01x10 - The Polar Bear

[bunniefuu]

[Tom Hiddleston]
Giant animals, living legends.

Fantastic creatures.

These are nature's big beasts.

But experience the world
from their perspective,

and you'll see it's not easy being huge.

[growls]

- The larger the animal...
- [growling]

...the higher the stakes

and the more epic the adventure.

With temperatures regularly 40 below,

survival in the Arctic
would seem impossible.

Unless you're a giant.

[grunting]

The bigger the animal,
the better it retains heat.

So staying warm is not
a polar bear's greatest challenge.

It's finding food.

Enough to sustain her 500-pound body...

[grunts]

...and to keep her two cubs growing strong.

When summer comes
and the sea ice retreats,

this devoted mother
will face difficult decisions

if she is to keep her family alive.

The largest predator to walk the earth
needs to catch a seal every week.

During spring,
she knows where to find them.

[ice creaking]

[calling]

All she needs to do is be patient.

- And pick the right breathing hole.
- [sniffs]

But with a four-inch blanket of fat
to keep her warm,

she waits for dinner to come to her.

It may be barren out here,

but beneath the ice,

cold, fertile waters support lots of life.

A one-ton Greenland shark.

It can live for 400 years

and is the only shark
that survives in the Arctic year-round.

But there are even bigger giants
in the sea.

- A male walrus, as large as a car...
- [bellowing]

...gets all his food from the seafloor.

He stirs up the sand by squirting water
from his mouth.

Feels for his prey
with 400 delicate whiskers.

Then, he sucks up 55 pounds of mollusks, crustaceans

and worms a day.

Walruses can dive to
200 feet to reach the bottom.

[growling]

But every 20 minutes
they must surface to breathe.

[huffs]

These amphibious animals spend
a third of their time out of the water.

[grunting]

But they're so cumbersome on land they try
to stay close to the edge of the ice.

[grunts]

[growling]

Six inches of blubber keeps them warm
even against the worst weather.

[grunting]

In the Arctic, storms and blizzards
can strike at anytime.

They whip across the frozen ocean
and batter the treeless terrain.

[wind whistling]

[growling]

Musk oxen stay snug
in severe spring weather.

- Thanks to an insulating underlayer...
- [grunts]

...and an overcoat of
3-foot long shaggy hair.

[grunts]

But these 800-pound beasts
have to scrape by

on moss and lichen buried
beneath the snow.

[growling, grunts]

The males are struggling to stay strong,

but soon they must be ready to
fight for breeding rights.

[grunts]

Thankfully, change is coming.

[bellowing]

When summer sets in,
the Arctic transforms.

- Strengthening sun reveals fresh grazing.
- [birds chirping]

But just as the musk oxen
prepare to feast,

the giants who rely on ice

are watching their world fall apart.

Glaciers calve.

Six million square miles
of frozen sea break up.

And with a warming climate,

it's melting
faster and earlier than before.

[grunting]

Less ice means more swimming
for a polar bear.

Once wet,
that thick coat doesn't insulate so well.

At least she can use
the ice as a giant bath mat.

Her hollow, air-trapping hairs shed water
to the more absorbent snow.

[huffing]

Getting wet is no big deal.

But feeding the family is getting harder.

No use waiting for
breathing holes anymore.

Seals can pop up anywhere,
so she has to hunt them down.

Polar bears have
the fattiest diet of any animal.

[sniffing]

This bearded seal is so blubbery,
it could last her days.

Just as well. Because now
they're much harder to catch.

She keeps a low profile
by stalking in the water.

[barks]

For the final attack,
she needs to get back onto the ice.

- But it's so thin, it ruins the surprise.
- [ice cracks]

At this time of year, fewer than
one in ten hunts are successful.

This male has had more luck.

While well-fed, he poses little threat.

But as the ice shrinks,
bears are forced even closer together.

Sometimes big males k*ll
and eat their own kind.

Time to get back to the cubs.

With huge fat reserves, she could go
three months without a full meal.

But not when nursing her young.

[huffing]

Right now, her extra-rich milk
is their only source of food.

[cubs roaring]

And if her luck doesn't change,

soon she'll have no more to give.

[cubs pulsing]

[grunting]

Walrus mothers also work hard
to support their big babies.

A calf is born the weight of
a full-grown man

and must put on 11 pounds every week...

by drinking two gallons of milk a day.

Mum suckles in the sea...

because space out of the water
is at a premium.

Come summer,
two-ton walruses struggle to find ice

where it's thick enough to haul out.

This island is the only land close to
their favorite feeding grounds.

[grunting]

And it's getting crowded.

[grunting]

[growling]

Being crushed is a real risk for a baby.

