[David Attenborough] Just 50 years ago,
we finally ventured to the moon.
For the very first time, we looked back at our own planet.
Since then, the human population has more than doubled.
This series will celebrate the natural wonders that remain
and reveal what we must preserve
to ensure people and nature thrive.
The Earth still has sanctuaries,
and, on occasion, they hold spectacular gatherings of wildlife.
They provide vital space, but they're disappearing fast.
[wildebeest lowing]
A fifth of the land on our planet is covered by desert.
The driest of all is the Atacama in South America.
There are places here where rain has never been recorded.
Deserts may appear to be barren and empty,
but they are of crucial importance to life.
For those that can overcome their challenges,
they provide a vital refuge.
[wind whistling]
Socotran cormorants,
emerging from a dust storm in the Arabian desert.
It is the very emptiness of this landscape that has brought them here,
and they have come in immense numbers.
[birds squawking]
Fifty thousand of them.
A quarter of the total population.
They have come because here they can breed...
undisturbed.
But nesting in a desert is difficult.
Temperatures can reach 40 degrees Celsius.
Yet, both the adults and their white chicks
are ready for this challenge.
[birds panting]
They cool themselves by panting.
Any adult that appears to have food in its crop is mobbed.
An adult will only give food to its own chick,
which must be here somewhere.
The chicks chase an adult out into the desert.
No luck.
Now, they must get back quickly to the safety of the colony.
This desert provides the cormorants
with more than just a secure refuge.
Every morning, a mass movement begins.
It's the rush hour.
A shallow arm of the sea, right beside the colony,
is full of food.
[cawing]
This richness comes from the desert itself.
Dust, blown from the land,
contains nutrients that fertilize the surrounding waters.
So, it is the desert itself that enriches the sea.
In Oman, during the summer monsoon, fogs roll in from the sea,
billowing over the Dhofar mountains.
The mists bring just enough moisture to sustain a little vegetation...
and this sparse greenery becomes a focus for life.
Ibex must cross the near vertical cliffs to reach one of the few springs.
But they're nervous...
and with good reason.
An Arabian leopard,
one of less than 200 that survive in the wild.
This male's territory
extends over 350 square kilometers of high mountains and deep wadis.
The southern edge of the Arabian Peninsula
is one of the few places left where there is enough prey
to sustain a population of these leopards.
But even so, there are probably less than 60 individuals
in over 15,000 square kilometers.
These leopards have always been rare,
but now conflict with people
is causing their numbers to decline still further.
[bird chirps]
Few leopards are left,
so what our hidden cameras now capture verges on the miraculous.
A female leopard,
and she is tracking a male.
Such meetings are becoming increasingly rare.
[growling]
This briefest of unions
may ensure the short-term future for these leopards.
But in the longer term,
their fate will depend on their territory being protected.
To the north of the Dhofar mountains
lies a place of almost unimaginable emptiness.
The Rub' al Khali,
the Empty Quarter.
The very name of the place
resonates with the romance of these desert lands.
This is the largest sand sea in the world.
There are parts where human beings never venture.
Only the greatest desert specialists can survive here.
Arabian oryx.
Their ranges are vast,
extending for over 3,000 square kilometers.
This is one of their last refuges.
Once hunted close to extinction,
they have now reclaimed their ancestral territory.
With the help of conservationists, they have returned home.
But reintroduction cannot save all desert animals.
[elephants huffing]
Desert elephants.
Less than 150 survive, here in Namibia.
This oldest of deserts is scarred by dry riverbeds,
carved by water that flows for only one or two days in a year.
An adult elephant
must find up to 200 kilos of food each and every day if it's not to starve.
So, for these last survivors, life is an endless trek.
The herd is guided by a single old female, the matriarch.
She is leading her family
to a special place where food should be available
even in a drought.
She learned of its existence from her mother,
many years ago.
Now, she's teaching her own calf how to get there.
The elephants are not alone in their search for food.
Desert lions.
They are just as rare as the elephants.
The calf is protected by its mother.
So the lions let them pass.
Distant trees are a sign of water.
[brays]
The riverbed is dry.
The ana trees, however, are still green.
But there is a problem.
At this time of year,
seedpods from the ana trees usually litter the ground.
Rich food for elephants.
But this year, the crop has failed.
The matriarch has led her herd here for nothing.
Even the trees' leafy branches are out of their reach.
The family has no option but to move on.
A bull, standing nearly four meters tall.
He can reach into the canopy,
and he could be the solution to their problem.
The old female has known him all her life and turned to him for help before.
Elephants can only survive here
because of knowledge passed down over generations.
But less than 20 matriarchs still survive,
and if their knowledge is lost,
elephants may no longer be able to live here.
Deserts cannot support large numbers of animals the year round,
and even those specially adapted to these conditions
can only survive in small numbers.
But on very special occasions,
deserts are transformed.
[thunder rumbling]
Once in a decade,
there may be a cloudburst.
A single one can turn the desert green.
In southern California,
the change is visible from space.
Hundreds of square kilometers suddenly bloom.
If such transformations become regular,
a new habitat may develop.
Grasslands.
One of our planet's most productive landscapes.
They support the greatest aggregations of large animals on Earth.
The Serengeti sustains herds of over a million wildebeest.
They follow the rains to crop the newly sprung grass.
These vast herds attract predators.
Five male cheetahs.
One of the largest coalitions ever observed.
They dominate a territory of 450 square kilometers.
They patrol it together,
and that attracts attention.
[birds chirruping]
[braying]
A change of strategy is needed
if they're to hunt successfully.
