Wildest Islands (2012–…): Season 2, Episode 1 - Japan: Islands of Extremes - full transcript

(intense music)

- [Voiceover] Japan

is a land of wildly diverse environments.

From snow-covered mountains,

to steamy mangroves.

And animals have adapted
to survive in them all.

Unique residents and enigmatic
visitors are found here,

in Japan's islands of extremes.

(dramatic music)

Japan consists of around 7,000 islands

in the northwest Pacific Ocean.



They stretch for over 2,400 kilometers

and encompass a huge range of climates.

Everything from frozen seas

to lush forests

to sweltering mangroves.

The islands sit above three of the world's

seven tectonic plates.

As a result Japan is one of the planet's

most geologically unstable areas.

It can experience over
1,000 earthquakes a year.

And tsunamis can strike
with devastating effects.

(waves crashing)

Four fifths of the land
is covered by mountains,

forged by violent geological upheaval.



Among them, around 180 volcanoes,

over a third of which are active.

The islands are home to
a vast array of wildlife

found nowhere else on Earth.

Animals have adapted to survive

in the multitude of
different environments.

Often turning adversity
to their advantage.

(birds calling)

Nowhere is this more evident

than in the heart of central Japan.

Jigokudani is a mountainous
region in the middle of Honshu,

one of Japan's four main islands.

Jigokudani means "Hell's Valley."

And in the depths of winter,

it seems an apt description.

In this volcanic hotspot,

water bubbles and boils

and sulphuric steam filters ominously

through the valley floor.

(wind blowing)

Heavy snow blankets the ground

for four months of the year.

It looks bleak and inhospitable.

But one particular animal
thrives in Hell's Valley.

And exploits it to the full.

(sentimental music)

Japanese macaques, or snow monkeys,

are among Japan's most
mythologized animals.

And the most adaptable.

Macaques live throughout Japan.

Although more at home in
the subtropical forests

of the southern islands,

they venture into colder climes too.

(monkey chattering)

Apart from humans,

they're the only primates
that can live this far north.

Dense layers of fur allow them

to survive temperatures as low

as minus 14 degree centigrade.

Macaques can move their fingers

with human-like dexterity.

And have sophisticated
hand-eye coordination.

In Hell's Valley, that's vital.

It means they can
skillfully rummage through

thick snow for any traces of food.

(monkeys chattering)

Life here is greuling,

but one feature makes living
in Hell's Valley worthwhile.

(mysterious music)

Hot springs,

where the water is a blissful
40 degrees centigrade.

Warm volcanic pools called onsens

offer relief from the savage cold.

Onsen water is believed
to have healing powers

because of its high mineral content.

The pools are the perfect
place to relax and unwind.

Grooming helps keep coats
untangled and free of fleas.

It also helps maintain the bonds

vital in macaque society.

Macaques have a strict chain of command.

Each group is ruled by a
dominant alpha male and female.

And the pools aren't open to all.

Dominant males are quick to react

to any sign of defiance.

Only high-ranking females

and young monkeys are allowed to bathe.

The alpha male vets all entrants.

(monkeys chattering)

And this subordinate is
bathing where he shouldn't be.

(growling)

(screeching)

(intense music)

The intruder learns
the rules the hard way.

This is a lesson he won't forget.

As night approaches,

the temperature tumbles.

The troop leaves the warm waters

and slowly winds its way
back into the forest.

They'll survive the night
huddled together in the trees.

Come sunrise, they'll make
their way back to the pools.

The climate in Northern Honshu tests

the macaques tolerance
to cold to the limit.

Conditions further north are too extreme,

even for the world's
most adaptable primate.

In the depths of winter,

Hokkaido, Japan's northernmost island,

feels the savage bit of Siberian cold.

Arctic winds whip the
land and temperatures

plunge to minus 30 degrees.

The Shiretoko Peninsula
in northern Hokkaido

borders the coldest sea in east Asia,

the Sea of Okhotsk.

