[energetic music] - [Allison] What wisdom lies hidden in a world we've just begun to fathom?

In every corner of the Earth, lessons are being learned from unlikely teachers.

- [Daphne] Every single animal has touched my life in a very special way.

I mean, you're learning all the time.

With every single animal, you learn something new.

- [Allison] From the plains of Kenya to the Colorado prairies, lives are being transformed.

- [George] I should not be alive today.

It's only by the grace of God and the horses that I'm still here.

[birds chirping] - [Allison] In ways we don't yet understand, animals can awaken even the most distant soul.

[dolphin laughing] The smallest of creatures can ignite the imagination and cause our spirits to soar.

[child giggling] Even those we thought were knew so well are still offering surprising insights.

- [Linda] They have provided us with so much in this world.

So much knowledge.

- [Allison] Beyond our human boundaries, there's an uncharted land.

In it lies the legacy of every living creature, an ancient understanding still waiting to be explored.

[soft ethereal music] [energetic music] - [Announcer] This program was made possible by the Corporation for Public Broadcasting and by contributions to your PBS station from viewers like you.

Thank you.

- [Allison] Hidden in the remote mountain forest of Tanzania, there is a magical world.

[soft ethereal music] A world where creature and human share an ancient alliance.

Here the medicine men know how to read their forest like a book.

By watching the creatures around them, they have learned to heal their own people.

They have found cures for everything from headache to arthritis.

Their knowledge of remedies reaches deep into the jungle and deep into their past.

[deep thundering] [singing in foreign language] For as long as the Watungwa people have walked the Earth, they've observed wild animals using the medicines of the forest.

They've known that a sick chimpanzee might know where to find a cure that could heal their own people.

[chimpanzee vocalizing] These observations from the past provide a wealth of knowledge still used today.

[chimpanzee screeching] Mohamedi Safu Kilunda comes from a long line of traditional healers.

A game officer in Mahale Mountains National Park, he's teaching the wisdom of his ancestors to a modern medicine man.

[speaking in foreign language] His colleague, Dr. Michael Huffman, is a world renowned scientist, a trailblazer in a new field of research.

[speaking in foreign language] - Here at Mahale, Mohamedi and the chimpanzees themselves are my teachers, my instructors.

We've started out just following the chimpanzees, trying to figure out what the chimpanzees are doing when they're sick, how they heal themselves and what we can learn from them.

What kinds of plants they're using, the ways they're using the plants, in hopes that we too can use this to better the lives of people.

[speaking in foreign language] - [Allison] For over a decade, Michael and Mohamedi have been tracking the same group of chimpanzees deep within a 70 square mile expanse of forest.

Chimps are ideal models.

Like humans, they're vulnerable to malaria, arthritis, even polio.

But in his search for new medicines, Michael knows he's working against the clock.

- [Michael] This is one of the last places where the chimpanzee is safely protected and we still have so much to learn.

To wake up one day and see that that all of this is gone would be like throwing away the last medical textbook.

- Really down.

[speaking in foreign language] - [Allison] With Mohamedi as his guide, 15 years ago Michael found a clue he's been following ever since.

They observed a sick chimpanzee eating the tender shoots of a tree to cure herself of parasites.

[soft ethereal music] Lab reports confirmed the tree had acted as a remedy.

The chimpanzee had led Michael to the discovery of 13 entirely new compounds, compounds with anti-cancer, antibacterial, and antiparasitic properties.

[whispering in foreign language] - [Allison] It was a discovery that could have astounding consequences for the human race.

More than half the world's population suffers from parasitic diseases and the symptoms can be fatal.

- This is what they were eating.

It's the first medicinal plant that I found chimpanzees using.

But when Mohamedi and I first saw the first incidence, it was Mohamedi that told me that when his people are sick, showing upset stomach, diarrhea, things like that, that they also use this plant and it's a very important plant.

It's amazing that humans and chimpanzees are using the same plant for the same thing.

[speaking in foreign language] As a scientist, I'd like to think that I'm covering new ground, but in actuality, I'm retracing the footsteps of a very ancient civilization, both human and animal.

