South Korea: Earth's Hidden Wilderness (2018)

1
Korea.
An ancient mountain kingdom.
A land divided by conflict.
But in the natural world,
there is another side to Korea.
In the south are pockets
of untouched wilderness.
Rich habitats...
..with extraordinary creatures...
..and spectacular natural events.
HE SHOUTS
A place where nature and mankind
have lived in harmony for centuries.
This is Korea.
Korea lies on the eastern edge
of Asia.
The peninsula is 700 miles long
and 150 miles across...
..and is split into two nations.
But long before modern conflict
divided the land...
..tectonic plates collided
to create a dramatic landscape.
60 million years ago,
unimaginable forces raised
the jagged peaks that dominate
the east of Korea.
In the central region are lush,
temperate forests.
Further south, these give way
to fertile wetlands.
And where the land
finally meets the sea,
the shallow incline
creates vast tidal ranges...
..with endless mudflats...
..teeming with life.
Korea is surrounded
on three sides by ocean.
It has over 5,000 miles
of coastline.
In the far south,
the islands of Jeju
are home to a resident population
of Indo-Pacific bottlenosed
dolphins.
Dolphins are often wide-ranging...
..travelling from place to place
in search of food.
But this group chooses
to live here all year round,
in the bountiful waters
around these volcanic islands.
Bottlenose dolphins are highly
social creatures...
..and live in tight-knit
matriarchal pods.
Group members
communicate constantly.
Each dolphin is identified
by its own signature whistle.
And they are quick to recognise
the presence of any strangers
in their territory.
Today their curiosity is piqued
by a presence here that is almost
as ancient as their own.
Dolphins can be wary of divers,
but not of this one.
Like them, she dives free,
exploring the depths
on a single breath.
The pods have grown up
sharing these waters
with an all-female
free diving community...
..known as the Haenyeo,
sea women.
She scours the sea bed in search
of its natural treasures.
They live in harmony,
as they have done for hundreds
of years.
Soon the season will change,
and these waters will be filled
with prizes for the Haenyeo.
300 miles north,
on the Korean mainland...
..the palaces of the Joseon kings...
..an imposing legacy of the
powerful dynasty
that once ruled here.
But the palaces are now home
to a family of a different kind.
A family of raccoon dogs.
Though they are named
for their resemblance,
they are much more closely related
to dogs than they are raccoons.
This opportunistic family have left
their usual forest dwelling
for the safety
of the palace grounds.
For the most part,
life is good here.
But they're not the only ones
to take advantage
of the opportunities here.
There is a rival group that occupies
the other side of the
palace grounds.
With young pups, the family's
father must be extra vigilant.
At around four months old, pups
learn to forage for themselves.
But hunting insects requires
a little practice.
Raccoon dogs will eat
almost anything.
Tonight the family is anticipating
something extra-special
on the menu...
..cicada nymphs.
A lavish banquet of juicy beetles.
The nymphs emerge en masse during
a narrow window in the summer.
For one night only, the family will
have more food than they can eat.
The nymphs have spent five years
slowly growing in the soil.
They must now find higher ground...
..where they can metamorphosise
into their flying form.
Such rich rewards
attract hungry rivals.
A pack of young males from the far
side of the palace grounds are also
eager to have their fill.
Distracted by the feast,
the usually wary father has
strayed into harm's way.
He is outnumbered,
and in danger.
The mother and pups retreat
to a safe distance.
Their father escapes,
injured, but lucky to be alive.
His mate tends to his wounds.
The palace may provide rich
feeding grounds
but such wealth
comes at a price.
Some of the cicadas have reached
their destination.
After years of lying underground,
the lucky ones will get their wings.
During metamorphosis, they are
at their most vulnerable.
But up here, at least they are
safe from the hungry pups.
Now they will devote the last
chapter of their life,
just one month,
to finding a mate.
It is a cycle that has played out
here for hundreds of years.
During this time, the world
beyond these walls has changed.
