In the heart of Asia lie vast arid lands.
They stretch from Arabia in the west to eastern China.
These deserts and dry grasslands are so hostile,
they push life to the limit.
The Gobi Desert in Mongolia.
A punishing land.
Half a million square miles of emptiness.
Yet it is home to one of the rarest animals on Earth...
..the Gobi Bear.
Fewer than 40 are known to exist.
They are so rarely seen, they were thought to be a myth.
Life here, in the arid heart of Asia...
..has turned them into one of the toughest animals on Earth.
This is one of the last remaining Gobi Bears...
..fewer than ten of which are female.
They are clinging to existence.
In Mongolian, Gobi means "waterless place".
And therein lies the bear's greatest challenge.
Sources of water may be 100 miles apart.
They face a gruelling trek across the desert.
Theirs is a solitary life.
But there is a place where they go to connect with each other.
These are ancient poplar trees.
They use their extremely long roots to collect
water from beneath the desert floor.
There is nothing here for the bears to drink.
But these trees are still important to them.
As they rub, they leave behind a unique scent...
..a message to other bears, to say they've been here.
But with so few left, it may be months before somebody comes by.
This could be the closest they ever come to meeting another bear.
In the search for water,
the bears follow well-trodden paths across this vast desert.
And this is why.
An oasis...
..a freshwater spring fed from deep underground.
At last, a drink...
..and a refreshing dip.
The oases are a lifeline for the bears...
..particularly for those that are extremely precious.
A Gobi Bear cub.
The future of these bears rests on just a few individuals.
But this young one is a symbol of hope for the Gobi Bear.
To escape the heat of the day, most animals in the Gobi emerge at night.
But they don't all go on long treks across the desert to find water.
In fact, some don't drink at all.
A Long-Eared Jerboa.
This curious creature looks like a mixture of other species.
It has a tail shaped like that of a lion...
..ears like those of a rabbit...
..the snout of a pig...
..and the legs of a kangaroo.
But those are features that makes it the Gobi's most deadly hunter.
A beetle...
..with a subtle scent.
It's a good start, but it will need more,
not to satisfy its hunger, but its thirst.
That is because Long-Eared Jerboas get all the water
they need from what they eat.
GRASSHOPPER CALLS
A juicy grasshopper.
To track it down, it uses another sense.
No other animal has longer ears relative to its body length.
With hearing so acute,
even the slightest twitch will give the grasshopper away.
Don't move now.
For a little jerboa, all this action is tiring.
But it's summer and the nights are short.
Jerboas must work fast to get all the food they need.
A moth.
Catching it in near total darkness will require
all the jerboa's skills.
Nearly!
One last big jump should do it.
That's plenty to eat and drink.
Jerboas must get back to their burrows before dawn brings
the scorching heat of the day.
The Gobi Desert is one of the most oppressive places on our planet.
And west of here, in China, lies the Taklamakan...
..so hostile it's been called "The Sea of Death".
But on the southern edge of Asia's arid heart
lies a desert that is full of life.
The Thar, in India...
..the most densely populated desert on Earth...
..home to 20 million people.
Surprisingly, it is also filled with wildlife.
Demoiselle Cranes.
They have migrated thousands of miles to get here,
from their breeding grounds in the north.
In the village of Khichan,
the local Jain community have a spiritual connection with animals.
Jainism teaches that the path to enlightenment is through
caring for all living things...
..so they welcome the cranes with open arms.
Every day, the local people put out one ton of grain.
This act of kindness has created one of the greatest
bird spectacles on Earth.
30,000 cranes fill this little desert settlement with life.
The villagers of Khichan have become their guardians.
This was once no more than a stopover
on the cranes' migratory route.
Now, they spend their entire winter here.
These deserts offer little for the people live in them...
..so for them to give so much to the cranes is astonishingly generous.
On the edge of the Thar Desert lies a parched scrub forest.
It provides quiet sanctuary, away from the hustle
and bustle that surrounds it.
This is the last refuge of a very special big cat...
..the Asiatic Lion.
They were once found from here to the Middle East...
..but now this small corner of India is the last place on Earth
where they exist.
Like their African cousins, they live in prides...
..though theirs are somewhat smaller.
The cubs have a lot to learn
if they are to survive here.
They still rely on their mother's milk, but it is drying up.
And the adults haven't made a kill for over a week.
The baking heat has stripped the trees of their cover...
..making hunting particularly tough.
A chital deer would make a valuable meal.
It's time for the cubs to learn how to hunt.
With the forest so dry, she can't afford to put a foot wrong.
Just a bit too keen.
BIRD CALLS
The next lesson for the cubs is to always keep your eyes and ears open.
The calls of a hungry crow are worth tracing.
LION GROWLS
A leopard is no match for a pride of hungry lions.
