[ Animal calls ] -At Reteti Elephant Sanctuary... [ Dramatic music plays ] ...the Samburu people rescue orphans and nurture them back to health.

-[ Speaks global language ] ♪♪ ♪♪ -Each elephant is navigating its own path back to the wild.

While new arrivals adapt to this unlikely family... [ All chanting in global language ] ...the oldest members prepare to leave.

[ Elephant lows ] This will be the ultimate test of a journey years in the making.

♪♪ ♪♪ [ Mid-tempo music plays ] -Reteti is Africa's only community-run elephant sanctuary.

♪♪ Each of the 47 elephants here arrived with a tragic story.

Some were orphaned by poaching and conflict, others by the challenges of the wild.

-My baby, baby.

[ Speaking global language ] Baby, baby.

[ Soft music plays ] -Healing is helped by a sense of belonging, so they're grouped into herds -- the youngest calves... the middle group of 3- to 5-year-olds... and the oldest orphans, the release herd.

[ Elephant trumpets ] -Aww.

[ Smooching ] [ Speaks global language ] -Right now sanctuary life has never been busier... as the team gears up for the most significant event in its history.

♪♪ In just one week, the release herd will be returned back to the wild... set free from the sanctuary gates with the hopes they'll explore the vast expanse of the Samburu wilderness.

For keeper Colman, it's the result of years of dedication and care.

-Yeah.

[ Whistling ] [ Birds chirping ] -Colman has a particularly close relationship with the very smallest member of the herd.

Kelele's journey hasn't been easy.

Recovering from an infection, he almost didn't make the grade.

[ Uplifting music plays ] Along with Kelele, these elephants will walk from the safety of the sanctuary into the untamed wild.

♪♪ -This is real, kind of true wilderness.

There are no fences from here for thousands of acres.

-Co-founder Katie helped shape the plan for the elephants' release.

-This is the best chance that they've got to go back and really have a truly wild existence.

They're collared to keep track of them across the landscape.

The dream is that the elephants rescued from here would once again walk out back into this landscape, where they belong... be free-roaming, joining wild herds of elephants, and potentially even meeting up with the family herds that they came from.

To see that becoming a reality is a huge step, a huge part of it.

-This is a special type of rewilding mission, rescued elephants returning to roam free on the very lands they came from.

[ Dramatic music plays ] ♪♪ But on this same land, emergencies can happen at any time.

[ Static hissing ] A call has come in for the Reteti team.

♪♪ ♪♪ -Oh, baba.

Hello.

Hiya.

Huh?

-Dotted throughout the dry riverbeds in this region are water holes.

And a week-old baby has fallen into one.

-The elephants can smell water.

Those wells are deep.

You'll see little trunks that can smell the water, but can't quite reach it.

And they'll either lose their footing, or they're kind of nudged in by the excitement of the rest of the herd that are trying to also get to the water.

-Elephant herds are often forced to move on for their own survival, leaving calves behind when their rescue attempts fail.

-The plan is to get the elephant out of the well.

We can't lose hope.

[ Conversing in global language ] [ Elephant trumpets ] -Well-done.

[ Conversing in global language ] [ Elephant trumpets ] Well-done, well-done.

[ Conversing in global language ] You can actually see how long he was in the water because the bottom of his feet are all white.

Just like us, you know, if you sit in the bath for too long, you get wrinkly fingers.

You're just constantly thinking about them.

You're sort of waking up in the night, and it's the first thing you think about.

You know, you're checking in with the team at all hours.

[ Dramatic music plays ] ♪♪ -The team knows just how deeply the ordeal weighs on a young elephant's mind.

♪♪ [ Animal calling ] Back at Reteti, in order for this baby to heal, the keepers must earn its trust.

♪♪ -[ Laughs ] I'm sorry.

[ Laughing ] [ Soft music plays ] ♪♪ Hey.

No.

[ Laughs ] ♪♪ ♪♪ [ Metal clanging ] -All new arrivals have one-on-one care at night.

-[ Speaking global language ] [ Insects chirping ] Kimani.

[ Chuckles ] [ Speaking global language ] [ Insects chirping ] [ Dramatic music plays ] ♪♪ -The day everyone has been working towards has arrived -- [ Elephants lowing ] release day -- ♪♪ a milestone for Reteti... and for the elephants who are about to return to the wild.

♪♪ They'll be free to roam wherever they want across northern Kenya.

[ Conversing in global language ] ♪♪ It's six years in the making for everyone, including Katie and manager Peter.

-Are you nervous?

-Yeah.

[ Laughs ] -Yeah?

Oh.

There's gonna be challenges.

-Yeah.

-That's the thing.

[ Dramatic music plays ] ♪♪ ♪♪ ♪♪ -On this momentous day, from every corner of this valley... the community gathers to say their goodbyes.