The palace is now surrounded
by South Korea's capital city,
Seoul.
Seoul is home to one of the most
densely packed human populations
on the planet.
It is easy to see why the raccoon
dogs seek refuge in the palace.
But there are places where humans
and nature coexist
in perfect harmony.
The island of Marado...
..the southernmost point of Korea.
Beyond the cliffs and caves,
there is a small community,
the Haenyeo, sea women,
as they are known here.
Today they are preparing
for an important dive.
There are men on the island too,
but a sisterhood
drives the local economy.
Most divers are over the age of
60...
..and some are much older.
At this time of the year
the waters here provide
an abundant crop of conches -
a highly valuable mollusc.
The Haenyeo only harvest the conches
after the breeding season,
to ensure the harvest remains
sustainable.
Choon Geom Kim is captain.
She must decide
if it's safe to dive.
Wal Soo Ra is the oldest living
Haenyeo.
In fact, she is the oldest diver
anywhere in the world.
She is now 94 years old.
The dive captain has decided
they will dive.
Conditions are not ideal
but the conch season is short
and they must make
the most of it.
An experienced Haenyeo can dive
to depths of 20 metres
and hold her breath for more
than two minutes.
This places significant stresses
on the body.
There is a very real risk
of blackout,
as the Haenyeo repeatedly travel
between the surface and the sea bed.
As they dive,
their heart rate slows,
and blood is shifted from their
extremities to their core...
..increasing the availability
of oxygen.
The Haenyeo benefit
from this adaptation,
to enable them to keep working
on their long, cold dives.
But it's exhausting work,
even for the younger divers.
She may not be able to hold her
breath for as long as she once did,
but, at 94, Wal Soo Ra is still
capable of diving all day.
The women work together
against a rising tide.
The waters here are changeable...
..and the longer they stay,
the greater the risk.
But the season is short...
..so the women must persist...
..and reap the harvest
while it is there.
Back on the Korean mainland,
deep in the forests of Yangpyeong...
..there are other female workers,
reaping a harvest.
Eastern honey bees.
Workers collecting pollen.
They belong to an enormous colony...
..of 30,000 bees.
The colony has made its home here
in this hollow tree...
..which offers shelter
from the elements.
Inside the tree is a complex
and cooperative society.
All the bees are dedicated
to the colony...
..at times vibrating their bodies
to produce heat and maintain
a perfect temperature
for the next generation.
But the bees are not alone
in the forest.
An Asian giant hornet
has identified their location.
The hornet studies the nest
before returning to its own colony.
This scout has information to share.
Using an advanced form
of chemical communication,
the scout passes on details
of the exact location
of the honey bees' nest.
The scout returns.
The bees shake in unison
to warn off the hornet.
But this time he is not alone.
The hornets do sometimes eat the
bees themselves
but they are more interested
in the protein-rich larvae inside.
Individual bees have no chance
against the hornets.
Gradually they weaken
the bees' defence.
There are many casualties.
But it will take more than this
to overcome the colony.
The bees prepare to fight back.
The counterattack is started
by a handful of worker bees.
It appears suicidal.
But the bees are programmed to lay
down their lives
for the survival of the colony.
And the tables begin to turn.
Bee stings can't kill the hornets.
But they do weaken them.
As the bees gain the upper hand,
pushing their attackers back...
..they now release the full force
of their defence for
the last remaining hornet.
They swarm, immobilising it.
The bees vibrate,
raising the temperature
at the centre to a level
the hornet cannot withstand.
And the hornet is cooked alive.
The bees have developed this
unique and effective defence
over millennia.
Many more bees than hornets died
in this encounter.
But their colony has survived...
..and will continue to thrive
here in the forest...
..until the next encounter.
200 miles away...
..the mud flats of Suncheon Bay
in the south of the Korean mainland.
During the monsoon,
they receive one of the highest
levels of rainfall anywhere
in Korea.
It can rain constantly here
for weeks at a time.
