Original subtitles

The sun...

giver of light and life, shines most powerfully at the Equator.

Here, it powers an extraordinarily rich zone of life.

Brilliant and bizarre species from three continents...

three oceans.

More than a line on a map...

Equator is a powerful force of nature.

There's a place at the equator

where unexpected creatures live side-by-side in a cold desert.

lce age survivors meet tropical plants and animals,

on the flanks of active volcanoes...

in a country whose Spanish name Ecuador means equator.

The Andes of South America are

one of the most unusual places at the equator...

Every day here is a battle between sun and ice...

hot...

and cold.

The paradox of the Andes is that

the closer they are to the sun, the colder it becomes.

The highest slopes are an alpine desert the Quichua lndians

call the paramo, the "inhospitable lands"...

Hummingbirds and camels are

unlikely neighbours in a cold stony desert.

Vicunas are high altitude specialists.

They're resilient...

able to live in a world which is unpredictable and ever-changing.

Being at the equator there are no seasons, no annual cycle of change.

lnstead, there's a strong daily rhythm of hot and cold.

ln a single day, this extraordinary bird must survive temperatures

that can vary from below freezing, to scorching hot.

The tiny Ecuadorian hillstar is a hummingbird...

one that's forsaken lush tropical forests

to live in one of the harshest places at the Equator.

Every day in the hillstar's Andean home,

a conflict rages,

between cold created by towering mountains and the heat of the sun.

And this is just one challenge among many -

in Ecuador even the land is unpredictable and changeable.

More than 25 million years ago,

an enormous tectonic upheaval began

along the western edge of South America,

where the Nazca Plate collides with the South American Plate.

This great geological collision continues,

rumpling the continent up like a blanket,

atjust one centimetre a year...

slowly building the Andes, the longest mountain range on earth.

At the Equator, active volcanoes

are potent reminders of the power of mountain building.

As the Nazca Plate is sucked under the South American Plate,

intense heat and pressure cause the rock to melt...

When the pressure of molten magma can no longer be contained,

it explodes to the surface...

as an immense volcanic eruption.

These are among the most active volcanoes in the world.

On the high slopes of a six thousand metre peak,

the morning sun dries the wet coat of a newborn vicuna.

lt's warm now,

but last night temperatures dropped to minus six degrees celsius -

if the baby vicuna had been born then, he would have frozen to death.

But he's blessed with wool

that's among the finest and warmest in the world...

and female vicunas always give birth during the day,

to give their offspring the best chance of survival.

Just two hours old, the young male is already keeping up with his mother.

The dominant male watches over his big herd

offemales and this year's young.

He's alert for danger.

The presence of the newborn has attracted a young hawk,

hoping to scavenge afterbirth.

Vicunas have few predators -

their biggest challenge comes from the mountains.

The newborn's herd mates will recognise his distinctive smell

for the rest of his life,

even after he's forced out of the herd by his father,

in a few months time.

ln the featureless paramo, scent is an important landmark.

The vicunas use dung piles as sign posts...

they leave calling cards for other herds

which share the sparse feeding grounds.

Despite daily temperatures

that may vary by more than thirty degrees,

fine wool keeps the vicunas warm.

And like vicuna wool,

the hairy coat of this plant also traps heat.

lt's so effective, it can be more than seven degrees warmer

inside the plant than outside.

This is a brutal place,

and plants seek warmth where they can find it.

They stay low to the dry ground, or seek shelter next to rocks.

The high paramo plants' ability to endure cold

was honed a long time ago,

during the great ice ages.

More than twenty times over the last 2.5 million years

the paramos have been pushed down into the lowlands,

by freezing temperatures and growing glaciers.

Then as temperatures rose and lowland forests expanded,

the paramos retreated back to their mountain top strongholds.

The last ice age ended about 10,000 years ago,

but the tops of these volcanoes at the Equator

are still locked in ice and glaciers, year-round.

Even during the day, it's minus five on the summit...

yet 2,000m below it's ten degrees warmer.

The lower flanks of the volcano are a completely different world.

ln sheltered places the low paramo is a rich shrubland...

