BBC Two: Mountain Gorilla

In the heart of Africa, straddling the borders of Rwanda, Uganda and Congo

lies a remarkable mountain kingdom.

It's home to the world's last 700 mountain gorillas.

For over 50 years, they've been caught in the crossfire

of a brutal civil war, fuelled by an ever-increasing human population.

Yet still they survive, under constant surveillance

from a dedicated group of people.

A species in intensive care.

Our cameras have been given privileged access

to these amazing aniımals, revealing their secret lives.

We'll experience the challenge of keeping an extended family together,

the joy of growing up wild in a rainforest playground,

the love of a father for his abandoned child.

And above all,

the extraordinary battle to save one of our closest relatives.

For a million years, the Virunga Volcanoes

have dominated the heart of Africa.

A volatile presence in a volatile region.

On their lush slopes, nourished with centuries of volcanic ash,

lives the world's largest single population of mountain gorillas.

Since Dian Fossey started her pioneering research

here in Rwanda over 40 years ago,

they've become one of the planet's most cherished animal communities.

April is a dangerous month in the Rwandan Virungas.

The long rains arrive, and the gorillas head down

into the bamboo zone on the very edge of their protected area.

It can be a perilous journey.

The bamboo contains illegal snares set for forest antelope and pigs,

but potentially lethal for gorillas.

It's a worrying time for research scientist Felix Ndagijimana,

who has trekked through the mist to a height of 4,000m.

Continuing Fossey's work, Felix watches and records

every detail of the gorillas' lives so they can be effectively protected.

Today he's on the trail of silverback patriarch Cantsbee...

...the leader of the biggest gorilla family in the world.

This 46-strong group contains female consorts, junior silverbacks,

adolescent blackbacks...

...and a tiny newborn baby,

Jjust hours old.

At 32, Cantsbee is one of the most successful silverbacks recorded

since the research programme started in 1967.

He was even named by Dian herself.

Everybody thought that Puck, the mother of Cantsbee, was male

until the day she gave birth.

And when they told Dian Fossey, she sald, "It can't be."

So, from that day on, the name of the infant - Cantsbee.

Three decades on, the bloodline continues.

The clouds are building.

Soon Felix will follow the family on the difficult journey

down the slopes towards the bamboo, recording every move they make.

This privileged insight into their world is possible

only because of Fossey's pioneering work With a process known as habituation,

in which humans spend more and more time with the gorillas

until they're completely accepted.

40km north of the Virungas lies Uganda's Bwindi Impenetrable Forest.

It's home to the rest of the world's mountain gorillas...

...and to a scientist carrying the work of Dian Fossey into new territory...

„..American Martha Robbins.

Bwindi contains only 300 mountain gorillas,

and there are another 380, 400 in the Virunga Volcanoes.

We could put the entire population of Bwindi onto a jumbo jet.

It might be difficult to get them onto a jet, but...

And when you think about how few there are,

every birth really does matter, and every gorilla is very important

to maintaining this very unique, special population.

Like Fossey in Rwanda, Martha has carefully habituated

mountain gorillas to her presence.

Now, after a dozen painstaking years,

the 14 anımals in her research group trust her completely.

At the moment, she's particularly interested

in a 15-year-old junior silverback, Marembo,

an ape at a crossroads in his life.

Marembo's really at that age where he needs to start being

a big, mature silverback, but at the same time, he still likes to play.

One of the things that's really nice when you see gorillas

of very different age playing

is that the older ones really temper themselves down.

They'll play quite gently with the younger individuals.

Marembo isn't a child any more.

For several weeks, he's been spending more and more time alone.

He seems ready to break from his family and try life on his own.

But it's a big decision.

And like a human teenager leaving home for the first time,

he feels torn.

The Rwandan town of Ruhengeri at the foot of the Virunga Volcanoes

is the centre for all gorilla operations.

The National Park headquarters is here.

And the Karisoke Study Center...

...g hive of activity for trackers, field staff

and research scientists like Felix.

It's also the headquarters of the Mountain Gorilla Veterinary Project...

...g team of skilled specialists closely monitoring

the health of every known gorilla.

Their work extends across the three countries

that share the world's last 700 mountain gorillas.

On the Rwandan side, the biggest priority is little Umoja.

She's a small three-year-old female

and never strays far from her father, Kwitonda,

one of the oldest silverbacks in the National Park.

It's a touching relationship,

but the youngster's life hasn't been easy.

