Original subtitles

The sea turtle.

One of the oldest animals on earth.

These ancient mariners pre-date the dinosaurs.

They've remained essentially unchanged

for 100 million years.

The seven surviving species

are all now endangered.

Yet here, on the Arabian Peninsula, thousands gather

at one of the most important breeding sites in the world.

Females endure hardship...

..and their young face a heroic fight for life...

as they battle to become the next generation

of Arabia's sea turtles.

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The windswept beaches of the Sultanate of Oman

provide the dramatic setting

for one of nature's most enthralling breeding events.

Every year, four of the world's seven species

of endangered sea turtles come ashore here

to dig their nests and lay their eggs.

Cautious females wait just offshore until the sun sets.

As soon as darkness falls,

the first female emerges from the waves.

She can spend several hours at the waterline,

lifting her head to check for danger,

before starting her journey up the beach.

Nesting turtles are discouraged by light.

To capture this intimate moment of her life

without disturbing her,

the cameras switch to infra-red,

a light that's invisible to the turtle.

This is a Green sea turtle.

She hauls herself up the beach

by moving her large, powerful

front flippers simultaneously.

This helps her to gain traction

and move her heavy body.

Green sea turtles commonly weigh in

at around 330 pounds.

In the water, the sea turtle is graceful.

But on land, without the sea to support her weight,

moving takes a lot of effort.

Like all sea turtles,

she can only breathe when she's still.

The motion of her flippers impinges on her lungs

and interrupts her breathing.

She must take in a deep breath,

then hold it, in order to make her next move.

She reaches the high tide line.

It's safer to lay eggs beyond this zone,

away from the risk of the encroaching sea.

She selects her spot and starts to dig her nest.

She rotates her fore-flippers

and uses her powerful muscles

to force them back through the sand like shovels.

Again, she must hold her breath to do this.

She needs to lay her eggs in soft sand.

But this patch is too unstable.

Females will abandon nest sites

if they sense conditions aren't exactly right.

They may give up altogether,

returning to the sea without laying their eggs.

But she changes direction,

signaling her determination to try again.

She's no longer alone.

These beaches are home to one of the largest concentrations

of breeding Green sea turtles found anywhere in the world.

The beaches lie on the north-east tip of Oman

at Ras Al Jinz.

Every year, up to 15,000 female Greens

come here to lay their eggs.

They nest here year-round,

but numbers peak in June and July,

when hundreds come ashore each night.

Moonless nights, like tonight,

provide extra privacy, and so are the busiest.

The female finds a new place to start her nest again.

She chooses fresh sand

with no evidence of previous disturbance.

She rotates her body to help create

a shallow depression in the sand to lie in.

Once she's comfortable,

she's ready to start digging a hole,

using her shorter back flippers.

A steady stream of would-be nesters continues to arrive.

But this spot is taken.

Some are digging deeper than others.

Sand gets everywhere.

But sea turtles can flush it out of their eyes

using a secretion from a salt gland under their eyelid.

This gland primarily allows them to excrete excess salt

from the seawater.

Once she completes the nest hole,

she begins excavating the most important part -

the egg chamber.

This requires precision.

One by one, she curls each back flipper up

into a small shovel

to carefully scoop out the damp, compact sand beneath.

The egg chamber is shaped like a tear drop

and can be up to a further three feet deep.

She rests between movements

to catch her breath once more.

Tiring from her exertion,

she takes longer breaks in this final digging phase.

With one last scoop of sand,

the chamber is ready.

The female, now in a deep trance, lies almost still,

as she begins to lay her eggs.

Once she enters this phase, very little will disturb her.

She drops two or three at a time.

Each egg is just over an inch in diameter

and covered in mucus.

The shells are soft and flexible,

so they don't break on impact.

Here on the beaches of Ras Al Jinz,

females have been recorded

laying between 100 and 150 eggs a night.

Her back flippers now conceal the rest of her delivery.

Once she finishes, the female covers the nest with sand.

This prevents her precious clutch from drying out,

and aims to hide them from predators.

Arabian foxes patrol these beaches.

Sea turtle eggs are a nutritious meal.

Two hours after arriving on land,

the female starts her journey back to the sea.

Her role as a parent ends here.

If her eggs remain hidden from predators,

they'll hatch in two months.

She will come ashore up to six times this season,

laying up to 900 eggs before the summer's out.

After that, it will be two to five years

before she breeds again.

This multiple nesting strategy each time

is critical to the sea turtles' survival.

There will be heavy losses of eggs and hatchlings to come.

In the early hours of the morning,

it's easy to see why.

An Arabian red fox breaks cover.

Foxes are the biggest threat to sea turtle eggs

on these beaches.

This one scours the shore.

If it smells a nest, it will dig up the eggs.

Foxes on these beaches have adapted their diet

to take advantage of the year-round breeding season.

