All language subtitles for 321533

It was once the heart of the
Mayan civilization that ...

stretched across Central America,
a great city known as Tikal.

It's temples were the tallest
in the Western world ...

monuments to it's
kings and architects.

For centuries, Tikal grew larger,
it's science and arts flourished.

Then, a thousand years ago,
at the height of its power,

the city was suddenly abandoned.

What happened in this lost world?

What keeps all cities, all
civilizations alive ... then and now?

Cities like New York are triumphs
of human technology ...

they feel as if
they will last forever.

And they give us the sense that we're
somehow apart from the rest of nature.

In big cities, it's easy to take a
lot of things for granted:

Food comes from the supermarket,
water comes from the faucet,

or does it?

Eight million New Yorkers drink clean
water from the Catskill mountains,

a hundred miles away.

If New York had to build water
purification plants,

it would cost billions.

Here, nature provides that service,
free of charge.

If we could follow the rainfall
down through the leaf litter,

we'd find that what we think of as
dirt is a world teeming with life,

a metropolis much more densely
populated than the city it serves.

In every square inch,
billions of microbes ...

and other organisms,
go about their business,

building and enriching the soil
we grow our food in ...

helping condition the air
we breathe ...

and cleaning the rainwater
on its way downhill to the reservoirs.

It's just one example of what
scientists call biological diversity ...

the variety of interconnecting life that
keeps things healthy all over the planet.

Everywhere, nature has found
ways to thrive.

Each place, each ecosystem shapes its
own community of plants and animals.

In every ecosystem, there is a balance
of relationships that keeps it working.

The giant seaweed called kelp,

is many things to many creatures.
It's a hiding place —

It's a nursery for spawning fish —

and it's a food supply
for the sea urchin,

a spiny creature with
a big appetite.

If there are too many of them,

urchins can virtually clear-cut
the underwater forest.

Until the 1970s, this was happening
along the California coast,

all because an animal that
belongs here was missing —

an animal that loves to eat
urchins - the sea otter.

It had been hunted almost to
extinction for its thick coat of fur.

Then, people decided to protect
the sea otter, by law,

and their numbers grew.

The balance of life
began to re-establish itself.

Now, wherever there are otters,

the kelp forest flourishes
and so does everything in it.

In the tropical forest,
biological diversity reaches its peak.

There are countless opportunities
and life seems to seize them all.

Like the kelp forest, the health of the
rain forest is maintained by the ...

variety of its inhabitants as long
as the natural balance is undisturbed.

Animals can't live without
the habitats they're adapted to.

Many, like the South American Tapir,

are now threatened or endangered because
they're losing the places they live.

The forests are shrinking.

For thousands of years, more than
one third of Earth's land mass ...

was covered with pristine forests,
full of life.

The forests of China and lands
around the Mediterranean ...

were first to be cut as
towns became cities and nations.

The rate of loss speeded up
with the Industrial Revolution.

But in the last 50 years, we've cleared
more forest than in our previous history.

Less than half is left.

Scientists estimate that thousands of
species of animals, plants, insects,

and other organisms are being
driven to extinction each year,

with unknown consequences.

We are changing the world to quickly
for animals to be able to change with it.

In major institutions around the world,
scientists are now working against time,

to find and understand all the
diversity of life that remains.

Nearly two million species
from Beetles to Blue Whales,

have been classified,

but there could be ten times
that many, still undiscovered.

The priority now is to explore the places
with the most unique biodiversity ...

where the web of life
is still intact.

Fabian Michelangeli of the American
Museum of Natural History is going ...

back to his native Venezuela, to join a
Rapid Assessment Team on an expedition ...

to the fabled Lost World, that inspired
the novel by Sir Arthur Conan Doyle.

I don't think we'll find a dinosaur on
this trip, but in all of South America,

there's no place more incredible than the
Table Mountains of Southern Venezuela.

The expedition is being organized in
the capital of Venezuela - Caracas.

Leader of the Rapid Assessment Team
is biologist Margarita Lampo,

whose specialty is amphibians.

I always had a passion for animals,
ever since I was a little kid.

I liked the idea that everything in
nature was connected to something else.

For ten years, I've been
studying frogs and toads.

These creatures can tell us so much about
the health of the places where they live.

My colleague Celsi Senaris and
l are concerned by evidence ...

that frog populations are
declining all over the world.

Now we have the chance
to search for them ...

in a place were
few people have ever been.

For the next few weeks, we'll be
living in very different conditions.

We are heading
southeast towards Canaima.

The plan is to meet our guide at
the airstrip, go up river by canoe,

and hopefully, by helicopter
to the top of Mount Roraima.

Beneath us is the vast watershed
of the great Orinoco River.

Tonight we'll stay in a Pemon Indian
village where we've hired a local boatman.

The Table Mountains are
a lot closer now.

I like the Pemon word
for them "Tepuy".

But I can see why others have
called them the Lost World.

Now it's too shallow for the boat.

We'll hike from here to the helicopter
and explore the rainforest on the way.

I can't believe
the beauty of this place.

On the riverbank,
we found some fresh tracks.

Only hours ago, a Jaguar was here.

This tells us that the ecosystem
still has a full range of biodiversity.

Large predators control the number
of mammals like the Coatimundi,

so they don't overgraze the fruits and
seedlings, or eat too many birds eggs.

This balance helps to ensure
the health of the forest.

