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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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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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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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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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A hundred miles above the earth,

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the Aurora lights up the sky.

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00:26:41,040 --> 00:26:44,000
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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collide with the earth's atmosphere.

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Trillions of charged particles

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dance across the sky.

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00:27:04,880 --> 00:27:08,840
Above the Arctic,
the Aurora Borealis -

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the Northern Lights.

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00:27:11,075 --> 00:27:14,760
In the south,
it's the Aurora Australis -

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the Southern lights,

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that bring light
to Antarctica's long winter.

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These spectacular lightshows
are only a tease.

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Solar energy maybe,

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00:27:33,955 --> 00:27:37,040
but no warmth
that will help the emperor penguins.

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00:27:49,960 --> 00:27:52,880
The Arctic winter is brutally cold,

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00:27:52,915 --> 00:27:54,560
but in Antarctica,

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the darkest months
are even more savage.

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The male penguins
have not eaten for months,

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and have only each other
for protection from the gales.

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Each has been entrusted
with a single precious egg

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balanced on the top of its feet.

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00:28:36,155 --> 00:28:39,640
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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The emperors are not entirely alone.

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The Weddell seal.

226
00:29:02,115 --> 00:29:05,320
The only mammal to remain here
throughout the winter.

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00:29:11,840 --> 00:29:13,680
They must have breathing holes,

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00:29:13,715 --> 00:29:16,440
and so have to constantly
scrape away the ice

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00:29:16,475 --> 00:29:18,160
that threatens to close them,

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rasping away fresh build-ups

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with special wide-gaped jaws.

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00:29:27,960 --> 00:29:32,600
Beneath the ice, they are beyond the
reach of the bitter winter winds.

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The sea is -2 degrees centigrade.

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A warm bath, compared to
the conditions overhead.

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00:29:55,240 --> 00:30:00,440
The roof of ice insulates this world
from the wild fluctuations above.

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00:30:02,200 --> 00:30:04,960
The temperature down here
has barely changed

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for 25 million years.

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00:30:16,080 --> 00:30:19,760
Of course,
animals must still be hardy.

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00:30:19,795 --> 00:30:24,000
These borchgrevinki fish
have antifreeze in their blood,

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00:30:24,035 --> 00:30:27,600
so they are untroubled
swimming among the ice crystals.

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00:30:33,080 --> 00:30:36,000
Many animals here
are remarkably long-lived,

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perhaps because the conditions
are so stable.

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00:30:39,920 --> 00:30:42,960
Some sponges could be
a thousand years old

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00:30:42,995 --> 00:30:45,120
and large enough
for a human to hide in.

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00:30:47,600 --> 00:30:49,760
There could hardly be
a greater contrast

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00:30:49,795 --> 00:30:53,520
to the bleak, windswept world
just above.

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00:31:26,400 --> 00:31:29,800
But there is a constant danger here.

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00:31:35,000 --> 00:31:39,440
Swirling patterns in the water
reveal its presence.

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00:31:41,040 --> 00:31:43,320
They are made by brine.

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Super-concentrated salt water.

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00:31:45,835 --> 00:31:47,800
It's a warning.

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00:31:51,800 --> 00:31:54,360
New sea ice forming above

253
00:31:54,395 --> 00:31:57,680
leaves behind brine
that is so extremely salty,

254
00:31:57,715 --> 00:31:59,520
it sinks rapidly.

255
00:32:05,080 --> 00:32:09,280
As it descends, the sea water
around it freezes instantly

256
00:32:09,315 --> 00:32:12,440
and forms a sheath of ice,
a brinicle,

257
00:32:12,475 --> 00:32:15,400
that grows downwards
towards the seafloor.

258
00:32:24,880 --> 00:32:29,880
Winter is reaching down
from the cold world above.

259
00:32:43,160 --> 00:32:44,720
As it touches the seafloor,

260
00:32:44,755 --> 00:32:47,560
it kills whatever living thing
it contacts

261
00:32:47,595 --> 00:32:50,920
by encasing it in a tomb of ice.

