Original subtitles

Europe.

Home to 850 million people.

This is a continent that has been transformed by humanity.

It is a crowded world.

But not all of it.

There are still precious areas of wilderness

and, living within them, some very surprising animals.

Forest once covered 80% of Europe.

Now only half of it remains.

A brown bear.

One of only 1,500 that are left in Finland's forests.

Her cubs have recently emerged from their nursery den.

The long summer days means there's plenty of time for play.

With two boisterous cubs...

...it pays to rest whenever you can.

But their mother must be on her guard.

The cubs have spotted something.

A large male... looking for a mate.

The cubs aren't his.

So he might try to kill them.

Bear cubs are excellent climbers.

And now they're beyond his reach, 15 metres up.

Their mother warns him to keep his distance.

But the cubs are coming down too soon.

She can't take any chances.

That was a close call.

Finland's forests give us a glimpse of what Europe was once like.

A land of endless wilderness, where large animals roamed far and wide.

In the north, the continent extends beyond the Arctic Circle.

Here, the skies are illuminated by the aurora borealis,

the northern lights.

Trillions of charged particles,

ejected by electric storms on the sun,

react with the Earth's atmosphere

to create this surreal nocturnal spectacle.

But by day, this is a barren land.

The Dovrefjell mountains of Norway.

One of the last refuges for an animal that once lived

all across northern Europe.

The musk ox.

This bull is in his prime.

He protects the herd and fathers all the calves.

H is is a greatly sought-after rank...

...and that means that, in the mating season,

he has to deal with rivals.

And here is one.

Raking the ground is a warning to other males to keep away.

But some ignore it.

He now has no choice but to defend his crown.

The challenger attacks.

Each male weighs nearly half a tonne.

These clashes are usually short and intense,

but not this time.

As his family looks on, neither gives in.

The bull will need to draw on all his experience.

But he's beginning to lose ground.

Now he's broadsided.

If he's defeated, he will lose all his females.

With one final effort,

the bull pushes the challenger back up the hill.

It's over.

The old bull successfully defended his rights as head of the family.

And the challenger has to return to a lonely life for another year.

One of Europe's last remaining areas of wilderness lies at its heart.

A mountain range spanning 750 miles across eight countries.

The Alps.

Europe's mountain ranges may be inhospitable,

but wildlife has shared this terrain with people for centuries.

It's dusk in the mountain villages of Abruzzo, in central Italy.

And deep in the surrounding woods,

thermal-imaging cameras reveal the continent's most elusive predators.

Wolves.

Right on the edge of the village.

It's midwinter, and food is hard to come by.

This pack may not have fed for a week.

They can travel many miles in a night,

searching for prey.

Red deer.

It's pitch-black.

Perfect conditions for an ambush.

But even so...

...the odds are stacked against the wolves.

One wrong footstep,

and they have lost the advantage of surprise.

The deer scatter right across the mountainside.

And to make matters worse,

the hunt is interrupted.

The deer are now high up the mountain.

But the wolves use the road to travel faster and in silence.

They manage to get above the herd.

Now they make their move.

The pack needs to single out one animal.

A wolf is more nimble in thick woodland,

but a deer can run faster on open ground.

Once they're close, the pack drive the deer

straight down the mountain.

And now it's more likely to stumble.

In this case, the icy road proves fatal.

But the commotion has attracted sheepdogs from the nearby village.

They have been bred to protect livestock by chasing away wolves.

With the kill lost to the sheepdogs,

the wolves will go hungry

for yet another night.

Today, much of Europe's wildlife has to live alongside people.

The most adaptable can be found in our towns and cities.

Gibraltar, right on the southern tip of the continent.

Home to Europe's only monkeys.

Barbary macaques.

Four family troops live here.

In macaque society,

there is a strict hierarchy,

and status within it is inherited.

This female has just given birth to her first baby.

She is at the bottom of the pecking order.

So her son is, too.

They're bullied constantly...

...and forced to live on the fringes of the troop.

As outcasts, their only comfort is each other.

He's been snatched,

stolen by a higher-ranking female.

She is childless, and she wants a baby of her own.

He's only a few metres away...

...but if his mother approaches,

the rest of the troop could well attack her.

The kidnapper has never raised a baby before,

so this one is in danger.

They're headed towards a cable car tower.

The young mother can't let them out of her sight.

They're 30 metres up.

If she tries to grab her baby and fails,

he could fall to his death.

The kidnapper refuses to surrender him.

There's one last thing a mother can try,

and to do it

she needs to recruit another macaque.

Now the mother begins to groom her companion

in full view of the kidnapper.

All monkeys love to be groomed,

even by a low-ranking female.

It's the basis for peace in macaque society.

Eventually, the urge to join in is just too strong.

The kidnap is over.

And the youngster can climb back into his mother's arms.

There are pockets of wilderness even in Europe's cities.

Green oases among the urban sprawl.

Vienna, in Austria, has over 2,000 parks, gardens and cemeteries.

And down in the undergrowth, a rather unusual resident.

A European hamster.

Wild hamsters are found in grasslands throughout central Europe.

Here, in the city, they're doing extremely well.

This male is on a mission to find food,

and he's set his sights on one thing in particular.

Fresh flowers.

To survive the winter, hamsters must fatten up.

So there's no time to waste.