♪♪ [ All chanting in global language ] ♪♪ A final prayer is offered before the gates open.

[ Elephant lows ] ♪♪ ♪♪ [ Elephants trumpeting ] ♪♪ ♪♪ ♪♪ The elephants step into the wild, leaving the keepers' care forever.

♪♪ [ All chanting in global language ] ♪♪ ♪♪ ♪♪ [ Conversing in global language ] ♪♪ ♪♪ [ All chanting in global language ] [ All chanting in global language ] [ All chanting in global language ] [ Folk music plays ] ♪♪ ♪♪ ♪♪ [ Elephant lowing ] [ Birds chirping ] [ Soft music plays ] ♪♪ [ Elephant trumpets ] ♪♪ -34 elephants remain at Reteti.

And so the daily routines continue.

Sweetened with honey... fortified with supplements... the milk bottles are carefully prepared.

[ All chanting in global language ] Keepers know that the elephants feel the absence of the oldest herd.

That's why this bottle feed is even more important -- to provide comfort and reassurance.

[ All chanting in global language ] The release herd has moved on.

But a new chapter begins.

♪♪ ♪♪ [ Animals calling ] [ Mid-tempo music plays ] ♪♪ -To ease her nerves, Kisima is given time to grow familiar with her new surroundings.

♪♪ ♪♪ [ Animals calling ] ♪♪ -[ Laughing ] -Rescued Kimani is also at the very start of his Reteti journey... -[ Speaking global language ] -...and trying to make sense of the absence of his mother.

-Good boy!

Well-done.

Kimani, Kimani.

Kim-Kim, Kim-Kim, Kim-Kim.

[ Dramatic music plays ] ♪♪ -It's been a week since the graduates left Reteti.

Each has been fitted with a radio collar to track their movements.

Colman expects to find them close by.

It looks like they've traveled far.

So Colman is setting out with manager Peter to check on them.

[ Dramatic music plays ] But with the radio collars only pinging once every few hours, tracking isn't straightforward.

-Yeah.

-They've come to the end of the road.

♪♪ The herd is completely inaccessible, heading on a new course.

[ Elephant trumpets ] Climbing higher offers richer vegetation and shows the elephants are adapting fast to their new freedom.

[ Uplifting music plays ] ♪♪ [ Conversing in global language ] ♪♪ Keeper Mary is looking after newest arrival Kisima.

[ Soft music plays ] Helping orphans through their fear and loneliness is part of everyday life here.

Mary's helping ease the young zebra's separation anxiety... gently encouraging her to bond with the other animals.

[ Elephant trumpets ] -[ Speaking global language ] -And one of them knows that struggle well.

Long'uro lost his trunk in a hyena attack when he was just a month old and found it difficult to bond with other elephants.

[ Dramatic music plays ] -[ Speaks global language ] -Long'uro's come a long way, learning to play and connect with his heard.

But after receiving so much one-on-one care to help him adapt... ...he's become a little territorial.

♪♪ [ Conversing in global language ] Overnight, the team has rushed one of the released herd back to the sanctuary.

Kelele's radio collar showed he had separated from the herd.

The reason is clear to see.

Sorry, sorry, sorry.

-Vet Sharon has to be hands-off.

-Kelele.

-Examination could cause more discomfort.

-Yes.

No problem.

[ Dramatic music plays ] ♪♪ ♪♪ -Kelele will undergo an intensive course of anti-inflammatories carefully mixed into every milk bottle.

With rest and recovery, the vets are hopeful he can still be rewilded.

♪♪ ♪♪ Over the next three months, the dry season descends upon Samburu, transforming the land.

Rivers shrink, vegetation withers, and temperatures soar above 100 degrees.

Survival for everyone becomes a daily challenge.

And it's no different for the elephants of Reteti.

[ Elephants lowing ] [ Elephant trumpets ] For the youngest herd, the heat brings a new lesson with keeper Dorothy.

Elephants have an extraordinary sense of smell.

Normally, babies follow their elders, learning their way over time.

But these orphans have to rely on their instincts much earlier.

[ Mid-tempo music plays ] ♪♪ ♪♪ ♪♪ [ Elephant lows ] ♪♪ Dorothy's youngsters have followed their noses... [ Soft music plays ] ♪♪ ...and found a natural pool.

[ Elephants trumpeting ] 25 miles away, high in the mountains... the release herd has found a water source of their own.

Elephants drink not just for hydration, but for essential mineral salts abundant in this mountain range.

It's a clear sign they've remembered the lessons Reteti taught them.

-[ Speaking global language ] -Naomi's herd, next in line for release, are also feeling the weight of the dry season.

[ Soft music plays ] With little left to graze, Naomi is teaching them how to survive.

And for Long'uro, it's even more difficult.

He spent his early life learning to graze while kneeling.

