01x10 - Growing Old

[bunniefuu]

[Bonneville] Experience a
world beyond imagination

where fish can fly...

lizards walk on water,

apes master tools

and frogs disappear
in plain sight.

Animals do the
smartest things...

through every stage
of their lives.

[meerkat barks]

From leaving home...

to raising a family.

From finding food...

to making friends.

[elephant trumpets]

They find ingenious
ways to survive

against all odds.

[bellows]

Welcome to The Secret
Lives of Animals.

A rocky outcrop in Kenya.

Home to a troop of


[baboon grunting]

This is the top male.

He fought hard to
gain his status.

But it's a demanding job

and he's getting on a bit.

A younger male senses
the time is right

to challenge for his position.

[baboon grunting]

[screeching, grunting]

The older baboon knows
when he's beaten...

and retreats.

Alone, he's vulnerable
to predators.

To stay safe, he must find
a new role within the troop.

[baboons chattering]

While his young successor enjoys
the benefits of the top job...

the elder spots an opportunity to
get back into the heart of the group.

[baboon barks]

Surprisingly, this
infant is the key.

A yawn with his teeth covered
shows he means no harm.

His plan is coming together.

[infant baboon grunting]

The new top male is not happy
with him being so close...

but the old boy knows
exactly what he's doing.

The females see the top male's
aggression as a threat to the youngster.

Baring their teeth

and raising their eyebrows

makes it clear they
won't tolerate it.

This time, it's his
turn to back down...

leaving the wise old
male and baby safe.

Over time, the elder baboon develops
into a kind of benevolent grandfather.

Babysitting...

and mentoring the youngsters.

He's not as strong
as he once was...

but he's wise and still has
plenty to offer the troop.

Growing old can be a
time for new beginnings.

With age comes knowledge,

responsibility
and great rewards.

The oldest desert
in the world...

Africa's Namib.

Water here is hard to find.

This female desert elephant
is the oldest in the herd.

[elephant rumbling]

It's her responsibility
to keep the rest alive.

They can't survive for more
than four days without a drink.

[rumbling continues]

So she leads them to the only
permanent water hole for ten miles.

[baboons screeching]

But experience tells her
something's not right.

[flies buzzing]

It's contaminated.

If they drink here,
they risk illness.

[rumbling]

She must look for
water elsewhere.

The longer they walk, the
more dehydrated they become.

But this old elephant has
a trick up her sleeve.

[rumbling]

She has one of the best
memories of any animal,

and drawing on it...

she recalls every
feature of this landscape

and creates a mental
map of the area

so she can take the fastest
route through the desert.

Here, the bushes are green.

She knows the water
must be close.

But the riverbed is dry.

The youngest in the herd
are desperately thirsty.

Using the most powerful sense
of smell of any land mammal,

she turns detective.

And does something
truly remarkable.

She digs...

four feet down,

until she strikes...

fresh water.

It's safe to drink.

The rest of the herd
follow her lead.

And there's enough to guzzle
up to 40 gallons each.

Her unrivaled knowledge of
this desert has saved the herd.

Growing old can be tough.

But for some, it marks
a new lease of life.

A Caribbean reef.

This three-year-old female wrasse
is the eldest in her shoal.

Every day, she and the other
females visit this sea fan.

It's home to the only
male wrasse on the reef.

His coloring gives their species
its name, bluehead wrasse.

He fertilizes the eggs
of every female here.

And the oldest is always
at the front of the line.

But in the ocean, circumstances
can change very quickly.

And the next day when the old
wrasse reaches the mating ground,

the male has disappeared.

Without a male on the reef,
the females can't breed.

Within minutes, the old female reacts
with an extraordinary solution.

She stops producing the
female hormone estrogen...

and her scales begin
to change color.

She becomes more aggressive.

Her body starts to
subtly alter shape.

And day by day, the difference
becomes more dramatic.

After three weeks, her
transformation is complete.

She has become a he.

By blocking her female hormones
and producing male ones,

this brilliant old
fish has changed sex.

As the new male,

he will now fertilize all the
wrasse eggs spawned on this reef.

For some, reinvention in
later life comes easily.

But for others, it's
a long, hard slog.

