All language subtitles for Wild.Canada.2014.Part4.1080p.BluRay.H264.AAC-RARBG

[♪]

[Wind whistles]

[David Suzuki]:
The end of the last Ice Age

signalled the birth
of modern Canada.

But thousands of years later,

much of the north
is still buried under ice.

People have shaped and exploited
other areas of Canada,

but the ice and cold

have made the far north
seem impenetrable.

Few people or animals
feel at home here.

Less than 1% of North American mammals

can survive year-round
above the tree line.

Ice defines the Arctic,

and what happens to ice here

will influence the entire planet.

Ice suits one creature more
than any other in the Arctic...

The Polar bear.

Last fall, this mother built
her den in the frozen ground

and gave birth to a pair of cubs
over winter.

She hasn't eaten for eight months.

But she's lost almost
half her body weight,

and relies
on a double-layered coat of fur

to keep warm.

She needs to find food soon.

But she will have to wait

until her cubs
are confident enough

to travel long distances.

They have no immediate worries,

as their mother will nurse them
for around two years.

So for now,
they can explore and play.

The ice that will become
their greatest ally

is at first strange and new.

In early spring,

this family will travel
hundreds of kilometres

to reach hunting grounds

before the break up
of the sea ice.

Polar bears hunt seals
in many different ways,

but they all rely on sea ice.

To anyone who hasn't spent
their life here,

Arctic ice appears to be
a single entity.

In fact, it takes
many different forms

both on land and sea,

varying massively in age,
consistency, and behaviour.

Some communities in the north

have 70 different words
to describe sea ice,

even more than they have for snow.

Ice can be many different things,

from gigantic glaciers

to the smallest crystals,

and some ice behaves
in astonishing ways.

With the right conditions,

one of the Arctic's secret
ice wonders

starts to grow.

They are called frost flowers,

a phenomenon where
beautiful patterns of ice

form on the frozen sea

when temperatures suddenly plummet.

No one knows for sure
why they form,

but scientists know

that they contain a high
concentration of bacteria,

the building blocks of life.

Only hours after they appear,

their intricate structures
start to fade,

leaving no trace behind.

Sea ice is almost always in flux,

and it can move in all sorts of ways.

Seen from the level of the frozen sea,

it looks as if the cliffs
are climbing to the sky.

But this illusion is created

by some of the largest tides
in the world,

which are still flowing
underneath the ice.

When the tide comes back in,

the temporary ice cliffs vanish
once again.

This landscape appears to breathe.

These forceful tides present
hidden opportunities,

but are also extremely dangerous.

With all other traditional food sources

hard to find in february,

these hunters will take the risk.

They know that at the lowest tides,

the sea under the thick ice
retreats so far back

that if you know what to look for,

you can find stable
hollow spaces under the ice.

This gives them access

to the rich bounty of the seabed.

It's knowledge that has been passed down

from generation to generation.

They are willing to risk the danger

from tonnes of ice

just centimetres above their heads,

all for an unlikely source
of nutritious food...

Thousands of rich mussels,

enough to feed all their families.

They have less than an hour
to collect them

before the tide returns.

When the sea starts to come back,

there's no time to lose.

They must leave now before
the cave fills with seawater,

trapping them beneath the ice.

In moments, the ice seals over,

and there's no trace of anyone
having been there.

[Wind blows]

Like the Inuit,

the animals that live year round
in the Arctic

also know how to exploit
local conditions

to find hidden food.

Even though the sea freezes over winter,

there are places

where the current and wind
keeps the water open.

Called Polynyas, they act like oases,

and are magnets for animals.

In the middle of Hudson Bay,

common Eider ducks are drawn

to one of these patches of open water

to find food.

They appear to fly

as they dive to depths of 15 metres

to forage on the ocean floor.

They are looking
for mussels and urchins.

Their digestive juices are so powerful

that they can eat
the mussels, shells and all.

They can dive a long way
on a single breath,

knowing the way back up
only takes seconds.

In the deep winter,

with a wind chill
that makes it feel like -70,

the opening in the sea ice
is starting to close.

Without open water,

the birds have slim chances of survival.

The stronger birds sense
what's happening

and fly off to find new water,

even though they have no idea
how far that might be,

or if they'll make it.

But to stay is also risky.

The temperature needs to warm up
to keep the water open.

At some indefinable point,

the ducks' options are gone.

Their energy is fading,

and they can't dive to get more food.

