Mountain Worlds Mexico: Earth's Festival of Life

In the heart of the Americas,

where continents collide,

there's a land full of natural riches.

BEAR GRUNTS

BIRDS CALL

HOWLING

A land of towering giants...

..scorching sands...

..and secret rivers...

..where great civilisations rose...

..and fell.

MAN WHOOPS, HORSE WHINNIES

To succeed here takes passion and spirit.

This is a country rich in colour and culture.

A festival of life.

This is Mexico.

BIRD CALLS

BIRD CRY ECHOES

In the far north-east of Mexico is an ancient mountain world...

Serranias del Burro.

It's home to an abundance of creatures.

And its most surprising resident

is the black bear.

This mother has three young cubs, just eight months old.

BEAR GRUNTS SOFTLY

It's autumn and the family needs to fatten up

before the winter hibernation.

This year, the oak trees are laden with acorns -

an important source of fat.

The bears have plenty to eat,

but their challenge here is finding enough to drink.

CATTLE LOWING ECHOES

The limestone mountains soak up the rain,

so there are no permanent streams.

Fortunately for the bears, there is another source of water.

CATTLE LOW

Serranias del Burro is prime cattle country and the ranchers provide

year-round water for their herds by tapping into underground springs.

The water tanks are a magnet for all.

Mother bear, with her young cubs, must approach with caution.

CATTLE LOWING ECHOES

Bears occasionally kill cows,

so the ranchers let their cows' horns grow long

as a natural bear deterrent.

The family gets the message -

loud and clear.

The cattle have had their fill, now it's the family's chance.

BIRDS CALL

But someone else has got his eye on the tank.

BEAR GROWLS

A big male.

He's best avoided.

CUBS CALL OUT

This male wants more than a drink,

he wants to cool off in his tub.

At last...

Mexico's black bears were once on the brink of extinction,

but they clung on in mountain hideaways like Serranias del Burro.

The ranchers here don't just tolerate the bears,

they help them out, even providing a leg up for the cubs.

The population is flourishing,

making this mountain world an important stronghold for bears in

North America.

Mexico is a vast country, around 2,000 miles long...

..dominated by a great range of mountains, the Sierra Madre...

..stretching all the way from the country's northern border

with the United States, down to its southern border with Guatemala.

Travel down Mexico's rocky spine -

and there are many more diverse mountain worlds.

The grandest of them all is found in the north-west of the country,

in a region known as Copper Canyon,

covering 25,000 square miles.

A maze of gorges,

some even deeper than the Grand Canyon.

In the 16th century, Spanish conquistadors came here,

hunting for gold and silver.

But they weren't the first to arrive.

The Raramuri have lived in these mountains for over 2,000 years.

To escape slavery in Spanish mines,

many sought refuge in the most inaccessible places.

To navigate the canyon's vast terrain quickly,

the Raramuri became skilled long-distance runners...

..able to cover 200 miles without stopping.

Centuries of running at high altitude has made them

unrivalled endurance athletes.

THEY SPEAK IN SPANISH

Today, the Raramuri still live in remote regions of the Copper Canyon

and running remains an important part of their culture.

Sisters Carmen, Mequejilda and Elida

are from a proud family of runners.

Their brother, Santos, is already a champion, winning several marathons.

But today, it's his sisters' turn.

Their traditional running sandals called huaraches,

once fashioned from animal hide, are now made from old car tyres.

Wearing them from childhood

strengthens the foot muscles

and stiffens the arches of the feet.

Preparing this new generation of Raramuri for a life on the move.

They are heading to the nearest town for a race.

Here in the town of Porochi,

a race day is a chance for distant neighbours to catch up.

BUZZ OF CHATTER

The girls' race is the first of the day.

HE SPEAKS IN SPANISH

They will be competing over three miles.

Uno, dos, tres...

fuera!

In this traditional team event,

the girls toss a hoop, called an arihueta, for the first lap.

One lap down, one to go.

Sister Elida now takes the arihueta.