95 per cent of their diet

is sea turtle eggs and hatchlings.

This one doesn't smell the newly-laid eggs,

so is out of luck this morning.

The rising sunlight now reveals the extent

of the overnight comings and goings.

Pathways of sea turtle tracks litter the beach -

evidence of the multiple night-time nesters.

From above, it's easy to see the circular nest,

with its arrival and departure tracks each side -

a clear indication of a female's route of the beach

and back again to the sea.

In its more usual habitat, beneath the waves,

a Green sea turtle moves with ease as it looks for a meal.

Its weight is supported in the water.

Its curved fore-flippers act as both wings and propellers

against the sea current.

The sea turtle uses almost vertical strokes

as it appears to fly through the water.

Its shorter, rear flippers act mainly as rudders,

allowing the turtle to make sharp turns.

Green sea turtles are exceptionally streamlined

and are highly efficient swimmers.

Like all sea turtles,

Greens are long-lived.

They have the slowest maturity rate

of any sea turtle,

sometimes taking up to 40 years

to become sexually mature.

This juvenile is at least five years old,

as it's feeding here in coastal waters.

It will have spent its early years in the open ocean.

Young sea turtles are mostly carnivorous,

eating marine invertebrates.

As Green sea turtles grow up, their diet changes

and they move into these shallow coastal waters to feed,

where they become vegetarian,

feeding on seagrass, kelp and algae,

making adult Greens the only herbivorous sea turtles

in the world.

This juvenile tugs at carpets of algae on the hard coral.

Its serrated jaw enables it to clip and chew plants.

Oman's coast provides plenty of feeding opportunities.

Seagrass meadows lie off the central coast.

Algae-rich coral reefs lie to the north and south.

A sea turtle's shell is made of keratin,

the same substance as human hair and fingernails.

It's also known as a carapace.

And each species has a distinctive pattern.

In Greens, five scutes, or plates, run down the center,

with four more on either side.

The scutes fuse together over the bony shell,

which provides a protective shield.

This effective defense

means turtles more than two years old

have few predators in the ocean.

Their greatest threat is from human activity.

Hunting and entrapment in fishing gear

are perils in the sea.

Dangers on land are from people harvesting eggs

and destruction of nesting beaches.

Greens aren't the only sea turtles

feasting in these waters.

Nearby, a critically endangered Hawksbill

scours the same reef.

Fully grown, this Hawksbill is smaller than a Green.

It's most easily identified by its raptor-like beak,

that gives it its name.

Unlike the Greens,

Hawksbills remain omnivorous throughout their lives.

A favorite food is sponges.

But they will look for other marine animals to eat.

This one settles on a tasty patch of Octocoral,

so called for its eight hollow tentacles.

It uses its beak to bite off chunks of coral,

which it crushes in its powerful jaws.

Hawksbills and Greens are just two of the four species

of endangered sea turtles that breed here in Oman,

making the country's beaches

one of the most important nesting sites in the world.

The juvenile Green sea turtle now has company.

Despite being mostly solitary,

aggregations of juveniles

are not uncommon in prime feeding grounds.

Like all reptiles,

the sea turtle breathes air through a pair of lungs,

so it must head to the surface to breathe.

How often they come up

depends on how active they need to be.

Sea turtles can spend

as little as three per cent of their time

at the sea surface.

These short bursts of breath

give the Green sea turtle enough oxygen

to hold it under the water for up to five hours.

This incredible breath-holding ability

is largely due to an extremely slow metabolism.

This enables the sea turtle to release oxygen very slowly

from large stored reserves in its blood and muscles.

Their lungs are specially adapted

to cope with high pressure under water,

enabling them to dive at depths of up to 360 feet.

A resting Green sea turtle can even conserve oxygen

by slowing its heart rate

to just one beat every nine minutes.

But these active youngsters show no sign of slowing down.

Along the Ras Al Jinz beaches,

strong summer winds cause turbulence

in the Arabian Sea.

Concealed amongst the waves,

a sea turtle appears at the surface.

This is not one turtle...

..but two.

A male has hold of a female.

Waves batter the couple as they mate just offshore.

Closer to the beach,

a second pair struggles to stay together

against the force of the breaking waves.

The male hooks onto the female's shell

using a long claw on each of his fore-flippers.

As he desperately tries to cling on,

the claws may inflict damage

to the soft flesh around the female's neck.

The pair eventually separates,

either by choice or by the force of the waves.

The female will mate again with multiple males

to increase genetic diversity and for sperm storage.

The females now wait offshore until darkness falls

and the nocturnal nesting begins once more.

Further north, on a handful of smaller

and fox-free beaches,

there's a small stirring in the sand.

Green sea turtle eggs, laid 60 days ago, are hatching.

Tiny baby sea turtles begin their short but epic journey

down the beach.