During winter it becomes almost
completely covered with ice.

The ice originates in eastern Russia

and is pulled south by ocean currents.

In early winter ice around
the Shiretoko Peninsula

can reach three kilometers wide

and 50 kilometers long.

At the same time cold currents
arrive from the north,

warm currents arrive from the south.

As they collide, the number
of plankton explodes.

Huge shoals of fish come here to feed.

These waters become some of the richest

fishing grounds in the world.

And they attract some of
nature's most skillful hunters.

(somber music)

A third of the world's
population of stellar sea eagles

migrate here from Russia every winter.

(birds calling)

Stellar sea eagles are among

the largest eagles in the world.

In full flight, their
wingspan reaches 2 1/2 meters.

(dramatic music)

Slowly circling the ice,

razor-sharp eyes scan the
sea for any signs of prey.

A flicker of movement is all it takes.

But catching a fish does
not guarantee a meal.

There are jealous eyes everywhere.

Up to 2,000 sea eagles gather here.

And competition is fierce among

these normally solitary birds.

Fights over food are
common and can be bloody.

(birds screeching)

Eventually the hunter prevails.

And after the effort it took
to keep hold of its catch,

the eagle seems hungrier than ever.

Stellar sea eagles aren't
the only birds of prey

to visit Shiretoko in winter.

White-tailed sea eagles come here too.

In many places,

white-tailed eagles
have little competition.

But here, they can play second fiddle.

In fights over food,

stellar sea eagles are often victorious.

For an ancient tribe who live in Hokkaido,

the stellar sea eagle is honored
as the god of the eagles.

(chanting)

The Ainu have lived here
for thousands of years.

As hunter-gatherers they are totally

in tune with their surroundings.

This ensures that they can
survive the harshest of winters.

(yipping)

The Ainu people have a
deep reverence for nature.

And there is one creature they regard

as the god of the marshes.

The red-crowned crane.

They are the largest birds in Japan

and are known as tancho,
which means "red mountain."

(elegant music)

Hokkaido is home to one
of the world's two large

breeding groups of red-crowned cranes.

The other lives in
northeastern China and Russia.

(cranes calling)

The Ainu say the cranes are
dressed in clothes from Heaven.

And they put their looks to good use

when searching for a mate.

A young male sets his eyes
on a potential partner.

And the best way to impress her

is with a dramatic courtship dance.

(squawking)

The female likes what she sees

and shows her acceptance
by mirroring his moves.

Red-crowned cranes can
live for more than 50 years

and they pair for life.

As more courting couples join the fray,

they reinforce their
bonds with loud calls.

(squawking)

Their cries can be heard up
to three kilometers away.

More cranes arrive all the time

and the dancing seems to be contagious.

The Ainu celebrate this special event

by performing their own dance,

the haruaki, which imitates
the birds' movements.

It's seen as a way of
warding off the ill spirits.

As night approaches, the
cranes gather in a river.

Grouping together helps deter predators.

And in winter, the water
is warmer than the air.

As night draws in, they
take it in turn to sleep,

so at least one bird is always on watch.

Savage winter conditions
make survival difficult,

even for Hokkaido's hardiest creatures.

Some are forced to come
out of hiding to forage,

like one of Japan's most
distinctive animals,

the Japanese serow.

Celebrated in ancient stories

for being peaceful creatures
that protect the forest.

Some people say they
have the legs of a goat,

the body of a deer and the fur of a wolf.

Japanese serow are only found on Honshu

and two other Japanese islands.

They usually live alone
and, unlike most animals,

forage for food both night and day.

This loner will try to endure winter

on any leaves and shoots it can find.

As the sun sets, the weak
won't survive the cold.

In Hokkaido's winter wilderness,

opportunists are always ready

to take advantage of others' misfortune.

(mysterious music)

Early morning,

and a northern red fox is on the prowl.