Sadly for the ducks,

the march of the ice here is unstoppable.

By april,

the sun is back
for a good 12 hours each day,

and the land gradually warms.

The rise in temperatures
triggers the spring melt,

a period of frenetic change
and activity in the Arctic...

Which is focused at the floe edge,

the boundary between
the open water and sea ice.

It's the ice that is the key

to the blooming of life here
at this time of year.

Long strands of algae grow,

which feed vast blooms
of microscopic plankton,

the food for the explosion
of life here each spring.

Under the ice,

there is twice the productivity

that would occur in the open ocean.

Fish, like the Arctic cod...

Seabirds...

And large mammals, like the seal,

are all drawn in.

In a matter of weeks,

this seemingly desolate frozen sea

has become a hotspot for life...

And that means it's the perfect time

for the Arctic's top predator
to show up.

It's springtime at the floe edge,

and Polar bears are here
to hunt ringed seals.

Seals are most vulnerable
when basking on the sea ice,

so they choose open areas

where they can see and smell
approaching predators.

The Polar bear goes hungry...

Again.

Nine out of every ten hunts
end in failure.

The Polar bear rarely stops
looking for food,

and there's plenty around here.

Polar bears are not
the only big predators

who have come to the floe edge
to find seals.

[Wind whistles and blows]

With harpoon ready,

the Inuit hunter patiently waits
perfectly still by a seal hole.

The approach is so similar to the bear's

that it's hard not to suppose

that the Polar bear
inspired the Inuit

thousands of years ago.

[Dogs bay and bark]

Today, this seal isn't for the humans.

It's destined for the hunter's pack of dogs

that brought him out to the floe edge.

The meat is so rich and nutritious

that it will keep the dogs fed for days.

Finally, the Polar bear
has succeeded in getting a seal.

But he's gone about it
in a most unusual way.

He's found the leftovers
of the dogs' dinner...

[Dogs whine, bark]

Much to their distress.

[Dogs howl and bark]

He has to build up enough fat reserves

to last throughout the summer,

as hunting will become much harder

when the sea ice melts.

[Dogs barking]

A mother and two yearling cubs

arrive at the foot of cliffs
near the floe edge.

She's skinny
and desperately needs food.

The thousands of murres

who are starting to nest
on narrow cliff ledges

have caught her attention.

The hungry mother heads up
the cliff to investigate,

taking one cub with her.

Later in the year,

the bears will feast
on murre eggs and chicks,

but right now,

the adult birds
are just too hard to reach.

The second cub, still on the ice,

gets lucky when it finds an injured murre.

This makes for a small
but much-needed meal.

Up at the top of the cliff,

the mother and cub
aren't getting anywhere.

The cub resorts to eating moss.

The lone cub catches up
with the rest of the family...

And they are happily reunited.

[♪]

And on snow, what goes up must slide down.

At the bottom, their interest
in the murres finally pays off.

The mother is able to feed as well.

She needs to eat

as she is still providing milk
for the cubs.

This tight family unit will stay together

until next year,

and then the cubs will head off
and fend for themselves.

As spring continues,

the sea ice starts to break up.

Even for the Inuit,

who know this ice better than anyone,

the ice is much more unpredictable now

than in years past.

The dogs can sense the thickness
and stability of the ice

through their paws,

and so offer more protection
than riding on a snowmobile.

Gradually, the speed
of the break-up accelerates.

Life for those who depend on the ice

becomes more precarious.

[Splashing]

With rising temperatures,
the fragmentation continues

and creates long passages
between ice sheets

called leads.

The magical narwhal,

with its spiralled elongated tooth,

have been waiting for this moment.

With no dorsal fin,

they are perfectly adapted to the Arctic.

They can dive under
and between the ice

the moment it begins to break up.

They are heading up long inlets

to find a safe place to raise their calves.

This break-up signals

the start of the short
but intense Arctic summer.

Each summer,

the Arctic landscape is transformed.

More than half
of all the Arctic sea ice melts.

And now it's disappearing
at a faster rate

than anyone could imagine.

We still don't know

how these changes
will affect the life here.

Although walrus use ice
to rest on,

they also love to bask on rocks
in the summer sun.

Walrus are bottom feeders.

They shoot water from their mouths

to excavate clams.

Sensitive bristles

help find them in the muddy seabed,

then they suck them out
with their huge rubbery lips.

