Original subtitles

The decision to adopt is never easy.

But just imagine if your new baby needs to grow up

in a completely different world from you.

Carolina Vargas studies giant otters.

But nothing has prepared her for raising an orphaned cub.

CUB SQUEALS

Just keeping him alive will be difficult.

Returning him to the wild will lead them both into uncharted waters.

No one in Brazil has attempted this before.

Raising baby Sancho

will bring Carolina joy,

frustration

and heartbreak.

SANCHO SQUEALS

But it will also give her extraordinary insight

into the lives of these endangered animals.

SANCHO SQUEAKS

In south-west Brazil lies the world's largest wetland,

the Pantanal.

It's a vast, ever-changing landscape of impenetrable swamps

and forgotten backwaters.

And one of the last remaining strongholds of the giant otter.

These charismatic animals have had an almost magnetic effect

on one woman.

Carolina Vargas had embarked on a career as a city vet,

but when she discovered this maze of waterways

and the endearing nature of wild otters,

it was love at first sight.

BRAZILIAN ACCENT: Since the first time I saw a group of giant otters,

I got completely in love with them.

And I really appreciate the way they live, the social behaviour

and the care and respect they have between them in a group.

And I think they are really beautiful and expressive.

I like the way they show their feelings in their faces.

And, I think I'll never get tired of watching them.

Carolina left her home, her job and her family

and moved to the Pantanal,

eager to take on a new role as Giant Otter Researcher.

They are inquisitive animals, but that has led them into trouble.

It's made them easier to hunt, and demand for their soft fur

has pushed them to near extinction in many parts of South America.

But they seem to be doing well here because it's so remote.

Carolina wants to understand how they live

and what they need to survive.

But, just two years into her research,

life took an unexpected turn.

A local fisherman found a baby otter, alone and destitute.

He was clearly too young to make it on his own.

No one knew what to do with him, so rangers called on Carolina.

Without her immediate help, he would die.

Even though she had no experience of raising otters,

Carolina decided she could not let him down.

She named him Sancho, put her research on hold,

and became his surrogate mother.

It's been hands-on right from the start.

Sancho was very small when I took him off the local rangers.

He had the eyes still closed,

so I think he was about 20 days old.

Very small and he usually spent most of the time sleeping.

It was very hard because, in the beginning,

he had to be bottle fed.

Each took two hours, night and day.

He just woke up to feed and sleep again and I got this routine,

so I had to to wake up to feed him and after that I slept again,

to recover my energy.

SANCHO SQUEAKS

We kept him in a dry place in the first two months

and gradually we put him in the water,

just to make him swim and... get used to the water.

SANCHO SQUEALS

We didn't know how to deal with him, cos it's the first time

this work was done in Brazil, and we got the information we had

about giant otters in the wild and tried to copy that routine.

So, we stimulated him to do things the giant otters do in the wild.

Sancho's made a good start, but now he's a lot more active

and Carolina will have to work hard to keep up.

Each phase of his development throws up new problems

which he will have to solve along the way.

SANCHO SQUEAKS

If she's to give Sancho any real chance of returning to the wild,

she's going to have to think back to what she's observed along the river.

Her field notes on wild otters

will have to serve as a makeshift parenting manual.

This is turning out to be the biggest challenge of her life.

One of the main problems Carolina faces,

is bringing up Sancho on his own.

In the wild, he would be part of a large, intimate family.

One group she's been studying is a family of ten,

with three young cubs about the same age as Sancho.

Everything she's learnt about the dynamics of this family

will now help her work out what Sancho needs.

This is Italo, the dominant male of this group,

and he's always the first one

to approach the boat and say hello.

Understanding the subtle relationships between each member

of the group has required many hours of patient observations.

Fortunately, there's a relatively easy way

of telling each giant otter apart.

In order to identify them, I use the white marks they have on their neck,

and when they do this kind of movement, the periscoping,

it's the best time I have to catch the mark.

OTTER SNORTS

Now Carolina knows who's who,

she can start to work out their roles within the family.

It's very important to identify them, to know exactly what they are doing,

like Italo. It's part of the job.

He's taking care of the group and...

OTTER SNORTS LOUDLY

Italo, the dominant male,

is constantly communicating with everyone else.

OTTERS SNORT AND CALL

Compared with other otters, giants are highly articulate

and have an extraordinary repertoire of noisy calls.

Alarm snorts, screams of excitement

and hums of reassurance, all help maintain cohesion in the troop.

And the cubs learn a lot from these elaborate vocalisations.

OTTERS SQUEAL

Carolina has picked up some basic otter language,

but she's far from understanding the complexities of giant otter society.

And she's concerned this could be a major disadvantage for Sancho.

