All language subtitles for z04

Just off the east coast of
Australia lies a miracle of an
island, one built entirely on sand.

But somehow it has become
a magnet for life.

Ocean giants, peaceful and
playful, grace its waterways,

pursued by not-so-gentle giants.

Great rainforests, acid swamps,

and improbably lakes
conceal devious killers

that fight to outwit
and devour the weak...

and each other.

It's a tough place to be
top dog.

A restless battleground

where life holds on
against all odds

on this great island
of shifting sands.

Fraser Island.

[♪]

It's spring, and
the humpback whales

of the southern hemisphere

are on the southbound leg
of an annual 3,000-mile journey

from their breeding grounds
inside the Great Barrier Reef

to the rich feeding grounds
of cold Antarctic waters.

En route, many mothers and
their newborn babies

take a little side trip
to a favourite site:

the sheltered waters
of Fraser Island.

Platypus Bay between the island
and the mainland

is a perfect spot for
the little ones to nurse

and grow strong for
the epic journey ahead...

and to have a little fun.

[♪]

[♪]

The bay is too shallow for the
males that sometimes escort them

to attempt their courting
and mating rituals,

so mother and calf
can bond in peace.

Suckling on her mother's
fat-rich milk,

this young calf will nearly
double her birth weight

in a matter of weeks.

Her mother, however, won't eat,

and will lose a third
of her weight

on the southward migration.

Whales send messages
to each other

by slapping the water with
their fins and tails.

Tail-slapping may be a form of
short-range communication.

They employ vocalizations
for long-distance calls.

Out in deeper water,

the males sing their haunting
songs as they continue south,

whereas the females
remain silent.

The complex songs are particular

to this East Australian population.

They can last hours and be heard
hundreds of miles away.

After a five-day sojourn
in the bay, it's time to go.

The calf will travel in
her mother's slipstream

to ease her journey.

The mother and her calf head
north and east out of the bay,

slipping around the tip
of Fraser Island

and heading south against
the prevailing currents.

Fraser Island, just one mile
from the mainland,

lies at the southern tip of
the Great Barrier Reef.

Its creation began hundreds
of thousands of years ago,

as mainland rivers
carried sediment

from Australia's east coast
into the ocean.

Currents swept billions
of tonnes of sand

up along the coast,

where rocky outcrops forced
the ocean to drop its payload.

Eventually, an enormous island
of sand rose out of this earth.

Today, Fraser is 75 miles long
and 14 miles wide,

and some of its dunes
tower 780 feet high.

The Aboriginal people call it
K'gari, or "paradise".

More than 15,000 years ago,
when sea levels were lower,

Platypus Bay would have
been an exposed sand flat

connecting the island
to the mainland.

Across that sand flat

came Australia's largest
surviving predator mammal:

the dingo.

When sea levels rose again,
cutting off the island,

its dingo population scratched
out a living in isolation.

Without possible interbreeding

with the mainland's
domestic dogs,

Fraser Island's dingoes remain
the purest dingo population

in Australia.

While they're the top predators
on the island,

dingoes can't afford
to turn their noses up

at any source of food.

On the east coast, a whale
whose journey south ended

almost as soon as it began
becomes a welcome opportunity.

The dingo is not alone.

The island's largest lizard,
the lace monitor,

has also caught the scent
of the rotting carcass.

It, too, is both hunter
and scavenger.

But dingoes also hunt
lace monitors.

So the lizard wisely decides
to look for dinner elsewhere.

The dingo's mate joins him
at the carcass.

They're the alpha pair
of the local pack.

This female is suckling
a litter of pups,

and needs to supplement
her diet

with whatever comes her way.

While it's a mega-meal, it's
also a tough one to unwrap.

Until the whale hide
weakens over time,

the dingoes focus on
the softest parts.

While the dominant pair
are at the carcass,

other pack members
keep their distance.

There are dozens of
dingo packs on the island.

Each pack has about
a dozen members

and is controlled by
the alpha male and female.

The female's pups are
entirely reliant on her milk

for their survival.

She makes her way inland,
deep in the forest,

where she's hidden her
day-old pups in a log den.

[Dingoes whining]

Unlike domestic dogs,
dingoes breed only once a year.

The pups won't be independent
for another seven months,

when they'll take their place
in the pack hierarchy.