[singing in foreign language] [soft ethereal music] [singing in foreign language] - [Allison] Within the tropical forest is a medicine cabinet waiting to be opened.

In its archives are drugs like quinine, heart medications, and possible cures for cancer.

By unlocking the wisdom of generations past, Michael hopes to secure a future for generations to come.

- The observations that I made about 15 years ago of a chimpanzee using leaves to medicate herself, sparked an idea to try and combine the wisdom of chimpanzees with the methodology of science so the cure will last forever.

If I can do that, I'll be a happy man.

[soft ethereal music] - [Allison] Following in the footsteps of medicine men before him, Michael Huffman continues his quest.

While half a world away, a very different sort of healing is taking place.

[soft ethereal music] [horse nickering] [soft string music] - [George] If it weren't for the horses, I'd be in one of three places.

I'd be in jail, I'd be in an institution, or I'd be in my grave.

[birds chirping] [soft string music] The horses, they give me something to care about.

Even when I was down and I didn't even care about myself, you know, now I have something to care about.

And now I have something that I know cares about me.

Inside that just feels really good.

- [Thurman] I didn't know how to care for things.

Me and my mother was having a hard time.

Me and my friends and everything.

I didn't care about anything.

I just didn't care.

If it wasn't for these horses, I'd be on the street because my family didn't want me.

So that's how it changed my life.

[horse nickering] - [Allison] On a ranch in Eastern Colorado, young boys are mending their shattered pasts in the company of horses.

The Colorado Boys Ranch is a nonprofit treatment program for neglected and emotionally disturbed boys from across the nation.

Some have been placed by the judicial system as the last resort.

Here they're given another chance.

Director of the horsemanship program, Jim Kerr, has seen some remarkable transformations.

- [Jim] Most of these kids didn't have somebody there every morning that fed 'em breakfast, took care of 'em, got 'em off to school, whatever, you know?

These horses grow to know that these boys are gonna be here every morning.

They're gonna feed 'em.

They're gonna take care of 'em.

The kids turn that all back too and say, "Hey, guess what?

"You know, they take care of me in a multiple of ways, too."

So we feel there's a lot of emotional healing that takes place.

- [Allison] Here at the ranch, the lessons learned outside the classroom are often the most profound.

- Slow down.

Horses can do things for these boys that, that you and I can't.

Most of these kids look at adults and are very untrusting.

They feel let down.

If you tell 'em you're gonna be there, you better be there.

These horses are always there and they take care of these kids.

Go easy, Sean, don't hurry him until you warm him up.

Those kids have to learn to share control with this 1100 pound animal out there on the mesa.

And most of these horses will babysit and take care of them in a way that you wouldn't believe.

[soft string music] - [Allison] With the horses, each boy at the ranch is learning his own special lessons.

For 17-year-old Thurman, it's a lesson in family.

- The boys get to be an active part of the foaling process and see the nurturing and the love that the mothers can give to the young ones, you know?

A lot of these kids have never had that.

So we try to help those kids understand what family life should be, what sharing should be, what caring should be.

And these, the animals do it themselves.

Get him going.

[soft ethereal music] Yeah, when you're working with young horses, Thurman, you have to be patient, take your time.

They'll learn to believe in trust in you.

Let's see if she'll follow.

- Come on.

She if she'll follow momma.

- [Thurman] Come on.

[tongue clucking] Come on.

[horse whinnying] - He's associating the pull coming from you.

- [Thurman] Okay.

- The pressure's coming from behind.

It's a gentle and easy way to make the pressure come from somewhere besides you pulling on their heads.

They don't associate that with you.

We do the same thing in treatment with the boys.

We let them make the decisions with our guidance and our structure, but they're doing it, you know?

And the same way here, we're not pulling on the head of that colt.

See if you start pulling on it, that's what you get.

They'll run backwards.

They'll leave you.

You do what we've done with the rope, you're pulling down below, you're not pulling on his head.

The pressure's coming from somewhere else and he'll follow you.

[soft country western music] - [Allison] After years on the streets, 16-year-old George has begun to turn his life around.

Thanks in large to a champion show horse.

