Original subtitles

(hyenas barking)

(gentle music)

During the Pleistocene Age

much of the earth's land was covered

by short, grass steps, including Africa.

Huge herds of prey were laid bare

for a host of hunters.

(suspenseful music)

The fearsome Sabertooth Megantereon

with its enormous fangs lay in ambush.

(suspenseful music)

Two species of hyenas tested the herds

for signs of weakness.

(suspenseful music)

Jagged toothed Homotherium, pack hunting Sabertooths,

were rampant across the world.

From Africa to the Americas.

(suspenseful music)

They were after something big.

Really big.

Like a young, straight tusked elephant.

(suspenseful music)

(elephant wailing)

For millions of years, the Sabertooths and hyenas

have been the world's top land predators.

But new forces threaten the old order

with skills the planet had never seen before.

Big cats.

(suspenseful music)

Every species of Sabertooth vanished.

Almost all the big cats survived.

Why them?

What's their story?

Which unique adaptations gave the big cats the edge

in this battle for survival?

We go back in time to when lions

were just beginning their ascent

to discover how they conquered the world

and how the tiger became

the real king of the jungle.

(suspenseful music)

1.8 million years ago,

there was a newcomer on the scene.

A predator with completely different tactics

to anything that had gone before.

A hunter that brought new abilities

to a competitive world.

The lion.

It's body was designed for power and acceleration

with huge muscles on his haunches.

The main competition for lions at the time

were the cat-like Sabertooths.

Their power was front loaded with massive neck muscles

to drive formidable canines into prey.

Megantereon was smaller than a male lion

but with those teeth,

was a dangerous adversary.

Homotherium was the same size as the lion

although it's serrated fangs were shorter,

it too was a force to be reckoned with.

These extinct animals are commonly called cats.

But they separated from the cats we know today

millions of years ago and are actually quite different.

in the Pleistocene, all three species shared these plains

but lions outlived the others and went on

to dominate the globe.

For more clues as to what gave them the edge

in this world of deadly predators,

we can look at the behavior of modern lions.

Lions are the most social of all cats.

(purring)

They can live in large prides of up to 35

including adult males,

related females and their cubs.

(gentle music)

Close physical contact strengthens bonds

within the pride

and makes them smell the same.

Together, they can share the rearing of cubs,

kills and defense against predators.

(suspenseful music)

This teamwork was perhaps one ability

that helped lions survive alongside

their prehistoric rivals.

The social Homotherium and hyenas.

So how did the lion gain a competitive advantage?

Lions today are almost completely nocturnal

as they most probably were in the past.

And it's their night hunting

which perhaps holds the key to their survival

into the present day.

At dusk, lion prides head out onto the plains

led by the most experienced females.

With specialist filming techniques,

we can see what's going on after dark.

Infrared light and heat sensitive cameras

reveal rarely seen behavior.

(suspenseful music)

These lions may look as if they're out for a stroll,

but they're hunting.

Alert to every sound.

(suspenseful music)

Their knowledge of the terrain

and highly tuned senses will be key

in helping them pinpoint their prey.

They'll need to catch something bigger than a gazelle

to feed the whole pride.

Not this big.

When hippos are angry, they're very dangerous

and could easily kill a lion.

(suspenseful music)

Wildebeest are what they're after.

On dark nights, they huddle together for safety.

They don't make a sound.

The lions can't hear them

and they're too far away to see them.

But they can smell them.

(suspenseful music)

The pride spreads out and encircles the herd.

Two sisters team up.

(suspenseful music)

They're completely focused and in sync.

(suspenseful music)

They separate and flank the Wildebeest

who are completely unaware of their presence.

Without infrared light or heat sensitive cameras,

this lioness's countershaded body

is extremely hard to see.

From where the Wildebeest are sitting,

they have no chance of seeing her at all.

To humanize, only the stars would be visible.

Lion eyes are eight times more sensitive than our own.

This is dark.

The kind of hunting lions are designed for.

One lioness takes the wing.

The other silently moves right into the middle

of the herd.

During the day on open plains,

they'd never get this close.

(suspenseful music)

The winger gets the herd moving.

(suspenseful music)

The one in the center bides her time.

From her low vantage point,

she can see the animals clearly against the sky.

Like most cats, lions have lots

of very fast twitch muscles for short,

sharp bursts of speed but are low on endurance.

Timing is critical.

(suspenseful music)

That was a close call for the Wildebeest.

The lions will continue

for as long as it takes.

