All language subtitles for Moon.Natures.Secret.Force.S01E03.Guided.By.The.Moon.1080p.NOW.WEB-DL.DDP5.1.H.264-FFG_track3_[eng]

Our Moon is
a familiar face in the night sky.

She illuminates the way
for animals on the move.

But even when her light fades,

she has an unseen power,

which guides creatures
across the entire planet.

A humpback whale mum and her new calf

relax in the warm waters
of the Hawaiian archipelago.

It's the perfect nursery.

The calf was born
just a few months ago.

The tropical waters give him warmth.

There's shelter from the waves...

...and from the strong currents
of the open ocean beyond.

But he'll have to face them soon.

He must build his strength,
Mum must rest.

Their journey is about to begin.

They'll need to use the unseen power
of the Moon to find their way.

Our Moon shapes life on Earth
in extraordinary ways.

Creating the swelling tides...

...dictating the length of day...

...summoning the seasons.

She can light the way to love...

...reveal hidden pathways...

...bring times of plenty...

...or strip away chances of survival.

With each phase,

from full moon to new,

less light is reflected to Earth...

...but the more powerful
the Moon becomes.

As the Moon aligns with the sun,

their combined gravitational pull
on our planet

is at its strongest.

This shift in gravity...

...is the signal
to start an ocean odyssey.

This calf has only known the shelter
of these Hawaiian seas

since he was born.

The waters may be calm,
but they are not always safe.

A male.

He's looking
for the chance to impress.

And now he's joined by other males,
who are all searching for a mate.

It's not known why,

but a new moon brings
out their competitive side.

They are keen to show the female
they've got what it takes.

In these displays, they can
accidentally drown a young calf.

The males use the deeper water
to fight for dominance.

Mum takes a chance to slip away.

She has led her calf
to the safety of the shallows.

In a few short months,

he's already doubled in size
drinking mum's rich milk.

But she hasn't eaten in six months.

This nursery comes at a cost.

There's not enough food for mum here.

And their feeding grounds
are 5,000km away

in Northwest Alaska.

It's a journey all the humpbacks
here in Hawaii must take,

and one the calf must learn.

This is the only time
his mother will guide him north.

There's little margin for error.

Set off too early,
and they'll arrive in frozen seas.

Stay too long, and they'll starve
on the long voyage ahead.

The new moon is their signal.

Mum and calf can sense
the greater gravitational pull.

For mum, it's time to head north.

For the calf, this new feeling

is the first lesson
on the unseen power of the Moon.

They'll need to keep on course,

and pinpoint their feeding grounds

among thousands
of kilometres of coastline.

And the Moon's power will guide them
each step of the way.

Every month, the Moon changes
not just her phase, but her position.

Higher in winter,
appearing longer in the night sky...

...lower in summer,
shining for less time,

only skimming the horizon.

It's these changes in phase
and position

which set animal migrations
in motion.

In the lowlands
of Southern England...

...a nightjar rests in the heath.

She's a nocturnal hunter...

...and she's waiting
for the Moon to rise.

In the cool of the night...

...the heath comes alive.

The full moon signals
to the nightjar.

It's time to come out into the light.

She's searching for moths.

They spend these summer nights
looking for a mate.

Using the Moon to navigate,

they'll keep it at a constant angle
as they fly.

But tonight,
the full moon is their downfall.

The nightjar's huge eyes

drink in every photon of light
the Moon provides.

Tonight's bright full moon

helps her pick out insects
silhouetted against the dark sky.

Under a full moon,

nightjars are twice as effective
at catching prey.

And she must catch
as many moths as she can.

Packed with protein,

insects are the ideal fuel.

But this Moon is
more than a hunting aid.

It's a countdown
to the start of her migration.

In late summer,

the low full moon will only stay
above the horizon for a short while.

Nightjars' lives are tuned
to the phase and light of the Moon.

And she won't be alone
on this journey.

Nightjars all across Europe
will start their migration

ten days after this low full moon
of late summer.

Using the Moon as a clock,

they can synchronise their departure,

ensuring there's safety in numbers
on their long journey ahead.

Thousands of nightjars
will head to Central Africa...

...chasing an endless summer.

The changing height and phase
are both clock and calendar...

...a seasonal signal
and a call to arms.