They need cover.
An adult wildebeest is a formidable opponent.
Four of the cheetahs start the stalk,
walking directly towards the prey.
The fifth creeps around the side.
They need to get really close before making their final sprint.
They're nearly there.
All five break cover,
each cat chasing a different target.
It's chaos.
A single cheetah is not strong enough to defend its prize.
They must work together.
These dramas only continue because the Serengeti is protected,
and has been for over 65 years.
But the Serengeti is an exception.
Across the planet, space for grasslands has been steadily disappearing.
[huffs]
A hundred and eighty years ago, herds of bison, millions strong,
grazed the Great Plains of North America.
They roamed across a prairie a hundred times larger than the Serengeti.
This was the true wild west.
[roaring]
Every summer, the males roared their challenges
and fought for possession of the females.
As the rut intensified, the fights became more brutal.
Today, however, most of the prairie is silent.
Humans slaughtered the great herds.
Less than 30,000 wild bison remain,
and 90 percent of the prairie has been lost,
most of it to agriculture.
What we eat, and how we produce it,
will determine the future of our planet's grasslands.
Our past could show us how we can feed ourselves
and still leave room for nature.
The ancient hay meadows of Hungary, still farmed in the traditional way,
provide habitats of extraordinary richness.
Butterflies are abundant.
One species has an almost unbelievably complex life cycle.
The Alcon blue.
Each female must mate and lay eggs on just one species of plant,
the marsh gentian.
The eggs soon hatch into caterpillars.
High up on the plants, they're safe from predators below.
But then, the caterpillars do something seemingly suicidal.
They abseil down on threads of silk to the ground below...
and into danger.
They have no defense against the marauding ants,
which carry them off.
But this is exactly what the caterpillars need to happen.
They're producing a scent like that emitted by an ant larva.
The ants respond by taking them back to their nest.
There, they deposit them in the colony's brood chamber.
The purple-colored caterpillars, lying among the ants' own white larvae,
give off just the right signals.
And the nurse ants rush to feed them.
But there is more.
The caterpillars now start to mimic the sounds made by the queen ant,
and, as a result, the ants treat them like royalty.
If food gets short,
the ants will even feed the caterpillars instead of their own young.
They give them such quantities of food that the caterpillars grow hugely.
And there, underground, the caterpillars feed and grow for nearly two years.
Until, one day, there is nothing for the ants to feed.
The caterpillars have pupated.
But a few weeks later,
out crawls an Alcon blue butterfly.
Now, they begin to leave the nest
that has been their home for the last 23 months.
The young adult makes its way out of the nest
and clambers up a grass stem.
Its wings expand as it prepares to fly off and find a mate.
This complex life may be laborsaving for the butterfly,
but it's risky.
If anything happened to the ants or to the gentian,
the Alcon blue would become extinct.
Only tiny fragments of these ancient meadows
are left in Europe.
But beyond them to the east,
once stretched grasslands that extended for a fifth of the way around the world,
from Romania to China.
Here, there are places where, for mile after endless mile,
there are no roads or fences.
Here, where there are no trees, eagles nest on the ground.
Once, these eagles would have preyed on antelope that numbered in millions.
And some are still here.
These are saiga, antelope that live nowhere else in the world.
Their extraordinary noses are specially adapted
to filter out the dust kicked up by the immense herds
that once lived here.
Now, they're critically endangered.
Poaching and the loss of habitat have had a devastating impact on them.
But conservation efforts have recently started to make a difference.
There is still hope for these extraordinary plains dwellers.
And the proof of this can be found further east, in Mongolia,
where the grasslands still remain largely intact.
These are Przewalski’s horses.
Fifty years ago, they were extinct in the wild,
but a few adults survived in captivity.
Careful breeding from 12 of them increased their numbers
until there were sufficient to release on the plains.
These are their descendants.
A stallion protects each harem.
They must be vigilant, and they race to defend their herd...
or chase off bachelors trying to lure away a mare.
With their numbers now topping 300,
the future for these wild horses looks more secure.
Their recovery was only possible
because the vast Mongolian steppe still remains largely untouched.
These grasses are some of the tallest to be found anywhere on our planet.
They're so tall they can conceal elephants.
They make the giants that live among them seem small.
A last hiding place
for the highly endangered greater one-horned rhino.
This is India,
one of the most populous countries on Earth.
Yet here there is a great determination to protect these crucial grasslands.
What must it be like
to live in this dense, claustrophobic world?
Just moving about could mean walking into danger.
The grasses conceal tigers.
Stripes and shadows blend.
Long grass may hide a tigress from her prey,
but it also hides the prey from her.
She must get within 20 meters of it.
And she must always know exactly where the prey are hidden.
She may have lost them.
She risks a look.
[bleats]
[bleating resonates]
Every deer around now knows exactly where the tiger is.
Others have heard the signal that announced her failure.
Her cubs.
She had left them hidden in the grass.
[growling]
In the last hundred years,
the number of wild tigers has declined by over 95 percent.
But here in India,
despite the enormous pressure from poaching,
and a growing human population,
tiger numbers are actually increasing.
Protect the precious space that grasslands and deserts provide,
and the animals will bounce back.
Please visit ourplanet.com
to discover what we need to do now to protect wild grasslands.
♪ I can hear the whole world Singing together ♪
♪ I can hear the whole world Say it's now or never ♪
♪ 'Cause it's not too late If we change our ways ♪
♪ And connect the dots to our problems ♪
♪ I can hear the whole world Say we're in this together ♪
♪ We're in this together ♪