(roaring)

The matriarch lets the rest of the pride know

it's time to regroup.

(roaring)

This is how a big pride stays together in the dark.

The roar can be heard over eight kilometers away.

(suspenseful music)

They wait and smell the air.

(suspenseful music)

They've located another herd.

(suspenseful music)

Again, one lioness creates panic in the herd.

But they're completely unaware of her accomplice.

(suspenseful music)

She uses her strong canines and vise-like grip

to administer a suffocating bite

to the Wildebeest's throat.

By killing her prey silently,

she's less likely to alert rival predators.

Although one lioness brought down this 200 kilo Wildebeest,

it was a group effort.

During the Pleistocene,

team tactics would have been crucial

for defense against Sabertooths.

Lions would have certainly come into conflict

with the ferocious Megantereon.

This Sabertooth with its long teeth

could perhaps kill one lion.

But not a pride.

(suspenseful music)

(growling)

(suspenseful music)

Taking on a pack of Homotherium

would have been more of a challenge for lions.

However, analysis of Homotherium's eyes

and brain structure from fossil skulls

suggests they were daytime hunters.

Which is perhaps why lions chose the night

for most of their hunting.

(growling)

For lions today,

the night still offers no respite from another pack animal.

Lion's ancient nemesis, the spotted hyena.

(hyenas growling)

They're aggravated.

The lions have invaded their patch

and chased the prey away.

When the male lions aren't around,

the hyena's, Africa's second largest carnivore,

intimidate the lionesses.

(hyenas laughing)

The adult females do their best

to keep the intruders at bay.

But there are enough hyenas here

to overpower them.

They'll kill cubs if they get the chance.

(suspenseful music)

In the Pleistocene, hyenas would have been

a serious threat to lions as they are now.

It could be that both species

needed to be social just to deal

with each other.

(suspenseful music)

One of the males turns up.

(suspenseful music)

His brother provides back up.

Male lions won't hesitate to try and kill a hyena.

And the hyenas know it.

If it wasn't for teamwork,

the cubs might be dead.

The pride can now feed in peace.

Lions can eat as much as 30 kilos a night.

But even the king of the beasts

is willing to share his meal.

The pride is in high spirits.

(lions growling)

(gentle music)

(birds chirping)

With its social nature and the ability

to hunt at night, the lion was able

to find its own niche alongside prehistoric competitors.

Its first step in becoming the master of the plains

that we know today.

But even a pride can be overpowered.

(suspenseful music)

In times gone by, elephants would have lived in fear

of Homotherium and developed an enduring hatred

for large cat-like animals.

(jungle music)

(elephant roaring)

Once there was several species of elephants

roaming these plains, keeping the grasslands open.

There's just one species left.

A survivor of turbulent times.

In the crucible of evolution that was

the African plains of the past,

the lion's next test was about to begin.

There was another predator just emerging.

Like the lion, it would change

the history of the earth.

And in the end, would challenge

all big cats for supremacy.

Homo erectus.

The first species of human to hunt large prey.

These early humans were implicated in wiping out

at least three species of elephant in Africa

and many other large mammals that were crucially

the prey of Homotherium.

In Africa, the age of the Sabertooths

was coming to an end.

Humans were replacing them.

Yet lions managed to live alongside

these early people.

Being wary and nocturnal

may well have helped them avoid conflict.

Around 1.7 million years ago,

early human hunters expanded their range

outside Africa into Southern Europe and Asia.

Almost a million years later,

lions finally followed them, crossing the Sahara

during a green spell.

Europe and Asia became the lion's new home from home

and soon they had spread from Spain

all the way to Japan.

Despite their neo global domination,

there were large parts of South

and East Asia that were out of bounds for lions.

Lions may have ruled the plains

but they were never the king of the jungle.

That crown belongs to another cat.

Weight for weight, it was as strong

and powerful as a lion.

While a pride could transit in the open,

this solitary cat preferred to stay in cover

in the forests and tall grasslands of Asia.

This was the tiger.

(gentle music)

In the depths of the ice ages,

the plains and frozen savannas

were crowded with large mammals.

(horses exhaling)

Rhinos, mammoths, wizzant, and auros.

Potential prey of both lions and tigers.

All have defensive horns and tusks.

Once used against Sabertooths

were now needed against these two cats.

With the Sabertooths gone,

the lion and the tiger became Asia's top predators.

One perfectly adapted to the open plains,

and the other to forests and tall grasslands.