Elsewhere it's lush grassland, home to a remarkable ice age survivor.

This is a rare encounter with a most elusive animal...

a spectacled bear may roam more than 20 km in a day,

through the vast wilderness of the low paramo.

This young female is looking for food,

for plants and fruits -

but for now she must search elsewhere.

From the other side of the valley,

an Andean condor watches the bear's progress.

The condor is an icon of the Andes...

and this rugged valley is a perfect home for a nesting pair.

The pair takes it in turn to incubate their single egg.

After more than 50 days the egg is close to hatching.

The female signals to her mate that she's about to leave the nest.

The egg will chill rapidly if it's left alone

for more than a few minutes...

the male must soon take over incubation duties.

The equatorial sun is the condors' ally.

lts heat creates thermals of rising warm air for them to glide on.

Their highly visible presence is a warning to other condors,

to stay away from their breeding territory.

Condors are long-lived, and only breed every second year.

Once this egg hatches it'll be more than a year

before the youngster is independent of its parents.

With wings spanning more than 3m,

condors are the largest land birds in the world.

Far below them the world's smallest birds, the hummingbirds,

are the low paramo's most active residents.

The sparkling violet-ear is a tiny, agile acrobat,

who beats his wings nearly 20 times a second.

Because the sun nurtures year-round flowers here at the equator,

hummingbirds have an active, sugar-fuelled lifestyle.

This hyperactive bird weighs just a few grams.

He must drink nearly his own bodyweight of energy-rich nectar each day.

After feeding the violet-ear rests,

waiting for the flowers to recharge their nectar.

The paramo shrubland waits to be recharged with moisture,

that comes from the two great weather systems that meet at the Andes.

Warm moist air rising from the Amazon,

collides with damp air from the Pacific.

As the warm air rises up the volcanoes slopes,

it cools and condenses into cloud.

The plants of the low paramo trap the damp cloud,

and drip-feed it to the ground.

The lower slopes of the volcanoes are a living sponge.

This well-watered valley is home to a female spectacled bear.

She has a cub that's nearly a year old.

Spectacled bears are named for the markings on their faces -

each bear has a mask as unique as a fingerprint.

The male cub will soon be independent, but for now he's his mother's pupil.

Each day, as they search for food,

they move between the low paramo and the cloud forest.

At 3,500m altitude

the temperature averages a benign eight degrees...

it's warm enough for trees to grow.

Warmed by the sun and moistened by mist,

the cloud forest is one of the richest habitats on earth.

The forest offers a damp home to an incredible array of plants and animals.

ln Ecuador, spectacled bears live alongside

18,000 different kinds of plants.

There's such fierce competition for space among the plants,

that more than 20% of them perch on branches like birds.

Among the perching plants are an incredible diversity of bromeliads.

Their tightly-fitting leaves trap water

and create miniature frog-ponds, high above the ground.

After many years perching,

most bromeliads flowerjust once in their life.

On a single spectacular spike,

tiny flowers open, one after the other...

a glowing puffleg knows he'll find nectar here for many weeks.

The many bromeliads feed many hummingbirds -

more than a hundred and thirty species in Ecuador alone.

A rainbow star-frontlet feeds from an unusual bromeliad,

whose flowers sprout on slender stems.

Scientists have only recently recognised

that the tropical Andes are the world's

most outstanding biodiversity hotspot.

These forests are exceptionally rich in plant and animal life,

because they're both on the slopes of the Andes, and at the Equator.

The cloud forest provides a year-round supply of flowers

and fruit for nearly 1 ,600 species of birds.

Golden-plumed parakeets are amongst

the highest altitude parrots in the world.

A pair have a nest high in a tall dead tree...

a location also favoured by bromeliads.

Spectacled bears are also known as Oso Achupayero,

the bromeliad eating bears.

But most bromeliads grow high up, to catch as much sun as possible...

so that's where the female heads.

ln the paradoxical world of the equatorial Andes,

it's no surprise to find an ice age bear

feeding on tropical plants, high in a tree.

Bromeliads are plentiful and available all year-round...

they're a sensible choice for bears that eat in bulk.