[gate clanging] - His name is Ostentatious.

He's a great big, massive quarter horse with this humongous personality.

He can bring back a feeling in a person that disappeared long since.

My sisters were always mad at me and, in turn, I was always mad at my baby brother, you know, because I didn't know anything else except anger.

And then finally I gave up.

I was by myself.

I was on the street a lot.

I was in jail doing no good to myself, no good to other people.

I owe everything to the horses, you know?

I mean, they'll sit and they'll listen to you, you know?

They kind of nuzzle you with their nose or they they'll let you know it's okay and that you're gonna pull through.

And I've needed that.

And I've gotten it.

It's just a wonderful feeling to be here and to finally know love.

Because a horse isn't gonna let you down.

You know, he'll be your friend through the thick and the thin.

Well, get off the hose you knot head.

Come on.

Oh, there you go, stay there.

A creature this size, I mean, he knows he could just trample me.

He, I believe he knows he can.

And to know that he's not only means that he must trust me.

And that's kind of special because not too many in the past, not too many people in the past have trusted me, you know?

- [Allison] With Ostentatious, George has been challenged to reach beyond his past.

For six months, he's been showing the champion at competitions around the state.

Tomorrow, they'll be in Pueblo.

- [Broadcaster] This is the final call for entry number 426.

Thank you.

- [George] Getting ready, it's really nerve wracking sometimes.

And then it's kind of like, hurry up and wait.

And that really gets your nerves wracking.

And then when you wait, you can't help but think.

- [Participant] I dunno what this stuff is.

[fairgrounds chatter] - [Broadcaster] If I can have your attention, please.

We do have a vet on the ground.

If you need seen, please come to the office and let me know.

Thank you.

- Since I've been here, Jim, he he's been like a father to me.

He doesn't let me stray too far from the path.

- If I poke you, scream.

- Scream, I was gonna ask for forgiveness.

- Oh, I'll give you that, too.

- I have that.

That's all I need.

They're on the mares already.

Did you comb it this morning?

- Yeah.

Holey moly.

- Ow.

I'd be hurting me, too.

Let's see.

- [George] I'm good.

That's why I'm nervous right now.

- Once you get to the [mumbles], just nice little grin, nice little smile.

They see that.

They like that.

Okay?

Be proud of yourself.

[mumbling] - [Allison] With Ostentatious by his side, George will face the judges.

- [Broadcaster] Number 453, Ostentatious.

Owned by the Colorado Boy's Ranch and exhibited by by George Danver.

- [Allison] But for George, there are far more important challenges ahead.

[soft uplifting music] Here at the boys ranch, lessons learned from horses are helping young men rise beyond the wounds of childhood.

[horse nickering] With their gentle persistence, the horses are leading these boys to a second chance.

- [Thurman] The horses showed me how to love.

That's kinda like parenthood.

I don't want, I don't wanna have a boy.

- Hi baby.

- [Thurman] Every time I care for my baby and every time I love my baby, I think about how I love the animals.

[soft ethereal music] - The horses at the ranch, they've showed a great deal of patience.

And I guess that's what I needed.

The way they don't give up is like, it's helped me to learn more about myself.

You know what I need to do not to give up.

[soft ethereal music] - [Allison] Halfway across the world, there is a creature that has not forgotten the meaning of family.

[soft orchestral music] [guttural sounds] Here on the plains of Kenya, early morning has brought with it a momentous occasion.

After nearly two years in her mother's womb, a calf has been born.

With her first tentative steps, she is welcomed into the herd.

[guttural sounds] These bonds will last a lifetime.

- [Daphne] To be a baby elephant must be wonderful.

Surrounded by her loving family 24 hours a day.

Touched by the family.

Cuddled, comforted with tremendous love and compassion exuded by every family member.

I think it must be how it ought to be in a perfect world.

- [Allison] Perhaps more than any other person, Daphne Sheldrick has a special understanding of baby elephants.

[speaking in foreign language] For 50 years, she's been surrogate mother to dozens of orphans.

She's raised most of them here at her home in Nairobi, alongside her human family.

- Look who's here.

[speaking in foreign language] Yes.

