aerial team
are perfectly placed.

429
00:51:39,520 --> 00:51:43,560
'They're making their,
definitely making their move.
There's buffalo on the move.'

430
00:51:44,680 --> 00:51:46,200
The chase is on.

431
00:51:46,200 --> 00:51:48,600
Extreme concentration is now needed,

432
00:51:48,600 --> 00:51:51,800
both from the pilot and the
cameraman to keep the shots smooth.

433
00:51:53,520 --> 00:51:55,760
'Yeah, there's more coming in now.

434
00:51:55,760 --> 00:51:58,200
'There's a nice tight little
pack challenging them.

435
00:51:58,200 --> 00:52:01,560
'We've got a nice shot on the pack,
the wolves coming up at the back.

436
00:52:01,560 --> 00:52:03,520
'You have the still?
Yeah. I got them.

437
00:52:03,520 --> 00:52:07,520
'I'm going to bring it up a bit.
OK, OK, tighten up just a hair.

438
00:52:07,520 --> 00:52:10,720
'I want to get two shots of
the wolves at the back of the pack.'

439
00:52:10,720 --> 00:52:13,440
The wolf pack have picked out
a young bison.

440
00:52:15,120 --> 00:52:16,880
'Holy BLEEP! '

441
00:52:16,880 --> 00:52:19,440
As Michael struggles
to hold the shot steady,

442
00:52:19,440 --> 00:52:22,160
no-one is prepared
for what came next.

443
00:52:22,160 --> 00:52:25,600
'Oh! Hey, look, I just knocked
him down, pretty much.'

444
00:52:27,440 --> 00:52:29,480
A one-ton bull charges through,

445
00:52:29,480 --> 00:52:32,160
taking out both the wolves
and the young bison.

446
00:52:33,920 --> 00:52:36,360
I've never seen anything like that
in the wild.

447
00:52:36,360 --> 00:52:38,720
That is unbelievable.

448
00:52:38,720 --> 00:52:42,480
The team have filmed extraordinary
new behaviour from the air,

449
00:52:42,480 --> 00:52:45,120
but Jeff was nowhere nearby.

450
00:52:45,120 --> 00:52:47,840
To complete the sequence,
they will need to work together.

451
00:52:48,960 --> 00:52:51,720
Only by using the helicopter
to position Jeff

452
00:52:51,720 --> 00:52:55,440
will they be able to get both air
and ground coverage.

453
00:53:04,240 --> 00:53:08,320
This pack will now feast for days,
so the crew must move on.

454
00:53:09,960 --> 00:53:12,680
Jeff takes the team
deeper into the wilderness

455
00:53:12,680 --> 00:53:15,440
in search of a new wolf pack.

456
00:53:15,440 --> 00:53:19,040
With everyone onboard,
there are more eyes for spotting.

457
00:53:20,280 --> 00:53:23,480
Bison on the run can only mean
one thing - wolves.

458
00:53:23,480 --> 00:53:26,360
But this time, only a pair.

459
00:53:26,360 --> 00:53:28,160
'I got... No, there's a big...'

460
00:53:28,160 --> 00:53:31,240
Jeff must anticipate
the animal's every move

461
00:53:31,240 --> 00:53:35,080
and direct their helicopter
to where he needs to be dropped off.

462
00:53:35,080 --> 00:53:36,720
They're going this way.

463
00:53:38,280 --> 00:53:41,160
I had to figure out
where the buffalo were going to run

464
00:53:41,160 --> 00:53:43,760
and try to get there ahead of them.

465
00:53:43,760 --> 00:53:46,640
If I got dropped off in the wrong
position, we would blow it.

466
00:53:47,880 --> 00:53:49,920
There wasn't going to be
a second chance.

467
00:53:59,040 --> 00:54:01,880
That moment,
when you get out of the helicopter,

468
00:54:01,880 --> 00:54:03,480
and it leaves you behind,

469
00:54:03,480 --> 00:54:06,160
you feel an incredible sense
of isolation.

470
00:54:08,600 --> 00:54:10,760
On the lake. I'll guide you in.

471
00:54:10,760 --> 00:54:12,240
Just down to the right.

472
00:54:12,240 --> 00:54:13,960
Down. Zoom in.

473
00:54:15,400 --> 00:54:18,560
Watch it. You're on the back guy.
We're on the back guy.

474
00:54:18,560 --> 00:54:21,000
'On the back.
Which one is he going for?'

475
00:54:21,000 --> 00:54:24,040
I don't know.
Oh, there's one broken off. Oh!