Bromeliads are also rich...

the female targets the tender heart,

where the sugars and proteins are concentrated.

Spectacled bears are South America's only species of bear,

and the best climbers in all the bear world.

The cub is determined to join his mother,

but although he has the will...

he does not yet have the skill.

Spectacled bears are dedicated plant eaters,

ironic as they're descended from the largest land carnivores

that the world has ever known.

Their ancestors were the short-faced bears,

that thrived in North America during the ice ages.

Spectacled bears are the short-face bears only living descendants...

they're ice age relics, perfectly adapted to the cold.

High above the struggling cub,

his mother leaves a trail of destruction as she feeds...

pushing over the bromeliad's frog ponds,

and showering the forest with cloud water.

The cub is a fast learner - on his second climbing attempt,

he makes much better progress.

ln Ecuador's Andes,

a journey from sea level to the summit of a 6,000m volcano,

is like travelling from the equator to the north pole.

The higher you go, the colder...

and more challenging it becomes.

lt means that this high altitude cloud forest

is similar to brown bear habitat in places

much further north such as Canada...

but there's one big difference.

Canada's bears must cope with an enormous variation in temperature

between summer and winter,

but here at the Equator there are no seasons...

food is always available, and animals live here all year round.

There are no long bitter winters, so bears don't hibernate...

and birds don't migrate.

But they all face a daily challenge, of weather which is changeable...

unpredictable.

The sun wins a late morning skirmish with the cloud,

which subsides into the valley.

ln just a few minutes the seasons change from spring to summer.

Many creatures have found opportunity in this unpredictable world.

This is a puya, a remarkable bromeliad

that's moved out of the forest up into the low paramo.

Some hardy hummingbirds have moved, too.

The tropical puya has become a giant.

lt now lives on the ground, instead of perching in a tree.

lts five metre-tall flower spikes are enough to feed two hummingbirds...

but hummingbirds are very territorial about their food,

and don't like sharing.

The puya has evolved a hairy coat to keep its flowers warm...

and fierce spikes for protection.

Puyas are well-adapted to the low paramo...

but that's as far as they can go.

Only the hardiest creatures survive on the volcano's higher slopes.

Vicunas are one of the few animals

resilient enough to endure the high paramo.

Today they're baking in a summer heat wave...

the temperature has soared into the twenties.

But it could change, quickly.

This is a place of extremes...

in minutes it could be close to zero.

Up here, most plants hug the ground for warmth...

but chuquiraga bushes stand defiantly

a metre or more above the ground.

They flaunt bright flowers year-round,

to seduce an unexpected pollinator.

lt's the highest altitude hummingbird in the world...the hillstar.

The bright pollen on this female's head shows she's found

a good supply of chuquiraga flowers.

The tiny hillstar has two chicks.

This resilient solo mother has built a thick,

well-insulated nest to protect them during her frequent absences.

lt's a good thing...

the equatorial sun disappears behind clouds

and the heat wave vanishes.

The high paramo is plunged into a misty autumn.

The weather is changeable,

but one thing remains a constant challenge up here - the air is thin.

At 4,500m each breath contains only half the oxygen

it does at sea level.

But despite the low oxygen levels,

vicunas can sprint at nearly 50km/h.

And when a male chases other males away from his herd,

what begins as a sprint can turn into a marathon.

How do vicunas sustain this effort when the air contains so little oxygen?

A vicuna can use all the oxygen available

in every breath of this thin air.

lts blood contains red cells that are very small,

able to quickly absorb oxygen...

and has twice as many red cells as human blood.

The blood is also very thin...

and easily and rapidly pumped by its big heart

to hard-working muscles.

Physiologically, vicunas are better adapted

to altitude than any other mammal...

and hillstars are better adapted to life here than any other bird.

But high altitude throws another challenge at the hillstar.

The air up here is half as dense as air at sea level...

it's harder to fly.

So, unlike hummingbirds lower down the volcanoes that hover as they feed,

the hillstar perches, to conserve energy.

Vicunas face constant challenges from each other...

but rivalry is key to their survival.

Tensions are rising in the bachelor herd,

among the outcasts, who've been unable to claim a group of females.