To the Ainu, the red fox
is the god of cunning,

and not to be trusted.

If hunters kill one,

it's said they tie its mouth shut

to prevent its spirit escaping.

(squawking)

Loud squawks alert the
scavenger to a possible jackpot.

A sika deer has failed
to survive the night.

(birds cawing)

The fox has no trouble
in claiming its prize

from a flock of crows.

Razor-sharp teeth make light
work of the frozen carcass.

The angry crows are left
squabbling for scraps.

It's March in Hokkaido and
winter finally draws to a close.

Change is in the air as spring arrives.

Temperatures climb and
the pack ice surrounding

the Shiretoko Peninsula
begins to break up.

The cracking ice is a signal for

stellar sea eagles to take flight.

After four months of feeding and fighting,

they start the long journey back

to their breeding grounds
in eastern Russia.

Melting ice is also the cue
for another visitor to leave.

(somber music)

(swans squawking)

Whooper swans gained their name

from their deep, honking call.

They are the noisiest swans in the world,

especially when they're
preparing to migrate.

10,000 have spent winter in Hokkaido

to escape the severe weather
in their Siberian home.

Hokkaido's warm volcanic
waters bring relief

from the cold and ensure the visitors

a constant supply of
food throughout winter.

(swans squawking)

As the temperatures rise,
the swans take to the air.

As they leave for their
nesting grounds in Siberia,

some Japanese people say the swans

carry winter on their wings.

Spring's arrival is
heralded by a sea of color

as cherry trees burst into life.

The annual cherry
blossom, known as sakura,

is one of Japan's most celebrated events.

A pink and white tide
sweeps across the country.

It starts in the far
southern islands in January

and reaches Hokkaido
towards the end of April.

Wherever the blossoms appear,

their beauty is short lived.

Within weeks of blooming,

the flowers vanish.

950 kilometers south of Hokkaido,

are the northern Japanese Alps.

As temperatures climb
snowmelt feeds the rivers

flowing down from the mountains.

This is a time of rebirth.

(slow instrumental music)

Spawning fish herald a busy time

for one of Japan's hardest working birds.

A custom has been
practiced in central Honshu

for over 1,300 years.

It's called usho fishing

and it's an industry like no other.

Early afternoon, an usho
fisherman prepares his team.

A flock of highly-trained sea cormorants.

(cormorants chattering)

Each bird is carefully examined
to make sure it's healthy.

Gently feeling the bird's throat

tests its health and helps keep it calm.

Once all the cormorants have been checked,

they're let outside to relax.

(cormorants chattering)

Each bird was captured in the wild

hand reared and taught
to fish in fresh water.

They could easily fly away, but don't.

They're looked after so well,

many live twice as long
as cormorants in the wild.

But they need to earn their bed and board.

Late afternoon and several birds

are carried downriver in special baskets

by the fishermen who train them.

Each one is given a last careful check.

As the sun starts to set,

soon it will be time for the
cormorants to earn their keep.

Before the trip begins in earnest,

different fishing crews
gather on the beach.

They discuss which section of
the river each boat will fish

and decide on a plan of
action for the night ahead.

(speaking Japanese)

Routes agreed and plotted,
now the hard work can begin.

Each bird is carefully tethered.

Special hemp rope tied
around their throats

prevents them from swallowing
any fish they catch.

As the usho prepare to leave fires are lit

in iron baskets and hung
in front of the boats.

They light the way and make
it easier for the cormorants.

The flames draw shoals of trout-like fish

called ayu to the surface.

Now the cormorants go to work.

They dart beneath the
surface as the fishermen

fight to keep their tethers untangled.

For expert fishing birds like cormorants,

this is easy work.

Each bird can hold up to
six fish in its gullet.

When they're full,
they're hauled on board,

and their catch disgorged on deck.

Some can catch up to 60 fish an hour.

