Prehistoric Planet (2022) s03e03 Episode Script

1
[sloth snoring]
[squeaks, snorts]
[Hiddleston] A family
of very sleepy sloths
unlike any you've seen before.
- [growling]
- [squeaks]
They've been sheltering in this cave
since the baby was born two months ago.
But now the mother is hungry,
and that means a difficult day ahead…
because they're marooned
in the middle of a desert,
and all that's left to eat
is at the top of a mountain a mile high.
This is the Ice Age.
Far to the north, temperatures
are plummeting as ice sheets grow,
but in the south, drought rules the land.
Deserts are five times
the size of those today.
[growling]
Inhabited by the strangest creatures,
like supersized kangaroos,
killer koalas
- and giant wombats…
- [growls]
…fighting for survival in the driest
landscape seen for millions of years.
[huffing]
[Hiddleston] There are over 50 species
of Ice Age sloth,
but this one could be the bravest.
It's a perilous climb…
but the mother has no choice.
Without food, she'll run out of milk
and her baby won't survive.
Even in the middle of this desert,
moisture collects on the highest peaks,
allowing plants to grow.
But the best food
is right at the top.
[breathing heavily]
[birds chirping]
She needs to pick
the very freshest leaves,
hundreds of them,
and that takes time.
Under the scorching sun,
the clock is ticking
because rising thermals
will soon bring deadly hunters.
If the family is caught in the open,
they'll be in trouble.
Finding food isn't the only thing
that makes life difficult in the desert.
Since the start of the Ice Age,
rainfall levels have halved.
A thorny devil.
It can make the most
of a tiny pool of morning dew…
just by stepping in it.
Its scaly skin sucks up water
and channels it to its mouth.
In these conditions,
everyone needs a trick to survive.
[Diprotodons bellowing]
A herd of female Diprotodon,
rhino-sized relatives of wombats…
and the largest marsupial of all time.
Their trick is to migrate,
traveling for hundreds of miles
between water holes.
And finding them is
the job of the herd's leader.
She has great skill
and an excellent memory.
[growling]
Leading the herd on secret paths
forged over many decades.
[growls, pants]
But now, she's old
and frail.
[sniffs]
This year,
the drought has proved too much.
[sniffing]
[Diprotodon growls]
For her, it's the end of the road.
[sniffing]
The herd needs a new leader.
[sniffs, growls]
[both bellowing]
Two rivals.
[both growling]
Their bite has twice
the power of a tiger's.
[both growling, snarling]
[growling]
The winner,
the old leader's daughter.
And the herd quickly accept her.
[huffs]
Her first job is to find
the next water hole.
Instinct and memories kick in.
Then, it looks like another herd
enjoying a cooling drink.
A good sign.
[Diprotodons panting, growling]
But the water hole is dry.
It was just a mirage.
Others have made this mistake.
They're now a feast
for wedge-tailed eagles.
[flies buzzing]
[Diprotodon growls, huffs]
The herd will never make it
to another water hole.
Their new leader has failed them.
[sniffing]
Or has she?
The riverbed looks dry,
but she digs anyway.
[sniffs]
Water.
It's just enough.
Her persistence and ingenuity
have saved them.
[growling]
She's passed her first test…
and won the support of the herd…
[growls]
…but this is just one of
the many challenges ahead.
As deserts here grow
to cover 90 percent of the continent,
the journey between water holes
will only get longer and harder.
These barren landscapes
also make life hard for hunters.
Marsupial lions…
related to koalas,
but these are predators.
[yawns]
And right now, they're suffering.
[cubs cooing]
For the cubs, playing takes their minds
off their empty stomachs.
Every day the adults head off to hunt…
but it's weeks since they caught anything.
Their hunting grounds are turning
from forest to scrubland…
[birds cawing]
…now inhabited by formidable prey.
Giant short-faced kangaroos.
At seven feet tall,
adults are out of the lions' league,
but the young look just right.
[sniffing]
She's an ambush hunter…
but in these new scrublands,
cover is hard to find.
[leaves rustling]
[kangaroo blusters]
These kangaroos are slow.