THEY SHOUT ENCOURAGEMENT

The first hoop to cross the finishing line wins.

At last, the home straight.

MEN SHOUT

Elida is first to cross the finish line...

CROWD APPLAUDS

..upholding her family's winning record.

THEY SPEAK IN SPANISH

The races continue long into the night.

Mexico has one of the largest indigenous populations in Latin America.

More than 25 million people and 68 different languages.

Living in the Copper Canyon has moulded the Raramuri's whole way of life.

All of Mexico's mountain worlds

shape life in profoundly different ways.

Nowhere is this more apparent than among a very unusual group of mountains...

1,000 miles to the south,

where ancient tectonic events have crumpled the land...

The Sierra Gorda, or opulent mountains.

Here, the temperate and tropical collide,

creating a mosaic of different habitats.

BIRDS CALL

In this one region, there are more than 2,000 different types of plant...

..over 340 bird species...

BIRDS CALL

..and 800 kinds of butterfly.

Fairy tale oak forests are a secret garden

for more colourful tropical species.

The most bewitching of all,

orchids.

Over millions of years,

these flowers have developed an unusual relationship

with a very colourful character...

..the orchid bee.

For just a few months each year, when the orchids are in bloom,

the orchid bees visit them in droves.

Not to sip their nectar -

but to sweep up fragrant oils using brushes on their front feet.

They scrape the oils into a special pouch on their hind legs.

BEE BUZZES

These orchid bees are mixing their own cologne...

..made from up to 80 different scents collected from the forest.

This complex fragrance helps the males attract the females.

BEES BUZZ

The most fragrant oils are produced by one very special kind of orchid...

..Stanhopea.

This orchid blooms for just one day each year.

In this crucial 24 hours, it must spread its pollen far and wide.

As soon as it opens,

the flower emits a hypnotic perfume...

..that smells like freshly ground cinnamon...

..sending the orchid bees into delirium.

BEES BUZZ INTENSELY

But Stanhopea's sweet smell belies a cunning purpose.

Its petals are covered in slippery oil droplets.

And their intricate shape forces the bee to walk backwards.

The bee slips

and the orchid sticks a packet of pollen onto its back...

..which it will unwittingly carry to other Stanhopea flowers.

With its pollen distributed in just a single day,

the flowers' job is done.

As the sun sets,

the petals wilt and die.

BIRD CALL ECHOES

Travel further south down Mexico's spine and ancient peaks give way to

younger mountains in the fertile heart of the country.

Much of this land is over 6,000ft above sea-level.

A landscape of extensive farmland and pine oak forest.

The soils here are especially rich because this is the home

of restless giants.

Popocatepetl is Mexico's second-highest peak...

..over three miles above sea-level - and still growing.

It's the country's most active volcano.

LOW RUMBLING

Mexico is one of the most volcanically active places on earth

because it lies at the collision point of three tectonic plates,

producing a great chain of mountains that stretch right across central

Mexico, known as the Transvolcanic Belt,

with more than 20 active volcanoes.

They can cause death and destruction

but they're also givers of life.

Their volcanic ash enriches the soil,

making this a highly productive region of Mexico...

..and the most inhabited.

The country's capital, Mexico City,

lies on a high plateau in the shadow of volcanoes.

People first settled here almost 10,000 years ago.

DISTANT DOGS BARK

It's a riot of colour...

CAR HORNS BEEP

..noise...

and culture.

CROWD CHEERS

This sprawling mega-city is home to over 20 million people

and 80% of all the food consumed here comes from a single place...

..the largest wholesale food market in the world...

..La Central de Abasto.

30,000 tonnes of produce changes hands every day...

..much of it grown on Mexico's volcanic belt.

NOISY CHATTER

The country's most iconic foods, chillies, maize and avocados,

all originate in Mexico's Highlands.

Many are exported worldwide

and there's one product that's earned a formidable reputation.

BELL TOLLS

TRANSLATED FROM SPANISH:

16-year-old Martin is a sometime bull rider but a full-time jimador,

a farmer who harvests the blue agave plant...

