All language subtitles for Extreme Africa - 01x04 - The Southern Drylands Eng

The southern drylands of Africa

are some of the most arid
and treacherous on earth.

Places of
wind whipped sand dunes

and slowly crumbling mountains.

Where the scars
of dead rivers remain,

Closely guarded by the sun.

Here some remarkable
desert specialists

have adapted
to exist almost without water.

Theirs are the secrets to
survival in this hostile realm -

This is the story of southern
Africa's Greatest Drylands.

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In the sandy interior of south
west Africa's Namib desert,

two elephant bulls
are on the move.

They're searching for water.

In a place like this,

their quest is long
and by no means guaranteed.

For the Namib
has almost no surface water.

The elephants have little choice
but to continue their trek.

Only those animals and plants

specifically adapted
to desert life can live here.

They each know
the secret of this place.

Although invisible
for the most part,

moisture has never completely
abandoned the Namib.

The key to living here

is learning how to find it.

For these ultimate desert
wanderers, the search continues.

Namibia contains some of the
most arid environments on earth.

Much of which receives
less than 1 inch of annual rain.

These are the southern drylands.

Remote and barren landscapes
of desolate beauty.

There are giants here

that dwarf
even the mighty elephants.

These wind-whipped hulks

are some of the largest
sand dunes in the world.

They dominate the coastline
of the Atlantic ocean.

And extend inland
into a sea of sand

as beautiful as it is hazardous.

This is one
of the driest places in Africa.

Where rain is practically
non-existent.

Yet there is life here.

Its support system
is carried in from the sea.

Arriving as life-bringing fog.

As the cold ocean cools the
prevalent south westerly wind

it creates fog, which blows in
towards the land.

Here it spreads a vital
but fleeting layer of moisture

up to 37 miles inland -

allowing life to take
a precarious but lasting hold

on the sandy landscape.

Even with this minute
daily veil of moisture,

those that live here
have to be exceptionally good

at solving the problems of
living in a super-heated land.

The Namib sand gecko's huge eyes

and pale,
almost translucent skin

make it appear poorly equipped
for the rigors of desert life.

It has a simple solution
to staying cool in the heat -

it hides from the sun,

sleeping under the sand by day

where temperatures
are less extreme.

This gecko spent the night
hunting insects.

But now as the desert warms
in the morning sun,

it will soon be forced
to retire underground.

But before that

it needs to
clean its bulbous eyes.

Which are
getting blasted by sand.

They're its main tools
for finding food in the dark

and it's of paramount importance

that they are kept
in good working order.

Using a sticky, dexterous tongue

the gecko gently wipes
any excess grime

off its sensitive eye balls.

Now it's time to find
a subterranean hideout

to avoid the heat of the day.

But it's picky about real estate

and will only occupy compacted
windward facing dunes.

Where hard crusts of sand

make for a solid roof
over its head.

Living on the ground

means the Namib sand gecko
doesn't need the sticky toes

common
to most tree dwelling geckos.

It has swopped adhesive ability

for another
much more useful adaptation.

It has shovels for feet.

Webbed toes
are a rare specialization

which help it move
loose sand quickly.

The gecko
will emerge again to hunt

only in the cover of darkness.

There is another reptile
in the southern drylands

that has a different solution

to life under the baking sun.

Undoubtedly one of the desert's
most unusual inhabitants

is the Namaqua chameleon.

Chameleons are often found
in lush tropical forests

and like her cousins,

this female Namaqua chameleon

has eyes
that can swivel independently.

She's also cold-blooded

and cannot control her body
temperature internally.

So how does the chameleon
manage to regulate body heat

in a desert where the
temperature can quickly jump

from
60 to 140 degrees Fahrenheit?

The secret is in her skin.

It contains
pigments and crystals,

which the chameleon can control
to vary her color.

In the cold mornings

when temperatures in the desert
are still low

the Namaqua chameleon
turns her skin a dark brown,

increasing the amount of heat
she can absorb.

Soon she reaches the upper limit

of her preferred
body temperature,

which is about
100 degrees Fahrenheit.

Now she's at risk
of overheating.

But the highly adaptive
chameleon has a solution.