- [Allison] Her encounters with elephants have taught her lasting lessons in compassion.

The most recent arrival is three-week-old Ilinguesi.

If she's to survive, the nurturing she would've gotten from her wild family will have to be replaced.

- And if you've had your own children, as I have, and now have grandchildren, it's not difficult to see they're very family-minded animals.

These little elephants are a bit deprived, but they have a human family in place of the elephant one, but it's not quite the same thing.

- [Allison] Daphne learned this lesson the hard way 25 years ago.

- [Daphne] When I had my first baby, Isha, I didn't have any keepers.

There was just me.

And I fed her every four hours like you would a human baby.

And put it in her little stable at 10 o'clock at night with one of my dresses hanging in her stable.

But that actually wasn't enough.

She got to six months.

But when I left her for four days, because my daughter was getting married, she simply died of a broken heart.

Then I learned that they must have a family.

[speaking in foreign language] - [Allison] Elephants mature at much the same rate as humans.

Their lives can span 80 years.

Like Daphne's grandson, these infants will be dependent upon their human family for many years to come.

Their keepers are the key to their survival.

- Meshach's a hot favorite with all our elephants.

He's our most experienced keeper.

And these are the men are trainees.

You know, they get, they're being taught.

No pushing, no pushing.

She's tried to push him out of the way so the others don't get there.

[speaking in foreign language] And when you want to see whether a baby elephant's in good condition, you always look at the face.

You should not see this bone.

You see?

This little one is a little bit, tiny bit on the lean side still.

The cheek bone is just visible here.

But they're all pretty on condition.

You can see this, she's getting fat cheeks too, aren't you?

[speaking in foreign language] The elephants must be very fond of their family and the family must be fond of the elephants.

And you can tell who's a good keeper and who's not just by the reaction of the elephants.

They can read your heart.

[soft serene music] [speaking in foreign language] [soft serene music] - [Allison] To look at these infants now, one would never guess the trauma they've so recently been through.

[soft serene music] This little one was only six weeks old when her mother was shot in Southern Kenya.

Like the others she's made a remarkable recovery.

The keepers are with the orphans around the clock, even through the night.

[birds chirping] It is ironic that even an infant like Ilinguesi can teach lessons in resiliency.

[soft serene music] - [Daphne] Elephants of certainly taught me how to put the bad things behind, turn the page and get on with living.

Understanding the traumas that elephants have to put up with and how they cope with it has, I think, made me a stronger person as well.

[soft serene music] - [Allison] If elephants dream, might this one be dreaming of the family she once had?

[uplifting music] And she knows that if she survives, someday she'll have a family in the wild once again.

[guttural sounds] Only 200 miles away from Daphne's orphanage lies Tsavo National Park.

It is here that Ilinguesi's future family awaits her.

In a small section of the park sits a compound, phase two of Daphne's orphanage.

Here lives a herd of six orphaned elephants, all of whom arrived on Daphne's doorstep years ago as infants.

At Tsavo, they're learning how to be wild elephants.

Each day, they leave the safety of their compound and follow their keepers into the park.

Here they mingle with the wild herds learning the language of elephants.

Their self-appointed matriarch is 10-year-old Malika.

She keeps a close watch over her little family.

[guttural sounds] Back at the compound, the keepers are concerned about their youngest charge.

She was orphaned two weeks ago and is still dependent on milk.

She's too young to join the others in the bush and her health is poor.

Daphne has flown from Nairobi to bring medicine and see what she can do.

[speaking in foreign language] - Okay.

[speaking in foreign language] - [Allison] Despite the efforts of the keepers, the baby is listless and reluctant to eat.

- She's in shock and grief and a little bit sick.

Which is not too bad.

You are going to make it, aren't you?

- [Allison] Daphne knows it will take more than the keepers and food to pull the little one through.

She desperately needs the company of other elephants.

- Malika, come on.

Malika.

[speaking in foreign language] - The next morning, Malika is asked to leave two members of the herd behind.

The youngest females are held back to provide companionship for the little one.

- [Daphne] Malika is very agitated having her family split.