..the essential ingredient of tequila.

Agave plants can take a decade to mature before the plant is cut down.

DOGS BARK

By slicing away the spiky leaves, the jimadores expose what they're after,

the sugar rich heart, the pina.

Martin toils in the shadow of Volcan de Tequila,

which last erupted 220,000 years ago...

..its ancient ash fertilising the rich red soils.

This one region of Mexico, Jalisco, produces 80% of the country's tequila,

crafted in special distilleries.

The pinas are first roasted and then crushed, squeezing out the sugar-rich juices.

These are then fermented.

Yeast turns the sugar into alcohol.

Finally, it's distilled...

producing the highest grade tequila.

MEN SPEAK IN SPANISH

To improve the quality of their crops,

some farmers are trying something new.

For the first time in 200 years,

they are letting a proportion of their agave go into flower.

The plants funnel all their sugars into towering blooms...

..rendering them useless for tequila

but offering a lifeline for a threatened species.

Thousands of female lesser long-nosed bats migrate along

Mexico's mountains to reach their breeding caves in the north.

They can fly over 60 miles a night and need frequent sips of sugar-rich nectar.

The agave provides them with a critical source of food.

The bats also benefit the farmers by pollinating their crop.

MEN CHAT IN SPANISH

If their agave is exposed to a greater mix of pollens,

the plants will be stronger and more resilient to disease.

THEY SPEAK IN SPANISH

THEY LAUGH

By helping the bats, the agave farmers are safeguarding their own future...

..and ensuring the continued legacy of Mexico's most iconic drink.

Central Mexico's mountains have attracted people for millennia.

Immense empires grew in this volcanic heartland...

..and the remnants of some of their cities still stand.

1,500 years ago, Teotihuacan was a thriving metropolis,

home to over 100,000 people.

But perhaps the most famous ancient empire here

was the Aztecs.

They dominated central Mexico in the 15th and 16th centuries.

Aztecs believed mountains connected Earth to the heavens

and the underworld.

50 miles south of Mexico City is the Temple of Tepozteco.

This shrine was abandoned long ago

but a very resourceful animal has since made it home...

SOFT GRUNTING

..coatis.

They are the most social of the raccoon family...

..forming bands up to 30 strong.

They normally live in tropical woodlands and open forest.

COATIS SNUFFLE AND SQUEAL

Coatis are omnivores.

They can eat pretty much anything.

Here at Tepozteco, there are plenty of options.

This important archaeological site attracts many visitors,

and tourists bring opportunities.

This is no ordinary coati clan.

These adaptable animals have become artful thieves.

The coatis are thriving thanks to teamwork

and a shameless streak.

COATIS SQUEAK

Below the volcanic heartland,

Mexico's Sierra Madre stretches on south towards the tropics.

At its southernmost tip,

where it meets the Pacific Ocean,

the mountains catch the moisture from clouds rolling in off the sea.

10% of all of Mexico's rain is captured here,

helping to create a lush cloud forest known as El Triunfo.

The combination of humidity,

altitude and warmth makes the perfect conditions for life to flourish.

BIRDS CALL, INSECTS BUZZ

This secret mountain world is home to an abundance of rare creatures,

many found nowhere else on earth.

High in the canopy,

100ft off the ground, lives the alligator tree lizard...

..and the horned guan.

GUAN MAKES DEEP-THROATED CALL

The last survivor of an ancient bird family,

it's been evolving independently for more than 30 million years.

BIRDS CALL VOCALLY

In forest clearings, male long-tailed manakins dance to entice females,

a ritual that may take a decade to perfect.

Travel deeper into the heart of this cloud forest,

and you might discover the true spirit of El Triunfo...

..a mythical creature rarely seen.

Sacred to the ancient Aztecs,

who treasured its feathers more than gold.

It's considered the most beautiful bird in the Americas...

BIRDS CALL

..the aptly named resplendent quetzal.

It's the mating season and these males' three-foot-long tail feathers

have helped him successfully attract a mate.