-Long'uro, go.

Yeah.

Hi, boy.

[ Speaking global language ] -In stepping back, the keepers are helping Long'uro to fend for himself.

[ Down-tempo music plays ] ♪♪ ♪♪ Now out of quarantine, Kimani is joining another young orphan.

-[ Laughing ] ♪♪ -Where their mothers would have dusted them to keep them cool, Dorothy steps in.

[ Soft music plays ] ♪♪ -[ Speaking global language ] ♪♪ [ Laughs ] ♪♪ [ Cattle lowing ] [ Cowbells clanging ] -The Samburu have long mastered the art of survival in this harsh environment.

And as temperatures rise, their search for water gets more intense.

[ All chanting in global language ] They dig up to 15 feet deep to reach hidden reserves belowground.

They sing a unique song as they go, a melody calling each cow to its herder.

-[ Chanting in global language ] [ Cowbells clanging ] -These singing wells are not only a vital lifeline for livestock... but, also, for the wild elephants that roam this region.

[ Dramatic music plays ] ♪♪ [ Insects chirping, animals calling ] [ Elephants lowing ] Under the cover of darkness... elephants gather at the many wells dotted throughout the dry riverbed... taking over where the herders left off.

The extra-hot days mean the whole herd is dehydrated.

[ Elephants lowing ] [ Dramatic music plays ] The water is almost unreachable for the smallest members of the herd.

[ Elephant trumpets ] ♪♪ The biggest danger of the dry season is babies falling into the wells.

And this is how many orphans come to Reteti.

[ Elephant trumpets ] The mothers know to be especially cautious, shielding their youngsters.

♪♪ But in the desperation for water, the young can easily slip or be pushed too close to the edge.

[ Elephant trumpeting ] ♪♪ This tiny baby has had a lucky escape.

[ Elephant trumpets ] [ Soft music plays ] ♪♪ ♪♪ After extensive rest... -Kelele... [ Uplifting music plays ] ♪♪ -...Kelele is now making good progress.

[ Branches rattling ] To aid his recovery, the keepers rely not just on western medicine... but on something prized by both the Samburu and elephants -- an essential lifeline in the dry season.

-[ Speaking global language ] -Kelele.

Kelele.

-If Kelele continues to heal... -[ Speaks global language ] -...the team hopes he could be returned back to his release herd family.

[ Soft music plays ] ♪♪ Integration isn't always easy.

Kisima struggled at first.

But with time, she's found her footing among the other animals.

[ Uplifting music plays ] ♪♪ ♪♪ [ Birds chirping ] Another of Reteti's residents has made great progress.

Long'uro has endured the long dry season, foraging for himself and emerging with an independent spirit.

-[ Speaking global language ] ♪♪ ♪♪ Long'uro now has a future full of possibilities... one where he can thrive on his own beyond the sanctuary.

-[ Speaking global language ] -Kimani is settling in well.

And one member of the herd can't wait to meet him.

-[ Speaking global language ] [ Soft music plays ] [ Elephant lows ] ♪♪ [ Elephant lowing ] [ Conversing in global language ] ♪♪ -Bonds like this help orphaned elephants heal, not just physically, but emotionally, too.

-[ Speaks global language ] ♪♪ -As the dry season comes to an end, the next chapter for Reteti begins, as one generation is ready to welcome the next.

[ Conversing in global language ] [ Soft music plays ] ♪♪ [ Elephant lows ] -[ Laughs ] [ Elephant trumpets ] ♪♪ [ Conversing in global language ] ♪♪ -These little ones are just beginning to form bonds, to become part of the Reteti family for the next six years, before they, too, return to the wild.

♪♪ [ Elephant trumpets ] [ Elephant lows ] Drawn to the last remaining water sources, the release herd has descended into the valley and passes close to the sanctuary.

[ Dramatic music plays ] It's not something the keepers would ordinarily do, but Dorothy can't resist going to see the elephants she helped raise.

[ Uplifting music plays ] -Oh, my God!

♪♪ ♪♪ [ Speaking global language ] Oh, my God.

[ Birds chirping ] Yes.

[ Sniffles ] [ Laughs ] [ Laughs ] Bye, everyone.

[ Soft music plays ] -But the goodbyes aren't quite over.

-[ Speaking global language ] [ Soft music plays ] ♪♪ Hi.

[ Laughs ] Ah.

Oh, my God.

♪♪ [ Engine starts ] ♪♪ -[ Speaks global language ] -Bye!

-Mwah!

Thank you!

[ Laughs ] [ Elephant trumpets ] ♪♪ [ Elephant trumpets ] [ Elephants lowing ] ♪♪ ♪♪ ♪♪ ♪♪ ♪♪ ♪♪ -To learn more about what you've seen on this "Nature" program, visit pbs.org.

[ Elephant trumpets ]