That's an unnatural thing to do.

But she loves and trusts the keepers and having been an orphan herself, she understands that that little calf is not very well.

- [Allison] The older orphans instantly comfort and reassure the newcomer.

The change is almost immediate.

- [Daphne] Just because she's with these other elephants, she's trying to eat much more.

There's been a big difference.

She's making much more of an effort today than she has previously.

So the will to live is kicking in, which is really great.

[soft uplifting music] There's a tremendous lot we humans can learn from elephants.

An elephant's relationship with its family continues beyond death.

They will visit the bones of a loved one for years afterwards, come to that place, remember.

Sometimes will come and take a piece of a body to carry off with them and always remember that with tremendous love a family member.

Really, in a perfect world, that's how we all ought to be.

[soft uplifting music] - [Allison] One needn't travel to Africa to find wisdom in the wild.

Even Earth's tiniest creatures hold tremendous secrets we've just begun to unlock.

[soft buzzing] If we take the time to look closely, we'll find there's a world of wonder right in our own backyards.

- [Child] Last one there is a rotten egg.

[children chattering] [dog barking] - [Allison] Those very creatures we might take for granted have inspired doctors, scientists, and even engineers for centuries.

- Wow, hold on.

- [Allison] Take the butterfly.

Its navigational skills are nothing short of remarkable.

On a diet of nectar, some butterflies can travel up to 100 miles a day.

Each year, the Monarch navigates all the way from Canada to Mexico, nearly 3000 miles.

Another outstanding flight specialist is the dragonfly.

- [Child] Where are you going?

Go over here!

[fanciful music] - [Allison] These ancient flying machines can outmaneuver even our most sophisticated helicopters.

Two sets of wings move independently, allowing them to fly in any direction, even backwards.

- [Child] Hmm, I missed.

- [Allison] They've been clocked at speeds of 60 miles an hour.

[fanciful music] During their 300 million years on Earth, they've evolved into a masterpiece of engineering.

[soft ethereal music] More and more often, scientists are looking to nature's smaller organisms for inspiration.

[water splashing] - [Child] Come here, look.

- Wow!

- [Allison] For well over a century, we've been studying a creature who tends to keep a low profile, the salamander.

When it loses its tail, it grows a new one.

This brilliant adaptation has specialists hoping to someday regenerate human limbs and spinal cords.

[water splashing] - [Child] One's there.

- [Child 2] There are a bunch over there.

[frog croaking] - [Allison] Amphibians, it seems, might harbor an entire pharmacy in their mysterious world.

[frog croaking] The colorful skin of poisoned dart frogs has extraordinary properties.

Recently, a drug 200 times stronger than morphine was created from the skin of this little frog from Ecuador.

[frog trilling] [children giggling] What else has yet to be revealed?

- [Child 2] Oh, down here, down here!

- [Child] Here I come.

[children chattering] - [Child 2] No, thank you.

Ew!

- [Child 3] Ew, spider webs!

- [Child 2] Hey, there are more over here.

- [Allison] Spiders are ingenious engineers.

Their silk is five times stronger than a piece of steel cable the same weight and far more resilient.

[soft ethereal music] By means we don't yet understand, some silk will adhere to any surface.

If we could find their blueprint, we could build better suspension bridges, create sutures, even artificial ligaments.

Researchers covet the inventions of even the most unlikely creatures.

[birds chirping] - [Child 3] Wow, that's a big slug.

- [Allison] Even the lowly slug has developed an exceptional product.

- [Child 3] It's all slimy.

Surprised it doesn't cut itself on the glass.

- [Allison] Secreting one of Earth's greatest lubricants, a slug can climb over razor blades without being cut.

We have yet to create such an effective lubricant ourselves.

- Let's go get the girls.

- Yeah.

[children screaming] - [Allison] As day gives way to the wonders of night, another little genius emerges from the shadows.

- [Child 2] Here's some over here.

[children chattering] [soft ethereal music] - [Child] Oh, there's another one there.

- [Allison] These tiny lanterns of the night have elevated the art of lighting to a fine science.

- Oh cool.

- [Child 3] Oh, neat.