262
00:33:17,400 --> 00:33:20,200
Even in the relative warmth
of the water,

263
00:33:20,235 --> 00:33:22,040
the lethal cold of winter

264
00:33:22,075 --> 00:33:24,280
threatens life on the seafloor.

265
00:33:34,280 --> 00:33:39,560
Another more constant attack
rises from below.

266
00:33:39,595 --> 00:33:42,200
Pressure in the depths
keeps water liquid,

267
00:33:42,235 --> 00:33:45,360
even though its temperature
is far from freezing.

268
00:33:48,360 --> 00:33:52,400
Currents bring up this colder water,
but it turns to ice,

269
00:33:52,435 --> 00:33:55,560
covering everything
that can't move away from it.

270
00:34:17,800 --> 00:34:21,160
And then, the ice,
being lighter than water,

271
00:34:21,195 --> 00:34:25,440
begins to float,
lifting away anything attached.

272
00:34:46,240 --> 00:34:49,920
Even some of the faster-moving
animals are caught.

273
00:35:05,360 --> 00:35:08,280
So the ice cleanses the seafloor

274
00:35:08,315 --> 00:35:10,560
and strews the ceiling above

275
00:35:10,595 --> 00:35:13,200
with remnants of life from below.

276
00:35:24,320 --> 00:35:27,560
A sign that winter is nearly over.

277
00:35:30,000 --> 00:35:32,880
The songs of male Weddell seals

278
00:35:32,915 --> 00:35:35,320
challenging their rivals to battle.

279
00:35:41,800 --> 00:35:45,680
The male seal's calls
can be heard over 15 miles away.

280
00:35:57,600 --> 00:36:00,560
He aims to control
the best breathing holes

281
00:36:00,595 --> 00:36:03,840
for they will determine
his mating rights in spring.

282
00:36:11,440 --> 00:36:14,800
His calls create powerful
shockwaves in the water.

283
00:36:16,040 --> 00:36:17,520
They are threats.

284
00:36:27,960 --> 00:36:30,920
This hole has already been claimed,

285
00:36:30,955 --> 00:36:33,560
and the owner will not surrender it
willingly.

286
00:36:43,920 --> 00:36:46,040
No change this time.

287
00:36:46,075 --> 00:36:50,120
The challenger will need to find
a hole with a weaker owner.

288
00:36:58,320 --> 00:37:01,760
The battles continue
until the females arrive,

289
00:37:01,795 --> 00:37:04,480
and that time is now close.

290
00:37:31,480 --> 00:37:34,480
The sun returns to Antarctica.

291
00:37:37,280 --> 00:37:39,560
The longest night on earth has ended

292
00:37:39,595 --> 00:37:42,360
and winter begins
to give way to spring.

293
00:38:13,000 --> 00:38:15,400
Female emperor penguins.

294
00:38:15,435 --> 00:38:17,320
After four months feeding at sea,

295
00:38:17,355 --> 00:38:20,240
they are returning sleek and fat.

296
00:38:51,160 --> 00:38:54,360
Penguins, it seems,
can fly after all.

297
00:38:57,280 --> 00:39:00,600
But a winter at sea has left them
a little out of practice.

298
00:39:53,360 --> 00:39:55,280
There is no time to waste.

299
00:39:55,315 --> 00:39:58,320
Far away, the males are waiting.

300
00:40:08,800 --> 00:40:12,080
While the females were gone,
the sea ice grew,

301
00:40:12,115 --> 00:40:15,880
and it's now twice the distance
from its edge back to their colony.

302
00:40:23,440 --> 00:40:27,960
70 miles away, the males
are in desperate need of help.

303
00:40:30,920 --> 00:40:33,800
Despite doing all they can
to conserve their energy,

304
00:40:33,835 --> 00:40:37,200
many are close to dying
from starvation.

305
00:41:28,600 --> 00:41:32,560
Reunited after three months apart.

