Original subtitles

For centuries, we've known Arabia

as a desolate and forbidding land.

A vast and barren desert, where little survives.

But there's one corner of Arabia

where life thrives.

A mountain range that rises dramatically from the ocean below.

Once a year, this coast undergoes an amazing transformation.

Making it home to more

wildlife than anywhere else in Arabia.

In the far south of Arabia, on the border between Oman and Yemen,

lies the Dhofar coast.

Here, beside the Indian Ocean,

a range of mountains rises 1,000 metres from the shore.

This remote region is home to an amazing variety of wildlife.

It's January in Dhofar.

The start of a year in which a team of biologists

will try to discover what makes Dhofar so rich.

Hadi and Khaled Al Hikmani

grew up on this escarpment.

Now, as Omani government researchers,

they want to find out just how many species live here.

Using remote cameras, triggered by an infrared beam,

they hope to film as many animals as they can,

including one so rare,

locals call it a living ghost -

the Arabian leopard.

These cameras will run throughout the year,

opening a window onto the private life

of Dhofar's most elusive animals.

But not all the creatures here are so shy.

A female Verreaux's eagle is on patrol.

She's a fussy eater.

A Pygmy owl won't do.

Her diet is so specialised,

she needs a partner to help capture it.

They're searching for a prey whose nearest living relative

is the African elephant.

The tusks are a giveaway.

A Rock hyrax.

They feed on bushes on the cliff face,

safe from most predators.

But these eagles use a tactic

rarely seen in the bird world.

They go to work as a team.

It won't be easy.

Fan-tailed ravens don't like eagles in their air-space.

This is a test of aerobatic skills.

A nesting kestrel doesn't want the eagles around either.

The eagles split up.

The female hugs the cliff edge...

..while the male soars in front of the sun...

...hiding in the blinding light.

But the hyrax have a unique blue-tinted retina

that acts like sunglasses,

allowing them to stare directly back.

They don't let the male eagle out of their sight.

But the male was merely a decoy.

His partner has already made the kill.

By working together, they've captured their favourite meal.

To feed themselves and a hungry chick,

the pair must kill over ten hyrax a week.

These little cousins of the elephant

are part of a rich food chain.

But it's not only the mountains of Dhofar where wildlife thrives.

Just offshore...

..is the Indian Ocean...

...home to one of the rarest animals on earth.

It's February and the waters

echo with a song heard nowhere else.

An Arabian humpback whale.

There are less than 100 left on the planet.

They're so special, they've become targets.

Researchers are now on the hunt for whale DNA.

The dart merely pricks the skin

and the whale barely feels a thing,

but the scientists have the sample they need.

The DNA results have revealed something amazing

about this population.

These humpbacks have not bred with any other whales

for over 60,000 years.

The last time they met with others of their kind,

sabre-toothed cats roamed the earth

and the Arabian peninsula was still joined to Asia by land.

Using underwater microphones,

scientists are recording whale songs never heard before

and think they may have discovered a new race of whales.

Perhaps the most remarkable discovery about these whales

is that they're the only humpbacks in the world that don't migrate.

All other humpbacks breed in warm oceans,

then travel to polar waters to feed.

Only cold water carries the nutrients they need.

But in 60,000 years,

these humpbacks of the Arabian Sea have never left.

For these giants to survive here year-round,

cold water full of food must arrive from somewhere.

This holds the key, not just for the humpbacks' survival,

but for all life in these coastal mountains.

But for now, these waters remain warm and barren,

just like the Arabian coastline.

It's April,

and not a drop of rain has fallen in the mountains for over six months.

Arabia is so dry that

not a single river flows permanently

on this entire sub-continent.

The daytime temperature reaches 45 degrees Celsius.

Shamal winds from the north

bring no relief for those living in the Dhofar mountains

Hadi and Khaled's families have herded goats here for generations.

They are Jabali people, originally from Africa.

At this time of year, they travel far and wide

to find grazing for their animals.

Hadi and Khaled's village sits on the top of the Dhofar escarpment.

Khaled's mother carries a weapon to protect her flock.

In these remote mountains,

their livestock are exposed to predators.

And in the heat of early summer,

it seems the predators are becoming more bold.

A neighbour has called for Khaled's help.

As a government researcher,

he's first on call when wildlife comes into the village.

Once a predator breaks in,

there's usually only one outcome.

The teeth marks suggest a large carnivore.

Losing one goat is bad.

The loss of eight goats will hit the family very hard.

In the past,

Khaled's village would've set out to hunt this killer.

Now Khaled wants to hunt for answers.

He suspects the killer will return to the scene of the crime.

