♪♪ [ Birds chirping ] [ Tender tune plays ] ♪♪ NARRATOR: The canids.
[ Howling ] One family.
Thirty-seven different faces.
Right now, across the world... ...people are going to extraordinary lengths... ...to understand and help these amazing species.
TODD: This is Pup 2.
NARRATOR: Making incredible discoveries... MAN: Oh, nice, a jackal.
NARRATOR: Getting closer than ever before to these elusive and secretive animals.
MAN: It's a beautiful gift of the nature.
NARRATOR: Uncovering what it takes to be a wild dog in our modern world.
Forever changing our understanding of this incredible family.
♪♪ [ Ethereal tune plays ] ♪♪ [ Birds chirping ] NARRATOR: African wild dogs.
Living in packs of up to 40 strong.
They hunt together... ...raise pups together... ...and defend their territories together.
[ Squeaking ] But it's their highly developed social and emotional bonds that sets them apart from other canids.
♪♪ And now, we're starting to uncover just how vital family is to their very survival.
♪♪ Cole du Plessis has been working with wild dogs for over ten years.
African wild dogs are shot and trapped by humans, who see them as a threat to livestock and game animals.
Cole and his team work tirelessly, rescuing these critically injured dogs.
[ Rotors whirring ] Relocating them to secure facilities.
Here, they receive round the clock care to nurse them back to health.
[ Flies buzzing ] [ Snuffling ] But Cole and his team have noticed something puzzling happening to the rescued dogs.
Du PLESSIS: We had an alpha female.
She had been caught in a snare.
A vet rushes out, catches the dog, takes it back to a rehabilitation center and, despite the physical injuries actually healing, she really wasn't getting any better.
[ Panting ] NARRATOR: Despite recovering from their injuries, the dogs were mysteriously dying.
Incredibly, the answers lie hidden in the dogs' postmortem results.
[ Suspenseful music plays ] One postmortem, in particular, led Cole's team to a groundbreaking discovery.
Du PLESSIS: In this particular case, they kept the dog there for ten days and she actually died ten days later.
When they did the postmortem, they were, again, shocked to find that this wild dog had actually died of broken heart syndrome.
It's effectively heart ruptures or stress around the heart, which is how the broken heart syndrome got its name.
NARRATOR: Broken heart syndrome is caused by extreme stress.
It's a condition that can affect humans after a bereavement.
And, astonishingly, this is what killed the dogs.
Dogs in the wild grieve the death of a family member, often becoming visibly depressed and withdrawn.
Cole noticed the dogs in rehabilitation were suffering from extreme grief when separated from their pack.
As much as they are resilient and tough animals, they are also very emotionally driven animals and they need that sort of emotional backing or support to help them.
And it's that real community structure that helps wild dogs heal.
[ Panting ] [ Tender tune plays ] NARRATOR: How can we treat rescued dogs in captivity without causing high levels of stress to these emotionally sensitive animals?
One fateful day, Cole received a call about a badly injured dog that was affectionately nicknamed Teardrop.
Du PLESSIS: One day, the pack had left the protected area and came in contact with a farmer that opened fire on them and shot several pack members.
NARRATOR: The dogs were shot simply because they ventured onto the farmer's land.
♪♪ Du PLESSIS: And the gunshot wound had come through her front left leg and exited just below her chest here.
NARRATOR: But how would Cole prevent Teardrop from suffering the fatal consequences of broken heart syndrome?
Du PLESSIS: We opted to take the surviving pack members and treat her with them, but she had to undergo six or eight months' worth of rehabilitation before she could, you know, once again, put weight on her leg and on her chest.
NARRATOR: By keeping other pack members that were rescued with Teardrop by her side throughout her recovery, she had the emotional support that she needed.
Du PLESSIS: We've seen some very horrific injuries before, but, you know, this recovery was just quite remarkable, to say the least.
NARRATOR: Today is a big day for Teardrop.
Having been carefully sedated, she and her pack are moving to a new, safer, home, in a protected national park.
And they get to travel in their own private plane.
Since Cole and his team made their remarkable discovery, every single critically injured wild dog rescued with healthy pack members has made a full recovery.
♪♪ And been successfully returned to the wild.