She changes her color again,

this time to a lighter hue,

which increases the amount
of light reflected off her skin,

so it will absorb less heat.

She also flattens her body and
points herself towards the sun,

reducing the surface area
directly exposed

to the warming rays.

These incredible adaptations

allow the chameleon
to keep her body temperature

in a comfortable range

and remain active all day.

Though active is a relative term
for her relaxed pace.

But what exactly
does the chameleon eat out here?

The answer lies
in the green patches of life

dotting the sand.

Few plants are more valuable
to the desert's inhabitants

than the Narra plant.

It provides both food
and shelter for many animals,

large and small.

Flower buds
house a host of insects,

like these tiny aphids.

This larger bug prefers the
ground level for its needs.

The plana beetle
is a pedestrian insect,

meaning it can't fly.

Right now
these three don't need to.

They are in a hurry.
But it's not a race to food

that's got
these beetles running.

This chase is actually a rather
complicated lover's triangle.

The beetle in front is a female,

the two behind are eager males.

Male plana beetles

are single-minded
in their quest to reproduce

and will attempt to mate
whenever they meet females.

But finding the opposite sex
is the easy part.

It's shaking the competition
that takes hard work.

Having such persistent suitors
is tiring

and she stops between sprints.

One way
of dealing with your problems

is burying your head in sand.

But this doesn't deter
her armored knights.

The moment is ruined
by the lack of common courtesy.

And the chase resumes.

In a moment of confusion

the trio splits,

giving the leading male
another chance.

In the race to mate,
male plana beetles

need speed and size
to come out on top.

Luckily they are the fastest
running beetles in the world.

Again the female buries herself.

This is actually her way
of taking shelter for the night.

But it serves the dual purpose

of allowing the male
to mate with her

and stay above her
to guard her against rivals.

The plana beetle
isn't the only dryland expert

that relies on the Narra fruit
for sustenance.

By eating moisture-rich melons

the handsome oryx

can go for long periods of time
without drinking,

allowing it to venture
deep into the driest interior.

But this special antelope has an
even more impressive adaptation

that lets it stay out
in the heat all day long.

In the sun its body temperature
rises slowly but steadily,

reaching a brutally hot
110 degrees Fahrenheit.

If blood at this temperature
reaches its brain

it would be fatal.

But the oryx has an ingenious
'blood flow radiator'

located in its nose .

This circulates
and cools the blood

before it reaches the brain.

This system of cooling
is crucial to the oryx

as it saves
vast amounts of water

that would otherwise be used in
staying cool through sweating.

This allows it to stay deep
in the heat haze for days.

Herbivores like the oryx
inevitably provide waste,

which enables the presence of an
industrious dryland inhabitant.

The Flightless dung beetle
is a hard worker,

committed to the tireless
recycling of animal waste.

But today it's looking for
a decent place to dig a hole

and escape from the heat.

Dung beetles are
superbly designed for digging,

with a broad bulldozer-like head

and strong flat forelegs.

But the sand here is loose
and difficult to dig.

Most dung beetles
would simply fly away

to a more promising location.

But for this species
that's not an option.

It's one of the few dung beetles
that cannot fly.

In a remarkable
evolutionary trade-off

it has given up
the luxury of flight

for the necessity
of retaining water.

Breathing out carbon dioxide
uses up precious moisture.

Instead the beetle
stores the carbon dioxide

in tiny tanks
where its inner wings once were.

This reduces its need to breathe

and means
it only has to 'exhale'

once every half hour.

In one of the driest places
in the world

being able to conserve
every bit of moisture

is the difference between
surviving and perishing.

But it still
doesn't help the beetle

find a decent place
to dig a hole.

Along the coastal dune belt
of the southern drylands,

fog provides enough moisture
to support the entire ecosystem.

In the mountainous
northern interior

an altogether
different water source

provides for a more
impressive cast of animals.

A dry river bed
is all that's left

of the body of water
that once carved its path

through these mountains.

Its history is now etched into
the desert's sandy surface.

In times of flood
the river may flow briefly

before the thirsty sand drags
all the moisture underground.

But for now,
the water is only accessible

to plants and trees
with long roots,

which can tap the hidden
reserves deep in the sand.