476
00:54:24,040 --> 00:54:27,440
Oh, my gosh!
They're coming in now.

477
00:54:27,440 --> 00:54:29,720
When I saw the herd
coming around the corner,

478
00:54:29,720 --> 00:54:31,840
I knew we'd picked the right spot.

479
00:54:31,840 --> 00:54:34,000
I was right in front of them.

480
00:54:34,000 --> 00:54:36,640
And the buffalo running
right towards you,

481
00:54:36,640 --> 00:54:39,040
it definitely does
get your heart pounding.

482
00:54:41,080 --> 00:54:44,240
The bison have poor eyesight
and can't see Jeff.

483
00:54:44,240 --> 00:54:47,040
It's now a test of nerves.

484
00:54:47,040 --> 00:54:49,720
Weighing one ton and running
at 40 miles an hour,

485
00:54:49,720 --> 00:54:53,080
one wrong step
and the bison could kill Jeff.

486
00:54:53,080 --> 00:54:54,960
At the last second, they spot him

487
00:54:54,960 --> 00:54:57,360
and three peel away
to the other side.

488
00:55:00,600 --> 00:55:03,400
At the back of the herd,
the wolves have closed in.

489
00:55:05,880 --> 00:55:08,920
They're trying to separate
that little one.

490
00:55:12,080 --> 00:55:15,040
Oh, they've got it!
Both wolves are on him.

491
00:55:15,040 --> 00:55:17,880
Both clamping down on him.
He got stomped there.

492
00:55:17,880 --> 00:55:21,720
What followed was one of the most
emotional and powerful scenes

493
00:55:21,720 --> 00:55:24,240
the Frozen Planet team
were ever to film.

494
00:55:26,000 --> 00:55:28,160
Jeff has picked his
position perfectly.

495
00:55:28,160 --> 00:55:31,080
He is now only 50 metres
from the animals

496
00:55:31,080 --> 00:55:34,400
and able to film
a truly epic battle.

497
00:55:35,560 --> 00:55:39,320
I had never been so close
to a wolf and bison battle.

498
00:55:39,320 --> 00:55:41,000
I could hear them breathing.

499
00:55:42,240 --> 00:55:44,480
And the power of the buffalo,

500
00:55:44,480 --> 00:55:47,720
the way he just threw this wolf
around like it was a rag doll.

501
00:55:49,000 --> 00:55:51,560
I couldn't believe the beating
this wolf was taking.

502
00:55:55,520 --> 00:55:57,520
The struggles we'd had
with the winter

503
00:55:57,520 --> 00:55:59,080
and the cold and the snow,

504
00:55:59,080 --> 00:56:01,600
just felt so insignificant

505
00:56:01,600 --> 00:56:03,600
compared to these two animals

506
00:56:03,600 --> 00:56:05,960
that were struggling
for their very lives.

507
00:56:08,040 --> 00:56:10,320
For over an hour,

508
00:56:10,320 --> 00:56:14,200
I watched this wolf and bison
battle each other to a standstill.

509
00:56:15,760 --> 00:56:18,480
They were both
unbelievably exhausted.

510
00:56:26,360 --> 00:56:30,280
Watching these two animals
engaged in this massive
life-and-death struggle

511
00:56:30,280 --> 00:56:33,600
was one of the most powerful things
I'd ever witnessed in the wild.

512
00:56:35,360 --> 00:56:39,720
As a film-maker, you're definitely
torn watching something like this.

513
00:56:39,720 --> 00:56:41,680
You know you need to keep filming,

514
00:56:41,680 --> 00:56:43,600
and you know this is a natural event,

515
00:56:43,600 --> 00:56:45,840
but it's also incredibly sad

516
00:56:45,840 --> 00:56:48,480
to know that one of these two
magnificent animals

517
00:56:48,480 --> 00:56:50,680
isn't going to make it.

518
00:56:53,920 --> 00:56:56,160
The bison is fatally wounded.

519
00:56:57,320 --> 00:56:59,000
The battle is over.

520
00:57:01,800 --> 00:57:04,680
The team have managed to capture
a remarkable hunt

521
00:57:04,680 --> 00:57:08,160
from both ground and air.

522
00:57:08,160 --> 00:57:09,800
All of them have been humbled

523
00:57:09,800 --> 00:57:14,040
by witnessing an extraordinary
winter struggle for survival.

524
00:57:25,240 --> 00:57:27,240
Subtitles by Red Bee Media Ltd

525
00:57:27,240 --> 00:57:29,240
E-mail subtitling@bbc.co.uk