[ Camera shutter clicks ] [ Camera shutter clicks ] [ Squeaking ] Every single wild dog that's saved plays a critical role in the survival of this highly endangered, emotionally intelligent species.
[ Panting ] We are in a golden age of canid scientific discovery and understanding wild dogs is the best tool we have to help them survive.
[ Wind whipping ] On the Great Plains of North America lives one of the planet's smallest dogs.
[ Birds cheeping ] [ Whimsical tune plays ] The swift fox.
♪♪ No bigger than a house cat, this characterful canid lives in tight-knit family groups.
Today the swift foxes of America are confined to pockets of the Great Plains.
But researchers Hila Shamon and Kimberley Todd are studying this fox, in an effort to reinstate their population far and wide.
SHAMON: Swift fox used to be very common across the Great Plains.
Saskatchewan, Alberta, all the way down to Mexico.
But around the 1930s, they were eliminated to less than 10% of their historical range.
[ Suspenseful music plays ] NARRATOR: The swift fox was a casualty of predator control programs that targeted wolves, coyotes, and prairie dogs.
Hila and Kimberley are at the start of a five-year project relocating fox families from this healthy population in Wyoming to Fort Belknap Indian Reservation in Montana, nearly 500 miles away.
They're reestablishing a fox population there and gradually expanding the species' range.
But not every family group is able to adapt to a new territory.
So, which of the fox families should be moved?
They believe the answer may depend on a surprising factor.
SHAMON: What we're doing here in Wyoming is trying to understand how different personalities and behaviors, how would that impact survival of translocated individuals?
TODD: Juvenile 3...resting.
NARRATOR: To work out the fox personalities present in each family, you have to observe their behavior.
Hila and Kimberley first test the personalities in the group by seeing how a family reacts to danger.
SHAMON: It's almost time for the eagle call.
When you're ready.
3, 2, 1, go.
[ Cheeping ] Juveniles 1, 2, and 3 vigilant.
Looks like Juvenile 2 kind of is crouched down now.
So, we are seeing a variation, even between juveniles.
Some of them were more bold, stayed out the den, they realized quickly there was no threat, while the other ones got a bit scared and went underground.
[ Cheeping ] NARRATOR: By observing their response, they can build a picture of the personalities within the group.
Cautious animals quickly retreat underground at the first sound of danger.
[ Squawk ] More bold individuals stay out in the open.
[ Whimsical tune plays ] Next, Hila and Kimberley deploy remote cameras... ♪♪ ...which they hope will reveal the foxes' true personalities.
[ Upbeat country tune plays ] TODD: We just collected an SD card from one of our trail cameras.
We're going to check out what we have.
SHAMON: Alright, looks like we have a pup TODD: [ Laughs ] SHAMON: checking out the cameras.
SHAMON: Two juveniles here, kind of playing around with each other.
[ Laughs ] Just goofing around.
SHAMON: Can we see the next one?
SHAMON: Being vigilant.
NARRATOR: Bold, timid, inquisitive, or cautious, these fox families show a wide range of personalities.
[ Chattering ] Adventurous families might explore a new home, finding food and resources more readily.
But previous studies of captive-born swift foxes have shown, the bolder the fox, the less likely it is to survive after release.
The more timid the individual, the more it avoids potential danger -- a key survival strategy for such a tiny fox.
TODD: If it's a bold individual, it may be very exploratory.
They may take risks.
They may go investigate whatever it may be.
As these foxes are being translocated, they need to be able to respond appropriately to a predator, so, if they encounter a coyote or a golden eagle in their new environment, they need to know, you know, when to be vigilant, when to retreat into a den, so as to avoid being predated, so there are definitely cases in the real world where being really bold and exploratory can have a very negative effect.
NARRATOR: It's early in their research, but once Hila and Kimberley have identified the different personalities of the fox families, they'll see how each group fares after they're relocated to their new home.
[ Mid-tempo tune plays ] That's key to securing the future of the species.
SHAMON: We have to keep going.
We have to keep asking those questions, we have to find the answers, and we have to improve our protocols and improve the tools that we have for reintroductions, not only for swift fox, but in general.
If Hila and Kimberley succeed, the plucky swift fox may, once again, reclaim its historic range and roam freely right across the Great Plains.