Now he has a young family to feed.

He works tirelessly for a month to satisfy his brood's voracious appetite.

His lush Mexican home is brimming with fruit and insects.

At the end of the mating season,

he will drop his spectacular tail feathers,

but the quetzal grows a new train every year.

Only in such a rich mountain habitat can animals afford to devote so much

energy to looking this good.

From north to south, all of Mexico's mountain worlds are unique.

And some are so inviting,

they compel creatures to journey vast distances to reach them.

Every winter, one creature travels nearly 3,000 miles

from as far as Canada,

to this special place, high in the mountains of central Mexico.

The trees seem to be draped in leaves, but in fact,

they are coated in millions of delicate creatures.

Silent, unmoving...

..monarch butterflies.

In their hundreds of millions.

These oyamel fir forests are their perfect winter sanctuary.

The low temperatures slow their metabolism,

putting the butterflies in a trance for five long months.

Mountain mists prevent them from drying out.

And the towering firs help protect them from winter storms...

..ensuring they don't freeze.

For thousands of years,

these monarchs have had a special significance for the people of Mexico's mountains,

who believe the butterflies to be the spirits of the dead,

returning to Earth from the heavens.

And their arrival in winter coincides with one of the most

important events in the Mexican calendar.

MAN SINGS IN SPANISH

Dia de Los Muertos - The Day of the Dead.

CHIMES TINKLE

SHE SPEAKS IN SPANISH

In villages across the Sierra Madre,

families like Catalina's are remembering those who have passed on.

TRANSLATED FROM SPANISH:

THEY SPEAK IN SPANISH

Catalina and her family gather around her husband's grave.

THEY CHAT AND LAUGH

The family keep their candles burning until first light.

But they are not alone.

Tonight, millions of candles are lit throughout Mexico...

..helping to guide the spirits of loved ones back home.

The party for the dead has only just begun.

FIREWORKS WHISTLE

WHOOPING AND CHEERING

Many Mexicans do not believe death is an ending.

They embrace it as an essential part of a natural cycle.

The people here have been celebrating the Day of the Dead

for more than 3,000 years.

Generation after generation.

But the spirits of the dead cannot stay for long.

Just as the spirits must return to the heavens...

..the butterflies will also leave.

This is Mexico's greatest natural spectacle,

up to a billion butterflies take to the wind.

These monarchs will never return to Mexico.

Their short time on this earth is almost over.

But they will lay their eggs on the journey north.

And next year their descendants will continue this ancient ritual...

..by making the same epic pilgrimage along Mexico's rocky spine,

back to this unique mountain world.

It's no coincidence that Sierra Madre means Mother Mountains.

Her great ranges nurture an incredible diversity of life...

..and helped give birth to some of the greatest civilisations on earth.

The Aztecs believed mountains brought you closer to the heavens.

In Mexico's Mother Mountains,

you can see why.

Of all the animals the mountains team wanted to feature,

one creature was top of the list.

Rarely seen, little-known, hardly ever filmed.

Mexico's black bear.

Filming them would be a great achievement.

To stand any chance of even finding them,

the team relied on Mexico's foremost bear scientist,

Diana Doan-Crider,

a Mexican American who has been studying and protecting these bears

for 25 years.

My mother's Mexican and my father's American.

When I was a kid, my grandfather, he would tell me stories of seeing bears.

As I grew up, I knew I wanted to study wildlife in Mexico.

Since the 1980s,

Diana's extensive research in the Serranias del Burro

has shown that these mountains are an essential stronghold

for black bears.

She has worked closely with ranchers and landowners to help protect

this important habitat.

But five years ago, disaster struck.

Five years ago, it quit raining for eight months.

So it dried up all of that fuel.

And then, in March, while I was here, a fire started.

That fire didn't stop until May.

And it burned 350,000 acres.

I will be honest, I was traumatised by what I saw because...

I'm sorry.

We saw a lot of dead bears.

I think a lot of us were, like, "Man, this is it. It's over."

