Nature

In South Central China

at the Wolong Panda Center,

there's a young cub that has never tasted freedom.

His life is about to change.

This cub is special...

chosen for the wild.

But first he needs to discover

what it means to be a wild panda.

And his training team has to discover more

about how pandas are brought up in the wild.

Even with teams of committed rangers and researchers

and radio collars to track them,

the released pandas have often struggled or even died.

Now there are just three years

to prepare him for a panda's life in the wild.

A giant panda is carried up

into the mountains... like an emperor.

Since 2003,

nine pandas raised in the Wolong Panda Center

have taken this journey to be released.

Even with teams of committed rangers and researchers

and radio collars to track them,

the released pandas have often struggled or even died.

A trickle of information back...

tells of violence and hardship.

Six mountain ranges draped in bamboo

that's nine feet tall and impenetrable.

Over a vast area, hidden, scattered,

are only 2,000 wild pandas -- all there are.

Filming them was thought futile.

Even just finding one is almost impossible.

Almost impossible.

Giant pandas are bears,

relatives of grizzlies, black, and polar bears.

But, surprisingly, pandas don't hibernate,

even though the temperature can drop

to 30 degrees below freezing.

They have to keep feeding.

Bamboo provides only just enough energy,

but it's almost all they eat for 14 hours a day.

To help it down, they roll the leaves into a sausage,

with the help of a boneless pad from their wrist,

the panda's unique "thumb."

Males start to search for females in spring.

Courtship, mating, and raising cubs in the wild

is mysterious --

barely seen before and never filmed.

Wild pandas can be dangerous

with huge claws powered by muscular front legs.

Many faces are scarred by old battle wounds.

The pandas here in the mountains are totally wild.

None have been released or have radio collars here.

That makes it harder,

but it is the best chance to understand truly wild pandas.

In South Central China are around 40 reserves.

They stretch across 300 miles of mountains.

The cub's story starts at the Wolong Panda Center.

For the pandas growing up here, it's a five-star hotel

compared to living in the mountains above.

There's the "all you can eat" dining...

and the kindergarten.

The best part is hanging out with friends and family.

Giant pandas in the wild are solitary,

but in captivity, they are social.

It's not known why --

maybe generations of living with people

or a quirk of evolution perhaps --

but they are natural clowns.

Ah, this is the life! It's... exhausting.

Looking after 40 or so pandas in Wolong are 85 staff

with 59 enclosures, a research lab,

and a panda hospital.

It's almost impossible to breed pandas.

Decades of matchmaking in zoos failed.

Artificial insemination was the breakthrough.

Our mother-to-be is pregnant, 5 months in, and about due.

Head keeper Wu Daifu is feeling the pressure.

The camera's ready to capture a rare moment.

There.

The cub is born...

blind, deaf, and hairless.

It weighs just 3 1/2 ounces.

This cub is special...

chosen for the wild.

Like all bears, pandas have tiny, helpless young.

The cubs are the smallest newborns

of all placental mammals relative to the mother's size.

They'll both be isolated in a large enclosure

to encourage his natural instincts.

She's been chosen for being

a protective, instinctive mother,

but she was born and brought up in captivity.

She knows nothing about living in the mountains.

He needs to discover what it means to be a wild panda.

Different altitudes have different species of bamboo,

so pandas have learned to move around

to find the best kinds for their diet.

They're not the only ones on the move.

Takin, giant golden goats that look like wildebeest,

move up and down the mountains to feed on summer bamboo.

There's a world of other animals.

Golden snub-nosed monkeys,

like elves with blue faces, live here.

These mountain monkeys are unusual and rare.

There's another type of panda -- a red panda.

They're not actually related to giant pandas

but part of the raccoon family.

In summer, pandas also come up here to avoid overheating.

But water is harder to find near the peaks.

Even above 6,000 feet, pandas can suffer from heat stress.

As the climate shifts,

so will the best bamboo, trees, and water.

Animals will need more space to find new homes.

High in the mountains, autumn comes early.

It's a bounty of colors.

In 1985, researchers found a hollow

that had been used as a wild birthing den.

What they learned became another lesson for the cubs

they were training for the wild.

In the wild, sometimes the mother

will not leave the den at all.

She stays with the cub

and is forced to fast for the first month or so.

Like any bear milk, hers is among the richest in the world.

It carries more antibodies than any other animal's

because the cubs are so underdeveloped and vulnerable.

He's a month old now.

He's grown from 3 1/2 ounces to 4 1/2 pounds.

And when he's awake, he can see and hear.

Over 10 years of motherhood,

she can only have three or four young.

That is the lowest potential birth rate of any mammal.

Autumn brings a dramatic change of season.

The monsoon from India and Myanmar

is channeled up valleys through the Himalayas

as far north as the Qinling Mountains.

It arrives as mist and carries rain or snow.

Pandas -- mothers and cubs -- come down the mountains

to spend the winter in the valleys.

The mist settles as low cloud, hiding the pandas' wild world.

At the base of the mountains,

the Wolong Panda Center is milder.

It's November, and he's now three months old.

An animal's personality develops early.

Emotional responses like courage or fear

can be affected by as little as a single incident

in the first few months.

He's starting to get curious but struggles to escape.

His mother leaves more regularly to feed herself now.

So, at last, he's able to explore his world.

Pandas have a phenomenal sense of smell,

better than a bloodhound.

Their hearing is good, too.

Eyesight, less so.

Strange...

A weird-looking panda.

Head keeper Wu Daifu and the team

have to become pandas to visit our youngster.

They even spray themselves with panda pee.

The last thing these surrogate mothers

want to be seen as or smell like...

is human.

It's worth being a bit ridiculous.

Contact is kept to a minimum and always in disguise.

But today they have to do a health check.

This is the only contact he'll have

with anyone other than his mother.

Being able to film this is a rare privilege.

Size, weight, teeth, and claws. All healthy.

His life is more natural here

than being with the other cubs all playing together,

but is it anything like being a wild panda?

The training team are hoping to discover more

about how pandas are brought up in the wild.

In the meantime, Operation Undercover is successful.

Totally fooled.

Well, maybe.

It's winter back in the mountains

and 30 degrees below freezing at night.

In the high summer feeding grounds, the snow just piles up.

But in the deep valleys below 3,000 feet,

there is life.

Bamboo is evergreen.

The wild parents feed while the cubs remain hidden.

By early March, low-lying areas are beginning to thaw.

Over the next month or two,

the animals start to head back up the mountain.

The breeding season, "the rut," is about to start,

and males head to claim the best areas.

Single females follow.

Mothers have a more difficult decision.

The mating grounds are dangerous,

and females with young seem to go into hiding.

Takin, the golden wildebeest...

and golden monkeys follow.

This year, they are shadowed

by the first month-long expedition from Wolong.

The team is on a key mission.

As part of the reintroduction process,

the head keeper, Wu Daifu,