♪♪ [ Suspenseful music plays ] NARRATOR: It's believed there are 37 species of canid alive in the world today.
But following a series of new discoveries, this figure is changing constantly.
In 2018, over 13,000 feet above sea level in the highlands of New Guinea, scientists discovered a dog [ Howling ] that had been declared extinct in the wild 30 years before.
[ Barks ] The New Guinea Highland dog.
[ Barks ] A close relation to the Australian dingo.
[ Howling ] DNA analysis of individuals living in this remote part of the island proved the species was, amazingly, still alive and well in the wild.
[ Howling ] And even more amazing discoveries like this could be just around the corner.
♪♪ Deep in these ancient forests, Naturalist Hiroshi Yagi and his dog are on a mission.
Hunting for a ghost.
Twenty-six years ago, he had a truly extraordinary encounter.
Yagi believes he had stumbled across an animal thought to have gone extinct over 100 years ago... [ Lullaby plays ] ...the Japanese wolf.
Wolves roamed the forests of Japan for tens of thousands of years... ...but in the 1800s, the country opened up to the West.
Newly arrived domestic dogs brought canine diseases to the islands.
And it is thought that the Japanese wolf could not withstand this epidemic of foreign illnesses.
By 1905, the species was declared extinct.
Ever since his encounter, Yagi has been searching for proof that the wolf still exists.
He already has evidence.
Luckily, that night, he had a camera ready.
Yagi is convinced the Japanese wolf is not lost to history.
[ Ethereal tune plays ] And he's not alone.
Every year, he receives reports of wolf sightings in these mountains.
Over 200, to date.
One of the most recent reports came from a monk performing a conch blowing ceremony at this mountain lake... ...and, remarkably, hearing a wolf howl in the process.
[ Conversing in foreign language ] This amazing encounter has given Yagi an idea.
♪♪ His plan -- to recreate the ceremony and listen for a wolf to respond.
YAGI: [ Speaking foreign language ] NARRATOR: Wolves use howls for long distance communication and respond to sounds that are in a similar audible range.
MONK: [ Speaking foreign language ] [ Hollow thudding ] ♪♪ [ Echoing ] ♪♪ ♪♪ [ Echoing ] ♪♪ ♪♪ [ Echoing ] ♪♪ ♪♪ [ Echoing ] ♪♪ [ Suspenseful music plays ] [ Bird trilling ] ♪♪ NARRATOR: The silence is a blow for Yagi.
But he's not about to give up hope.
♪♪ As part of his work, Yagi has over 70 camera traps lining the sides of these mountains.
They keep catching glimpses of wolf-like creatures.
And, recently, one of his cameras recorded something truly intriguing.
Three deer running past trigger the camera to record and then, if you listen carefully... [ Howling ] Yagi has had this audio compared to a wolf's howl.
The report concluded that the howls were nearly identical.
Although the Japanese wolf has officially been declared extinct, this recording clearly begs the question -- could wolves still be hiding in these mountains?
♪♪ Yagi's hunt is not over and, for now, the mystery of Japan's ghost wolf remains.
♪♪ [ Howling ] All across the globe, dedicated people are working nonstop to understand and help wild dogs.
In the vast Saharan desert, the tiny fennec fox is fighting for its life.
Not because of this hostile environment, but because of the tourist trade.
Ali Obassidi has been monitoring the fennecs here for over 20 years.
Because of his expert knowledge, Ali is taking our film crew to find the foxes.
And what he reveals shocks them to the core.
MAN: So, the desert must be like your back garden.
OBASSIDI: Yeah, desert is my garden from my first moment in this life.
NARRATOR: With Ali on the team, they soon see signs of fennec foxes.
OBASSIDI: Look at the track of our car yesterday... [ Bright tune plays ] and they're just after.
MAN: This is after our car?
And around, I didn't see new, fresh tracks go out.
It means he's inside.
NARRATOR: The tracks are leading to a potential den site.
For days, they wait, ready to film.
But there's no sign of life.
MAN: They're so tuned in to the -- the natural sounds round the desert, but anything that's out of the ordinary, they'll either inspect it or they'll take that as an opportunity to just scarper and go.