Beneath the glow
of a high winter moon

in Southern Australia...

...a transformation is underway.

Every year, spider crabs must moult
their spiky armour

in order to grow.

But it'll take days
for their new shell to harden.

So they're vulnerable.

Long legs help this crab travel
around seven kilometres

from the rocky depths to the cool,
calm shallows.

He's searching
for a safe place to moult,

and needs to find it fast.

His body has already started
to transform,

it can't be stopped.

The Moon has triggered others
to migrate here to moult...

...but they've been followed.

A three-metre-long broad ray.

With no place
for the crabs to hide...

...a lone crab is defenceless...

...and delicious.

They pin them to the sea floor.

Port Jackson sharks mop up
the stragglers.

The Moon draws more crabs
out of the deep.

In winter,
the water is calm and cold...

...the perfect conditions to moult.

The full moon allows
thousands of crabs

to co-ordinate their march
to the shallows.

And as they gather,
they begin to band together.

To shed his shell,

this crab needs to find
the safety of the swarm.

He can't drop his guard.

He's no heavyweight...

...but can still pack a pinch.

Nipping at the ray's
soft undersides...

...is just enough to put it off.

The safety of a huge mound
is in sight.

It's a lucky escape.

Now he has an army
who's got his back.

The mountain of crabs
should make an easy meal.

But the mound is now
a sea of spines and claws...

...which sways and shifts.

So the ray can't grip
even a single crab.

There are as many as 20,000 crabs
in this small sandy bay.

And with this sheer force of numbers,

they create an impenetrable fortress.

Surrounded by his band of brothers,

he'll moult, transforming in safety,

until his new armour hardens.

The crabs will disappear back
into the depths until next year...

when the high winter moon signals
the army to rise up once more.

The full Moon is 400,000 times
less bright than the Sun.

But it's no pale imitation.

She can extend the day
and open up new opportunities.

And there's no more important time
than when raising a family.

In the lush forests
of Kyushu Island, Japan...

...a red shield bug guards
her tiny babies,

tucked into the leaf litter.

This is the only brood
she'll ever have.

Shield bugs' lives are short.

Being a mum is
the last thing she'll do.

To ensure they can get
the best start in life,

she must leave them
in search of food.

Among the tangle of vines
and trees...

...she's searching
for a special type of ripe fruit.

She keeps an eye on the pattern
of light and shade in the canopy,

which will guide her home.

She's locked on to a scent.

The fruit of the Boro Boro tree.

But the light is fading...

...and her map has gone.

She can't find her way
back to her babies.

A dark forest is a dangerous place
for a lost little bug.

But the Moon is here to help.

It reilluminates the canopy.

It may not be as bright as the Sun,

but the contrast
between the moonlight and dark

creates a clearer pattern.

The little bug can read these
like points on a map.

So she's able to take the most direct
route home to her babies

in minutes, not hours.

It's these full moon nights

which give her
valuable extra foraging time.

Tomorrow,
the Moon will shine less bright,

the canopy map dimmer,

harder to read,
less time to feed her babies.

But tonight,
it won't set until dawn,

so she must make the most
of this extended opportunity

to find food on this long,
moonlit night.

On the nights after the full moon,

the amount of reflected light
fades fast.

A crescent moon is barely visible...

...but even a silver sliver
can keep animals on track.

African savannah elephants

take the definition
of a midnight snack to the extreme.

They can spend 16 hours eating,

and consume over 100kg of food a day.

They'll spend so much time eating,

that they're awake nearly all night.

And all that food
has predictable consequences.

Life in the shadow of giants
is a dangerous game.

This little beetle
could easily be crushed.

But it's a risk he must take
if he's to win a mate.

For this beetle,
dung is a prized possession.

A big ball of dung is exactly
what a female beetle is looking for

to lay her eggs in.

And this pile has
already attracted other males.

To beat the competition,
he needs to be quick.

It's time to get dirty.

Using his strong legs,

he sculpts a ball
five times his size.

He needs the moonlight
to make a clean getaway.

A straight line is the fastest way.

But which way to go?

The small amount of light
from a crescent moon

is scattered by particles
in the atmosphere.

And this creates lines of light
in the night sky...

...known as polarised light.

Even head down and facing backwards,

he can follow these lines of light.