306
00:41:42,840 --> 00:41:44,880
The reward for her return?

307
00:41:44,915 --> 00:41:47,360
A first glimpse of her chick.

308
00:41:53,040 --> 00:41:56,920
The reunion made,
it's time for the handover.

309
00:42:02,000 --> 00:42:04,920
The father finds it hard to let go.

310
00:42:07,440 --> 00:42:11,080
Some gentle persuasion is needed.

311
00:42:13,400 --> 00:42:16,560
He has endured the most appalling
conditions on earth

312
00:42:16,595 --> 00:42:19,120
to ensure the survival of his chick,

313
00:42:19,155 --> 00:42:21,680
and the bond is strong.

314
00:42:23,520 --> 00:42:25,440
The exchange must be quick,

315
00:42:25,475 --> 00:42:29,840
as the tiny chick, unprotected,
could freeze to death in seconds.

316
00:42:41,120 --> 00:42:44,320
A task that began in autumn
has been completed.

317
00:42:44,355 --> 00:42:47,280
Despite the huge odds against it,

318
00:42:47,315 --> 00:42:49,880
the precious chick
has survived the winter

319
00:42:49,915 --> 00:42:53,720
and is now with its mother.
And she has food.

320
00:43:03,800 --> 00:43:06,360
The chick's first fresh meal.

321
00:43:08,480 --> 00:43:10,680
Her mission is complete.

322
00:43:14,360 --> 00:43:15,920
But for other mothers,

323
00:43:15,955 --> 00:43:19,120
the journey ends in disappointment.

324
00:43:21,920 --> 00:43:25,320
Their chicks have not survived.

325
00:43:28,600 --> 00:43:32,000
The females' need to nurture
remains strong.

326
00:43:32,035 --> 00:43:34,320
Any chick that strays from
its parent

327
00:43:34,355 --> 00:43:36,840
is at grave risk of being kidnapped.

328
00:44:13,640 --> 00:44:18,480
The chaos may be a consequence
of frustrated parental urge,

329
00:44:18,515 --> 00:44:20,560
but the outcome can be tragic.

330
00:44:37,560 --> 00:44:40,640
For those emperor penguins
that survive,

331
00:44:40,675 --> 00:44:43,160
the worst is over for this year.

332
00:44:48,400 --> 00:44:51,800
There will soon be
abundant food for everyone.

333
00:45:01,200 --> 00:45:05,800
The emperors have taken on
the polar winter and won.

334
00:45:05,835 --> 00:45:07,840
The gamble has paid off.

335
00:45:08,920 --> 00:45:11,400
All other animals escaped,

336
00:45:11,435 --> 00:45:14,360
only they remained
to raise their young.

337
00:45:14,395 --> 00:45:17,520
And now, it is they
who will now benefit most

338
00:45:17,555 --> 00:45:20,200
from the rich southern spring.

339
00:45:28,480 --> 00:45:33,880
Another arrival is the certain
confirmation that spring is here.

340
00:45:33,915 --> 00:45:37,600
The Adelies, having spent winter
at sea, have come back,

341
00:45:37,635 --> 00:45:42,200
but they have not even mated yet,
let alone laid their eggs.

342
00:45:50,200 --> 00:45:53,600
Now, at last,
the male emperors can return

343
00:45:53,635 --> 00:45:56,000
to where they are most at home.

344
00:46:11,560 --> 00:46:14,880
One season ends and another begins.

345
00:46:16,120 --> 00:46:19,080
The penguins will soon
be joined by migrants

346
00:46:19,115 --> 00:46:24,200
and the far south will bustle
with life for a few frantic months.

347
00:46:34,080 --> 00:46:38,480
But there are only a special few,
north and south,

348
00:46:38,515 --> 00:46:40,520
who can survive winter

349
00:46:40,555 --> 00:46:43,880
at the farthest ends of our planet.

350
00:47:16,720 --> 00:47:22,160
Next time, Frozen Planet is with
the people of the polar regions.