Recently, as Kwitonda tried to prevent a rival male from stealing his females,

Umoja was caught in the crossfire and badly injured.

Her life was saved only by the timely intervention of vet Magda Braum.

Here was Umoja, with a badly injured wrist,

and intestines are hanging out of her tummy.

She was bitten and she was thrown high in the air,

fell down, was bitten again.

So they were pretty sure that she was dead.

Magda operated on the spot, and Umoja was returned to her mother,

who gently nursed her back to a fragile health.

Because what we've done was important, but I think

without what she has done, there was absolutely no chance of surviving.

But this wasn't the end of Umoja's problems.

Before she'd completely recovered,

her mother deserted the group for a rival silverback...

...leaving Kwitonda as Umoja's sole carer.

A female gorilla would normally give round-the-clock care

to her offspring for up to five years.

This is a big job for the male.

The gorilla vets and the National Park team

are now keeping an intense watch on the abandoned infant and her father.

They know that as the rains arrive and the nights become colder,

she'll miss the warmth of her mother.

In the Virungas of Rwanda, the world's largest group of mountain gorillas,

led by silverback Cantsbee, are heading down the volcano

towards the bamboo zone on the edge of their protected area.

As the clouds roll in, it will bring rain, prompting fresh shoots on the bamboo.

But there are dangers here.

Beyond the bamboo is the most densely populated area in Africa,

with an average of 350 people per square kilometre.

The gorillas are encircled by humanity.

The two forest islands of Bwindi and the Virungas

are under enormous PFreSSure.

When the gorillas get close to people, they're exposed to human diseases...

...and the risk of being caught in an illegal snare.

Gorillas go to the bamboo zone twice a year,

at the beginning of the rainy seasons, so In April and in December.

So this is when they leave other areas where they range

to feed on the bamboo, which is one of their favourite foods.

The gorilla patriarch must be careful.

The danger from undetected snares ils high.

With 46 gorillas to protect, he's got a tough job on his hands.

He has support from four junior silverbacks...

...and eight feisty younger blackback males...

„..Not all of whom can be trusted.

This young blackback is breaking the rules.

It's a privilege normally reserved for the dominant silverback.

But Cantsbee needs fo reward his lieutenants,

and sex is a powerful incentive

to keep them in line and the group together.

The dominant silverback needs to concentrate on the dangers

from the outside world.

The family are entering the bamboo zone...

...and they have company.

Fortunately, in this case it's the National Park's anti-poaching patrol,

acting on a Hip-off that snares have been set in this area.

Most of the snares are actually found in the bamboo.

They are very, very difficult to spot.

They have to, you know, look very carefully to find these snares.

We destroy around 1,000 snares each year.

People come in the forest and set snares for other animals,

for buffaloes, for antelopes, but gorillas end up getting caught in those snares.

Poaching has always been a problem in the Virungas.

In 1977, Dian Fossey's favourite gorilla, Digit,

was murdered and decapitated by poachers as he tried to defend his family.

Things have improved since then, but poaching is still a big problem.

In Uganda, teenage silverback Marembo and most of his group

have moved into the trees.

Unlike their cousins 40km away in Rwanda,

these gorillas spend a lot of time up here,

and it's where they find much of their food.

That means climbing is an important skill to master.

Junior silverback Marembo is on the edge of the family,

his eyes fixed on the dominant male.

In a group of this size, there's only room for one leader...

...and a teenager can feel increasingly marginalised.

Males have sort of two strategies as to how to become the leader of the group.

They can either leave the group and become a solitary male

and try to attract females and form their own group, or they'll try to become

dominant from within the group, where slowly, over time,

they'll try to outrank the dominant male.

Mating rights are monopolised by the dominant silverback...

...and since the leader has no real need for him in the group,

Marembo isn't permitted access to receptive females.

It's quite likely they'll mate maybe once every hour,

once every hour and a half, two hours, today.

IF the junior silverback wants to pass on his genes,

his best option is to leave.

In Rwanda, abandoned infant Umoja stays close to her father, Kwitonda.

Since her mother left the group for another male,

she's become completely dependent on her remaining parent.

Kwitonda Is an experienced silverback,

but he's relatively new to Rwanda, having crossed the border from Congo

with his family six years ago.

The land he left behind has seen much strife for gorillas and people.

In 2007, a gorilla family was brutally murdered here...

...their deaths almost certainly a result of the fierce competition

for the forest's precious resources.

Many of Kwitonda's family bear the scars of war.