[♪]

Back at the coast, this
sea eagle uses its keen eyesight

to spot prey from
up to 65 feet away.

While he usually
prefers fishing,

the lure of the whale carcass
is hard to resist.

The carcass will remain
a hub of activity

until it's picked clean or
washed back into the ocean.

Even a whistling kite will
scavenge the carcass,

grabbing a bite on the wing.

Not interested in sharing,

he takes his meal
into a nearby tree,

away from other scavengers.

Down below, the red-capped
plover has to keep on his toes.

The whistling kites
prefer hunting

and shorebirds are
a favourite prey.

Microscopic invertebrates and
algae living in the wet sand

supply him with all
the food he needs.

Beachcombing is busy work,

and he spends most of his time
foraging this way.

Further down the beach,

huge flocks of crested
terns congregate.

Drawn to Fraser Island to feast
in the rich waters.

[♪]

The seas are relatively calm
for now,

but this eastern edge
of the island

takes the brunt of
prevailing winds.

[Wind howling]

Here, on the most hostile side
of the island,

the pitched battle between
shifting sands and rooted plants

continues to play out

as it has since the days
when the island took shape.

Without plants to anchor
the dunes,

the sand would simply
keep marching inland,

and this would be a
completely barren place.

Hardy pioneer plants
like spinifex

are the first to put down roots.

They've evolved
extraordinary ways to cope

with the coast's
abrasive conditions.

Spinifex grasses have a covering
of fine, waxy hairs

that repel the salt
and retain water.

When mature, their
seed heads dislodge

and are blown about the dunes,

where they germinate and begin
their work

turning the sand dunes
into a thriving ecosystem.

The spinifex root systems and
creeping stems act like mesh,

securing the sand in
place below.

Once stable, sand dunes make
perfect nesting burrows

for the rainbow bee-eater.

Masterful hunters,
rainbow bee-eaters

acrobatically catch
insects on the wing.

This pair has mated for life,

and return to the island every
spring for the breeding season.

This means picking a
very stable dune

and excavating a three-foot-long
tunnel into it.

The female does most
of the digging.

These two are such old hands at this

that their burrow
from last year is still intact,

which will save them
a lot of trouble.

All it needs is a
little renovation

and their nursery will be
snug and ready

to welcome their eggs.

The lace monitor, rebuffed
from the whale carcass,

has travelled down the beach
in search of a meal

that he can really get
his mouth around:

bird eggs.

He haunts the dunes looking
for failed architecture.

High tides and winds
can dislodge eggs

from poorly placed nests.

The monitor reaps
the benefits...

and one pair of bee-eaters
helplessly watches

its next generation disappear.

The experienced bee-eaters,

with their deep and stable
nesting site, have less to fear.

Their eggs will hatch
deep out of reach

of even the most
determined lace monitors.

[Wind howling]

But not all the dunes on
the east coast can be tamed.

The assault of wind and sand
that build the island

still creates dunes that
relentlessly march inland,

blown by powerful prevailing easterlies,

the dunes align
with the onshore winds

that drive them and form ridges.

Over time, they assume
massive U-shapes

known as parabolic dunes.

Lakes often form in
the sheltered swoops

between these windblown dunes.

One of the liveliest
is Lake Wabby.

At 39 feet, it's the
deepest lake on the island

and unlike some of the island's
other lakes,

its emerald waters
are fresh,

harbouring catfish
and rainbowfish,

irresistible to the
local waterfowl.

Cormorants frequent Lake Wabby,

dipping and diving
for their supper.

Unlike many diving birds, their
wings do not produce oils

to make them waterproof.

Instead, their feathers have
microscopic structures

that repel water,

and these require careful
maintenance and drying.

But sometimes the elements
just won't cooperate,

and they simply have to put up
with a good soaking.

The rains that fall
on Fraser Island

seep into an enormous
dome-shaped water table

below the dunes

that in some places may reach
100 feet below sea level.

[Thunder rumbling]

Lake Wabby dips into
this aquifer,

and is known as a window lake.

But this is a lake under siege...

by the same dune process
that formed it.

Lake Wabby is being
engulfed by sand

at the rate of six feet a year.

In 100 years, the sand will
completely reclaim the lake.

[Insects buzzing]

Moving inland beyond
the advancing sand

and where the water table
is high,

swamps and
heathlands can flourish.