He sets a trap with remote-control cameras.

An image of the culprit may help efforts to compensate farmers.

Khaled is a goat herder himself, as well as a biologist.

On the one hand, he hopes to protect rare carnivores in these hills.

On the other,

his family rely on him to keep their goats safe.

It's a clear, starry night,

but there's no moon.

When the village lights go out,

it's pitch black.

Only by using a special heat-sensitive camera

can we witness the night's drama.

The thermal camera shows a cold, dark night

dotted with warm-blooded mammals.

To the human eye, there's nothing but darkness.

The night-watchman can't see the predators gathering.

Arabian wolves.

The Jabali often hear wolves,

but no-one knew they came so close to the village.

They have rarely been seen in groups bigger than four.

This pack numbers 12 individuals,

the largest ever recorded -

a clear sign there's more food for them

in the Dhofar mountains

than anywhere else in Arabia.

But they may not be the only ones feasting tonight.

The party's over.

There's only one beast not afraid to take on 12 wolves.

A female striped hyena moves into position.

The scout can't see the intruder in the darkness.

And the hyena makes her move.

One-on-one, a wolf is no match for a hyena.

She's not quick, but she's immensely strong.

With one bite, she could crush a wolf's skull.

In the darkness, the wolves lose their nerve,

and the thief helps herself.

Dhofar is one of the few places on earth

where wolves and hyenas come face-to-face.

But it won't be the rivalry between the two species

that affects their survival.

It's the conflict between predators and Jabali farmers

that Hadi and Khaled are most concerned about.

At dawn, Hadi and Khaled

download their cameras.

The villagers heard wolves,

but the appearance of a striped hyena is a surprise.

The video will be a useful first step

in resolving the locals' conflict with predators.

If they can identify individual culprits,

it may prevent indiscriminate revenge.

The cameras not only capture the behaviour of large carnivores,

they shed light on some more obscure night hunters.

Honey badgers usually forage alone.

In the mountains, it appears they roam in packs.

And then a sight of one

the rarest animals in the world...

an Arabian leopard.

These are the shots they're after.

They set out to check their cameras,

covering over 100 miles of the Dhofar mountains.

The cameras are capturing a rich food chain, from top to bottom.

Hadi and Khaled's results are revealing a remarkable web of life.

But what is the one thing that connects all this wildlife

and makes the Dhofar mountains so rich?

The answer lies in their position, right by the Indian Ocean.

It's May, the hottest month of the year.

And one predator knows that Dhofar's riches come from the sea.

An Arabian fox.

Tonight, this predator from the mountains

will come face-to-face with a creature from the Indian Ocean.

An ancient mariner has brought treasure ashore to bury.

An animal that has changed little since the time of the dinosaurs.

A female green sea turtle.

She is here to do what her ancestors have done

for over 100 million years.

With her hind flippers,

she carefully digs a hole of just the right depth.

Her tears excrete salt and keep sand out of her eyes,

as she lays over 100 eggs.

This is the only activity that will ever bring her ashore.

And it has not gone unnoticed.

Once her eggs are buried, her job as mother is done.

She returns to the sea for another year...

but it's her buried treasure that the thief is after.

An egg is a nutritious meal for this skinny fox.

A second female arrives to take her chances.

Two more, and the turtles are improving their odds.

But the fox isn't alone either.

These foxes can dig up eggs quicker than turtles can bury them.

Theirs is the most specialised diet of any fox.

90% of everything they eat in their whole life will be turtle eggs.

There is little the turtles can do to defend their clutch,

but they have one strategy the foxes can never match.

Numbers.

Each year, over 10,000 female turtles

lay over three million eggs along this coast.

It would take the foxes over 50 years

to eat this season's batch alone.

Riches from the Indian Ocean are feeding the Arabian land.

Ultimately, all of Dhofar's riches are sustained by the sea.

And the sea itself is undergoing a radical transformation.

Warm surface waters are being dragged away,

sucked to the north by the mighty Indian monsoon.

An oceanic vacuum is created,

and something must fill the space.

Cold water wells up from the depths,

bringing nutrients from the sea floor with it.

Chilled water also holds more oxygen,

and more oxygen means more life.

As the temperature drops, these seas are transforming

into some of the richest in the world.

Microscopic plankton flourish, and an explosion of life begins.

Fish from every corner of the Indian Ocean have come to feed.

Fusiliers.

Blue triggerfish.

And graceful devil rays.

Some have travelled from as far as Australia to enjoy these riches.

This is why the humpbacks never leave.

They don't need to migrate to cold waters to feed.

Cold water comes to them.