But beware the thief in the night.

With such a big ball,

stopping to check
your position can be risky.

Equally matched,
it's now a battle of stamina.

he needs to stay on top.

Losing the higher ground
could mean it's game over.

But he won't give up.

With the chance
of other dung-ball bandits nearby...

...he pushes on,
following the polarised light.

Finally, his new ball of dung

brings him
the female attention he desires.

The ball will become home
for their new brood.

He'll keep pushing,

until he finds soil soft enough
to bury the ball.

His moonlight guided great escape...

...finally complete.

Moonlight offers a visible guide
to animals on the move.

But the Moon has an unseen,

and even more powerful way
to guide navigators.

The Moon's proximity to Earth

means her gravitational pull
helps power an immense force.

Under the Earth's crust,

the iron-rich rock is molten.

Just as the Moon's
gravitational pull acts on the tides,

it also tugs on the swirling rock
deep underground.

This movement adds
electromagnetic energy,

creating powerful magnetic fields.

These fields align
and oppose each other...

...creating our North and South Poles.

When charged particles from space
strike this magnetic field...

...it causes the atmosphere to glow,

and it becomes visible as an aurora.

An ever-present power,

felt all across the entire planet.

Even in the middle of the world's
largest ocean, the Pacific.

155 million square kilometres

of endless blue.

Its sheer size means storms
and strong currents

swirl across it uninterrupted.

Our humpback mum
and her young calf...

...are 2,000km from land.

In the open ocean, they could
easily be knocked off course.

The calf sticks close to mum,
riding her slip stream,

saving valuable energy.

But mum is now burning through

hundreds of thousands
of calories a day.

Make a mistake in navigation now,
and it could cost them their lives.

As they journey, the visible Moon
will change phase and position,

so it can't be relied upon
as a guide.

But the magnetic field is
an all-pervasive power.

Inside their brains,

mum and calf both have
tiny iron particles,

called magnetite.

These align with the magnetic field,

triggering a cellular reaction.

It lets them sense how steep
and how strong the field is.

From this,
they can work out their position,

and in what direction to swim.

Their own biological map
and compass.

So mum can find her way across
this seemingly featureless ocean.

And now the calf is learning
how to use this sense...

...for a life
as a long-distance ocean voyager.

The magnetic field touches
every part of the planet,

from the deepest oceans...

...to high mountain peaks.

From the largest animals
on the longest migrations...

...to the smaller, but no less mighty.

Deep in a European forest...

...the spring sunshine stirs
a sleepy Alpine newt.

After a year in the woods,

instinct now drives him
to find water.

He's looking for a mate.

This finger length newt is too small
to see which way to go.

He'll need to rely on his superpower
to find his pond.

But he's not alone.

A grass snake,

energised by the sun, is on the hunt.

The snake relies
on its speed and strength

to chase down and strangle its prey.

Little legs struggle
in the dense forest.

But for a tiny newt,
there are plenty of places to hide.

The setting sun is a sign it's safe.

A grass snake can't hunt in the dark.

But now disorientated from the hunt,

he needs to work out
which way his pond is.

He, too, has magnetite in him.

His superpower, which allows him
to sense the magnetic field.

Just like following a compass,

he's keeping his whole body aligned
to the angle of the field...

...and can head in the direction
of the pond he left a year ago.

A spring storm
doesn't bother him, either.

The magnetic force flows
whatever the weather.

With his internal compass,

this tiny newt can travel
as far as four kilometres.

As the dense forest thins out,

the newt can now smell
that water is close.

Finally, his pond.

Time for a well-earned dip.

But he can't rest,
it's time to find a mate.

As the season turns to summer,

he'll return to the forest,

but next spring,
wherever he is in the woods,

he'll find his way back to this pond,

using the lunar-charged
magnetic field to point the way.

As the magnetic field wraps
around the planet,

its angle changes.

At the poles, it's vertical.

At the equator,
it's parallel to the surface,

creating a map
for those who can read it.

Where the waters
of the vast Atlantic

meet the Congo jungle,

the coastline is one
of the few places in the world

suitable...
for ocean giants to emerge.

Four kilometres of sand...

...just soft enough,
the beach not too steep.

This Leatherback turtle

touches land
for the first time in three years.

