All language subtitles for Natures Microworlds 13of13 Scottish Highlands 720p

Our planet is the greatest living
puzzle in the universe.

A collection of worlds
within worlds,

each one a self-contained
ecosystem bursting with life.

But how do they work?

The intricate web of relationships

and the influence of natural forces

makes each microworld
complex and unique.

So to discover their secrets,

we need to explore them one by one.

Untangle their interlocking pieces

and ultimately reveal
the vital piece,

the key to life itself,

hidden deep within
each of nature's microworlds.

The Scottish Highlands.

An ancient landscape
of startling beauty.

Craggy peaks peer over a terrain

of thick forest and wide open space.

Two contrasting habitats united
by their battle with the elements.

Presided over by Scottish emblems

like golden eagles

and red stags.

And it's home to some of the rarest
animals in Britain.

The hand of man has been felt

throughout the history
of the Highlands,

and yet its wildlife remains iconic.

How have the Highlands
remained a home for these species

despite the pressure
of the modern world?

To find out, let's explore its deep
forest and open heather moors,

discover the impact of the elements
on these landscapes,

and the role of their key characters

in keeping this remote corner
of the British Isles wild.

There's a famous
saying about Scotland -

it doesn't have a climate,
just weather.

Nowhere is this more true
than in the Highlands.

It's a landscape at the mercy
of gale-force Atlantic winds.

Winters have been known to hit -20.

And when it rains, it pours.

Have the elements had a hand
in keeping this place wild?

Up to five metres of rain
fall here every year -

that's the same as
in some rainforests.

With most other parts of Britain

receiving less than a quarter
of this,

it's easy to see why humans
might have chosen

to set up shop elsewhere.

But the Highlands' wild residents

are made of sterner stuff.

In fact, some rely on rain.

From the soggy earth
emerges a creature

feared throughout the Highlands.

The scourge of Scotland -

the midge.

This tiny millimetre-long vampire

hatches from eggs
laid in the rain-soaked ground.

As the midge feeds,

it sends off a chemical signal

inviting others in the area
to join the feast.

Cutting the skin
with their scissor-like mouthparts

and sucking up the pooling blood.

And with an estimated 40,000
capable of landing on a deer

or similar-sized animal
within an hour,

they can make life unbearable.

Midges die off before winter,

but the change in seasons

doesn't make life in the Highlands
any easier,

as the rain turns to snow.

On cue, the mountain hare population
turns from russet brown

to brilliant white.

The new coat is thicker and warmer,

but it also helps to keep the hare
safe from predators.

A brown hare on a white background

would stick out like a sore thumb.

The ptarmigan employs the same
colour-changing tactics.

Its feathery feet increase
the surface area,

acting like snow shoes,

preventing the ptarmigan
from sinking into the deep snow.

Humans would struggle to live
in these cold conditions.

But surprisingly, these hardy
animals can only survive here

because of the Highland's
extreme weather.

As Britain melted
from its most recent ice age,

around 12,000 years ago,

animals adapted for arctic
conditions were forced back

to the very highest, coldest points
of the British Isles.

While humans busily colonised
the rest of the newly temperate UK,

the Highlands provided a climate

in which these animal refugees
could survive.

So, has the tough climate
kept the Highlands wild?

While it's true that, as a rule,

the highest, coldest, wettest parts
of the world

are some of the least developed,

actually, the Highlands
share a similar climate

with major cities in other parts
of the world.

So, if weather alone
does not keep a place wild,

the Highlands must have
another secret up their sleeve.

There's less than 50 people
per square mile here

compared with 600
in the rest of the UK.

Perhaps the landscape
has a part to play.

There's one very special,
ancient habitat

that's found nowhere else
in the United Kingdom.

The Caledonian forest.

Dominated by the gigantic
Scots pine.

Growing up to 20 metres high

and a solid three metres in girth.

Each tree can live
for a very respectable 250 years...

..during which time, it supports
an array of Scottish wildlife.

It's the backbone
of the Caledonian community.

A familiar character is on the hunt
for food among its branches.

The red squirrel's agility
allows it to reach

the very top branches of the pine,

home to some of the choicest cones.

It's been estimated that a single
squirrel can eat the seeds

from as many as 20,000 pine cones
in a year.

Squirrels have the sharp incisors

common with the rest
of the rodent family,

which they use to tear
the tough cone apart.

Perfect tools for the job.

But even so,
these teeth will need to grow

as much as 15 centimetres a year

to keep up with wear and tear.

The squirrel knows just how tough
the winters can be,

so it plans ahead,

burying stores for leaner times.

Scent glands in its cheeks help

to guide it back to the cache.

But it might be months

before the squirrel
needs to excavate its hoard

and, unsurprisingly,
some seeds are forgotten

or dropped by messy eating.

On the forest floor,

they have a chance of germinating,

bolstering the pine population.

It's a mutually beneficial
relationship

that's been going strong
for millennia.