Top speed, around ten miles an hour…
but the marsupial lions…
are even slower.
Built for wrestling prey,
not chasing them.
They're definitely more koala than lion.
- [snarling]
- [kangaroo growls]
[panting]
She needs a new strategy.
[growls]
Back at the lookout, everyone's hungry.
The hunt has failed,
and the cub's mother is missing.
Without her, he will starve.
This dung beetle is looking for a mate.
When he finds one,
his ball of dung will make
the perfect gift…
but he's got a long way to go.
Forests are dying out.
It's been happening
for thousands of years.
And everyone has to adapt.
A giant moa.
Six feet tall.
He is also looking for a mate.
These days, he has
to cross deserts to find one.
[birds chirping]
[calling]
[Hiddleston] His calls
are full of information.
His age, fitness, size…
even the number of parasites.
[calling continues]
A female can find out
everything she wants to know…
just from the quality of his voice.
An answer.
[moa calling]
If he looks a bit nervous…
there's a very good reason.
[calling]
Female giant moas are ten feet tall.
The tallest birds that have ever lived.
But they like their males…
- [calling]
- …small.
She weighs a quarter of a ton
and could kill him with a single kick…
and he knows it.
To woo her, he needs to look
as small as possible.
[calling]
Small…
but not small enough.
[calling continues]
Better.
[growls]
That's quite enough of that.
A brief but successful encounter.
For the next two weeks,
he won't leave her side.
Making sure she eats the right food…
seeing off any competing males…
[grunts]
[snarling]
…and, of course, looking small.
Deep in the forest,
the male has found the perfect spot
to start their family.
A simple nest hidden away.
[birds chirping]
In moa family life,
it's the father that cares for the young.
The egg is too delicate
for the female to sit on.
Luckily, the male is three times lighter.
Being small also makes it easier
to hide from predators
while he waits for the egg to hatch.
The smallest moa fathers
raise the most chicks.
That's why the females seek them out.
[birds chirping]
And he's dedicated.
He'll not only look after his egg,
but when it hatches,
he'll take sole care of the chick
for six long months.
And if it's a female…
[chick chirping]
…in less than three years,
she'll be nearly twice as tall as he is.
Within these small pockets of forest,
moas can breed for most of the year.
[chirping]
Others wait for the short seasonal rains.
[chirping]
When they arrive,
this strange type of Ice Age kangaroo
makes the most of it…
by having twins.
Often one is bigger
and bolder than the other.
Time to explore.
Most kangaroos are gentle grazers,
but these…
are carnivores.
Baby Megalania lizards,
hatching from eggs beneath the sand.
Where there's one,
there can be 20 more.
It's a great opportunity
to practice hunting.
But these rock turrets even things up.
Game on.
[hissing]
But there's trouble on the horizon.
A fully-grown Megalania, 20 feet long.
Twice as big as a Komodo dragon.
They'll eat anything.
Even their own young.
These baby kangaroos are good climbers…
but so is this Megalania.
Luckily, there's one more thing
these kangaroos are good at.
Jumping.
[Megalania exhales sharply]
The little brother is safe,
and the family are reunited.
Maybe a valuable lesson has been learned.
This desert is a treacherous place
to raise young.
Even the most dedicated parent
can get it wrong.
The mother sloth
has spent too long feeding.
She and her baby are now in danger.
In the midday sun,
rising thermals give flying hunters
a free ride to the mountain tops.
Teratorns.
Deadly predators with a ten-foot wingspan.
[teratorn cawing]
Climbing down is much slower going…
and dangerous.
Teratorns are smart.
They know that if
they throw her off balance,
the fall will do their dirty work.
[pants]
[screeches]
The cave is tantalizingly close.
[exhales sharply]
[huffs, growls]
Teratorns don't give up easily.
[growls]
But the tables have turned.
[whimpers]
Sheltering here means
this family has found a way
to survive in the Ice Age desert.
It's the perfect place
to keep her baby safe.
[exhales sharply]
[birds chirping]
But not everyone is so lucky.