The fires also ravaged the oak forests,

whose acorns are a critical source of food for the bears.

This is Diana's first time back to find the bears since the fire,

so the shoot takes on extra significance.

After decades of conservation effort,

she is desperate to see if they have managed to survive,

and whether this fragile ecosystem has fully recovered.

This is my first time back, and this place here was completely devoid

of vegetation.

So this was a dead tree.

And what's really great is that we have acorn production now.

And that's what we were most concerned with,

was how long was it going to take for these patches,

especially severely burnt patches, to start producing acorns.

The mountains team have timed their visit carefully.

It's autumn, and the bears should be around,

fattening up on the flush of food.

Diana takes the team, along with landowner David,

to look for signs of bear activity.

What we have is branch breakage by the bears.

They climb up in here and they pack it down and then they sit up there

and feed. And this is a really good example.

There is further evidence, if a bit unsavoury.

How old would that be?

This is probably just a couple of days old because it has been

very hot and it is still moist on the inside.

I'd have to taste it to be sure.

LAUGHTER

Great news - proof that the bears are around.

But this is a vast landscape,

more than 1,000 square miles of wilderness.

The team need to know where they should focus their effort.

And Diana knows the right people to ask.

Ranchers. They know this land like the back of their hands...

..and the bears better than anyone.

I came in kind of with an attitude of telling them what I was going to do,

what I was going to learn about bears and, you know,

give them all the answers that they needed.

I remember the first meeting I had with them, and it was a group

of ranchers, and they sat down and they gave me a list.

And they told me, "This is what the bears do in the spring,

"this is what the bears do in the fall, this is how many cubs they have.

"This is what they eat."

And I can tell you this, every one of those things on that list were true.

There have been recent bear sightings.

And ahead of the shoot the ranchers set up some camera traps for

the team, hoping to find out where the bears are most active.

Oh, man. I can't believe it.

Look what he did.

A bear just came and knocked over the whole rock.

There's two down.

LAUGHTER

Look here. He made a hole.

This isn't exactly what they were hoping for.

These animals, they can't, like, not totally trash it.

Bears four, me zero.

We'll see if we have anything that's useful on these cameras.

I guess it's the best way we can work out where to concentrate our

efforts, as long as it hasn't been eaten up.

Can you see anything?

For the first time in five years, Diana sees her bears again.

-What are they doing?

-They are just goofing around.

And they both have chest blazes which makes me think that they

-are siblings.

-Siblings.

These two show up and they start romping around,

-playing with each other.

-It would be great if we could film them because

they are very playful.

What's interesting about this is you see the truck go by.

And not even four minutes later the bear comes back.

At least now we know which are the most active pools to concentrate on.

I'll be honest with you, I never knew this number of animals were

visiting these water sources.

With this information from the camera traps,

the team now concentrate on a few key water tanks.

It's really good cos we've just seen our first bear.

There is a mother bear and a baby there just feeding on some acorns.

For the first time since the fire, this is a bumper year for cubs.

-That's a wonderful jump.

-Oh, my gosh.

This is so amazing.

That's great stuff.

Today has been great. The dam broke, we've got some great play behaviour.

I mean, as good as I've filmed anywhere,

Canada or North America.

So it has been great.

Diana has been an absolute godsend to the shoot.

Having her wisdom and her 25 years' experience and her relationship

with the ranchers, she has opened the door to us, to tell, I think,

the most magical black bear story.

I quit coming for a long time and now I've come back, five years later,

and I'm actually floored over the recovery of the ecosystem.

And not just that, but the recovery of this bear population.

This place demonstrates how people can coexist with wildlife.

It's a really unique relationship.

The ranchers have learned to coexist with the bears.

The bears have learned to coexist with the cattle.

I love that. That's Mexico's heritage -

us living on the land.

Next time, we travel to Mexico's southeast,

and a unique peninsula.

The Yucatan,

the birthplace of the once-mighty Maya civilisation...

..where mysterious forests hide a secret underworld.