Food is not the only reason
the squirrel prefers the Scots pine.

The bark blends perfectly
with its rusty red fur

and camouflage is all important

when you have a predator that's
equally at home in the branches.

The pine marten rivals
the squirrel's agility...

..and in a high tree top chase,

is one of few predators able
to catch it.

A smaller male wants in on the meal,

but he's testing his luck.

This pine marten is
in no mood for sharing...

IT SQUEALS

..and chases the chancer out
to a thin branch.

IT SQUEALS

The squirrel makes a good meal

in an environment
where every calorie counts.

The young male will just have
to find his own food.

And by the looks of it,

he could be going hungry.

Pine martens are agile enough

to also prey on the pine's
resident birds.

Like the Scottish crossbill,

an endemic species found in
Highland Caledonian forests.

The bird's shape reveals its close
relationship with the pine.

Its curved, slightly crossed beak
is perfectly adapted

to prise seeds from tough cones.

It eats little else.

The tiny crested tit,

one of Britain's rarest birds,

is equally at home
in the Caledonian forest.

The tit supports the pine

by winkling insects
from crevasses in the bark

and preventing burrowing larvae
from doing serious damage.

But birds are not the only species
that groom the tree.

The caterpillars of the pine
looper moth and sawfly

mimic the needles that they feed on.

These caterpillars can
defoliate a whole tree.

But the Scots pine has an ally.

Wood ants, on patrol.

They detect their prey by vibration,

stalking and attacking.

The larvae may be
twice the size of the ant,

but this poses little problem,

because these ants
are team players...

..dragging the larvae from
the needles back to their nest.

The largest ant in Britain
has a suitably impressive home.

Each metre-high mound holds
up to 100,000 ants at a time.

The nest is constructed almost
entirely from pine needles.

With a queen ant living
for anything up to 15 years,

the nest must be constantly repaired
and improved to see out her reign.

Each one is a feat of engineering.

With the Scots pine providing

both food and construction material
for the wood ant,

it's no wonder that their nests
are a common site

throughout the Caledonian forest.

In fact, so many
of the forest's species

are interconnected
with the Scots pine,

relying on it for a food source,

a nursery or a home,

that it's known
as a keystone species.

The backbone of the forest community

and where many trees grow together,

the forest habitat
supports larger species.

CLICKING SOUND

IT CLICKS

This strange call belongs
to the capercaillie,

the largest member
of the grouse family.

The turkey-sized bird
lives across much of Europe,

but, in Britain, is predominantly
found in the Highlands.

IT CLICKS

This is actually a mating call.

It might not sound
particularly enticing,

but it's widely believed
that the subtleties of the love song

are too low for human ears
to register.

Capercaillies have been
breeding in the Highlands

since the ice age
gave way to forest.

Stands of Scots pine set a stage
for their mating displays

from the Highlands to Western Asia

and the males are dressed
to impress.

With the affection of the more
drably coloured hens at stake...

..testosterone-fuelled tussles
regularly break out.

CLICKING

The chance of injury is very real.

The victor gets his girl

and the chance to mate.

IT CLICKS

The Caledonian forests
and their Scots pine

are synonymous with the Highland
wilderness.

But they're only one habitat
within this microworld.

The forest exists side by side

with another completely
contrasting landscape...

..moorland, as open
as the forest is dense.

Scotland's largest living mammal,

the red deer,

needs both these habitats.

Deer feed on new pine shoots,

but need open space to breed.

IT BELLOWS

Large males bellow
across the heather,

advertising their superiority.

The stag rounds up
a herd of females.

By keeping them under his watch,

he can ensure that no other male

breeds with them and that
only his genes are passed on.

But that's easier said than done.

Other males will want
the females for themselves

and are ready to fight
for the right.

THEY BELLOW

These are ferocious battles

to prove strength

and determine dominance.

The rut has been fought
in the open heather moorlands

for more than 11,000 years.

It's the perfect arena, stretching
for miles without a single tree,

let alone sign of human habitation.

Without natural shelter,

it's no wonder humans
avoided the moors,

but deer are not the only
animals to thrive.

Despite first appearances,

the open moorland is as rich
with life as the pine forest.

The red grouse is as dependent
on the heather

as its cousin, the capercaillie,
is on the pine.

IT CLUCKS

Feeding on seeds, flowers
and shoots as the seasons change.

The heather, like the Scots pine,

relies on the relationships
with other species.

Its striking purple flowers
are pollinated by bees,

while passing animals help

to distribute its seeds.

And it creates a territory

for one of the most powerful birds
on Earth.

The golden eagle,

a symbol of the wild Highlands.

It's a predator,
adapted for purpose.

Keen eyesight allows it to scour
the heather for movement

from up to two kilometres away.

Powerful talons and beak
help it to dispatch prey

many times its body weight.

And this formidable bird
needs these open spaces...

..to hunt.

Following a particularly cold
winter, the snow's melted,

but the mountain hare's fur
hasn't quite caught up.