This vegetation sustains
a variety of wildlife.

Including the largest
land mammal on earth.

These are
desert-adapted elephants

that have travelled
long distances

to this remote river course

in search of water.

This is one of the last herds
of desert elephants

left in southern Africa.

They are a family of
related females and their young

led by the matriarch.

Who is the oldest
and most experienced among them.

The matriarch
has been here before

and knows that there is
enough food for her family

and somewhere,
hidden in the baking sand,

water.

Her challenge is to remember
where it is.

The bulls
travel separately from the herd

and are still far out
in the immense desert.

The water source
that they're searching for

flows invisible beneath the sand
for thousands of miles.

While it supports
plants and animals above ground,

it holds strange secrets below.

Where there is water
life always follows.

This underground cave is home to
the drylands' rarest creature.

The Golden catfish.

A species so rare

that it has been found
nowhere else in the world.

Only a handful of individuals
live in this small pool,

making the Golden catfish
critically endangered.

Its long, eel like body

is an eerie pinky-gold
due to a lack of pigmentation.

The bizarre little fish
is totally blind.

Sight is superfluous
when you live in the dark.

The Golden catfish have existed
in this small water-filled cave

for generations.

So the real question here is -

what does it eat?

The answer comes from above:

Bat droppings.

High in the crevices above,

bats cling to the crags.

Their excrement
falls into the pool

where the catfish can find it -

using their four pairs
of thread-like barbels.

The bats thus provide the
ghostly fish with a ready meal.

The southern drylands
are full of mystery.

There are even occurrences that
science can't fully account for.

These round circles of grass
are part of a bizarre phenomenon

that remains unexplained.

Fairy circles.

Most scientists suppose
that the fairies who make them

may in fact be termites.

The insects are believed
to create the rings

by excreting a chemical that
stops the growth of the grass

in the center of the circles.

But this explanation
hasn't been verified

and other theories include
burrowing animals,

electromagnetic waves

and even grand speculations

like UFO landing sites.

Still the fairy circles
remain a great mystery

of southern Africa's drylands.

Grass like that
of the fairy circles

is incredibly resilient

and is considered one of the
perennials of the desert biome.

Along the coastal dunes
little else can grow,

yet it tenaciously
clings to the sand.

It appears at first glance

dry and dead.

Indeed for the most part it is,

until rare and precious rain
falls to reawaken it.

Even in a state
of suspended animation

the grass provides a home
for another dune species.

The Dune ant
is a dangerous creature,

not to be trifled with.

Living in large colonies,

individuals are equipped with
formic acid and powerful jaws,

which they use to quickly
dismember any unwary traveler

who comes into their territory.

Each ant
has a clearly defined role.

Communication is the key
to smooth operating.

This is done through
exchanging chemical signals

called pheromones.

These workers
in charge of burrow maintenance

are receiving
an alarming message.

Winds have wrought havoc
on the entrance of their home

beneath the grasses.

Clumps of sand and twigs
are strewn everywhere.

To the tiny insects,

this is the equivalent
of an earthquake

or land slide.

Luckily as a species,

ants have what would seem
to humans like super strength.

Some estimates suggest

that ants can lift up to
50 times their own weight.

But will this be enough to clear
what compared to the ants

look like massive fallen trees?

They need to work fast,

because
without the entrance clear

the safety of the colony
is compromised.

It's a Herculean task,

but finally their burrow
entrance is clear enough

that they can
continue with their day.

For these tireless ants,

life in the more extreme parts
of the southern drylands

is made possible
by the hardy grass.

For the elephants,

one of their lifelines
in the desert interior

also comes in the form
of a very special plant.

The Faiderbia Albida,
or Ana tree

is a beacon of support for many
in the driest times of the year.

Its long roots push down
as far as 260 feet

to reach deep groundwater,

allowing them to grow big

and produce nutritious
green leaves and seed pods.

This happens in August,

late winter
in the southern drylands

and a time
when most trees are dormant.

It's now that the Ana tree

drops its large,
nutrient dense seed pods.

The seeds are one of the reasons
the elephants have made

the long journey to the area
from the desert interior.