- [Child] Wow!

- [Allison] Nearly 100% of a firefly's glow is pure light.

- I caught more than you did.

- [Allison] A normal electric light bulb gives off only 10% of its energy of light while 90% is wasted as heat.

- [Child 2] Mom, we're back!

- [Allison] If we could harness the ingenuity of nature's little beacons, we'd surely have a brighter future.

- [Child 2] We were out catching fireflies.

- [Allison] So many creatures within our world still remain a mystery.

[dog barking] We've only just begun to probe the surface.

[soft ethereal music] Dolphins have intrigued humans for millennia.

So unlike ourselves and yet so accepting of our species, these remarkable creatures have unlocked the silent world of a young boy.

- [Thomas] Momma.

- [Father] Ball.

- Mom, momma.

- [Father] Say ball, ball.

- Momma, mmm, momma.

- [Father] Ball.

- [Allison] Eight-year-old Thomas Carlene was born with a rare genetic disorder.

For Thomas and his family, communication has been a heartbreaking struggle.

- I want a son who can turn around and call me dad.

I know he knows what I'm talking about.

And I know he knows what this ball is.

And what we've gotta try and get him to do is to, is to tell us exactly what it is he wants.

Because it's all about giving Thomas a life of his own.

[water splashing] There you go.

We always felt that we needed to find a key for Thomas, something that was gonna unlock his mind.

And I'm sure that in the dolphins, we found that key.

[dolphins whistling] [soft ethereal music] - [Allison] For the past four years, the Carlenes have traveled from the north of England to the Florida Keys for a special kind of therapy.

- [Mother] Do you need my off on?

- [Allison] Though it involves a trained therapist, the dolphins themselves are pivotal.

- [Father] Can you touch the dolphin?

They're actually opening his mind.

There's a connection that's happening between them and him.

And that's being sort of worked with by the therapist and really what it's doing is it's, it's getting his mind to actually think on something.

And we actually think it's this stimulation that is helping him to learn and developing this, this brain that is basically going much slower than any normal child would.

- Alphonse wants you to throw the ball.

Alphonse wants you to throw it.

Let's say ball.

- Ball.

- Very nice!

- [Allison] Thomas has developed a passion for the dolphins here at Dolphin-Human Therapy.

- One, two, three.

Whoo, good throw!

- [Allison] Speech therapist, Janet Skinner, uses Thomas's love for the animals to focus and motivate him.

- Put that tongue back in that mouth.

- [Allison] Without language, they have spurred him to reach beyond his limitations.

- Water, water.

- [Thomas] Water.

There you go.

Good job, Thomas.

- [Allison] For the first time in his life, Thomas has begun to communicate, something his family never dreamed possible.

[water splashing] - [Janet] They seem to have a sixth sense about children that need them.

And they're different with every child.

For some child that may have great physical impairments, the dolphin is extremely gentle and seems to have a sense of what the child needs.

Because the dolphin will be as different in each session with the different children as the children are themselves different.

[dolphins splashing] [child moaning] - [Marci] Ricky can be aggressive.

He's a little bit tactilely defensive.

So just the way the animals feel in and of itself is an excellent thing for us to work on with Ricky.

- No.

- Tell me yes or no.

- [Allison] Physical therapist, Marcie McMahon, has been working with eight-year-old Ricky for the past two weeks.

- Here you go.

He can push on the animals and they just kind of say, "We're gonna wait, we're gonna wait."

They'll stick with him.

They're very patient.

They'll come up, they'll stay right in his face until he reaches out and which is what I'm asking him to do.

And for Ricky, that's a really important skill to develop.

It's something that'll generalize into other areas and the animals are perfect for Ricky.

They're just perfect.

He's rubbing a lot.

Well, that's not quite what we wanna hold onto, but that's pretty good, Rick.

That's pretty good.

- [Allison] These 500 pound animals exhibited gentleness and patience that children respond to in extraordinary ways.

- Thomas, Thomas, mmm mmm, you want more?

- More.

- Beautiful!

Ah, nice job!

More?

- More.

More.

Tongue in your mouth.

- They instantly calm you.