With their feet in the sand,

the plants can find nutrients
hard to come by.

But these hardy survivors manage
to create sweet salvation

for the locals.

The energy these plants might
otherwise invest

into tall trunks and branches

goes into producing
abundant nectar,

attracting honey-eaters
that in turn

spread pollen from
plant to plant.

The nectar is in great demand,

and birds squabble among themselves

to defend their patch.

[Birds chirping]

Insects too are drawn
to the bounty.

But not all nectar is
what it seems.

On the heathland floor grows
a clever carnivore.

The drosera, or sundew plants,
put out modified leaves

that glisten with what looks
like irresistible nectar.

But these gooey droplets
are actually laced

with flesh-digesting enzymes.

Any unfortunate insect tempted
by the apparent feast

quickly finds itself
in a sticky situation...

and well on the way to
a syrupy end.

It's a brilliant solution

for a plant stuck in an
infertile, sandy environment.

With no nitrogen to
suck up from the soil.

It sucks it out of its
unlucky victims instead.

Fraser Island's ongoing battle
between sand and life

has turned the plants
into carnivores.

The jabiru, Australia's
only stork,

wades along the edges
of these swampy regions,

searching for frogs, fish,
and other tasty morsels

hiding in the reefs.

Its long legs are ideal for
swamp-walking, and its bill,

designed for stabbing
and grabbing.

Swamp hens take a different approach,

feeling their way
among the reeds

with their elongated toes
ready to snatch anything edible.

Those long toes also provide
great stabilization

for the gentle, if brief art,
of mating.

Ironically for an island
surrounded by salt water,

Fraser Island has a
higher concentration

of permanent freshwater lakes

than any other part of
the mainland,

with more than 100 of them.

But not all of the freshwater
lakes are welcoming to life.

Some are highly acidic,
thanks to the tannins

leached out of the decaying
vegetation in the water.

Remarkably, they're home
to some of Australia's

most delicate creatures.

Even though they absorb water
and breathe through their skin,

four species of frogs
on Fraser Island

have adapted to the harshly
low pH of the acid lakes.

They thrive in the absence of
competitors and predators,

who can't tolerate the acidity.

Known as acid frogs,

they huddle silently
in the reeds during the day.

But at night, they begin to make
their way upwards...

to sing.

[Frogs squeaking]

As the sun sets, the lakes
come alive with noise...

[Frogs squeaking]

...catching the attention of
nocturnal predators.

This male acid frog has found a
stage from which to serenade

the resident females.

[Frogs squeaking]

Magnified by an
enlarge vocal sack,

his calls echo around the swamp.

But it's not only the females
that take notice.

A brown tree snake, also
known as the night tiger,

is drawn to the vibrations
of his calls.

[Frogs squeaking]

Its long, lean body effortlessly
spans large distances

between branches.

It hunts by sight and
by tasting the night air

for the scent of prey.

The acid frog senses his
approach and freezes, silent.

[♪]

Despite the night tiger's
keen eyesight,

this meal has eluded him.

He'll have to search elsewhere.

Night-time is also the right
time for this little marsupial.

The squirrel glider.

His giant eyes give him
acute night vision.

He is searching for fruits

and insects washed down
with sap and nectar.

His slightly smaller neighbour,
the sugar glider,

is also out and about.

Both species are
perfectly adapted

to life in the forest canopy,

out of reach of the predators
that might be lurking below.

Stretchy membranes on
the sides of their bodies

give the gliders their name.

At the first sign of trouble,

this pint-sized parachutists can
launch themselves into the air,

trimming their furry membranes

to control their trajectory
and landings

with astounding accuracy.

[♪]

Beyond the swamps and open
forest where the dingoes hunt

lie the high central dunes,
650 feet up.

Here, a true miracle of the
island rises into the sky:

a massive rainforest,

the only one in the world to
grow in such high sand dunes.

Usually complex forests of
this size grow only on soil.

Some plants here are rare relics
from the age of the dinosaurs.

These are king ferns,

whose lineage stretches back
300 million years.

The fronds of this fern are
the largest in the world,

stretching some 26 feet
from their base.

Their kind existed
on the planet

before Australia separated

from the ancient
supercontinent of Gondwana.

Only a few pockets of them
still exist in Australia.

This stand from Fraser Island's
interior is one of the finest.