Now, this is it - the moment
I've been thinking about for weeks.

Our guide Nadim, says these pilots
know the mountains better then anyone.

Next stop,
the summit of Mount Roraima.

Mount Roraima is a
biological island lost in time,

eroded by eons of wind and rain.

The pilots don't want to shut off
the engine up here.

The weather changes too fast.

They have to get out
before the next storm,

and one is coming in fast now.

They'll be back with supplies
in three days ... if they can.

I had mixed feelings watching
the helicopter leave.

It was like being left alone
on another planet,

surrounded by images from
the dawn of time.

In these conditions,
shelter is the priority.

Science will have to wait.

Roraima is a natural laboratory
for studying ...

the adaptation of species
to harsh environments.

Fabian is the team's
plant specialist.

All over Roraima, there are
these beautiful miniature gardens.

Most of the summit is bare rock,
so the rain runs off quickly.

Plants only grow in depressions
where water and soil can accumulate.

If we carefully examine
these little islands,

we see that they are lying just
like rugs on top of the rock.

The soil is mostly sand,
with very few nutrients.

But it still supports an
incredible amount of life,

probably half of it exists only on
these mountains, and no where else.

In this nutrient-poor environment,

plants have evolved different
strategies for survival.

Some have become carnivorous,
trapping and consuming insects.

Other carnivorous plants lure insects
with vivid color and attractive scent.

And their pitcher-shape
is also a perfect trap.

Thousands of slippery hairs
cover the inside of the pitcher.

It's only a matter of time before the
victim slips into the bowl of rainwater ...

where larvae and other organisms
break down the insect.

The plant absorbs the nutrients
in the water.

Roraima seems like a great place
for amphibians,

with ponds and streams everywhere.

But at first we saw nothing at all.

And our samples showed that the water
is as poor a food source as the soil.

Any creatures living here have
to be very resourceful.

Then we found our first amphibians;

Tadpoles feeding on clusters
of unhatched eggs.

The mother frog apparently
produced extra eggs,

so her offspring would have
plenty to eat!

Nearby, we saw a frog
laying eggs in a plant,

the only carnivorous bromeliad
known to science.

The water below
is full of captured insects.

Once her eggs hatch, the Tadpoles
can make a feast of the soup ...

and maybe the plant gets something too
like nitrogen from their waste products.

At dusk, we heard a sound
we never heard before ...

definitely amphibian, but strange.

We looked for it,
until the sound stopped.

In the morning we heard it again.

Celsi recorded the sound, but we never
saw the creature that made it.

Later we did come across
something truly unique —

a tiny black toad,
threatened by a Tarantula.

It didn't jump, it just walked
away and climbed the rock.

When the Tarantula moved on, the toad
curled itself up and rolled down again.

Now, that I've never seen before!

Why would nature produce a tiny toad
that walks and rolls instead of jumping?

No doubt,
we still have a lot to learn ...

People often ask me why we should
care about creatures like this.

Well, it may have something we need,
like new medicine or chemicals,

or maybe because it's living
proof of nature's ability ...

to diversify and survive ...

in ways we never even imagined.

It's a long way from the Lost World of
Venezuela to the suburbs of New York,

but the diversity of life here is just
as fragile and just as important.

Like the life of remote
rain forests and mountains,

the creatures in our backyard
all play their part in the ...

balance of relationships
that keeps the world healthy.

Insects need flowers,
flowers need insects ...

and we need the food
that pollination produces.

In just one square meter, young explorers
on a field trip can find a lot of life.

If they look hard enough, they'll find
things even scientists haven't seen before.

We all need to know what lives here
what it does and what it means to us.

But as we take up more and more
space on the Earth,

we may tip the balance of life
without even knowing it.

It wouldn't be the first time.

The lost city of Tikal was discovered
just over a century ago,

buried in the tropical forest
of Guatemala.

Experts still debate what happened to
this metropolis of kings and priests,

warriors and farmers
where the rare black Jaguar,

sacred to the Mayans,
can sometimes be seen at dawn.

New studies suggest that,
if we could imagine Tikal as it was,

we might see that its expanding
population had stripped away the forest ...

for miles around, exhausted the
soil, water, and food supply ...

with famine, warfare and
collapse not far behind.

Over a thousand years
the forest has returned ...

but the high civilization of
the Mayans is no more.

Did the people of Tikal
lose their life support system ...

without ever understanding it?

Surrounded by the marvels
of a modern city,

we believe we are masters
of our destiny.

But everything in our homes, everything
that keeps us alive, comes from nature.

A hundred years ago,
the people of New York ...

had the foresight to preserve a
critical part of its life support system ...

the mountain forests and
soil that clean its drinking water.

Thirty years ago, the marine ecosystem
off the California coast began ...

to restore it self, because we had
the wisdom to protect the Sea otter.

When we protect nature,
we protect ourselves.

After a week on Roraima,
soaked by the rain,

we've flown to another "Tepuy"
for a few days work.

We'll be on our way home soon.

But in a sense, this is our home.

The air is fresh
and the waters flow endlessly.

These places give us life and remind us
that we are just a small part of nature.

Frogs seems to be a kind of
bellweather for the health of the planet.

If so, things are okay up here.

Will it stay this way?

I'd like to think that places
like this to be here for my children.

Maybe our work will help us to
understand the world we have ...

and the world we have to lose.

What could be more inspiring
than to begin the age of restoration,