They can see and hear me from like 50 meters and, annoyingly, the wind circulates in these bowls of dunes, so, they can also smell me quite easily as well.
[ Suspenseful music plays ] NARRATOR: It's several days before patience finally pays off, but the team's excitement is quickly shattered.
The fennec has a trap on its leg.
♪♪ The injured fox still manages to race over the dunes and vanish.
MAN: I really -- I really worry it's not -- It's just not going to last long out here, not in that condition.
NARRATOR: Sadly, this is not a rare sight for Ali.
OBASSIDI: We have this problem in last time here because the children from the village come to take them and to show to the tourists.
When the tourists come, they give them the fennec to take a picture and then tourists give to the children money.
NARRATOR: A license is needed to trade or hold fennec foxes.
But lucrative pet and tourist trades have encouraged illegal trapping for decades.
Human interference is such a threat, unregulated trade could wipe out local populations.
The problem has concerned Ali for many years.
OBASSIDI: I can't say how I feel.
It's make me sad, very, very sad.
NARRATOR: As well as the illegal trade, some irresponsible tourists have been causing further cruelty.
Ali's found a dead fennec near a popular spot for motorbikes.
OBASSIDI: I think there is no accident between the fennec and motorbikes, but the problem is the motorbikes follow him for a long time.
I think more than one kilometer, they follow him, then he's dead because he can't run for a long time.
NARRATOR: The desert is more than large enough to make space for both people and wildlife.
OBASSIDI: I think that we need to make like a zoning in this area, reserve it only for animals, for fennecs.
NARRATOR: After days without luck, the team's morale is running low.
But with hope disappearing, there's good news from camera operator Matt.
MATT: We dropped off, set up the hide, got the camera turned on.
I was just about to like, you know, frame up and do stuff.
You started the engine and then a head popped up and two ears.
OBASSIDI: And it was just, yeah.
Then this was like, as soon as you left, 9:36.
[ Tender tune plays ] ♪♪ ♪♪ ♪♪ OBASSIDI: Wow.
MAN: How did you feel when you saw them, Matt?
MATT: It's like it was just -- It was ridiculous like.
I couldn't actually believe it.
We'd been trying this long.
Tom's put so many hours in the hide, but as soon as the head pops up, I just -- I was recording, but I've never been like this, but I was literally shaking.
NARRATOR: With filming finally going well, there's an even more welcome surprise from the team's first fennec encounter.
Ali has been able to track down the snared fennec.
[ Chirping ] ♪♪ OBASSIDI: Help me please.
MAN: Yes, what shall I do?
OBASSIDI: Push this.
Push this one.
MAN: This one?
OBASSIDI: Yeah, take that.
Just take this one, like this.
Open, please, open the -- Thank you.
[ Chatters ] Good boy.
MAN: How's that leg look?
NARRATOR: There's no medical support here, but Ali's seen incidents before and is able to assess the wound.
OBASSIDI: Just give him our comfort.
NARRATOR: He believes this fennec will survive its ordeal.
OBASSIDI: I'm so happy.
MAN: Good work.
MAN: Good work.
Let's hope he's alright.
OBASSIDI: [ Indistinct] help.
NARRATOR: Ali has been sending his findings to the Moroccan government, with the hope that greater protections can be brought in to help save the species.
Even the smallest actions can lead to positive changes for canids across the world.
[ Mellow tune plays ] [ Insects chirping ] Brazil.
Once covered in natural grassland and forest, known as cerrado.
Over three quarters have been destroyed.
Crops, like sugar cane, are now grown here... ...covering over 200 million acres of land.
The vast plantations cannot support the vibrant array of wildlife that once lived here.
But reports of strange creatures living amongst the crops has brought biologist Rogério Cunha de Paula to find out more.
♪♪ And his network of camera traps has discovered something extraordinary.
Normally found in natural grassland, seeing them living in crops was remarkable.
And that wasn't the only thing his cameras picked up.
[ Whimsical tune plays ] CUNHA de PAULA: To see the mother with a puppy, for us, was amazing because those little guys walking [ Laughs ] just by a sugar cane plantation, we never expected that.
NARRATOR: Maned wolves are grassland specialists.