The sands of Fraser Island
even support true giants

such as these Satinay trees.

Towering up to 100 feet,

these trees occur only in this
sandy corner of Australia.

They were once highly sought
after as timber

because of their ability to
resist termites and borers,

and were used to build
the Suez Canal.

Now they are mostly protected

by the island's World Heritage status.

The enormous trees are no
obstacle to the lace monitor

in its never-ending
search for bird eggs.

They also provide an escape from
the attention of the dingoes

that are constantly
on the prowl below.

[♪]

The fallen timbers provide ideal
pupping and nursing dens

for another of the
island's packs,

and hollow boughs serve as
daytime sleeping places

for the gliders.

The rotting giants
eventually decompose,

giving back their nutrients
to the soil

and helping sustain
the improbable forest.

The thick carpet of leaves
on the forest floor

conceals a killer that is both
dangerous and endangered.

The death adder has an
ingenious hunting strategy

designed to
bring prey to it,

not the other way around.

Its stout body tapers into a
tail with an agile, wormlike end

that it can wiggle even
as the rest of its body

remains motionless.

The well-camouflaged body
blends into the background,

but the tail flaunts itself
as a lively, tasty worm.

Known as caudal luring,
this lethal mimicry

is the death adder's
weapon of choice.

A skink that falls for
the trick is doomed.

The death adder strikes with
an astounding accuracy,

delivering highly
potent venom,

with the fastest strike
of any snake in the world.

But this clever killer
is in dire straits.

Its numbers are rapidly
declining on the mainland,

a victim of the infamous
cane toad.

Introduced to Australia
in the 1930s

as an insect control measure,

the plan has gone
horribly wrong.

Cane toads are an
environmental nightmare.

They reproduce prolifically and
have few natural predators.

They eat anything they can put
their giant mouths around,

and anything that eats them
gets a giant dose of poison,

including the death adder.

Despite the presence
of the toads,

death adders are holding
on better here on Fraser Island

than elsewhere because of
the island's chemistry.

Many of its lakes and swamps

are simply too acidic
for the toad to survive in,

and there's another snake here

that manages to keep
the cane toad in check.

[♪]

The keelback has developed
a taste for the toad

and a tolerance for
the powerful toxins

that seep from the toad's skin.

Unlike most snakes, the
keelback attacks from behind...

...avoiding the full impact

of the toad's poison-laden
cheek glands.

The snake lives another day

and there is one less toad
in the swamp.

[♪]

The highest lakes on
Fraser Island

are almost 800 feet
above sea level,

too high to connect
to the water table below.

These perched lakes are lined
with decaying vegetation,

creating an impermeable,
compacted base layer

that collects and holds water
like a great saucer.

The waters of these lakes
are often so pure

they're crystal clear.

These are the sparkling waters

and snow-white beaches
of Lake McKenzie.

This is one of the last lakes
to be found on the ascent

from the east coast

before the island
slopes down once more

towards the sheltered
western shore.

Rain falling on this leeward
side of the island

is filtered and fed into
Wanggoolba Creek.

It flows westward and into
the narrow shallows

that separate the island
from the mainland.

Here, the island reveals
its alter ego:

a serene, sheltered environment

subject not to the
turmoil and uncertainty

of the winds and waves,

but the gentler push
and pull of the tides.

The west shoreline

receives a rich payload
of silt and nutrients

fed by the mainland's rivers.

This is where the sands run out
and the mudflats begin.

The ebb and flow of the tide
reveals and conceals

riches below the surface.

When the tide runs out,

vast armies of light blue
soldier crabs quickly emerge.

They defy crab-walking
convention

by marching forwards
rather than sideways.

As they march, they sift
through the wet sand,

searching for tiny morsels
of food.

They feverishly sort the edible
bits from the sand,

then race to bury themselves
before the tide comes in.

Corkscrewing into the sand
with their specialized claws,

they dig burrows complete
with air pockets

so they can breathe
while submerged.

But these hatchers leave
a tell-tale sign

for predatory birds.

Whimbrels stalk the crabs.

At the slightest sign of danger,

the crabs bury themselves
as quickly as possible.

The whimbrels use their sharp
eyesight to spot and seize

the helpless crabs.

Their downward-curved bills
can stab deep into the sand,

foiling the soldier crabs'
best defenses.