A pair begin to squabble...

and their mood proves contagious.

Fights begin to break out in the herd, as males pair off and square off.

All these males aspire to lead a herd...

but fewer than 20% of them will ever succeed.

To gain leadership they'll have to fight the dominant male,

and frequent practise is the best way to refine their fighting skills.

The sparring partners bite and kick,

and attempt to bring their opponent to his knees.

Size...strength...skill...

all factors which will determine the winner.

One fight turns into a grudge match.

Fighting is usually less physical, more psychological...

But today, the duelling duo can't resist a complete brawl.

The duo is well matched in size and stamina...

and the result is a draw.

Vicunas not only face challenges from each other...

they face a direct challenge from the sun.

The Equator receives much more solar radiation

than any other part of the world.

The sun is at a direct angle to the equator,

so its rays travel a shorter distance through the earth's atmosphere...

and are less likely to bounce back off ozone and other molecules.

Levels of damaging ultraviolet are a thousand times higher

at the equator than at the poles.

Animals and plants up here are protected

from radiation by hairy coats...

and frequent thick mists.

The little hillstar is a tenacious survivor.

These chuquiraga bushes offer him security in an ever-changing world,

where there can be four seasons in a day...

and sometimes in an hour.

The mist engulfing the high paramo is caused by warm air

rising up the flanks of the volcanoes.

Lower down, it has created intense thermals...

As the sharp-eyed condor soars on thermals,

one of the strangest... and rarest...

paramo inhabitants arrives in the valley.

The size of a small cow,

the mountain tapir is the largest animal in the Andes.

The unlikely looking tapir has even more unlikely distant relatives...

horses and rhinoceroses.

Like the bears, the tapirs are ice age survivors...

they live in remote, rugged areas.

Mountain tapirs are the bulldozers of the paramo...

they create trails that other animals, such as bears,

use as highways through the thick vegetation.

ln this changeable world, being big is a good thing.

Bulk is useful, for pushing through dense scrub, and for keeping warm.

Tapirs are mostly solitary, and they have enormous feeding ranges.

Because they're so rare, and range so far,

it's unusual to see two animals so close to each other.

Very little is known about these shy giants.

These two seem content to get on with fulltime task of eating the leaves

and fruits of many different kinds of plants.

There are three species of tapir in South America,

but the mountain tapir is the only one that's gone high...

to find opportunity in a place with few competitors or predators.

The mountain, or woolly tapir, has evolved a coat

that's black to absorb as much heat as possible

from the sun,

and thick for warmth.

lt's well prepared for the biggest challenge

for all life in the equatorial Andes - surviving the long night.

Like the tapir,

the spectacled bear family has spent most of the day eating.

lt's late afternoon, and the cub is exhausted...

soon his mother will lead him to a safe resting place.

The young bear has only a limited time to enjoy himself up in the treetops.

He's already the same size as his mother...

1 .5m long, and weighing 60k.

When he's fully grown he'll be much larger -

a male spectacled bear in his prime may weigh up to 180k.

he'll be far too big to climb these high branches.

To survive here,

the bears rely on their climbing skills

and the rich bromeliad offerings of the cloud forest.

Down in the valley,

the tapir's strategy is to have an eclectic palate,

to eat a little of everything.

They never linger too long in one place,

and spread seeds as they travel long distances through the paramo.

As evening approaches and temperatures drop,

the thermals lose their power.

The condors are forced to come in to roost on their nesting cliff.

They'll incubate their egg through the long cold night.

The condors have more than a year of parenting ahead of them.

Hummingbird motherhood, on the other hand is fleeting...

and intense.

lt took the female hillstar less than three weeks to incubate her eggs,

and in another three weeks or so her brood of two

will have left the nest completely.

She gives her babies their last feed of the day,

and tucks everyone in...

they must all stay warm if they're to survive the night.

This snug nest is home only while she raises a family.

Nearby, a young female with no chicks faces her usual lonely night.

She'll survive 12 hours without feeding,

by putting herself in torpor, using as little energy as possible.

The hillstar's heart rate is now a twentieth of its normal speed.