She has no idea whether she can teach a solitary otter

how to survive in the wild.

But she knows that that's the best place for him,

and wants to return him as soon as she can.

For now though, she concentrates on getting him into a routine.

Giant otters are active during the day,

so at first light, Carolina wakes Sancho from his den.

Giant otters live in family groups

and the cubs spend two years or three years with the parents.

And so, I believe they need this contact with their parents,

just to learn...how to be a giant otter.

Sancho hasn't got that. But at least he's got Carolina.

SHE CALLS: Come, come, come.

And because he's such a sociable little thing,

he's already very close to her.

Come, come, come, come.

Sancho recognises me as his mother.

That's why I believe he's very bonded with me.

Actually, I feel like he's my son, too.

SANCHO SQUEALS

At four months old, Sancho is already a very demanding cub.

He's now weaned off milk and has a growing appetite.

SQUEALS EXCITEDLY

The excitement with which he handles his first fish of the day

is something Carolina has never seen before in the wild.

It's time to introduce him to his real home.

The pulse of life in the Pantanal

is driven by a seasonal cycle of floods and droughts.

October storms herald the onset of the wet season.

Heavy rain swells the Paraguay River,

until she bursts her banks and floods an area the size of England.

For the next six months, savannahs and forests are transformed

into a land of swamps, pools and channels.

The slow-flowing water is rich in nutrients,

nurturing forests of aquatic plants.

This is the perfect nursery for more than 300 species of fish.

It's a giant aquarium, bursting with life.

And that's why giant otters do so well.

But they aren't the only predators here.

And for an inexperienced otter,

the Pantanal can be a very treacherous place.

It's up to Carolina to help steer Sancho away from danger.

But even she can't always see what's lurking below the surface.

And he's already had one very close call.

When Sancho was younger, he was very vulnerable

and I had to watch out for him all the time.

Probably, he was good prey for cayman, anacondas, maybe jaguars,

and he was, in fact, attacked by a cayman.

It was just after the feeding.

Sancho was playing

and the cayman just came to him and bite his head.

But in a few seconds, the cayman just...

..let Sancho go and he was very afraid.

He was scared about it.

And after that, Sancho started to be scared

of that place where he was attacked.

Carolina has to help him get over his fear

and encourage him back into the water.

HE SQUEALS

Her commitment to him is so strong,

she finds herself drawn more and more into the giant otters' world.

HE SQUEAKS

When we are swimming, it's very funny when he approaches me

and he starts playing with my feet and sometimes he bites me.

I do believe he's really enjoying swimming

and I can see it in his face, cos he shows that he's having fun.

With huge webbed feet and a strong, flattened tail,

Sancho is built for swimming.

His instinct and ability are there, but he's still a little clumsy.

It's very important to him we swim together, cos I think

he's more confident to explore and search for new things underwater,

cos, in the wild, he would probably be doing that now.

Even though Carolina's research is on hold,

she's learning more about giant otters

than she could ever have imagined.

I'd never dived with a giant otter,

so Sancho is teaching me a lot of things about giant otters,

the way they swim and the underwater behaviour.

At the same time he's learning, I'm learning with him.

I feel like my work is doing well

cos his behaviour is just like a wild giant otter.

I'm proud cos each day, I'm very pleased

with his behaviour and his progress.

Together, they have conquered Sancho's fear

and he's now much more at home in the water.

But Carolina knows he's still got a long way to go.

Wild otter cubs gain their confidence

by being at the very heart of the family.

At the head is a dominant couple.

Together for life, they are the parents

of everyone else in the group.

In the safety of such a large family,

the cubs have plenty of time to play.

They're also free from the pressures of finding their own food

because every member of the family helps provide for them.

Carolina has seen how a constant supply of live piranha

is delivered to the cubs, while they wait on the bank.

Everyone has a duty to help rear these cubs

and teach them how to tackle their food.

Carolina knows that somehow she is going to have to

recreate this lesson for Sancho.

She isn't just a surrogate mother to him now,

she has to stand in for every missing member of his family.

It's a tall order but Carolina is prepared to rise to the challenge.

Every day means getting up at 5am to catch piranha.

So far, Sancho hasn't shown any interest in catching his own fish.

But now's the time for him to start to pull his own weight.

Come, come, come, come, come.

HE GROWLS

In the wild, he will have to use all his senses to catch fish.

And Carolina has decided that a paddling pool full of muddy water

is the best way for him to get used to murky river conditions.

Not only does this work,

but some of his natural instincts are starting to kick in.

He uses his whiskers to sense where the fish are.

And when he's almost full,

he tests himself further by playing with his food.

Refining his skills like this seems to boost his confidence.

But Sancho will need more fishing lessons

before he's totally self-sufficient.