The baby marsupial lion
is alone and hungry…
but he hasn't been abandoned.
His mother is still out hunting.
She's found her new strategy,
but it's dangerous.
Short-faced kangaroos
lick their wrists to cool themselves down.
But in this heat, it's not enough.
They need shade…
and that's an opportunity.
It's a 35-foot drop.
No mistakes.
[kangaroo yelps]
[growls]
Success.
But now she has to drag this meal…
- [growls]
- …all the way home.
[footsteps approaching]
[footsteps continue]
The wait is finally over.
Thanks to their ingenuity,
the family is holding on…
but the harsh, dry climate is spreading
to every corner of the planet,
and it's here to stay…
creating yet more challenges
for life in the Ice Age.
As the Ice Age continues,
the climate forges a remarkable
and abundant new habitat.
Grasslands.
Weird and wonderful creatures
make the most of this huge source of food.
[growling]
Grazers gather in vast herds.
[bellowing]
- Violent storms sweep the plains…
- [trumpets]
…and deadly predators fight for supremacy.
[wind whistling]
The Ice Age brought the coldest
conditions for 60 million years.
But while much of the north
was covered in ice,
to the south,
it was a completely different story.
Not extreme cold, but dry.
Deserts.
The Ice Age fundamentally changed
the water cycle on Earth.
In one part of the world,
you've got huge amounts of ice,
but, at the same time,
some places were super dry.
[Hiddleston] So how
and why did that happen?
To really understand Ice Age deserts,
there's no better place to go
than Australia.
Prior to the Ice Age,
Australia would've looked very different.
It would've been much more lush.
It would've had a lot more water,
waterways, forests.
All of these kind of lush,
vegetated environments.
[birds chirping]
[Hiddleston] Today, Australia is
one of the driest continents on Earth.
What caused this dramatic change?
Hidden beneath the sand
in this vast desert
is an extraordinary fossil site.
[engine revving]
Over 600 skeletons that tell the story
of what happened
to Australia in the Ice Age.
[Camens] When we find a bone,
quite often, there's only
a tiny bit exposed on the surface.
We carefully dig around the bone
so they can then be removed.
In this pit is
an adult Diprotodon skeleton.
[huffs, roars]
[Hiddleston] Diprotodon were adapted
to migrating huge distances to find water.
There are hundreds
of Diprotodon fossils here,
so you might expect it
to be a place that was full of water,
but there's something strange
about this site.
It seems the animals here
all died the same way.
[Camens] Anywhere a fossil is present,
they seem to be flat out on the surface,
but more often than not,
there's one limb that's gone down
beneath the surface.
[Hiddleston]
The legs often stand vertically
with the rest of the body
slumped to the side.
This strange position suggests
they got trapped in deep mud.
This desert used to be a vast lake,
but instead of the water
the animals expected,
they found something different.
[Camens] Diprotodon are coming out onto
the lake surface in search of water,
then they're breaking through the crust
and they're getting stuck,
and that's where their journey has ended.
[Hiddleston] The sad story of
so many Diprotodon dying here
suggests that during the Ice Age,
this part of Australia
was drying out and turning to desert.
The whole landscape
is just completely changed.
[Hiddleston] This was happening
right across the planet,
and like everything in the Ice Age,
it's thanks to the ice.
During the Ice Age,
there was a huge amount of ice
in the northern hemisphere.
In fact, about 25 percent of the land
was covered in ice,
and there's a finite amount of water
on the planet.
When all that water is locked up
in the northern hemisphere,
it means less for rainfall,
for clouds, for rivers.
[Hiddleston] With so little water
in the atmosphere,
some of the world's deserts
became five times their previous size.
[Jackson] Animals which
weren't able to adapt
to those changing conditions
would've been struggling for water.
It's strange to think of animals
dying of thirst during the Ice Age,
but as the climate changed,
that would've put pressure
on all of these animals
and drove them to the point of extinction.
[Hiddleston] This happened in Africa,
Asia, South America and Australia.
Once lush areas dried out,
some became deserts.
A change that was ultimately
too great for many to survive.