Today, tigers are still found in these places

but here, in the Russian far east,

prey is now scarce.

The huge herds have gone

as has the lion.

The tigers now have to wander vast distances

in search of a meal.

But when they see prey, they take no chances.

The tiger is a master of stealth.

Unlike the lion, it has more endurance muscle

which means it can last longer in a chase.

(suspenseful music)

And when tigers catch something, they eat all of it.

Putting away a fifth of their body weight in 24 hours.

This stability to cope with feast and famine

is a trait that all can't share

and would have given tigers a competitive edge

in the prehistoric world.

Today, the Russian far east is at the edge

of their modern range, but it's thought

the tigers started life somewhere in China

and by 1.6 million years ago,

it had spread south into

a now submerged place called Sundaland

and on to the islands of Java and Sumatra.

It went as far west as Turkey

and to the far east all the way to Baringa and Japan.

Asia was the tiger's heartland

and vast waves of it

were covered by tall grass savanna.

There is a place at the edge of the Himalayas

that closely resembles the tiger's prehistoric world.

This landscape, known as the Terai,

is home to the densest population of tigers

in the world.

It's a land of giants.

(gentle music)

(water splashing)

Herds of elephants still roam here.

The world's second largest rhino.

The world's largest buffalo.

And heaviest wild cattle.

All equipped to defend themselves

against the largest living cat.

If they can see it, before it seems them.

By looking at how modern tigers live here today,

we can discover more about how they've managed

to survive the Pleistocene.

And even though there are many here,

you wouldn't know it.

The highly secretive Bengal tiger

is perfectly camouflaged.

Out of 40 species of wild cat,

the tiger is the only one with stripes.

Perhaps a unique adaptation for living

in these tall grass lands.

(birds chirping)

Much of the wildlife here congregates around water.

A place to drink.

Feed.

And cool down in the hot sun.

The one horned rhino's folded skin

over four centimeters thick

helps it to keep cool.

It may have also evolved as

a defense against Sabertooths.

The crocodile has thick skin too.

But instead, this cold blooded predator

basks on the banks to raise its body temperature.

Cheeky smooth coated otters

use their strength in numbers

to pester this deadly reptile.

Even the rhinos appear aggravated by the otters' antics.

(gentle music)

(birds chirping)

(monkeys screaming)

There's an air of nervousness

when the tall predator makes an appearance.

(suspenseful music)

Only a young bull elephant seems unphased.

(suspenseful music)

Tigers also come here to drink and rest

in the heat of the day.

But they won't turn down the chance of a meal

if something comes their way.

An otter would make a tasty snack.

These are much too wary.

A mongoose shows less caution.

(suspenseful music)

Another tiger, possibly her sister,

is keen to share the meager remains.

(tigers growling)

But there's clearly not enough for two of them.

(tiger growling)

She'll have to make her own kill.

Tall grasslands are hard places to live in.

With so many dangerous animals

and so little viability, predator and prey

have to be constantly vigilant.

Tigers are able to travel around more easily

by using paths that have been created

by rhinos and elephants.

(gentle music)

From the air, you can see just how vast

these networks of trails are.

(birds squawking)

(suspenseful music)

Being surrounded by a wall of grass

makes navigation difficult.

But researchers tracking the movements

of tigers realize they must have a mental map

of their environment.

This adult female has a home range

of about 25 square kilometers.

She'll know every feature within it

and regularly scent mark trees and bushes

to let others know this is her domain.

(suspenseful music)

She's just one of the females

that live within this dominant males territory.

The tigers in this part of the Terai

live in high densities

because of the abundance of prey.

The fading light of dusk

is a favorite time for tigers to hunt.

These hefty Gawa, once the prey of Sabertooths

are now on the tiger's menu.

At five times this male's weight,

it's hard to imagine how a tiger could take one on.

(suspenseful music)

But of all the cats, the tiger has

the strength and power to bring one down

with minimal struggle.

Something a lion would find hard to do single handedly.

This tall grassland habitat isn't a place

a lion pride could live or hunt in either.

But like the lion, it's possible the tiger

became a night hunter to avoid competition

from prehistoric predators like Sabertooths

and early humans.

Hunting at night is now the tiger's specialty.

And with sophisticated night vision cameras,

we're able to capture rare images of tigers

that wouldn't normally be visible.

This young female, around 2 1/2 years old,

is on the cusp of becoming independent.

She's still living within in the safety

of her mother's territory and learning to perfect

the skills of a hunter.

She uses the well worn animal trails

to move quickly and silently.