A giant Galápagos tortoise.

One of the most ancient
animals on Earth.

At a hundred and
fifty years old,

he's entering the
prime of his life.

He's still growing...

so must eat lots of
highly nutritious grass.

But the dry season
is fast approaching.

And the food here will
soon wither and die.

[tortoise groans]

With the wisdom of his years,

he knows exactly what to do.

The volcanic highlands provide
rich nourishment all year round.

The problem is, they
are six miles inland

and a 1,250-foot climb.

The height of the
Empire State Building.

It will be an epic migration.

Albeit a very slow one.

Surprisingly, his old age
is the key to his success.

His large size means he
can overcome obstacles

that younger, smaller
tortoises simply cannot.

After a month...

he arrives.

At the tortoise promised land.

A seasonal retreat for the oldest
and biggest residents of the island.

Mountain mist guarantees
nutritious food

even in the driest months.

By trekking here once
a year, he'll thrive...

even as he closes in
on his 200th birthday.

Getting healthier and stronger.

His old age really will be
the best years of his life.

And when winter arrives,

he'll make the long, slow
journey back to the coast.

The secret to eternal youth
may continue to evade us...

but here on the Canadian border,

one animal has found a way to put
the brakes on aging altogether.

This is a monarch
butterfly caterpillar.

She gorges on the only
plant she can eat.

Milkweed.

And she doesn't stop

until she's grown


Then transforms...

into a butterfly.

But winter is coming.

It will be too cold and wet for
her to survive this far north.

The freezing temperatures
could last for months.

Most monarchs only
live for a few weeks.

So, she does
something astonishing.

She blocks the production
of a hormone...

which in turn...

slows her aging.

And then flies over


to join millions
of other monarchs

in the shelter of a
warmer, drier fir forest.

The butterflies huddle together.

She shuts down all but her most
essential life-support systems.

When spring arrives
four months later,

she takes to the skies...

and heads back north...

to find a fresh
crop of milkweed.

She reactivates her hormones
and begins to age normally.

Now she is ready to breed.

Her clever trick means she lives
far longer than the average monarch.

The equivalent of us
reaching over 500 years old.

Age is no barrier
to dramatic change.

With experience, we can navigate
whatever life throws at us.

With the wisdom to adapt...

later life is a
time to flourish...

and take flight.

[Bonneville] Finding a family of
desert elephants digging for water

in the vast landscape of northwest
Namibia is a huge challenge.

So, the team joined
guide Rayne Brehem

who knows this land almost
as well as the animals.

As a kid from three years old,
I used to go out to the rivers,

playing in the sand and
sand is in my veins now.

[Bonneville] Just as well,

as the Namib desert sands
are always on the move.

It's super windy and dusty
which means the car is rocking,

the lens is covered in dust

and we're all inhaling about
a kilo of dust every second.

[Bonneville] Shifting sands mean tracking
must start from scratch each day.

[Brehem] So, in the morning, you're
looking for the most crisp lines.

At the back of the track, will
always be really clear, defined

and the front of the track will have,
like, a drag mark or a flick mark in front

and that'll show you the
direction that they're going.

[Bonneville] Now they know which
way the elephants are heading,

the team tries to catch them.

But who is following who?

I'm getting more tracks
on top of our tire tracks.

So, I think when we took this bend
around, they were already on this bend,

and so we've kind of done that.

[Bonneville] As the team drive,
Rayne notices a change in the tracks.

[Brehem] As soon as
you get close to water,

a lot of the time you
can see them form a line

because they're just in a hurry.

They've made up their mind,
they know where they're going.

[Bonneville] With the
elephants getting close,

the team must find them fast,

and the best way to do that...

is to put an eye in the sky.

With the elephants located,

the race is on to get in position
before they dig for water.

She's digging. It's the
first time we've seen it.

It's amazing.

[Bonneville] Not only is
the old elephant digging...

- [rumbling]
- she's passing on her life-saving skills

to her young.

[crew member] Let's get
a spray. We want a spray.

[Morgan] That's really nice.

[Bonneville] A combination
of Rayne's expertise

and modern technology...

[rumbling]

has revealed the
secret knowledge

of some of the oldest and
wisest animals in the world.