Her body temperature's dropped from thirty six degrees to six.

The equatorial sun departs quickly...

a mini ice age is about to begin.

Down in the low paramo a stream flows strongly.

lt never freezes,

even though the temperature has dropped to minus six.

This is the nocturnal hunting ground of an extraordinary creature...

The fishing mouse is a small, fierce predator,

with an unusual lifestyle.

She'll spend much of the night

searching the stream for aquatic insects or fish.

Like the bear and the tapir,

the fishing mouse is an ice age survivor,

designed to withstand cold.

Her solid body holds heat, and her fur is thick, warm...

and waterproof.

Also known as a water mouse, the fishing mouse is now very rare.

lt was once more widespread, but by the end of the ice ages

it had become a relic, found in just a few streams.

Eyesight and smell are of little use in this night-time world...

she uses long tactile whiskers to detect prey.

For a successful catch she relies on fast reflexes, strong hands...

and some luck.

This species is extremely well adapted to this lifestyle.

None of the small number of other rodents that also hunt in

and around the streams of the paramo are such good swimmers and divers.

And only this species survives in the highest streams,

at altitudes of up to 4,000m.

Like a hummingbird,

the fishing mouse is small and hyperactive -

she needs big meals, often.

The little mouse has a big appetite, and one fish is never enough.

But she must hurry -

12 hours of darkness are drawing to a close.

Dawn on the high paramo.

lt's minus six...

and has been for hours.

Everything's frozen...

except, surprisingly, the plants.

The plants of the tropical Andes

have a remarkable way of staying metabolically active all the time.

Even though the sap is well below zero, it's still liquid...

because it's super-cooled.

lt doesn't freeze into ice that would damage delicate cell walls.

This strategy only works here,

because temperatures never sink below minus six degrees.

lf the nights were any longer...

and colder...

a super-cooled plant would risk snap freezing.

The coming of the sun ends the mini ice age,

but its morning kiss can be a plant's kiss of death.

With the first sun on its leaves a plant begins to transpire.

lts sap begins flowing... but then it slows.

The ground is still frozen...

roots can't suck up any water.

Just when things should be getting easier,

the plant faces physiological drought.

But within an hour the earth will have thawed

and the plant will be able to drink again.

Overnight, the hillstar's temperature and heart rate dropped dramatically.

Now she comes back to life, warmed by the sun.

lt's not long before she's off to find her first quick sugar fix.

The sun begins to breathe warmth back into the paramo.

ln just a few short hours it'll be the height of summer.

Hummingbirds are creatures of sun and heat,

that thrive here in the mountains at the Equator.

Because there are no seasons,

there are year-round flowers they can rely on for energy-rich food.

A Tyrian metal-tail, slightly low

on energy after the long winter's night,

takes the easy option -

why hover when there's a handy leaf to take some of your weight.

Luckily for these tiny birds, winter only lasts for one night -

not for months on end as in most other mountainous parts of the world.

The condors must stay on the cliffs for an hour or two yet.

They can't fly until the ground has warmed and the thermals have developed.

There's always a battle here,

between equatorial heat and mountain cold.

Every day the creatures of the paramo

and the cloud forest face the challenges

offour seasons.

The tropical puya is armed, and prepared for winter...

but its defences are not enough to deter a male spectacled bear looking

for a bear-sized meal.

Animals and plants have taken

different evolutionary paths to reach here.

Some, like the bears, are survivors from the ice ages.

Others, like the puya, are tropical species on a mountain top adventure.

Spectacled bears have shortjaws and massive muscles,

inherited from their ice age ancestors.

These give them power to crush and grind the tough stem of the puya.

A lifetime of growing - destroyed in a second, eaten in minutes.

This encounter between a tropical plant and an ice age bear

could only happen here in the paradoxical world

of Ecuador's Andes.

Unexpected plants and animals have found new opportunities

on these volcanoes at the Equator.

They've evolved ways of coping with the challenges

that living at altitude brings.

Persistence... perseverance...a thick coat...

all help creatures survive the daily battles,

between the immense power and heat of the equatorial sun,

and the cold of the Andes.