The white that provided camouflage
a month before

is now more of an advertisement.

With its two metre wing span,

the eagle soars on wind currents,

constantly spotting
for movement below.

While the hare is unaware
of the danger overhead,

the eagle locks in.

But the hare is no sitting target.

Once it spots the threat,

it will sprint through the heather.

By using pre-practiced routes
that it knows are obstacle free,

the hare is capable of hitting
60 kilometres an hour.

But with the eagle topping out

at three times this,

it needs something more
than speed to survive.

So the hare dodges and weaves,

throwing itself out of the eagle's
trajectory.

A last-minute zigzag saves the hare
by a whisker.

Heather plants can grow
for around 30 years.

After this time,
they degenerate and die back.

Bacteria in the soil
will break them down.

The increased nutrients
that this breakdown provides

is just enough for larger,
hardy plants to begin to grow.

Over time, heather will be replaced

by trees and, eventually, forest.

But something doesn't quite
make sense.

If this natural succession
was taking place,

the Highlands should
be full of trees.

Instead, Caledonian forest
only exists in small pockets.

This explains why some
of the species that it supports

are so rare in Britain,

as there's just not enough habitat
to go around.

But it hasn't always been this way.

Some 10,000 years ago,

after the end of the last ice age,

Scotland was covered in trees.

These primordial forests
would have been rich with life,

wolves, bears, wild boar,

animals missing from Scotland today.

WOLF HOWLS

So what has happened
to the Highlands?

How does a forest just disappear?

What's allowed the heather
to take hold in such vast areas?

And how has the natural succession
of the trees been halted?

The soil below the heather reveals
the answer to this conundrum.

By studying remnants of the habitats
from thousands of years back,

scientists have been able
to determine

that there was still forest in the
Highlands up to 5,000 years ago.

Before disaster struck.

The climate changed.

A small fluctuation compared
with the chill of the ice age,

but enough to make
the Highlands wetter.

The deluge that followed
was far more serious

than the worst of modern-day
Scottish winters.

The forests literally drowned.

It's thought that three quarters

of the original Caledonian
forest rotted away,

creating vast bare spaces.

Which suited not only the tough
heather, but another species.

Humans.

Open land allowed communities
to farm crops, build homes

and raise livestock.

For the first time, humans became
a dominant Highland species.

The climate eventually settled,

but only a tiny 10% of the once
vast Caledonian forest remained.

The landscape that we recognise
as the Scottish Highlands today

had been created.

This was, of course, great news
for open-space-loving species

like the grouse and mountain hare.

IT HOWLS

But many of the animals

that relied on the forest -

wolves,

the capercaillie,

red squirrel

and bears became extinct.

Those species that could survive
were excluded

to small pockets of woodland.

Over the centuries, the land use
of the Highlands shifted.

Farms were cleared to make way
for deer and grouse hunting.

The Highlands were kept bare.

Trophy species relied
on healthy heather,

and so patches were burnt
to encourage new growth

and extend the plants natural
30-year cycle.

A new habitat was created,

a patchwork of old and young heather
growing side by side,

in which not only the grouse, but
all moorland species could flourish.

But this wasn't a natural habitat.

Man was artificially managing
the Highland's wild populations.

Humans had become an intrinsic
part of the ecosystem.

Scotland's heather moorlands
were thriving,

but the few remaining areas
of forest and their inhabitants

were still isolated.

It was an environmental disaster
that triggered the demise

of the Caledonian forest
5,000 years before,

so it's fitting that another
would start to bring it back.

But this time it wasn't
brought about by natural forces.

Two world wars left Britain's
natural resources ravaged.

New trees needed planting

and, although their primary
purpose was for timber,

these forests also encouraged
species back into Scotland

that hadn't been seen in decades.

Red squirrels re-colonised,

supporting greater numbers
of their predators - pine martens.

Pine-loving populations of the rare
crested tit and the crossbill grew.

Landowners began to take
responsibility for the wildlife.

The focus shifted to forest
protection and regeneration.

But this posed a dilemma.

Left to its own devices,

the forest would naturally
replace the heather habitat

that now supported many more species
than just the grouse.

The regeneration of one couldn't
come at the expense of the other.

For these two habitats
to co-exist in the Highlands,

then humans would need
to be actively involved.

They'd have to site manage.

Today, the Scottish Highlands
are celebrated

as the last truly wild place
in Britain.

But it is a wilderness
under supervision.

Forests are being planted
and the heather managed.

Species have been re-introduced.

It is a microworld
under reconstruction.

One in which humans
are as fundamental to success

as any of its other animals
or plants.

The Scottish Highlands are,
at once, both wild and controlled.

People have had to learn how to
go about regenerating an ecosystem.

A long and delicate process
that's still not complete.

But the hope is
that, under careful guardianship,

these iconic characters
and ice age survivors

will have a place in the Highland
landscape for centuries to come.