The trouble is, the more Carolina prepares him for independence,

the more attached she becomes to him.

HE SQUEALS

Ow!

At six months old, Sancho is now totally at ease in the water

and his natural curiosity is blossoming.

Sancho is now more confident

to spend more time diving and searching for things.

He dives so deep.

It's very nice to see him doing that.

And he always comes back to me, just to check if I'm here.

And, so, he feels safe to go out again and keep searching for things.

But I have to be close to him, cos he's always checking.

He's becoming much more aware of his surroundings,

and, perhaps most importantly,

he's started to take a keen interest in fish.

Using his feet to steer and his tail for propulsion,

he can now reach high speeds underwater,

and has more chance of escaping his old enemies.

But he still looks to Carolina for reassurance.

She provides the protection he would expect from his family in the wild.

Giant otters do everything together.

Whenever they travel, the adults surround the cubs,

always on the lookout for danger.

Like Sancho, they are still vulnerable.

And despite the family's care, only one in three cubs will survive.

When the group finds fish, they begin to hunt.

The chaos created by ten otters

confuses the fish and makes them easier to catch.

But it's each otter for itself,

strictly hunting and eating alone.

The cubs pester the grown-ups and constantly call for food.

CUB SQUEAKS

The adults eat first before tending to the youngsters.

Then they offer smaller fish

and encourage the cubs to play with and chase them.

All good practice for tackling their own slippery prey.

On each fishing trip,

the cubs must learn an enormous amount from the adults.

But this is where Carolina's abilities

as an otter mother reach their natural limit.

She can only guess how young otters

learn to hunt from what she's witnessed at the surface.

Somehow, she's got to encourage Sancho to catch his own food.

And this is proving to be the trickiest part

of his rehabilitation so far.

Carolina has had to think long and hard

about a training programme for Sancho.

But, in the end, it's down to trial and error.

This is going to take a lot of practise.

Once he starts to fish by himself,

I will start to...break the bond he has with me

and that will be hard as well.

At the same time, I really want him to go and become a wild giant otter,

but when this moment comes,

I'll be proud of that, but, for sure, I will miss him.

Bringing up Sancho hasn't been easy,

but Carolina is beginning to realise

that the hardest part is yet to come.

She is going to have to let him go,

and the moment of separation is edging ever closer.

The rains have stopped and the Pantanal is drying out.

As the water levels fall, fish become trapped.

Life gets easy for abundant water birds.

But birds aren't the only ones to take advantage

of the glut of easy food.

It's a perfect time for Sancho to head off on his own,

but Carolina still has to think carefully

about where she can release him.

Wild giant otters are aggressively territorial.

Their home ranges can be over 12 miles

and they patrol them constantly.

The giant otters have different ways to mark their territory.

They can use the smell, scent glands and visual marking.

They scratch the river bank.

And sometimes they use their voice to mark that place.

These are clear signs to all other otters that this land is taken.

They have a special care with the scent marking

because it's very important to keep their territory

and avoid fights with other giant otters.

But she has no idea whether a close-knit family like this

would accept him or kill him.

If Sancho enters into another group territory,

the group may not accept Sancho and have a fight.

So...it's so important for me

to know the groups and their territory in this area.

CUBS SQUEAL AND CALL

This is going to be a tense time for Carolina.

She can point Sancho in the right direction, but ultimately,

it will be up to him to find and defend his own territory.

Sancho is now eight months old and Carolina thinks she has found

a stretch of no-man's land fit for his fresh start in the wild.

She continues to help him fish,

but she knows this is the beginning of the end of motherhood.

SANCHO SQUEALS

I decided to move Sancho in order to break the human contact

and show him another territory for him to start to explore.

In the first few days,

he was not confident to travel further,

but now, I can see that he's showing more interest in exploring new places

and he's spending more time on his own, which is good.

HE SQUEALS

Despite the great strides he has made, Sancho is still young

and Carolina knows she will always worry about him.

But the mothering will have to stop,

if Sancho is ever going to be self-reliant.

She decides to leave him for most of the day

in the hope that he will start searching for his own food.

This really is tough love.

For the first time, Sancho is on his own.

SANCHO SQUEALS

I'm not sure that Sancho is 100% able to defend himself.

When he's by himself,

he shows that he's not comfortable,

and he spends some time calling his mother.

So, I don't believe he feels safe all the time.

SANCHO SQUEALS

He cries for Carolina constantly.

Something no wild otter would do,

as it could attract unwanted attention.

HIGH-PITCHED SQUEAL

Unwittingly, he has called in a pair of wild otters.

OTTER SNORTS

Sancho has never seen another giant otter before

and has no idea how to react.