For them even the exposed root
of an Ana tree

can become a potential meal.

But getting it out of the ground

is harder
than it would first appear,

even for Africa's
most powerful mammal.

Try as she might, she can't get
a good grip on the tough root.

Finally she gives up
in a flush of frustration.

The trees also throw
wide covers of shade,

a valuable
resource for the elephants.

They move between the trees,

picking up seed pods
with their dexterous trunks.

Together the herd travels
vast distances

across the southern drylands
in search of water.

Their survival is made possible

by scarce oases of life
in an otherwise barren desert.

There is another animal here
that has a more obvious impact

on the Ana tree.

Their rounded canopies
are trimmed from below,

cut straight as if by the sheers
of a giant gardener.

Indeed there is only one animal
tall enough for the job.

Standing at 18 feet
when fully grown,

the giraffe browses
the lowest reaches of the trees.

It uses
its long prehensile tongue

to grab and pluck the leaves.

But even the tallest
land mammal in the world

sometimes comes up short.

And although a little awkward,

the giraffe won't turn its
nose up at the tasty seed pods

that have fallen to the ground.

Giraffes generally maintain
casual associations,

unlike the more
socially cohesive elephants.

This herd is made up
of mostly females,

with one dominant bull
among them.

Giraffes spend roughly
half their day feeding,

with females taking longer to
select more nutritious foliage.

Between bulls dominance is
decided by seniority and size.

Making this match up

rather uneven.

It's more like play fighting

with a younger brother
for the large bull.

Who's clearly
pulling his punches.

Giraffes are
superb desert dwellers,

getting all the moisture they
need from their food.

But the elephants must drink

and will need to find water soon
or face the risk of dehydration.

Luckily the morning dawns
with a gift from the heavens.

Low in the sky hangs fog

that has crept inland
from the ocean.

It's the very same
life-giving fog

that supports the dune seas
along the coast.

As the sun rises
the fog slowly burns off,

but not before being caught
by a very clever tree.

It looks out of place with its
verdant, pine like shape,

but the Tamarisk tree is an
accomplished desert survivor.

The Tamarisk uses a special
trick to catch the fog.

By producing a layer of salt
on its leaves overnight

the tree attracts moisture,

which keeps it cool
and well-watered.

Its high moisture
and mineral content

make it a favorite
of the elephants.

But it's not going to be enough

to keep them going for long
in this heat.

As the day progresses
temperatures rise sharply.

For the younger elephants
the heat is exhausting.

The adults cannot lie down

without risk of crushing
their internal organs.

Rather they take dust baths,

which help protect their skin
from the sun

and biting parasites.

Driven on by thirst,
they must keep moving.

Desert elephants are the same
species as those

found throughout Africa -

Loxodonta Africana.

But these have become
desert adapted over time,

with only slight changes

in their features
and characteristics.

Their legs are slightly longer
in proportion to their bodies,

with wider foot pads,

better suited
for walking on the soft sand.

They're also said to be able
to go for longer periods

without water
than savanna elephants.

Even so, it's been several days
since they drank

and they are parched.

The matriarch
has led them out into the open.

But she has done so
with good reason.

Here, finally
they've found water at a spring

that wells up from the depths.

The herd drinks deeply now,

with adults able to gulp down
as much as 40 gallons at a time.

Then in the distance

figures emerge.

The bulls have arrived.

The herd welcomes
the two biggest of their kind

with a tenderness characteristic
of these noble giants.

These bulls are no doubt father
and brother to many of the herd.

The coming together
of the family

is a rare and special happening.

With the usually solitary bulls
arriving to drink as if on cue.

Once the elephants have quenched
their collective thirst

they walk off together,

disappearing slowly
in to the desert.

Their journey
is a never ending march,

as constant as the movement
of the sun across the sky

in this great desert.

These drylands of southern
Africa have been wrought by time

into magnificent landscapes
of sand and stone.

They may be
stark and perilous,

but are filled with wild wonder.

Across their reaches

examples of nature's most
startling ingenuity abound.

These characters have evolved
to be hardy and desert-adapted.

And thus exist with consummate
skill where others would perish.

For only a special few

can make a home
in the most extreme of places:

The Southern Drylands.

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