351
00:47:23,840 --> 00:47:26,040
From traditional ways of survival...

352
00:47:27,280 --> 00:47:30,600
..to the very frontiers of science.

353
00:47:52,120 --> 00:47:55,000
More than any other season
in the poles, winter

354
00:47:55,035 --> 00:47:58,880
was to pose the greatest challenge
to the Frozen Planet crew.

355
00:47:58,915 --> 00:48:02,560
The team endured winds
of over 100 miles an hour

356
00:48:02,595 --> 00:48:06,000
and temperatures as low as
-50 degrees centigrade.

357
00:48:07,200 --> 00:48:09,720
Their boats were trapped in sea ice
for days,

358
00:48:09,755 --> 00:48:12,800
while bears trapped others indoors.

359
00:48:17,480 --> 00:48:19,760
Some of the coldest conditions
experienced

360
00:48:19,795 --> 00:48:22,960
were near the Arctic circle
in Northern Canada.

361
00:48:22,995 --> 00:48:27,480
In winter, temperatures drop
to -40 degrees, and stayed there.

362
00:48:29,280 --> 00:48:32,360
On the edge of the vast
Taiga forest,

363
00:48:32,395 --> 00:48:34,760
the team hoped to film
one of the most remarkable

364
00:48:34,795 --> 00:48:37,440
predator-prey relationships
on the planet.

365
00:48:39,280 --> 00:48:42,360
What they experienced was the
struggle against the elements.

366
00:48:42,395 --> 00:48:45,320
What they witnessed
was a more profound struggle

367
00:48:45,355 --> 00:48:48,200
for life and death.

368
00:48:58,040 --> 00:48:59,680
Wood Buffalo National Park

369
00:48:59,715 --> 00:49:02,560
covers 28,000 square miles.

370
00:49:02,595 --> 00:49:04,560
The size of Denmark.

371
00:49:04,595 --> 00:49:07,240
One of the few cameramen
to have filmed wolves

372
00:49:07,275 --> 00:49:10,040
and bison here is Jeff Turner.

373
00:49:10,075 --> 00:49:12,120
I first tried to film bison
and wolves

374
00:49:12,155 --> 00:49:14,800
in this national park 15 years ago.

375
00:49:14,835 --> 00:49:16,600
And getting around on the ground

376
00:49:16,635 --> 00:49:19,240
is incredibly difficult
at any time of the year,

377
00:49:19,275 --> 00:49:21,280
but in the winter, it's tough.

378
00:49:21,315 --> 00:49:24,200
We quickly realised the only way
we'd get anything here

379
00:49:24,235 --> 00:49:26,640
was we had to get up in the air.

380
00:49:26,675 --> 00:49:28,760
The Frozen Planet team
had never attempted

381
00:49:28,795 --> 00:49:31,200
aerial filming
in such low temperatures.

382
00:49:33,320 --> 00:49:36,480
The first challenge for director
Chadden Hunter

383
00:49:36,515 --> 00:49:39,600
was protecting
the sensitive aerial camera.

384
00:49:39,635 --> 00:49:43,680
At -40, electrical cables
short-circuit like fireworks.

385
00:49:43,715 --> 00:49:46,760
Oh! Ooo!

386
00:49:46,795 --> 00:49:50,240
How cold can you fly this chopper?
Minus 40.

387
00:49:50,275 --> 00:49:52,640
Aerial cameraman Michael Kelem

388
00:49:52,675 --> 00:49:54,360
comes from sunny California

389
00:49:54,395 --> 00:49:56,680
and has never experienced
temperatures so low.

390
00:49:56,715 --> 00:49:59,680
What kind of temperatures
can you operate down to?

391
00:49:59,715 --> 00:50:03,680
Me? Usually about 70-degrees
Fahrenheit in LA-kind of weather.

392
00:50:03,715 --> 00:50:06,000
Yeah?
I'm only rated for Santa Monica.