But it is not the
torrential downpours
that have shaped this landscape.
Suncheon Bay is a tidal ecosystem
that is neither land nor sea.
Each day, the tidal waters
of the bay withdraw
to reveal over eight square
miles of thick mud -
a seemingly inhospitable landscape.
But the local people thrive here,
as they have done
for thousands of years.
No modern vehicle can cross the mud.
Instead, the local people get around
here on specially designed boards.
It is hard going but the rewards
are huge.
The mud of the day is
rich in nutrients
and supports one of the most
diverse ecosystems in Korea.
Today the mud flat industry
is larger than ever before.
Seafood makes up a huge part
of the Korean diet.
And much of it comes
from Suncheon Bay.
Thousands of tonnes
are harvested here every year.
Yet, despite the increase
in fishing activity in the bay,
the mudflats are so rich
that they are quick to replenish
what is taken out
during the harvest.
Some of the most abundant
creatures here
are various forms
of mudskipper,
the misfits of the aquatic world.
They spend almost as much time
out of the water as they do in it.
And that's possible
as long as they remain moist,
allowing them to absorb
oxygen through their skin.
There are several different species
of mudskipper here.
Shuttles hoppfish
is among the smallest.
This male is just
five centimetres long,
and he has only just reached
sexual maturity.
Now this young hopeful
must find himself a mate.
70 miles north is Upo, the largest
natural swampland in South Korea.
This prehistoric wetland is
home to many rare species,
and it's a protected
conservation zone.
In summer much of Upo
is carpeted with lilies.
One of the most prolific
is the ancient and aptly-named
prickly water lily.
The jacana has developed
exceptionally long toes
to spread its weight
across the thin lilies
and create a bridge
above the spikes.
But even for jacana,
it takes a little practice.
Their reward is an abundance
of insect life
on the surface of the water.
As night falls over the wetlands,
another type of predator
takes their place on the lilies.
A raft spider.
For an ambush predator...
..location is everything.
She cleverly positions herself
where the traffic is busiest.
Highly sensitive to vibrations,
these spiders can detect
potential prey
beneath the surface
of the water.
But this is no ordinary
insect-eating spider.
She has bigger fish to fry.
She is poised, ready to strike.
The first attempt fails...
..and the prey escapes.
Patience, however,
is the fisherman's best weapon.
She bides her time...
Success!
The spider immediately sinks
its hollow fangs into the prey
to deliver
a lethal dose of venom.
And it's over within
a matter of moments.
20 miles away is Junam reservoir...
..the site of one of Korea's most
spectacular natural events.
A cloud of Baikal teal,
all soaring in perfect unison.
Junam reservoir is the largest
migratory bird sanctuary
in South Korea.
The lake never freezes,
making it a perfect winter stopover
for many migrating birds.
Each year, around a million of these
water birds arrive in Korea.
They migrate from eastern Siberia...
..in search of warmer climes.
They fly in dense formations,
wing tip to wing tip.
This hypnotic spectacle has earned
these visitors a unique place
in the heart of Korean culture.
In this part of the world,
many birds are seen as sacred.
One of the most revered species
lives in the mountainous forests
of central Korea.
Amongst the dense woodland,
an ancient tradition endures.
That of the falconer.
Yong Soon Park has recently
captured a goshawk from the wild,
and is crafting a sichimi.
Equipment like this
cannot be bought.
Each falconer must learn
to craft his own.
It is a part of the tradition.
The feather and bell
help to track his bird,
and the bull-horned head shows that
the bird belongs to him.
At least, for now.
Goshawks are as individual
as we are.
Some are nervous,
others are stubborn.
So the falconer must learn
to tailor his approach.
More than anything,
falconry requires trust.
Falconer Park has spent many,
many hours with his hawk,
to build that bond.
But however strong their connection,
it is also fleeting.
HAWK SQUEAKS
HE MAKES CLICKING NOISES
The most important tradition
of Korean falconry
is that the falconers
do not keep their birds for life.