The Moon has gifted her a high tide,

helping her part of the way.

She'll need all the energy she has
to haul herself up the beach.

Using a Moon-powered map,

she's travelled
from her feeding grounds in Brazil,

six thousand kilometres away,

back to the place
she first hatched...

...on the coast of equatorial Africa.

This time,
she's here to lay eggs of her own.

Her eggs will be incubated
in the warm sand...

...where they'll develop
a super-sense.

Mum has done all she can.

She's leaving her eggs
in the care of the Moon.

As the eggs develop,

the lunar charged magnetic field
courses through them,

deep in the sand.

The hatchlings have particles
of magnetite within them,

and can also sense
the angle of the magnetic field.

So each one is born
with a magnetic imprint

of this stretch of coastline.

This beach is their first mark
on their magnetic map.

But it's the visible Moon
which guides their first steps.

Instinctively, they head out

to the brightest part
of their new world...

...moonlight reflected on the sea.

They'll ride the ocean currents
in search of food.

As they travel, the angle
of the magnetic field will change.

They'll add new markers
on their internal map -

the key to long-distance navigation.

From the shores of central Africa...

...a whole ocean awaits.

The Moon has had influence
over the Earth

for billions of years...

...creating profound physical changes
to our planet.

These allow animals on the final
stretch of their long migration

to home in with amazing accuracy.

The gravitational pull of the Moon
strains the Earth's thin crust.

This has helped create
volcanic peaks,

and vast canyons, even underwater.

Such are the scale
of these formations,

their huge mass alters
the gravity on Earth,

slightly stronger
where there are mountains,

slightly weaker in deep canyons.

These are gravitational signposts
for those who can feel it.

Mum and calf can sense
the slight change in gravity

caused by the mountains
and canyons on the ocean floor.

They've made it,

across 5,000km of open ocean

to the cool Alaskan waters.

The calf now has a thick layer
of blubber to keep him warm.

But mum has lost
nearly half her bodyweight

since she left these shores
seven months ago.

These green seas

are a sign her fasting
will soon be over.

Plankton-rich waters have drawn
in millions of herring,

and this is why mum
and calf have come so far.

Weeks of travelling with the Moon
as their guide,

they've arrived at the right place
and at the right time.

And there's one final skill
the calf can learn.

How to work as part of a pod...

...and master the art of the hunt.

The males put their fighting aside,
and now work together.

Each humpback in the group
has a role to play.

One releases air,

whilst swimming in a circular pattern
towards the surface.

As the bubbles rise,
they form vertical curtains...

...forcing the fish together.

Calls from the others
further concentrate the shoal...

...and then, a co-ordinated surge.

The bubble-net size,
shape and amount of air is adjusted,

depending on the type of prey.

Not all humpbacks catch food
this way.

it's unique
to only a few groups in Alaska.

This calf is part
of a special community of whales.

He'll need to spend the summer
finding his place in the pod.

After a well-earned feed,
it's time to play.

But there's another reason
for his breaching.

It's now thought the young humpback

is also resetting his senses.

As he freefalls back into the water,

he's calibrating
to the gravity signposts

of the underwater mountains
and canyons

at these rich feeding grounds.

Once autumn arrives
and the herring leave,

the calf will join his mum
on the return back to Hawaii.

The next time he travels
back to these waters,

he'll do so alone.

On his long journey
triggered by the Moon phase...

...kept on course
by the magnetic field...

...and guided by gravity.

The Moon's
all-pervasive power and influence

will be with him
every step of the way.

To film the lunar lives
of leatherback turtles in Gabon,

the team partnered with a local NGO
devoted to their survival.

Didier doesn't have to go far
to reconnect.

Only ten kilometres
from the capital Libreville

is Pongara National Park,

one of the world's
most important nesting beaches

for endangered leatherback turtles.

Adult turtles can get tangled
and drown in discarded fishing nets.

And Pongara's proximity
to the capital

brings a greater threat.

Timber from Gabon's vast forests

is taken by sea to sawmills
in the capital.

Not all the huge trees make it.

Leatherbacks have existed
since the time of the dinosaurs,

and it's down to the hard work
of Didier and his team

to help them survive the pressures
of the modern world,

and ensure Pongara remains
a vital nesting ground -

critical not only for Gabon,
but of global importance.

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