The only problem - these flowers are in someone else's patch.

Graveside bouquets are worth fighting for.

The winner gets to keep the territory and all the food within it.

The loser has to beat a hasty retreat.

But the lure of fresh petals is just too much.

Plan B.

Stealth mode.

The coast looks clear.

But best not take any chances.

The trick is to get in and out before you're caught.

And now... dessert.

Candle wax - it's full of oil and high in calories.

A hamster's cheeks can hold a quarter of its body weight.

Just one more mouthful.

Oh, dear.

Big cheeks and narrow bottlenecks -

how very embarrassing.

Mission accomplished.

Europe's landscape has changed dramatically...

...but its temperate climate is still good for wildlife.

The continent has warm summers...

...and mild winters.

These conditions are a consequence of its position on the globe...

...and the influence of the Gulf Stream.

This current of warm water in the Atlantic Ocean heats the air

that then flows over the land.

And every year, Europe's unique climate

helps trigger an extraordinary natural event.

The Tisza River, in Hungary.

For a few days in June,

when day length and water temperature are just right...

...the largest of all mayflies emerge.

After three years of feeding and growing on the riverbed,

the males appear first.

With new wings, they can fly to the riverbank

and there undergo a final moult.

Now sexually mature,

they have just one purpose in life -

to find a female.

Each male has only three hours to live.

And now the females begin to emerge on the surface of the river.

The males scour the water surface, searching for them...

...each desperate to be the one that fertilises her eggs.

Every female is pounced on as soon as she appears.

With only minutes left for each male to live,

the competition becomes increasingly urgent.

And all too soon, the males' time is up.

All of them die.

But the females' journey has only just begun.

Now that they've mated,

they start to fly upstream

and continue for as much as three miles.

At the height of the hatch,

there may be as many as ten million insects on the wing.

Exhausted,

the females now collapse and rain down onto the water's surface.

And as they hit it, each releases thousands of eggs.

As the eggs slowly sink,

they drift downstream,

so that by the time each reaches the riverbed,

it will be in exactly the same spot that its parents emerged.

Just hours after the first mayflies appeared,

this great eruption of life is over.

Europe's extensive waterways are a haven for wildlife.

One of the richest of its wetlands

lies on the edge of the Black Sea, in Romania.

The delta of the Danube River.

Migrating birds are drawn here from as far away as central Africa

and Asia.

Great white pelicans.

Every summer, three-quarters of the world's population

flock to the delta.

They've flown thousands of miles to get here,

and they will spend the summer feasting on the delta's riches.

To find the best fishing,

they take to the air.

From half a mile up,

they search the entire delta,

200 miles across.

They can't see individual fish from this height,

so instead they look for others below that have already done so.

Cormorants.

They are diving deep to reach the biggest shoals,

flushing them to the surface.

A couple of pelicans land...

...and others soon home in on them.

The pelicans don't join the feast directly.

They mug the diners.

This brutal tactic enables each pelican to catch many more fish

more quickly than it would do if it worked by itself.

Once the shoals of fish have been plundered and dispersed,

the cormorants make their escape.

And the pelican pirates fly off in search of their next meal.

Water has shaped Europe's landscape in another way.

There is a vast wilderness lying within the rocks of the continent.

Caves.

Over 12,000 have been discovered in Slovenia's Karst region alone.

Each has been eroded by water over millions of years...

...and shaped drip... by drip.

The largest cavern is over 15 miles long,

and there are certainly many more still to be discovered.

Down here live some of the most specialised animals on the planet.

New species of them are discovered in Europe's caves every year.

This is a world that still holds many secrets.

In the deepest pools

lurk animals that were once believed to be baby dragons.

They have feathery gills which enable them to breathe underwater,

as well as on land.

They are olms.

They're completely blind,

but sensory pits around the mouth enable them to detect

the faint electrical currents emitted by their prey.

Food of any kind down here is hard to come by.

But an olm can go without a meal for a decade...

...and live for a century.

The olms' world has remained virtually unchanged for millennia.

Above, however, Europe has altered beyond recognition.

Its landscape has been transformed by humans.

Protected wilderness now covers less than 4% of its surface.

The disappearance of wilderness has had catastrophic consequences

for wildlife.

One-fifth of Europe's animals are now under threat.

Some teeter right on the brink of extinction.

The Iberian lynx.

One of the world's most endangered cats.

In less than two decades,

the lynx population decreased by nearly 90%.

At one point, there were fewer than 100 individuals.

Today, their last stronghold

is in the mountains of the Sierra de Andujar, in southern Spain.

Here, a natural park was created to help protect the lynx.

Only 25 miles across, it is small.

But for this male, it's just enough.

He's lived here all his life.

At ten years old, he's reached a remarkable age for a wild lynx.

Once persecuted, he's now protected.

For this old male, and Europe's entire lynx population,

this could be the beginning of a new chapter.

In this year alone,

nearly 200 kittens have been born,

and the population has risen to over 700.

But the fate of the Iberian lynx,

and indeed of all Europe's wildlife,

is far from certain.

The continent has now been so changed by humanity

that many of its animal species are under threat.

Only by protecting the few wildernesses that remain

and creating new wild spaces

can we ensure a future for Europe's precious wildlife.

Next time...

...a land of constant change...

...where pioneering animals make the most of every opportunity.

North America.