With her milk flowing once again, the cubs can now suckle.
These lions are clever opportunists,
a way of life the cubs need to quickly learn.
To the west of India lie some of the most inhospitable
deserts on the planet.
The Lut Desert, in Iran...
..the hottest place on the Earth's surface...
..a blistering 80 degrees Celsius.
Sustaining life in this otherworldly place is all but impossible.
South of Iran, in Arabia, lies a vast sea of dunes...
..the Rub Al Khali, or Empty Quarter.
This is the largest expanse of sand in the world, extending over
an area greater than the size of France.
This desolate land is entirely shaped by wind.
But the shifting sands help to create
life beyond the borders of this desert.
Sand from the Rub Al Khali is blown into the shallow
seas of the Persian Gulf...
..where it creates desert islands.
Seemingly lifeless, this island is host
to an extraordinary gathering...
..60,000 Socotra Cormorants.
They have come here to raise a family
out of the reach of predators.
Just over a week old, this chick is constantly hungry.
Both parents take turns to fetch food for it.
The Persian Gulf is fertilised by nutrients that accompany
the wind-blown sand...
..and turns its waters into a rich fishing ground.
But raising chicks in the desert is not easy.
They must be protected from the searing heat.
Yet the desert isn't their biggest threat.
There is danger within...
..gangs of juveniles.
Cormorants feed their young as frequently as possible,
until they reach adult weight,
and then abandon them.
This creates mobs of starving juveniles.
Their parents return with fish for their chicks.
But the juveniles have other ideas.
They mug the adults for their catch.
When parents are unable to get back to the nest with food,
their partners face a dilemma.
Stay, and their chicks may starve, or go to find food
and leave them exposed to danger.
The gang is still ravenous.
Their hunger drives them to become...
..cannibals.
Without food, chicks get weaker and weaker.
Parents have no choice but to leave.
CHICK CALLS
All alone, but calling for its parents may be a very bad idea.
Saved just in the nick of time.
And food finally arrives.
As the chicks grow,
they will eventually be abandoned by their parents.
So they, too, may have no choice but to become cannibals.
Many of Asia's deserts have existed for millions of years.
But here also lies the youngest desert on Earth.
On the border of Kazakhstan and Uzbekistan lies the Aralkum.
Shipwrecks in the desert are evidence of what this used to be.
Until recently, the Aralkum was the Aral Sea,
the fourth largest lake in the world.
But in the 1960s, the river that fed this inland sea was dammed
upstream to irrigate cotton fields.
Sand that once lay on the sea floor
now gets whipped up to form towering sandstorms.
These storms can travel eastwards across Asia.
Each spring, they overwhelm whole cities...
..covering them in a choking blanket of dust.
In China, these devastating storms are known as Yellow Dragons.
As the world warms, so Asia's deserts are expanding.
They are spreading into another great arid land...
..the Eurasian Steppe,
the largest grassland on Earth.
It stretches from Hungary in the west...
..to China in the east...
..one-fifth of the way around the world.
The Steppe is semi-arid, getting just enough rainfall for short
grass to grow, but not enough to sustain tall grass or trees.
So, here on the plains of Mongolia, there are very few hiding places...
..a problem this hungry Pallas's Cat needs to solve.
There are plenty of tiny rodents here.
The problem is getting close enough to catch them.
No easy task on an open plain.
But she has a way of dealing with that.
Time for a game of Grandmother's Footsteps.
When her prey looks up...
..she freezes.
When it looks away, she sneaks closer.
Once within striking distance...
..she performs her greatest trick.
Her waggling tail seems to mesmerise her prey.
It doesn't come without a fight.
She will need to do this dozens of times a day...
..because she has five kittens to care for.
They're barely two months old and have boundless energy.
With a meal delivered, she tries to get some rest.
But it's not long before she's off hunting again.
A mother's work is never done.
The arrival of winter transforms the steppe.
Temperatures fall to minus 40 and it's now stripped of grass.
Mongolian Gazelles are the great nomads of these plains.
Their ancient annual migration takes them south in search of food.
Most of these hardy creatures will survive the winter...
..as long as their migration isn't stopped.
This train is part of the Trans-Siberian Railway...
..an immense line, over 1,000 miles long...
..connecting Russia to China...
..splitting this great grassland in two.
The railway is fenced on both sides by razor-sharp barbed wire.
It's there to keep livestock off the tracks.
But to keep moving south, gazelles must risk their lives
and get through these fences.
TRAIN SOUNDS HORN
Many gazelles don't make it.
For those caught between the two fences, there is yet more danger.
A feral dog patrolling the tracks in search of prey.
The fence seals the gazelle's fate.
For those which escape, the migration continues.
But for many others, it ends here.