393
00:50:07,120 --> 00:50:11,680
Operating delicate controls
while wearing gloves is not easy.

394
00:50:11,715 --> 00:50:15,240
A computer and joystick are needed
to control the aerial camera

395
00:50:15,275 --> 00:50:17,920
attached to the outside
of the helicopter.

396
00:50:17,955 --> 00:50:21,080
It's actually warmed up to -38.'
Michael would have to choose

397
00:50:21,115 --> 00:50:24,280
between dexterity or warmth.

398
00:50:25,675 --> 00:50:27,720
With their camera
mounted on the nose,

399
00:50:27,755 --> 00:50:30,560
the aerial team could now fly
hundreds of miles

400
00:50:30,595 --> 00:50:32,120
in search of the animals.

401
00:50:33,560 --> 00:50:35,600
Jeff, meanwhile, is still on foot,

402
00:50:35,635 --> 00:50:38,080
scouting the other side
of the national park.

403
00:50:38,115 --> 00:50:40,680
'I wonder what Jeff's getting
on the ground?'

404
00:50:40,715 --> 00:50:42,600
Oh, man, it's cold!

405
00:50:42,635 --> 00:50:44,680
With the wind today, it's about -37,

406
00:50:44,715 --> 00:50:47,920
so...we've got to keep
these heaters in here.

407
00:50:47,955 --> 00:50:50,720
Keep the camera running
at these temperatures.

408
00:50:50,755 --> 00:50:53,280
From 3,000 feet up,

409
00:50:53,315 --> 00:50:56,960
Chadden catches a glimpse of the
elusive wolf pack. Yeah. Come in.

410
00:50:56,995 --> 00:51:00,080
'I can see wolves.
I can see wolves near buffalo.'

411
00:51:00,115 --> 00:51:02,520
10, 15. There's a big pack. 'Wow!'

412
00:51:02,555 --> 00:51:04,240
We've got a big pack of wolves here.

413
00:51:04,275 --> 00:51:06,800
The wolf pack turns out to number

414
00:51:06,835 --> 00:51:09,760
an extraordinary 25 individuals.

415
00:51:09,795 --> 00:51:11,400
One of the largest ever filmed.

416
00:51:11,435 --> 00:51:14,280
'There's two more
walking in from the left.'

417
00:51:14,315 --> 00:51:16,600
It looks like they're already
on the hunt.

418
00:51:16,635 --> 00:51:18,240
The helicopter allows the team

419
00:51:18,275 --> 00:51:21,320
to shadow the wolf pack
without disturbing them.

420
00:51:21,355 --> 00:51:25,000
So, let's go back into that nice
slow circle, move around them.

421
00:51:26,240 --> 00:51:28,160
'They look pretty determined.'

422
00:51:28,195 --> 00:51:32,560
The pack are moving in on their
prey, and the aerial team
are perfectly placed.

423
00:51:36,240 --> 00:51:40,440
'They're making their,
definitely making their move.
There's buffalo on the move.'

424
00:51:41,520 --> 00:51:43,040
The chase is on.

425
00:51:43,075 --> 00:51:45,360
Extreme concentration is now needed,

426
00:51:45,395 --> 00:51:48,680
both from the pilot and the
cameraman to keep the shots smooth.

427
00:51:50,240 --> 00:51:52,320
'Yeah, there's more coming in now.

428
00:51:52,355 --> 00:51:54,920
'There's a nice tight little
pack challenging them.

429
00:51:54,955 --> 00:51:58,320
'We've got a nice shot on the pack,
the wolves coming up at the back.

430
00:51:58,355 --> 00:52:00,320
'You have the still?
Yeah. I got them.

431
00:52:00,355 --> 00:52:04,320
'I'm going to bring it up a bit.
OK, OK, tighten up just a hair.

432
00:52:04,355 --> 00:52:07,480
'I want to get two shots of
the wolves at the back of the pack.'

433
00:52:07,515 --> 00:52:10,280
The wolf pack have picked out
a young bison.