[ Chirping ] They can eat a variety of food... ...small mammals, fruit, and even vegetables.
At first glance, these maned wolves seem to be living successfully in this agricultural landscape... ...something that Rogério had never seen before.
But he's discovered a problem.
CUNHA de PAULA: We found that puppies were dying.
[ Crickets chirping ] All the families we were monitoring were losing their puppies.
[ Suspenseful music plays ] NARRATOR: To find out what is happening to the pups, Rogério and his team want to closely track the adult wolves' movements using GPS collars.
♪♪ The collar is lightweight and harmless to the wolf.
♪♪ ♪♪ By laying the GPS locations of the wolves over a map of the farm, Rogério can build up a picture of where they live in the farmland.
CUNHA de PAULA: This picture shows that we have the tracking data for one single wolf.
This is a female.
Here, you have the animal concentrating in the sugar cane when the sugar cane was taller.
NARRATOR: This data shows Rogério that the taller crops provide a vital habitat for the wolves.
Here, there's an abundance of prey for them to hunt.
[ Bell tolling ] Until harvest time... ...when the maned wolves' world is flattened.
CUNHA de PAULA: So, in one day, you have tall sugar cane.
The following day, you have nothing, like a desert.
NARRATOR: Harvested fields can't provide the mother wolves with the food they desperately need to raise their pups.
But what can be done?
[ Tender tune plays ] Working with local farmers, Rogério has come up with a brilliantly simple solution.
By leaving some areas uncut during harvest season, the wolves have just enough crop to hunt in.
And enough food and shelter to raise their pups.
♪♪ In return, the wolves help control rodents that eat the farmers' crops.
CUNHA de PAULA: By doing all this management on the croplands and the harvesting, we start improving the quality of habitats.
And, doing this farm by farm, we have a better habitat, in general, for this entire region.
NARRATOR: Now, Rogério's work is starting to have an impact.
And, for the first time, he's seeing maned wolf pups grow into adulthood and survive in these plantations.
It's small, positive steps like these that make a big difference for the maned wolves of Brazil.
♪♪ ♪♪ While some canids are managing to survive with some help... ...others are showing up where they have never been seen before.
[ Chattering ] In Eastern Europe, a very tenacious wild dog is making a new stronghold in Romania's Danube Delta.
The golden jackal.
[ Birds chirping ] One of the most adaptable members of the canid family.
[ Owl hoots ] [ Barks ] They're a medium-sized predator with a diverse diet and flexible behavior.
They can eat almost anything and live almost anywhere.
Originally from India, in recent decades, their population has exploded.
[ Creatures croaking ] Researcher Cristian-Remus Papp wants to find out how rapidly the population is spreading, and why.
PAPP: The golden jackal appeared in the region of India in the late Pleistocene.
After the last Ice Age, it crossed the Bosphorus and entered in Greece.
At the present day, it is widespread in the Balkans.
In the last two decades, the number of jackals really increased significantly.
[ Suspenseful music plays ] NARRATOR: Cristian needs to record how many jackals are in this area.
That's important to understanding their fast-changing population and any impact they might be having.
PAPP: We are starting at dusk because this is the time when the jackals are starting their activity.
They are nocturnal species and starting with dusk, they are hunting, they are roaming around, they are checking their territories.
NARRATOR: But it's not easy to see jackals in the dead of night.
So, Cristian turns to sound... [ Howling ] ...broadcasting a recording of a golden jackal howl.
[ Howling ] Jackals can hear this from over three miles away... ...and their instinct is to howl back.
[ Howling ] PAPP: There is one reply from north.
[ Howling ] A second one is much closer, from northeast.
NARRATOR: During his survey, [ Howling ] Cristian will cover over 30 miles.
He records the location of each howl he hears, building a picture of the jackal population in the area.
[ Howling ] In response to the call, jackals move closer to investigate.
[ Howling ] Cristian uses a thermal camera to pick out the approaching animals in the darkness.
[ Ethereal tune plays ] PAPP: Yes, I can see one.
NARRATOR: Sneaking through the thick undergrowth, the jackals' warm bodies light up as a glowing yellow shape against the cool purple surroundings.
PAPP: [ Whispering in foreign language ] Look!