The summer's heat also triggers
a massive change inland,

on the tundra.

As the snow melts,

female caribou migrate
hundreds of kilometres

to their calving grounds
in the far north.

More than half of all the females

will give birth
within a few days of each other.

It's called "predator swamping."

This year, the summer melt
has come early,

so the river current is strong.

The soft snow makes it hard

for the pregnant caribou to get out.

But caribou are some
of the most resilient animals

on earth.

On one of the longest days
of the year,

the mothers start to give birth.

[Caribou snorts]

Within minutes, the newborn calf
is up on its feet.

Within hours, he can walk well.

And within days, he can keep up
with his mother

over long distances.

Fresh green vegetation
grows vigorously

with the 24-hour sunlight,

and gives the mother the energy

to produce rich milk.

Today, across the Arctic,

caribou numbers are falling dramatically.

Their finely tuned body clocks
are out of sync

with the variability
of the seasons now.

At the height of this most productive time,

they share the tundra
with many other species.

But with no trees,

nesting birds are vulnerable

to predators like the Arctic fox.

Canada geese make themselves
big and threatening.

But the fox is not
actually after the birds.

The fox buries the egg,

knowing that harder times lie ahead.

It can return to the exact spot
at any time for a ready meal

when there's less easy prey about.

In the Arctic,

it's all about reaping the rewards

when they are on offer.

It's harder for some Arctic animals

to adapt to their changing world

than others.

As the ice season gets shorter,

Polar bears have less time to hunt.

During the longer, warmer summers,

their metabolism slows
right down to conserve energy.

Some bears that didn't catch enough seals

eat seaweed to fill their stomachs.

Others pluck individual berries
off thorny bushes...

But these are slim pickings

and provide nowhere near
enough calories

for the bears.

What they need is fat and protein,

and that means they must hunt.

A few ingenious bears in Northern Québec

have learned that Arctic char
can be found here

at this time of the year.

The fish can't survive
in the icy winter ocean,

so they all return inland
before it gets too cold.

And this gives the waiting Polar bears

a chance to catch them.

Polar bears hunt best
in and around ice.

They need a new strategy here.

And unlike grizzly bears,

this kind of chase doesn't seem
to come easy to them.

At last, this bear gets a meal
with some protein.

But for the Polar bears
that stayed at the coast,

the ice can't return fast enough.

At the height of summer

in the Canadian Arctic,

thousands of beluga whales
head to somerset island

for a seasonal get-together.

Like the narwhal,

they're adapted
for a life in the Arctic.

They don't have a dorsal fin,

and they have a huge amount
of blubber,

up to 50% of their body weight.

But they haven't come here to feed.

They are here for the equivalent
of a health spa.

This shallow estuary contains
a mix of fresh and sea water

which is warmer than the open ocean.

The water and gravel allow them
to have a body scrub,

which helps get rid
of their old skin.

They appear to love it.

But beluga can't relax too much.

They face new threats

caused by the changing summer conditions.

[Blowing]

Killer whales have
traditionally found it hard

to hunt in the Arctic

because of their massive dorsal fin,

which can be taller
than an adult human.

They aren't able to travel far
under the sea ice

because of their dorsal fin,

which interferes with their ability

to surface and breathe.

But as more of the sea ice is melting,

they appear to be increasing in number,

coming in from the atlantic

to hunt large marine mammals
like beluga and narwhal.

[Blowing]

Many feel they are fast becoming

the Polar region's top new predator.

Although Polar bears can swim
vast distances,

hunting in an ice-free ocean
is virtually impossible.

We now know that the sea ice
will be gone in the summer

within a few decades.

For so long,

the far north of Canada
was a stable haven

for the animals that were adapted

to life in the extreme cold.

And it seemed to be a place
too vast and too extreme

to be affected dramatically by people.

But that didn't turn out
to be the case.

From a distance, and unintentionally,

humans have triggered
the massive changes

now underway here.

The future is uncertain
in an Arctic landscape

that is undergoing

some of the most
intense and rapid fluctuations

in the history of the planet.

Ever since the melting
of the continental ice sheet

began 15,000 years ago,

animals and humans alike

have shaped the landscapes
of Canada.

And humans continue to play
a defining role,

although the speed and scale
of our influence

is accelerating.

Canada's unique natural history
has created

one of the richest and most
beautiful countries on earth...

And one that, at least for now,
remains surprisingly wild.

[♪]