434
00:52:11,960 --> 00:52:13,720
'Holy BLEEP! '

435
00:52:13,755 --> 00:52:16,200
As Michael struggles
to hold the shot steady,

436
00:52:16,235 --> 00:52:18,920
no-one is prepared
for what came next.

437
00:52:18,955 --> 00:52:22,440
'Oh! Hey, look, I just knocked
him down, pretty much.'

438
00:52:24,280 --> 00:52:26,200
A one-ton bull charges through,

439
00:52:26,235 --> 00:52:29,080
taking out both the wolves
and the young bison.

440
00:52:30,680 --> 00:52:33,160
I've never seen anything like that
in the wild.

441
00:52:33,195 --> 00:52:35,480
That is unbelievable.

442
00:52:35,515 --> 00:52:39,320
The team have filmed extraordinary
new behaviour from the air,

443
00:52:39,355 --> 00:52:41,880
but Jeff was nowhere nearby.

444
00:52:41,915 --> 00:52:44,720
To complete the sequence,
they will need to work together.

445
00:52:45,720 --> 00:52:48,400
Only by using the helicopter
to position Jeff

446
00:52:48,435 --> 00:52:52,280
will they be able to get both air
and ground coverage.

447
00:53:00,920 --> 00:53:05,200
This pack will now feast for days,
so the crew must move on.

448
00:53:06,760 --> 00:53:09,480
Jeff takes the team
deeper into the wilderness

449
00:53:09,515 --> 00:53:12,240
in search of a new wolf pack.

450
00:53:12,275 --> 00:53:15,920
With everyone onboard,
there are more eyes for spotting.

451
00:53:17,080 --> 00:53:20,320
Bison on the run can only mean
one thing - wolves.

452
00:53:20,355 --> 00:53:23,160
But this time, only a pair.

453
00:53:23,195 --> 00:53:25,000
'I got... No, there's a big...'

454
00:53:25,035 --> 00:53:28,040
Jeff must anticipate
the animal's every move

455
00:53:28,075 --> 00:53:31,920
and direct their helicopter
to where he needs to be dropped off.

456
00:53:31,955 --> 00:53:33,560
They're going this way.

457
00:53:35,040 --> 00:53:37,920
I had to figure out
where the buffalo were going to run

458
00:53:37,955 --> 00:53:40,360
and try to get there ahead of them.

459
00:53:40,395 --> 00:53:43,480
If I got dropped off in the wrong
position, we would blow it.

460
00:53:44,600 --> 00:53:46,800
There wasn't going to be
a second chance.

461
00:53:55,800 --> 00:53:58,680
That moment,
when you get out of the helicopter,

462
00:53:58,715 --> 00:54:00,240
and it leaves you behind,

463
00:54:00,275 --> 00:54:03,040
you feel an incredible sense
of isolation.

464
00:54:05,320 --> 00:54:07,440
On the lake. I'll guide you in.

465
00:54:07,475 --> 00:54:09,120
Just down to the right.

466
00:54:09,155 --> 00:54:10,840
Down. Zoom in.

467
00:54:12,200 --> 00:54:15,320
Watch it. You're on the back guy.
We're on the back guy.

468
00:54:15,355 --> 00:54:17,680
'On the back.
Which one is he going for?'

469
00:54:17,715 --> 00:54:20,760
I don't know.
Oh, there's one broken off. Oh!

470
00:54:20,795 --> 00:54:24,080
Oh, my gosh!
They're coming in now.

471
00:54:24,115 --> 00:54:26,560
When I saw the herd
coming around the corner,

472
00:54:26,595 --> 00:54:28,680
I knew we'd picked the right spot.

473
00:54:28,715 --> 00:54:30,840
I was right in front of them.

474
00:54:30,875 --> 00:54:33,360
And the buffalo running
right towards you,

475
00:54:33,395 --> 00:54:35,960
it definitely does
get your heart pounding.

476
00:54:37,840 --> 00:54:41,080
The bison have poor eyesight
and can't see Jeff.