There it is.
I could see the eyes of the jackal.
NARRATOR: Eventually, the jackals' instinct to investigate becomes so strong... ...they appear in the spotlight.
PAPP: They are really curious and they're trying to approach us.
[ Howl ] NARRATOR: Cristian's surveys reveal that, in just over five years, the number of jackals in Romania has doubled.
[ Chattering ] It's estimated there are now 20,000 jackals here.
The species is doing so well, it's venturing west and north across the European continent.
And the cause of this incredible spread?
People hunting one of their main competitors.
PAPP: The golden jackal started to spread in Europe due to several factors.
The most important is the fact that the number of the gray wolf decreased.
NARRATOR: The adaptable jackal is moving in where the wolves once lived, taking advantage of the lack of competition for food and territory.
Jackals have been seen for the first time in Italy... ♪♪ Austria... and, astonishingly, in 2021, it was confirmed hat a golden jackal had even made it as far north as the Arctic Circle in Norway.
♪♪ In our rapidly changing world, this amazingly adaptable wild dog is coming out on top.
♪♪ [ Birds chirping ] [ Sirens wailing ] Some canid species set up home in the most unlikely of places.
[ Chattering ] In the middle of the bustling city of Minneapolis, [ Whimpering ] this coyote family, incredibly, has created a den in a drainage pipe.
[ Chattering ] Here, there's a lack of other predators that might compete with them.
It's recently been discovered that urban coyotes can even change their daily routine to adapt to city living... ...becoming more active at night, to better avoid people.
[ Snarling ] ♪♪ [ Barking ] In the UK, city-living red foxes are physically changing because they live in a human environment.
♪♪ They have shorter, wider muzzles than their countryside cousins -- an adaptation that could allow them to access food left out by humans more efficiently.
[ Chatters ] [ Panting ] For millennia, humans have been impacting wild dogs.
[ Birds chirping ] And, to better understand their possible futures, we need to know how we have affected them in the past.
[ Panting ] The most iconic canid.
♪♪ Working with captive-born gray wolves, researcher Friederike Range wants to find out more about the effect humans have had on the canid family tree, [ Howl in distance ] by studying the difference [ Growls ] between wolf and pet dog intelligence.
To do this, she uses a range of tests...
NARRATOR: ...to discover if the wolves can problem-solve by working together.
And working together is essential for their survival in the wild.
To get the food, two wolves must pull the rope simultaneously to move the table towards them.
If one pulls too early or too late, the table will not move.
RANGE: If it understands it needs a partner, the wolf should wait before starting to pull.
♪♪ NARRATOR: Only highly intelligent animals, such as dolphins, elephants, and chimpanzees, can successfully complete this task.
♪♪ The wolves make it look easy.
Subtle body posture, facial movements, even eye expression,, are all sophisticated ways the wolves can communicate and coordinate their actions.
And now, it's the domestic dogs' turn.
[ Panting ] ♪♪ RANGE: [ Calls ] Some of the interesting results come up when we are running these experiments that the wolves are actually very good at cooperating with each other, where the dogs usually fail.
So, it was really, for us, a real surprise.
NARRATOR: Friederike believes this difference in the wolves' and dogs' ability to complete the task is not because the dogs are less intelligent than the wolves... ...but because the pet dogs are domesticated.
They experiment is run again.
[ Panting ] If a human leads the action by pulling the rope, will the dog follow?
RANGE: The dogs, they just, "Okay, so what do we do next?"
And then they follow the human.
So, instead of going ahead, most of them just wait, watch what the human is doing, and then they follow the human.
NARRATOR: These tests show that two wolves together can solve problems like this easily, whereas, dogs cooperate better when paired with a human.
RANGE: So, intelligence is probably related to how you interact with your environment and how you can solve the problems of your environment and there are likely differences between wolves and dogs, due to the domestication.
So, the wolf has to cooperate with each other.
They have to bring down big prey and share it afterwards, so, they are adapted to that environment and they have the necessary cognitive abilities to solve these problems.
Whereas, for the dogs, the environment changed a lot through the domestication process.
NARRATOR: Thousands of years ago, humans became the main providers of food to the wild ancestor of the domestic dog.