[groaning]

The only other option
is to swim to the coast.

[walruses calling]

It's too long a journey for a young pup.

But many adult males
are already heading for land.

As the ice breaks apart,
new opportunities open up.

Ten-foot tusked narwhals follow channels
to reach previously frozen shores.

Summer migrants are beginning to arrive.

[birds squawking]

And all across the Arctic,

millions of seabirds
come to nest on the cliffs.

[squawking, screeching]

Further inland, the musk oxen
make the most of the short summer.

[grunts, huffs]

Gorging on fresh vegetation

and shedding fur to avoid getting too hot.

[growling]

The females are preparing to breed.

[grunts, sniffs]

While the males are preparing for battle.

[grunts]

The most powerful will win access to
all the females in the herd.

[growls]

This year,
there's a new contender on the scene.

And he's getting ready
to go head-to-head with the dominant bull.

[growls]

Summer is a challenging time
for all Arctic giants.

[huffing]

But polar bear cubs
still find time to play.

Digging into pretend dens...

and wrestling ice cube seals
is good practice.

But they're nowhere near
catching one for real.

Hunting is no game for Mum.

After hours of trying...

[huffs]

...still no luck.

And now she needs to get back to her cubs.

[growl]

A male.

Twice her size,
and coming too close for comfort.

[growling]

[huffs]

Mum's not taking any risks.

[grunts]

Fortunately, he has other plans.

While most polar bears drift north
with the sea ice...

some head for shore.

With 12-inch webbed paws
and a layer of fat to keep afloat,

polar bears can swim over 400 miles
and stay in the water for days.

[grunts]

But it burns vital calories.

And now the warming climate
is increasing the ice's retreat,

land is even further away.

By midsummer, ice around the walrus colony
has all but disappeared.

So, it's essential
the baby increases her strength.

She'll have to spend more time
in the water,

until she's big enough to fight for
her space among the adults on the rock.

[groaning]

[growling]

The more crowded it gets...

[growling, groaning]

...the more dangerous it becomes.

[birds squawking]

Right across the Arctic,
large animals are struggling to survive.

Finding food on land
isn't easy for a giant

that specializes in hunting on the ice.

During summer,
polar bears can lose two pounds every day.

[grunting]

Some get so hungry
they resort to eating plants.

But there are other options.

Reaching guillemot chicks
on the cliff face is risky.

[guillemots chattering]

[wind whistling]

But it's better than starving to death.

It's been a very different story
for the musk oxen.

After a summer spent grazing,
they've regained their strength.

[grunting]

Keeping his herd together has kept
the dominant bull very busy.

And now he has the new challenger
to contend with.

[grunts, growls]

[growls]

Two bulls.

Each almost half a ton.

[grunts]

[bellows, grunts]

At 35 miles an hour

they commit their full weight
to every impact.

[bellows]

[grunting]

Usually one backs down...

but these two are evenly matched.

When the dominant bull
gains higher ground,

he uses it to his advantage.

[lowing]

[grunts]

Victory to the defending champion.

[grunts]

And the chance to sire
the next generation of calves.

[sniffing]

[bellows]

- Inheriting his size and determination...
- [bellowing]

...will give them the best chance
in this hostile land.

[huffs, grunts]

Musk oxen enter autumn in prime condition.

[grunts]

But this is the hardest time of all
for polar bears.

Hungrier than ever,
they turn to desperate options.

[grunting]

[walruses barking]

Fully-grown walruses
are too thick-skinned.

- Too well-armed for most bears to take on.
- [growling]

But pups are at greater risk...

[groaning]

...which is why most mothers
stay away from the shore.

[groaning, puffs]

As more adults try to squeeze onto
the rocky island, aggression intensifies.

[grunts, growling]

Danger increases.

[growling intensifies]

The rising panic creates a stampede.

Even in the water,
mum and baby aren't safe.

They must get away.

They make for the last scraps of ice.

It's every giant for itself.

[growling]

There isn't enough room for everyone.

The calf will drown if it can't rest.

[groaning]

Finally, something just big enough.

- [ice cracks]
- [grunts]

But they barely have
the strength to haul out.

- [growling]
- [cub barking]

As the world continues to warm,

the large animals of the Arctic
are particularly vulnerable.

[walrus huffs, growls]

- And the choices a mother makes...
- [cub groaning]

...are becoming ever more important.

Drifting closer to the north pole...

this polar bear family
also has some respite.

[crunching, puffing]

This time, staying with the sea ice
seems a wise decision.

But as summer ice becomes more scarce,

in the future
that option might not be there.

Arctic giants face enormous challenges.

[groaning]

But for now, at least,
as the sun's power fades

and the winter freeze sets in,

life will get a little easier.