The hatchlings are just two inches long.

Both Green sea turtles and Hawksbills

breed on these northern beaches.

Temperature determines the hatchling's sex.

Those incubated in warmer conditions,

often nearer the surface, tend to be female.

Those developed in cooler temperatures,

in, say, deeper sand,

tend to be male.

This is known as temperature dependent sex determination

and is common to sea turtles, crocodiles and some lizards.

Unlike their mothers,

baby sea turtles alternate left and right flippers,

moving diagonally-opposite limbs together

to propel themselves over the sand.

There may be many obstacles to overcome...

..small pebbles on the sand...

..giant boulders.

As they reach the smooth, wet sand,

they pick up their pace.

The vulnerable hatchlings

instinctively head to the water,

guided by the light reflecting on the waves

and the slope of the beach.

Sea turtles usually emerge at night

to reduce their exposure to potential danger.

With no land predators on these beaches,

the youngsters risk it in the late afternoon light.

This is an extremely rare sight.

The first plucky adventurers reach the water.

This baby sea turtle must now swim for its life.

Frantic flipper movements, known as a swimming frenzy,

move it rapidly away

from the dangers of shallow water predators.

Where these hatchlings go next is still a mystery.

Somewhere out in the open ocean.

Females that survive to adulthood

will eventually return to the beaches

they were born on to nest.

Back on the southern nesting beaches,

hatchlings have a far more perilous journey ahead.

Armies of Ghost crabs patrol this shore.

They're the fastest crustacean on land,

moving at up to seven feet a second.

Foxes aside, they pose the greatest danger

to baby sea turtles.

They get their name Ghost from their pale color

and their ability to vanish in an instant.

The crabs can tunnel through the sand,

breaking into turtle nests to raid the eggs,

but are at their most menacing

when the hatchlings emerge.

Crabs will snatch up a hatchling

with their large claws.

Some will then drag their hapless victims

into their burrows.

Gulls will be ready for any latecomers in the morning.

The scene is set for a battle between predator and prey.

As darkness falls,

the females continue to come ashore to lay more eggs.

Even in low season,

up to 30 can make this important journey each night.

As they lumber up the beach to dig new nests,

life is emerging from eggs laid two months earlier.

Hatchlings often stay buried under the sand

for several days

before clawing their way to the surface.

This tiny pioneer scrambles rapidly

towards the moonlight reflected on the waves.

But a minefield of danger awaits him.

The two-inch crabs

will easily grab a hatchling their own size.

The plucky baby sea turtle evades the first.

But it's still several feet from the water.

Finally, success.

Others begin their own treacherous journeys

to the sea.

Some get a lucky break.

Others are not as fortunate.

Dodging death-traps can be a matter of luck

more than judgement.

The crabs appear to be winning.

They devour their hapless victims alive.

The odds appear overwhelming.

But hatchling survival is a numbers game.

With up to 150 tiny sea turtles per nest,

more scramble to the sea

than can be scooped up by hungry crabs.

A final hatchling embarks on its mad dash to the water.

Its brief taste of life seems over in an instant.

But this little guy is a fighter.

For those that make it this far,

their perilous journey is only just beginning.

As dawn breaks,

the hatchlings have all but vanished.

A gull picks off an unlucky young straggler.

The last of the night's nesting females

are also departing.

Those that have laid all their eggs

will start to migrate back to their feeding grounds.

Many will head to other areas around the Arabian Peninsula.

Some will travel as far as Africa, or the Maldives.

One latecomer is still hard at it.

She's laid her eggs but she still has to hide them.

With so many dangers facing her offspring,

this female takes extra time

to cover her tracks in daylight.

Females can spend up to two hours

disguising the nest from land predators.

A flesh wound beneath her shell

is likely an injury sustained whilst mating offshore.

But it will heal soon enough.

This may be her last nest of the season.

A final clutch of eggs among a possible 900

she could have laid this year.

Not all will hatch.

And of those that do, on these beaches,

less than one in 1,000 will make it to adulthood.

This female was one of the lucky ones

who survived her inaugural mad dash for the ocean,

and many years at sea since.

She was born on this beach.

Returning here to nest makes her at least 20 years old.

For years, scientists were mystified

about how sea turtles are able to find their way back

to their natal beaches.

Some travel over 1,500 miles.

Recent research reveals that sea turtle hatchlings

may use tiny magnetic particles in their brain

to imprint on the magnetic field

around the beach they're born on.

They may use this unique signature

to find their way back as adults.

If a nest site worked for her mother,

it will probably work for her.

90 per cent of Oman's female Green sea turtles

lay their eggs on the beaches around Ras Al Jinz.

This mother's efforts,

and those of all the nesting females,

mean they have done as much as they can

to secure the legacy

of Arabia's Green sea turtles.

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