[ Tender tune plays ] Domestication gradually made these ancient wolves more dependent on humans, instead of members of their own species.
This process eventually produced the pet dogs we know today.
RANGE: The dogs, they really want to do things with us and you see that.
I mean, you go in an enclosure and they come and they jump up on you and they are there.
The wolves, they're happy to see you.
They come, they greet you, there's a mutual respect, but it's not this dependency, so, if the wolf says, "Okay, now, I have enough of the petting.
I will go."
[ Panting ] NARRATOR: Friederike's work suggests the key traits we most admire in pet dogs today -- intelligence, cooperation, problem-solving -- were not a result of domestication, but have been present in the wolf for thousands of years.
♪♪ As our understanding of these incredible species grows, so, too, does the urgency to protect them.
And, thanks to small groups of passionate people, there's hope.
♪♪ In the foothills of Missouri, conservationists are embarking on a remarkable plan.
Regina Mossotti has spent years working with wolves.
It's feeding time.
[ Ethereal tune plays ] ♪♪ MOSSOTTI: They look good after yesterday's health check.
WOMAN #1: Yeah.
WOMAN #2: Yeah, they do.
[ Panting ] NARRATOR: This is a red wolf.
One of the most endangered canids in the world.
[ Sniffing ] Less than 20 remain in the wild.
In her battle to protect them... ...Regina cares for these captive-born red wolves, in the hope they could, one day, save the species from extinction.
MOSSOTTI: The American red wolf is actually a species that is close to my heart because it is solely native to the United States.
And what surprises me the most, when I am talking and working with the public is that most people don't even know the red wolf exists, let alone that it's on the brink of extinction.
[ Grumbling ] NARRATOR: Hunting, habitat loss, and the few remaining wild wolves hybridizing with coyotes have all hampered conservation efforts that have been going on for over 30 years.
MOSSOTTI: The issues that the American red wolf and the gray wolf face are all the same... [ Sniffing ] ...that persecution in the late 1800s led to a dramatic decline in all those populations.
But what has perpetuated it -- it's the way that our culture looks at wolves.
Think of what you've grown up with -- "Little Red Riding," "Three Little Pigs"; when you're teenagers, it's werewolf movies.
Everything in our culture is telling us that the wolf is something to fear.
And, when you fear something, you don't want to save it.
And the irony is, is that wolves are big [ Huffs ] scaredy-cats.
I don't know how else to put it.
[ Laughs ] They run away from people when they're in the wild.
They want nothing to do with humans.
NARRATOR: Now, conservationists are in one final push to save the red wolf.
[ Squeaking ] [ Lullaby plays ] ♪♪ Pups, born in Regina's care, are key to what could be a game-changer for the red wolf's survival.
MOSSOTTI: A very creative biologist, learning about wolves and seeing their behavior and their nurturing character, had the concept of pup fostering, which is taking tiny puppies - I mean potato-sized, less than two-week-old puppies -- and placing them into wild dens.
NARRATOR: Once a wild wolf mother has given birth to a litter, captive-born pups of a similar age are introduced into the den.
MOSSOTTI: They want to take care of their puppies.
They protect them, they clean them, they feed them.
And by just placing a few more puppies in there, she doesn't know the difference.
She takes them in as her own.
[ Whimpering ] And why it works is because wolves are so incredibly nurturing.
And the best part is here's a wild mom and a wild dad who know how to protect their territory, who know how to hunt elk, who know how to stay away from people, can raise these puppies and teach them those really important skill sets, so those puppies survive and thrive.
NARRATOR: Regina and her team have shown that cross-fostered wolf pups have a higher rate of survival than other kinds of wolf release.
MOSSOTTI: The reintroduction of wolves isn't just about bringing something back to the landscape that we've lost.
It's bigger than that.
[ Poignant tune plays ] It's about restoring the ecosystem, making it healthier, making it healthier, not just for the animals and plants that are there, but also for us.
NARRATOR: Ultimately, the future of these incredible wolves... ...and all wild dogs across the planet... ...lies in our hands.
♪♪ ♪♪ ♪♪ ♪♪ ♪♪ ♪♪ To learn more about what you've seen on this "Nature" program, [ Howling ] visit pbs.org.