They accept that a hawk is wild
and can never be fully tamed.
HE SHOUTS
The goshawk has short, wide wings,
allowing it to pass through gaps
at speeds of up to 40mph...
..and a long rudder-like tail
for sharp turns.
That makes it an extremely
successful hunter.
In Suncheon Bay, it's the mating
season for mudskippers,
and this young male is searching
for a suitable mate.
It appears the odds are stacked
against him.
In his quest,
he must cross open water
to reach a potential mating site
on the far side.
There are predators in these waters.
He makes it across, but is not yet
completely out of harm's way.
Mudskippers, although hardly
considered a delicacy...
..are eaten.
They are also used
in Chinese medicine
and there is a profit to be made
for this fisherman.
A near miss.
The young mudskipper escapes and
moves on to unexplored territory.
Other species of mudskipper
can be territorial.
Some are highly aggressive.
He wisely moves on.
Eventually, the young male spots
a patch he likes the look of.
Far fewer rivals.
This will do very nicely.
A single female.
He performs his courtship dance.
She seems unimpressed.
But he shuffles a little closer...
..and tries again.
She is much larger,
so this is very much
her decision to make.
Just when it looks like
the young male's luck has run out...
..she appears to have
a change of heart.
He sucks her face...
..and she is not completely put off.
The pairing has been agreed.
But the next stage won't happen
in front of an audience.
Their mating will take place
below ground...
..safely inside a mud burrow.
North of the mudflats
of Suncheon
is a very different
but equally rich environment.
60% of South Korea is forested and
much of its biodiversity is found
in these ecosystems.
This peculiar-looking creature
is a beetle larva.
It is following a trail
across the forest floor.
A slime trail...
..left by its intended prey.
The helpless marsh snail
produces a foaming mucus
in an attempt to confuse
its attacker.
But to no avail.
The larva injects paralysing
digestive fluids
directly into the snail...
..and begins to feed.
It may seem cruel...
..but the beetle must feed
to fulfil its role in life.
The nutrients it has gained
will help its transformation.
Bioluminescent chemicals in its
abdomen begin to glow.
It is a firefly larva,
and once freed from its casing,
it lights up the dark skies...
..a spectacle South Korea
is renowned for.
Proof that in nature,
scenes of great beauty
can often conceal a darker reality.
In the southern province of Jeju,
the conch season
is drawing to a close.
For many years, the island was known
as Geumdo, meaning "forbidden",
because of the treacherous
conditions here.
The sea is rough
but the Haenyeo
have been diving all day.
There is still an abundance
of conch to collect.
The Haenyeo are highly sensitive
to any changes
in the underwater currents.
Even a small change down here can
signal life-threatening conditions.
But the Haenyeo are tenacious.
Today, despite the increasing risk,
they decide to stay in the water
and now, they must work quickly.
Finally, with their nets filled,
their work is done.
Exhausted from hours of diving,
they are vulnerable.
Having lost one woman to the sea
last year,
they know all too well
the cost of making a mistake now.
With a final effort, they drag
their heavy nets out of the water.
All that remains now is to weigh
the day's catch.
The signs are good.
The harvest has been
a successful one.
The risks that they have taken
have paid off.
But, the day has taken its toll...
..more so for some than others.
The Haenyeo will return to dive
again tomorrow.
But perhaps not all of them.
Wal Soo Ra has worked in the waters
of Marado for 80 years,
sharing them with the others
that live here.
She hopes that the knowledge
she has gained will be passed on...
..and that the Haenyeo culture
will continue to prosper here...
..existing in harmony with the seas.
The traditional ways of life
that endure in Korea today remind us
that people have thrived
for millennia,
living harmoniously
with the natural world...
..and its many fascinating
inhabitants.
In Korea today, as in much of the
developed world...
..things are changing quickly.
But wild Korea still
has its treasures...
..and its place
in the country's heart.