Rhinos can smell where she's been.

In the light of a full moon,

the biggest challenge is to avoid being spotted.

(deer barking)

The deer favor grazing in the open areas.

From our high vantage point,

we can easily see them.

But from eye level, even the thinnest grass

obscures almost everything.

Any glimpse of a tiger and the deer call.

(deer barking)

She knows she has no chance here.

(suspenseful music)

She stands her best chance on a starry night.

(deer barking)

Without the light of the moon,

she has the upper hand.

Now only infrared and thermal cameras

allow us to see what happens.

(suspenseful music)

But the tiger will have to use all of her senses

to gauge where the deer are.

Relying on her hearing to track prey down

until she's close.

(suspenseful music)

Wherever the deer go,

the tiger follows.

(suspenseful music)

Crocodile infested rivers

are no barrier.

(suspenseful music)

In the pitch black, the tiger has scent, sound,

and her mental map to guide her.

(gentle music)

(birds chirping)

These deer know this is tiger country

and can never fully relax.

She can't see far in the long grass

so has to rely on her hearing,

the most acute of her senses.

(deer barking)

(birds chirping)

Her hearing is so sensitive

that she can pick up the faintest echo

of her own footsteps.

It's possible she uses this information

as a kind of echo location

to gauge the distance of the objects around her.

Her ears rotate to pick up the slightest sound.

It's crucial she stay silent too.

(grass crunching)

One wrong move

and her cover is blown.

(deer barking)

These rare images capture how the deer respond

to the tiger's presence

barking warning calls loud and clear.

(deer barking)

(suspenseful music)

The tiger retreats into the long grass.

She's completely invisible now.

(gentle music)

And waits for the animals to settle down.

The tiger can hear some deer nearby.

(suspenseful music)

(animals screaming)

(deer barking)

(suspenseful music)

(deer barking)

This time, she won't go hungry.

(deer barking)

(gentle music)

Tigers survived a series of extinctions

during the Pleistocene that saw the demise

of the Sabertooths and many other large animals,

perhaps simply because they learned

to hide from early humans and hunted at night.

At the height of their power,

several hundreds of thousands of tigers

would have roamed across Asia.

(upbeat music)

But while the tiger was securing its place

in Eastern and Southern Asia,

lions were following the open plains northwards.

(upbeat music)

And cross the Bearing land bridge,

by 340,000 years ago, they were spreading

from North to South America.

(gentle music)

In the Americas, the lion came face-to-face

with some old enemies, Homotherium.

Although this Sabertooth had long gone

from Africa and Asia, it was still thriving here

and it lived alongside a monster Sabertooth.

Smilodon.

(lion growling)

Twice the size of its extinct ancestor, Megantereon,

and with even longer fangs,

perhaps competition with Smilodon

is why the American lion became

the biggest big cat ever,

weighting up to 400 kilos.

Incredibly, these three terrifying species

managed to co-exist for hundreds of thousands of years

sharing the bounty of prey on offer.

(upbeat music)

Across the world, wherever the lion

was surrounded by other powerful predators,

it was its ability to hunt at night

and strong social bonds that were key

to its survival.

(upbeat music)

Now with the lion and tiger distributed

across the globe,

this really was the age of big cats.

(upbeat music)

But their reign would not last forever.

Around 60,000 years ago,

a new force emerged out of Africa

and swept the globe.

Homo sapiens.

By the time these cave paintings

of lions were made in Ice Age fronts,

modern humans were just establishing their supremacy

in the frozen north.

Whatever the primal thoughts behind

these striking images fear or even reverence,

one thing seems certain:

the lives of these two social predators

have been interlinked for a very long time.

(upbeat music)

Today lions and tigers face an uncertain future

in this human dominated era.

(whistling)

During the golden age of big cats,

lions and tigers covered the globe.

But this age has long gone.

Now there are less than 20,000 lions

and fewer than 4,000 tigers.

The last remaining populations

are mainly confined to national parks and reserves.

If we want to share a future with big cats,

they need prey and space to roam.

(upbeat music)

Areas like the Masai Mara and Serengeti

are the lion's last strongholds.

These rich, green pastures plump from

the seasonal rains,

have always attracted massive herds.

During the rainy season, it's a time of plenty.

A good start in life for the youngest members

of the pride.

They practice their hunting skills

on anything that moves.

(upbeat music)

Like all big cats, they'll need to rely

on every skill they possess

to survive in this changing world.

(upbeat music)