They instantly sort of reassure you.

And I think with Thomas, that's something that must be connecting with him.

And I think the interaction goes beyond the therapist.

I think there's something going on that we can't see.

I'm sure of it.

- Up.

Here comes Thomas.

- [Allison] They seem to touch a place deep within Thomas that no one else has reached.

They give him friendship without judgment, communication without words, and with their help, they allow him to reach heights he's never before known.

[giggling] [soft uplifting music] - Okay.

Alphonse is saying, "Come back and see me."

- [Allison] At the end of each session comes a goodbye and the heart of a young boy breaks.

- Want to come sit for me?

- Oh.

- [Trainer] It's the worst part of it.

- I know, I know.

[Thomas crying] - Oh.

Give me your hand, give me your hand.

- [Allison] But Thomas's father has found a means of keeping the dolphins close at hand.

[Thomas crying] - The dolphins never leave Thomas's life.

They're there every day for him when he wants them.

Come on, let's take your shoes.

I think it's a connection that I'll never be able to put my finger on.

I don't think anyone will.

And you can see it now when I'm watching it.

I mean, I'm talking away, he's totally focused on what's going on in there.

It's a whole experience that he's got inside his head and hopefully one day he'll tell us about it.

He'll tell us what the truth is, I don't know.

[dolphin chattering] [soft ethereal music] - [Allison] While many creatures remain so much a mystery, others we have come to know nearly as well as we know ourselves.

- Hey, you remember me?

Hey.

[soft uplifting music] A little older, huh?

- [Allison] Just hours north in Florida, a woman has come to revisit some dear old friends.

- Are you smiling?

I'm smiling.

I'm so happy to see you.

Chimpanzees has provided us with so much in this world.

So much knowledge about ourselves, about our social lives, about our dispositions, because they are so much like us as beings.

- [Allison] Our closest living relatives have given us perhaps more than any other creature.

So intelligent and hauntingly familiar.

Entertainment was only the beginning of their legacy.

In the 1950s, young chimps were drafted into our burgeoning space program.

When we deemed it to risky to send our own kind, we sent infant chimpanzees to probe the outer limits of our universe.

With a physiology so much like ours, they were the perfect pioneers.

Sharing 98% of our chromosomes, they soon became the ideal models to test life saving drugs, vaccines, and countless medical techniques.

But all of this came at a price.

During the 1960s, with hepatitis on the rise, chimpanzees were once again enlisted.

In the fight to find a vaccine, hundreds of chimps were subjected to ongoing tests.

For years on end, routine liver biopsies and solitary lives in cramped steel cages was all that some would ever know.

This is the story of three such chimpanzees, a female named Swing, a young male named Sparky, six-year-old Doll, and the woman whose life they would change forever.

Linda Koebner was a 23-year-old graduate student when she was asked to participate in a bold new project.

A hepatitis vaccine had been found and certain chimps were no longer needed.

Would they be capable of a normal existence after life in the lab?

[soft ethereal music] On a January morning, a small group of chimpanzees caught their first glimpse of the sun in over six years.

- [Linda] They were terrified to get out of the security of that transfer cage, whether it was afraid to step on the grass.

They hadn't been on anything but hard bars for years or just the feel of the wind and the sun and they just huddled in the doorways and wouldn't come out.

Over time, we coaxed them and Doll was right up the tree, but some of the others had never tasted any kind of freedom since they were infants riding on their mother's back.

And they had been in these little boxes for years and years.

[soft ethereal music] - [Allison] For the next four years, Linda spent every day with the chimps watching over them, observing their journey back to wholeness.

It was a grand experiment.

No one knew whether it would work.

But it did.

- Swing.

Girl.

- [Guest] What a pretty girl, isn't she?

- You're a good girl.

- [Allison] Twenty-five years later, Linda's come back for a long awaited visit.

A few of her old friends still remain.

- Girl.

- [Guest] She's a good girl.

- Hah hah hah, hah hah.

- [Guest] Not quite the little babies that you left.

- No.

You remember me?

- [Guest] Doll's making her smile.

- I wonder if they remember everything that I remember about our relationships.