(water splashing)

In Japan, cormorant-caught
fish are a delicacy,

and their beak marks are
a hallmark of quality.

As the cormorants work draws to a close,

in Honshu's southern Alps,
another night hunter stirs.

A creature which has remained unchanged

for nearly 30 million years.

(ominous music)

It's a Japanese giant salamander,

the world's largest amphibian.

They can grow to nearly two meters long.

Giant salamanders don't have gills

and need to live in flowing rivers.

Heavy folds of skin
increase their body surface

so they can absorb more
oxygen from the water.

A man-made tunnel makes
a perfect den for a male.

But it needs to stay alert and on guard.

A rival male wants the den.

It's a big mistake, salamanders
are highly territorial.

The tresspasser gets
away relatively lightly,

some fights are to the death.

The male has good reason
to be extra defensive.

A female has laid a clutch of
eggs, which he's fertilized.

Until they hatch, he will
protect them at all costs.

But the sudden burst of energy

has seriously sapped his strength.

He needs to feed.

Although they have poor eyesight,

salamanders are skillful hunters.

Special sensors detect minute
changes in water pressure.

Like the kind made by a passing fish.

With an explosive burst of energy,

prey is dispatched with a sudden snap.

With no competition from
other large predators,

giant salamanders have free
reign of the mountain rivers.

But with their habitats being destroyed

as forests are cut down
to make way for industry,

they may need to evolve
if they're to survive.

Further south, one species
has been forced to evolve,

or face the possibility of being

destroyed by a powerful foe.

At these Buddhist temple
gardens in southern Honshu,

spring brings a flurry of activity.

(bees buzzing)

A colony of Japanese honeybees

has taken over the garden hives.

Workers scour the gardens for food

to feed the thousands of new arrivals.

The hive bristles with energy

and it's an irresistible target

to the honeybees' ancient rival.

(ominous music)

The Japanese hornet.

Hornets also have young to feed

and this scout has found
a major source of food,

the honeybees' hive.

The hornet is five times
the size of its prey.

And the venom from its sting is so potent,

it can dissolve human flesh.

Just a few hornets could decimate

the colony in a matter of hours.

It's an opportunity too good to miss.

First, the hornet's scent marks his find,

for others to follow.

The honeybees reply in kind

and fan pheromones through the air

to alert the colony to danger.

As the bees retreat, the
hornet makes its move.

(suspenseful music)

Seizing the bee in its
jaws, it starts to feed.

But all is not what it seems.

As if on cue, the bees strike back.

Japanese honeybees have a unique
and grisly defense tactic.

Up to 500 bees form a ball

and their vibrating bodies heat

its core to 47 degrees centigrade.

Slowly, the hornet overheats.

The bees' secret weapon
is a greater tolerance

to heat than their enemy.

Just two degrees makes the difference

between life and death.

The invader is roasted alive.

The bees remove the scent mark

so other hornets can't
follow the scout's steps.

Soon, there's no trace left of it at all.

For Japanese honeybees, heat is a weapon.

In Japan's extreme south,
it's a way of life.

Okinawa is a group of around
160 islands in southern Japan,

including the remote island of Iriomote.

(majestic music)

These sun-kissed islands are a world apart

from the rest of the country.

As summer arrives the temperature
climbs to over 30 degrees.

Iriomote is the second
largest island in Okinawa.

Dubbed the Galapagos of the East,

subtropical forests, waterfalls,

and mangroves dominate the land.

A host of rare animals and plants

live in the lush jungle covering

more than 90% of the island.

And the island's giants
tower above them all.

Sakishima sappan trees.

Standing 18 meters tall,

this is the largest
sappan tree in Okinawa.

It's huge buttress roots fan out

like tentacles over the forest floor.

They're designed to soak up minerals

from the surface of the soil

and anchor the huge tree in place.

To some of Iriomote's residents,

the island's maze of trees and roots

is vital to everyday life.