Of all the large animals that live in this arid grassland,
perhaps the most well adapted are the horses.
In the 13th Century, Genghis Khan conquered most of Asia on horseback.
But there is one kind of horse he never tamed.
These are Takhi...
..the last truly wild horses on Earth.
They live in small family groups.
It's springtime here in Mongolia and there are new foals to care for.
Grooming reinforces their family bonds...
..and they will come to rely on the strength of these
bonds for their survival.
As the sun begins to set, the atmosphere changes.
The horses are on high alert.
DISTANT HOWLING
Wolves roam these wild lands.
In the blackness of night, a wolf has the upper hand.
The mares keep their precious foals close.
It's they that the wolf is after.
HORSES WHINNY
With the element of surprise gone,
a lone wolf will not be able to make a kill...
WOLF HOWLS
..so it summons reinforcements.
The pack aims to cause panic and grab a foal in the confusion.
The wolves close in...
..but the horses fight back.
The foal is safe,
for tonight.
By sticking together,
these horses deal with the many challenges of the steppe.
Life in the arid heart of Asia demands extraordinary resilience.
And the animals that live here are among Asia's great survivors.
The Asia team are heading to one of the remotest
places on the planet to film the world's rarest bear.
Helping in their search is Gobi Bear specialist
Dr Odko Tumendemberel.
I'm a biologist, and I have been working on Gobi Bear over 15 years.
I love Gobi Bears because they are very unique animals.
It's just amazing that they can live here, surviving in this desert.
Odko's knowledge and experience will be vital if the crew are to succeed.
Three days and 1,000 miles of driving later,
they arrive at base camp.
To stand any chance of filming one of the most elusive animals on
Earth, cameraman Joe Riis needs to set up remotely triggered cameras.
Mongolian biologist Nassa helps him find the right spots.
Looks like a bear print right there.
With positive signs of bears,
Joe can get to work setting up the cameras.
Beautiful, beautiful!
Whilst Joe and Nassa are out rigging the cameras,
Odko is busy with her work.
She wants to understand how the bear population has changed
since it was last measured in 2017.
The last estimate was 32 individuals.
Since it's a very small population,
we need to find a way to increase population size.
Whether Odko discovers an increase or decrease in bear numbers
will help decide the conservation strategy.
We need to understand how many there are,
and then find a way to protect these few bears.
To determine the size of the bear population, Odko needs their DNA.
She gets it at these feeders.
To help the bears survive the leaner months,
the national park puts out extra food.
When the bears visit,
they inevitably leave a hair sample behind.
Using this method, Odko has "met" virtually every surviving
Gobi Bear through their DNA.
With the last camera trap in place, it's now a waiting game for Joe.
Looks nice.
Not just a few weeks, but months.
When Joe returns, he has no idea if a bear has been filmed.
No bears.
Nothing.
No bears. The lack of bears is concerning for Joe,
but also for those, like Odko, who are trying to save them.
I am worried - we may not have enough time,
but we can try our best to conserve what we have here now.
And today, the need to protect the bears has never been more critical.
Even here in this remote part of the planet, there are threats.
In the last 70 years,
average temperatures in Mongolia have increased by more than
two degrees Celsius, leading to severe droughts.
And vast mineral wealth under the Gobi leads to mining...
..which is a real threat to an animal
that relies on space and solitude.
Knowing the threats facing the bears,
the team decide to leave the area undisturbed for longer.
Oh, look, the camera's been moved, it messed with that camera too
and that one, all three of them.
There's definitely a bear here.
That's Gobi Bear hair right there, and this, is from its teeth.
Come, check this out.
Not quite the footage Joe's after, but at least he's getting closer.
I was hoping for a nice couple shots of Gobi Bears,
what we got is messed-up cameras instead.
He keeps checking the cameras in the hope the bears have left some alone.
Here comes a bear!
Yes!
Success, at last.
The bear comes in the water pool right here.
It's amazing!
It's three years of work for me. Right here.
And the news just keeps on getting better.
Joe can't wait to share the most exciting piece of footage
with the team.
Aah!
THEY CHUCKLE AND CHATTER
So, when was the last time you saw a cub?
SHE TRANSLATES: In 2015.
Wow, seven years!
It's a long time.
The team's success is reflected in Odko's study.
Early indications suggest the bear population is stable.
But with numbers still in the 30s,
the survival of the Gobi Bear is resting on a knife edge.
It's very hard to achieve the successful recovery,
but we have to keep going
and I truly hope that we can increase the Gobi Bear population.
The cub filmed by the team is a glimmer of hope.
And Odko's research will bring some much-needed attention to the
plight of the world's rarest bear.
Next time...
..meet extraordinary people...
..battling against the odds to find ways to save Asia's wildlife...
..for future generations.
Get ready. Go!