Doll, come here.

- [Guest] Well, come on, let's get in the boat.

- Okay.

- [Allison] It's been 18 years since Linda has had any contact with Doll and Swing face-to-face.

[sorrowful music] - It's been so long.

- [Allison] There's no telling how they'll react.

- Oh, you look great.

- [Allison] Even her old friends are now wild animals.

- Oh yeah.

Do you remember me?

[chimps squealing] Good girl.

Hey.

Remember me?

Oh yeah.

- [Guest] Who's that, huh?

Who's that?

It's okay.

- Good girl.

It's okay.

That's good, Doll.

- Oh, Doll.

[crying] Oh.

[soft ethereal music] I've missed you.

Oh, yeah.

- [Guest] They want hugs.

- [Linda] These chimpanzees have taught me about resilience and all of these have gone through such tremendous adversity and yet they're forgiving and they're whole again.

- Good girl.

I guess if you remember me, you remember a lot of things, don't you?

Back to Africa, in the lab.

Right?

When we came down here, remember when you got so sick?

You let me carry you off the island.

It's good you got better.

It's good you've had a good life here.

Doll, let me see.

Do you still have the tag?

I don't think Lion Country even knew it when it started, but it, it has provided wonderful sanctuary for these chimpanzees.

- [Allison] Over 30 chimpanzees have found their way to this refuge in Southern Florida.

Each chimp arrived with a history.

Some were once pets, but discarded when they grew too strong to handle.

Others were research chimps.

A female named Inky was crippled during polio trials.

They all bear the scars of the past, but here they've been given the chance to live out their days with others of their kind.

Today, Lion Country has reached its capacity and there are many more chimps who still need homes.

Linda's concerned that there are more than 600 chimps no longer needed in research and there's no place for them to go.

- There are many hundreds of them, hundreds of them that are sitting still in laboratories.

Many of them have a very enriched environment, but still they're in laboratories.

They don't have the freedom to just be chimpanzees.

Oh, look at my girl.

You are your own girl.

- [Allison] Inspired by the success of Doll and Swing, Linda is determined to provide homes for other chimpanzees in need.

- My dream is to replicate, even on a grander scale, what we were able to do for the chimps that came Lion Country with us.

And I just hope that this is a model and that we can give them the respect and the freedom to live out their lives at least together.

- [Allison] But there's one chimpanzee who may never see Linda's dream come true.

[lamenting music] - Hey, Spark.

Oh, my Sparky, look at you.

- [Allison] One of her old friends, Sparky, is in the hospital.

- [Linda] I'd love to groom you a little.

- [Allison] Only 32 years old, he looks like an old man of 60.

Thanks in large to this chimpanzee, today we have a vaccine for hepatitis.

But Sparky paid the price.

- Spark.

I've been hoping to really have a good diagnosis and be able to treat him.

But nothing's gonna work.

And so I'm fortunate to be able to say goodbye to him.

I love you.

[sorrowful music] Sleep tight.

Goodnight.

And goodbye.

[sorrowful music] - [Allison] Sparky died two days later, but his legacy lives on.

Linda and her colleagues have been given 200 acres of land in Shreveport, Louisiana for the nation's first large scale chimp haven.

Her dream is coming true.

- Something that is in my heart and I think is in Doll's heart and Swing's heart that we share to give something back.

It's important, not just for me, but it's important for all of us as a species to realize that all animals are individuals and they have feelings and thoughts and they suffer the pain and the joy that we do.

And they're entitled and deserve an opportunity.

[soft lamenting music] - [Michael] To wake up one day and see that that all of this is gone would be like throwing away the last medical textbook.

- [Child] Hey, you guys, over here.

- [Daphne] We tend to think that we're different and that we are above the animal kingdom, but we are still animals and we share many similarities.

[giggling] [horse nickering] - [Allison] We've just begun to explore the uncharted land that lies between us.

There are volumes yet to learn and so much to lose if we let them slip away.

[soft ethereal music] - [Announcer] This program was made possible by the Corporation for Public Broadcasting and by contributions to your PBS station from viewers like you.

Thank you.

[uplifting music]