Original subtitles

The family is one of the most powerful forces in nature.

Family life is full of wonder...

Beauty...

And drama.

For the past four years,

we've been following some of the most celebrated and endangered species

on earth.

We follow their fortunes from here on the plains of Zimbabwe,

to the jungles of India.

From the edge of the Sahara,

to the frozen wastes of Antarctica.

We join each family at a crucial moment in their lives

when they're battling against the odds.

Fighting for survival

against the elements,

and against rivals.

We've got closer and filmed in greater length

and in more detail than we've ever tried to do before.

In our modern world,

ensuring the survival of the next generation

is becoming ever more difficult.

For these families, to win against the odds

will be their greatest challenge.

This is dynasties.

Senegal, west Africa.

Home to a remarkable troop of chimpanzees.

It gets so hot and dry here,

it's the very limit of where they can survive.

This territory is ruled by one strong and determined leader.

An Alpha male known as David.

His rule gets him the best of everything.

But he can trust no one.

He's surrounded by rivals prepared to kill him

for bis crown.

This is a story of power,

politics,

and the fight for survival.

David's torn ears are testament to the many battles he's fought

and won to protect his status

and his family.

He has ruled over his troop for three years.

Leaders here don't usually hold power for much longer than this

and now as the dry season begins,

David's rivals are gathering again.

Successful Alpha males normally have many allies to support them.

But David is alone.

He has never been more vulnerable.

In the dry season, these huge mounds of earth

are magnets for all 32 chimps in the group.

The mounds are full of food.

Rich in fat and protein...

Termites.

These chimps have learned to use grass stems as tools

to fish out the insects.

As leader, David gets his pick of the feeding spots.

But he is wary

as he must feed alongside old enemies.

He has two particularly ambitious rivals.

David's toes begin to twitch.

A nervous tic he can't conceal.

This is Jumkin

who has long sought the top spot.

And this, Luthor.

A tempestuous younger male...

With an aggressive streak.

The troop is together for the first time in months

and jostling for good feeding spots can easily lead to clashes.

It's vital that David keeps order and defuses the situation.

All eyes are on him.

His display shows he is in control.

But in chimp society,

strength alone is not enough.

David must be political to hold on to power.

He needs to make an ally.

This is K.L.

He's strong but grey-bearded and past the age

where he would challenge for the role of Alpha.

David makes an approach.

Grooming builds bonds of friendship.

Buying support and giving benefits in return.

You scratch my back and I'll scratch yours.

Only time will tell if this new alliance will pay off.

Temperatures soar.

It's already 40 degrees.

The arid land might seem one giant sand pit

for the infants.

But for the adults,

existing tensions are starting to surface.

And David has his eye on jumkin.

Jumkin attacks an elderly female.

It's a display of his aspirations for power.

David can't tolerate this,

but K.L. steps in.

And gives jumkin a sharp lesson.

It's swiftly followed by one from David himself.

With a final huge lunge at his rival,

Jumkin comes crashing down.

Together, David and K.L. Are now a force to be reckoned with.

Fires destroy three-quarters of the group's territory.

Much of their food and shelter has gone.

And with temperatures continuing to rise,

water is becoming perilously scarce.

The group must stick together to survive.

Gathering in a dried-out river bed,

they use knowledge passed down from generation to generation.

A hidden water source

under the parched earth.

For David, there is more than just drought to worry about.

He can't avoid his rivals.

K.L. Is proving to be a loyal ally to David.

And David is going to need him more than ever.

By rare coincidence,

three of the seven females have become sexually receptive,

at the same time.

Their swellings attract the attention of all the males.

The females will try to mate with as many males as possible.

David must control them all

to ensure that he is the one who mates.

But some of the troop, like Luthor, have other ideas.

All the other males see this could be their chance.

There has never been a more important moment

for David to assert his power.

He makes the first move.

His rivals respond with their own display of strength

and start to close ranks.

David and k.L. Seem to be outnumbered.

Everything turns to chaos.

At some point during the night, the younger males turned on David.

The females and their infants come to his side.

To support him and tend his wounds.

They can’t stay here.

They and their young need water.

The whole group move on to the nearest water hole.

Even K.L. Has to leave David behind.

It's a six-mile trek to the next source of water.

David is left for dead.

There is now a power vacuum at the top

and Luthor sees an opportunity.

Creating fear within the group is one way to become leader.

He tries to intimidate the group.

But a bid for leadership is never instant.

He'll have to keep this up for many days.

Friendless and wounded,

David somehow musters the energy

to search for food.

He has to rejoin the group before he's exiled for good.

But first he must regain strength.

Time is running out.

Remarkably, one week after the attack,

David makes the long journey to find the group.

Luthor, meanwhile, has ramped up his bid for leadership.

David has almost made it.

But he’s in no fit state to fight.

Luthor spots David's approach.

And readies himself for battle.

David's only chance against Luthor

is to make himself look as strong as possible.

Intimidated, Luthor has to run.

Without a blow being struck, David is back.

David is finally reunited with his comrade K.L.

Grooming each other reaffirms their bonds of friendship.

For David, returning is only half the battle.

Exhausted and fragile,

he's only hanging on to his leadership by a thread.

Luthor appears defeated.

With a submissive gesture,

he seeks forgiveness from David.

But David is unwilling to accept.

Over the following weeks, Luthor finds himself sidelined.

The other males now gather round David.

And Luthor has no choice but to step in line.

David has his group around him once more.

But he doesn’t show them how weakened he really is.

His injuries haven't healed

and the males could turn on him again at any moment.

For now, he seems to be fooling them all.

He's buying himself time to regain his strength,

before another female comes into season,

when he will face competition once again.

At last rain filled clouds bring an end to the drought.

David's territory is transformed.

There is water everywhere, and a glut of food.

The pressure on the group is lifted.

Everyone can relax a little after months of hardship.

David's strength appears to be returning.

His displays in front of the group become ever more assertive.

But in truth, he remains weaker than he lets on to the others.

Whenever possible, he disappears to gather extra food.

He gorges on everything he can find.

Fruit...

Leaves...

Even ants.

He's almost back to full health.

But that alone might still not be enough for him to hold on to power.

Soon, another female will be ready to mate.

Last time, one ally was not enough for David.

He tries a new strategy.

He starts grooming other males.

First one...

Then another.

Slowly over weeks,

he surrounds himself with a band of allies.

An army of elders.

Experienced fighters, but too old to steal his crown.

Now he must wait and see if he's done enough

to prevent a recurrence of dissent in the ranks.

Sure enough, a female has come into season.

Her swelling doesn't go unnoticed.

Last time, David was vulnerable.

This time, he has allies...

Prepared to charge ahead and clear his path.

Displaying his strength reminds rivals to stay away.

If David has fully secured his position as Alpha,

he will be the one who mates with the female.

She catches his eye.

With a number of allies positioned throughout the group,

none of his rivals dare to challenge him.

This is David's time to mate.

Nine months later,

a new baby boy.

David's reward for maintaining power.

His rule and the future of his dynasty is secure.

By being Alpha, David will have sired twice as many offspring

as any other member of the group.

And one day, one of his sons

might just have what it takes to be a future leader

David has become the most powerful, longest reigning Alpha

this group has ever seen.

But there will always be another dry season.

And there will always be rivals waiting for their chance.

Next time, a dynasty of thousands.

A great march into the frozen wastes

of Antarctica.

To face the coldest and cruellest winter on earth.