The Nakama River is one of several

crossing Iriomote Island
on route to the sea.

Fresh water meets salt water

and helps nurture exotic mangrove forests.

The forests thrive thanks to the powerful.

Kuroshiro current which
ferries warm waters

to Japan's southern islands.

The current keeps the seas at a minimum

of 20 degrees centigrade,

allowing mangroves to flourish

further north than normal.

(calm instrumental music)

This is home to a vast array
of fish, amphibians and birds.

And one species is especially aptly named.

Mud creepers.

(ominous music)

This is one of the largest gatherings

of snails in the world.

Up to 150 can live in one square meter.

Mud creepers can survive without food

for up to four months.

But when they are hungry,

the mangroves provide all they need.

Adults are drawn to the smell
released by damaged leaves.

Mealtimes are long and leisurely affairs.

Young mud creepers don't grow the teeth

they need to break down
leaves until they're adults,

so slowly sift the sand for leftovers.

The mangroves are fertile hunting grounds

for many creatures.

And a paradise for opportunists.

(mischevious music)

Hermit crabs need to keep
upsizing their shells

as their bodies grow.

When the ideal home comes on the market,

the rush to grab it can be fierce.

Iriomote's mangroves teem with

many different species of crab.

Fiddler crabs try to attract a mate

by frantically waving
their oversized claws.

While soldier crabs march en masse,

as they rush to dodge
the tide and find food.

Crabs and mud creepers
aerate the sand as they feed

and are vital to the
lifecycle of the mangroves.

But there's one Japanese creature

whose eating habits set it apart

from the rest of the animal kingdom.

925 kilometers north of Iriomote,

on the tiny island of Koshima,

a scientific discovery has been made.

It involves the animals which can survive

in all but the most extreme
of Japan's many environments.

Japanese macaques.

Koshima is home to around 80 macaques

and unlike Hokkaido's snow monkeys,

they don't need thick winter coats.

For this troop, it's staying
cool which is the challenge.

Especially at the height of summer

when temperatures climb to 28 degrees.

The macaques visit the
beach to enjoy the breeze.

And there's another reason too.

Macaques, like humans,

don't like eating sand with their food.

And the troop on Koshima Island

have come up with a solution.

They wash what they eat first.

Sand free, meals taste a lot better.

They use their human-like hands

to thoroughly clean what they want to eat.

Some even like to season
their food with saltwater

and dip between each bite.

It's a straightforward task,

and one which has captivated
scientists for decades.

The macaques habit of cleaning their food

has not come through genetics,

but by watching and copying others.

It's one of the greatest examples of

learned behavior ever seen
in the animal kingdom.

And scientists feed the troop

so they can study their behavior.

(monkeys chattering)

Yong macaques learn the
ropes by watching adults

and normally master the technique

by the time they're two and a half.

Until then, infants grab what they can,

although adults always get first refusal.

But such a wealth of food
draws other attention too.

An army of bugs on the hunt for scraps.

Sea slaters are king-sized
relatives of the woodlouse.

They can grow to three centimeters long

and they perform a useful task.

By gorging on the mess left
behind by overzealous macaques,

they help keep the beach clean.

Mealtime over, it's time to relax.

Cheek pouches bloated with food,

grooming is now the order of the day.

No other animal has adapted to Japan's

many environments quite like the macaque.

Not only do they endure freezing cold

by using hot springs,

they pass down special skills

to make the most of any
feeding opportunities.

Macaques don't just survive,

they thrive, whatever comes their way.

(adventurous music)

Stretching over 2,400 kilometers,

the Japanese islands encompass

a vast range of climates and conditions.

And animals have adapted to them all.

Wildlife flourishes in everything from

frozen mountains to sweltering jungles.

This is home to some of the
hardiest species on Earth,

many found nowhere else in the world.

And all have found the secret to survival

in Japan's islands of extremes.

(adventurous music)