They aren't the only
birds hunting crabs.

The beach stone-curlews
join the feast,

eating as many crabs as
they can

before the tide returns.

The danger is never far away.

This brahminy kite keeps
a close watch,

hoping to catch one
of the birds off guard.

But the driftwood that lines the
shore provides excellent cover

for the curlews.

They camouflage themselves
amongst the debris.

The west coast is the
perfect environment

for some of the
hardiest and most salt-tolerant

of all plants:

mangroves.

Their sturdy prop roots
provide a firm footing

in the silt-laden underworld.

These are drowned and
revealed each day

with the ebb and
flow of the tides.

And they're a rich hunting
ground for some local residents.

The rakali is a native rodent
with partially webbed feet,

thick water-repellent fur,
and long whiskers.

Australia's equivalent
to the otter.

It is one of Australia's shiest
and least-known native mammals.

To even catch a glimpse
is a rarity.

But their insatiable taste
for freshwater mussels

means you can always tell
where they've been.

They're masters at making
themselves scarce

when they sense danger,

and this saltwater crocodile
definitely counts as danger.

The salty is the world's
largest crocodile.

They can grow to over 20 feet
and weight a tonne.

They haunt rivers and estuaries

and make great oceanic journeys
in search of prey.

But a visit from the mainland

to the rich hunting grounds
of the Fraser Island mangroves

is barely a day-trip
for this great predator.

This classic ambush predator
lurks just beneath the surface,

with only its prominent eyes and
nostrils visible as it hunts.

It will eat anything it can get
its impressive jaws on.

One of the sea's gentler giants
is also drawn to Fraser Island.

Dugongs can only survive
where seagrass grows,

and the great sandy straits
support seagrass meadows

the size of Rhode Island.

This dugong cow is part
of a healthy local herd.

Her heavy bones give
her negative buoyancy,

anchoring her to
the sea floor

as she grazes
on the seagrass beds.

A relative of the
American manatee,

she can munch her way through
60 pounds of seagrass

in a single day.

She can stay under for up
to six minutes

before surfacing to breathe.

Sea grass meadows stabilize
the shifting sediment

and trap nutrients.

The world's seagrass meadows

also act like great
carbon sinks,

sequestering twice
the amount of carbon

a tropical forest of
the same size can store.

Just 2.5 acres of seagrass
can capture

more than 30 million
tonnes of carbon each year

and produce over 26,000
gallons of oxygen per day,

enough for nearly 200 people
to breathe.

Green sea turtles also
come here to feed,

grazing on the seagrass
before heading north to breed

on the Great Barrier Reef islands.

Towards the end of spring,

they leave the shallows
and head to the waters

off the northern tip
of Fraser Island.

These are amongst
the most important

courting and mating grounds

for the Pacific Ocean's
green sea turtles...

and predators know it.

The large blunt-nose tiger shark

is known to eat almost anything
that crosses its path,

but it's specially equipped
to deal with large turtles.

Having killed this turtle,

the tigers proceed to eat
the easy bits first:

the flippers.

They then use their
serrated-edge teeth

to saw through the turtle's
hard shell.

[♪]

But green sea turtles
have adapted

and spend little time
at the surface,

where they can be ambushed.

Instead, they grab a
quick breath

and head right back to the
relative safety of the bottom.

The fertile sands of
Fraser Island

serve as a valuable
fuelling station

for many migratory seabirds.

This bar-tailed godwit

is preparing for one of
the most incredible journeys

in the animal kingdom.

It will gorge itself on
molluscs, worms, and insects,

in preparation for the
long-haul flight ahead.

By the time it embarks
on the journey,

more than half of its body
will be fat reserves.

These reserves will provide
much-needed energy

as the godwit's flight is
the longest nonstop journey

made by any animal.

It leaves Fraser Island and
does not touch ground again

until arriving at their breeding
grounds in Alaska,

over 7,000 miles away.

From the windswept shores
of the east coast,

across the marching
dunes and placid lakes...

through towering forests

with their feet in
shifting sands,

down to the seagrass meadows
on the west.

Fraser Island truly lives up
to its more ancient name:

K'gari.

Paradise.

A paradise that these great
whales return to every year,

that protects the purest strain
of dingoes in the world,

where plants and animals

have found their own
unique way of surviving...

on the world's largest island of sand.