477
00:54:41,115 --> 00:54:43,840
It's now a test of nerves.

478
00:54:43,875 --> 00:54:46,520
Weighing one ton and running
at 40 miles an hour,

479
00:54:46,555 --> 00:54:49,960
one wrong step
and the bison could kill Jeff.

480
00:54:49,995 --> 00:54:51,760
At the last second, they spot him

481
00:54:51,795 --> 00:54:54,200
and three peel away
to the other side.

482
00:54:57,440 --> 00:55:00,240
At the back of the herd,
the wolves have closed in.

483
00:55:02,720 --> 00:55:05,840
They're trying to separate
that little one.

484
00:55:08,880 --> 00:55:11,720
Oh, they've got it!
Both wolves are on him.

485
00:55:11,755 --> 00:55:14,680
Both clamping down on him.
He got stomped there.

486
00:55:14,715 --> 00:55:18,560
What followed was one of the most
emotional and powerful scenes

487
00:55:18,595 --> 00:55:21,120
the Frozen Planet team
were ever to film.

488
00:55:22,760 --> 00:55:24,960
Jeff has picked his
position perfectly.

489
00:55:24,995 --> 00:55:27,880
He is now only 50 metres
from the animals

490
00:55:27,915 --> 00:55:31,280
and able to film
a truly epic battle.

491
00:55:32,320 --> 00:55:36,120
I had never been so close
to a wolf and bison battle.

492
00:55:36,155 --> 00:55:37,920
I could hear them breathing.

493
00:55:39,040 --> 00:55:41,280
And the power of the buffalo,

494
00:55:41,315 --> 00:55:44,560
the way he just threw this wolf
around like it was a rag doll.

495
00:55:45,800 --> 00:55:48,440
I couldn't believe the beating
this wolf was taking.

496
00:55:52,320 --> 00:55:54,360
The struggles we'd had
with the winter

497
00:55:54,395 --> 00:55:55,920
and the cold and the snow,

498
00:55:55,955 --> 00:55:58,440
just felt so insignificant

499
00:55:58,475 --> 00:56:00,360
compared to these two animals

500
00:56:00,395 --> 00:56:02,800
that were struggling
for their very lives.

501
00:56:04,880 --> 00:56:07,120
For over an hour,

502
00:56:07,155 --> 00:56:11,080
I watched this wolf and bison
battle each other to a standstill.

503
00:56:12,600 --> 00:56:15,360
They were both
unbelievably exhausted.

504
00:56:23,080 --> 00:56:27,080
Watching these two animals
engaged in this massive
life-and-death struggle

505
00:56:27,115 --> 00:56:30,480
was one of the most powerful things
I'd ever witnessed in the wild.

506
00:56:32,160 --> 00:56:36,480
As a film-maker, you're definitely
torn watching something like this.

507
00:56:36,515 --> 00:56:38,480
You know you need to keep filming,

508
00:56:38,515 --> 00:56:40,400
and you know this is a natural event,

509
00:56:40,435 --> 00:56:42,680
but it's also incredibly sad

510
00:56:42,715 --> 00:56:45,200
to know that one of these two
magnificent animals

511
00:56:45,235 --> 00:56:47,560
isn't going to make it.

512
00:56:50,800 --> 00:56:53,040
The bison is fatally wounded.

513
00:56:54,120 --> 00:56:55,880
The battle is over.

514
00:56:58,560 --> 00:57:01,560
The team have managed to capture
a remarkable hunt

515
00:57:01,595 --> 00:57:04,960
from both ground and air.

516
00:57:04,995 --> 00:57:06,600
All of them have been humbled

517
00:57:06,635 --> 00:57:10,920
by witnessing an extraordinary
winter struggle for survival.

518
00:57:22,000 --> 00:57:24,040
Subtitles by Red Bee Media Ltd

519
00:57:24,075 --> 00:57:26,080
E-mail subtitling@bbc.co.uk