And this bounty

attracts one species that arrives not in thousands,

not even millions.

The Indian oil sardine arrives in billions.

A single shoal can be over three miles long.

By moving in unison, they confuse predators.

Rays are too slow.

Socotra cormorants struggle to pick a target.

But synchronised swimming won't protect them

from the ocean's most voracious predator...

man.

The arrival of the sardines means the Jabali mountain-men

become part-time fishermen.

Over half a million tonnes of fish will be brought in.

While the cold water is a boon for sardines,

it's brought hard times for the resident corals.

The water temperature has dropped ten degrees in a matter of weeks.

Tropical species are now being overrun by a cold-water bully.

Kelp grows up to 50 centimetres per day, smothering the reef.

Most warm-water residents have no choice but to stay put.

A lone clown-fish. He has made his home in a small anemone.

A tiny tropical island in a sea that's turned cold.

For these tropical species, their world has been turned upside down.

The Indian monsoon has struck the Dhofar coast.

The monsoon brings with it the magic ingredient

that sustains life in these mountains.

The chilled waters cool the air above them.

Creating clouds which pour inland.

The air is so humid,

the clouds need only touch an object to release their moisture.

The mist is about to work miracles.

Condensation settles on everything.

Some homes are water-logged.

A female golden orb spider.

Her oily exoskeleton helps keep water out,

but shedding the droplets isn't easy.

Her male is one-tenth her size, and even less skilled at drying off.

Through June, the monsoon builds

into one of the biggest weather systems on earth.

Cool ocean winds meet warm Arabian air

creating vast cloud banks.

The Dhofar escarpment provides the perfect barrier...

trapping the clouds and hijacking their precious moisture.

There is more rainfall here than the rest of Arabia combined.

In July, the monsoon's blanket rests heavy on the land,

and mist turns to rain.

Plants grow on other plants to gain height

and steal as much moisture as they can.

Even the animals here have

amazing methods of catching rain.

The Arabian chameleon absorbs water directly through his skin.

And the head-shield funnels raindrops to his mouth.

Perhaps a little too much, today.

Down below, the ground is now so sodden

that others are emerging from months underground.

Snails have been avoiding the heat,

but now conditions are just right, and there's lots to catch up on.

Snails are seeking other snails.

And the tree trunks have become singles bars.

Within a few short months,

the monsoon moisture has worked its magic...

...turning the once-parched hills into a green paradise.

This is a side of Arabia that few of us could imagine.

A practically hidden ecosystem springs to life.

The Dhofar coast has become the jewel of Arabia.

By August, the earth cannot soak up any more water

and the Dhofar mountains drain what they can't hold.

When creeks turn to rivers, some opt for a spot of fishing.

There are beginners...

and experts.

A few fish have clung on though the dry season in tiny pools,

and now their numbers explode.

Each pond contains species different to the next,

some found nowhere else on earth.

Millions of litres of water have permeated the mountains,

a treasure that will trickle out all year round

in the form of springs, sustaining life for another year.

Many animals rely on the summer monsoon to build fat reserves

for the lean times ahead.

In the final days of greenery,

the Jabali gather their camels together

to graze in their thousands.

Hadi and Khaled continue their research through the wet season.

After a few short months, the monsoon begins to fade.

September gives way to October,

and the Arabian sun regains control.

Arabia is once again a land without rivers.

Her mountains face the Indian Ocean, awaiting next year's gifts.

By December, Hadi and Khaled's cameras have been running in isolation for a year.

Their persistence has paid off.

Their holy grail appears closer than expected.

Technology has brought them face to face

with one of the most elusive predators on the planet.

Their cameras are not only capturing images,

but the first-ever sound recordings of the leopard's mating call.

Hadi and Khaled will use this footage to raise awareness of the Arabian leopard.

With support from the Oman government, they hope to ensure

the cats' survival in these mountains by the sea.

For the Arabian leopard,

the Dhofar mountains are their last stronghold.

Caves in these cliffs

provide shelter for these secretive creatures.

For the first time ever, we have a glimpse

into the private life of these elusive animals.

And we know now that the leopards

share these mountains with some equally remarkable predators.

The story of the striped hyena is intricately linked with that of the Arabian wolf.

All these large carnivores

sit at the top of a fragile food chain.

A web of life that relies on the spectacular setting of their mountain fortress.

As long as the Indian monsoon sweeps past each summer,

Dhofar will remain home to the greatest diversity of life in Arabia.

There are less than 200 Arabian leopards left in the world.

They are critically endangered.

And yet a simple mist is all

that's needed to sustain this living ghost,

and everything that lives in these Arabian mountains.