On the first day, Sancho was a little bit afraid of the couple

and he stayed most part of the time close to me, just watching.

HE SQUEALS

It's a new experience for Sancho.

At the same time he's losing human contact,

I think it will be very stimulating for him.

Maybe it will help him to...

..finally find his way.

Over the next few weeks,

Carolina watches as the couple visit Sancho regularly.

His initial nervousness begins to dwindle

as he realises he speaks their language.

OTTERS SQUEAK

Luckily for Sancho, this couple seems friendly.

In fact, their meetings help to build his confidence.

All of a sudden, Sancho seems ready to take the final plunge

into the giant otters' world.

Carolina starts to reduce his fish rations.

Until one day, she discovers he doesn't need her any more.

SANCHO SCREAMS

We just found him eating a big fish,

so, we realised that he'd just caught his first fish.

Actually, I think he was already catching his own fish

but hiding from us.

It's great and after this day, he's started to fish

almost every single day.

Sancho has finally proved he can look after himself.

Torn between pride and sorrow,

Carolina seeks solace in her role as a researcher.

There's a lack of information about this period of giant otters' lives -

when they leave the family

and start to travel to find a mate and a territory.

So, I think Sancho will be very important

and he will give us a lot of information about this period.

Although the separation will be hard for her,

Carolina's confident she will continue to learn from him.

But then, the moment every mother dreads.

SHE CALLS: Come, come, come, come, come, come, come, come.

Come, come, come.

Come, come, come.

I've arrived here this morning and Sancho was not here.

He hasn't travelled far from here and...that's why I am concerned,

cos what happened to him to just decide to go away,

if he doesn't know this place?

It could be that Sancho has grown up quicker than Carolina realises.

Come, come, come, come, come, come, come, come.

In the wild,

giant otter cubs do become independent at nine months old.

But they're still at risk.

I think he is still potential prey for cayman, a big cayman.

And if...

..if he was sleeping on the ground, he was potential prey for a jaguar.

I have to look for him.

So, I'll take the canoe and...

..and try to find...

..try to go to the places I have already been with him.

And...

Unfortunately, I have to look for, erm...

SHE SOBS

I have to say that I have to look for his body,

I have to do this,

but I'm still thinking positive about it.

He's just a rebel.

Maybe he's trying to...

..show he's angry about us

leaving him alone for a long time,

or giving him less food, I don't know.

But I'm still thinking he'll come back, soon.

Come, come, come, come, come.

Come, come, come, come, come. Sancho?

Sancho?

Come, come, come, come, come, come, come.

Come, come, come, come, come, come, come.

Sancho?

Come, come, come, come, come, come, come.

Sancho?

Three months have now passed since Carolina last saw Sancho.

He's left a huge hole in her life.

She has found some comfort in resuming her research project,

even though she spends a lot of time looking for him.

But Sancho has left her with more than just memories.

Wild otters are normally very shy and difficult to get close to.

But this is the pair that Sancho befriended all those months ago.

So used to seeing her with Sancho, they have accepted her.

She is rewarded with an exceptional front row seat.

OTTER SQUEAKS

She's trusted enough to have a rare glimpse of their newborn cubs.

I'm monitoring this couple

since they started visiting Sancho a few months ago,

and I'm following all the process

since they copulated and showed the first signs of pregnancy.

So, seeing them now with the cubs is very special.

I feel like part of their family and I am very happy to know that

they are living fine here.

Deep down, Carolina hoped that Sancho might have joined forces

with this young couple.

Evidently, that was not to be.

But Sancho gave Carolina a real insight,

a deeper understanding of what it actually takes to be an otter.

Seeing cubs reminds me of Sancho all the time,

and I'm glad in seeing in these cubs the same behaviour I saw in Sancho.

The whole process with Sancho

is helping me now to understand what's going on here.

Carolina's relationship with Sancho also changed her life.

Raising Sancho was a special experience in my life.

Being in touch with such a beautiful and lovely animal was amazing,

and at the same time challenging.

And I tried to teach Sancho lots of things

but I'm sure I learned much more from him,

and now all these things I learned are helping me to understand

the cubs' behaviour in nature.

Carolina did everything she could for Sancho,

but she still doesn't know if it was enough.

Perhaps the hardest part for Carolina is the not knowing.

But now, as she travels the waterways of the Pantanal,

her research has an extra dimension,

a glimmer of hope that he could be out there, somewhere.

I have now one special reason to keep my monitoring work.

I have to look for Sancho and I'm sure, one day,

I will find him with his family.

Next week, Natural World goes on a spiritual journey,

spending a year exploring the wildlife of the moors, woodlands and rivers of Dartmoor

with Satish Kumar, ecologist, former Jain monk, and pilgrim for peace.