♪ NARRATOR: They are the greatest predator since the dinosaurs, the most widespread carnivore on the planet, and one may be living in your home.

Cats are a diverse and formidable family of predators.

But what makes a cat a cat?

New research allows us to piece together their story like never before.

Across the planet, 37 different species live in nearly every landscape.

MAN: It's our last remaining large carnivore in the mountains -- surviving next to one of the largest urban areas in the world.

NARRATOR: Even at 20,000 feet above sea level, scientists made a remarkable discovery.

REGMI: When I saw the photo, I completely surprised.

I did not sleep all night.

[ Laughs ] NARRATOR: This is the story of cats... [ Roars ] ...an 11 million-year evolutionary journey from ancient rainforests and the African savanna and into our homes.

♪ NARRATOR: Every member of the modern cat family can trace its roots to Asia.

11 million years ago, rainforests were home to their primitive tree-climbing ancestors.

[ Purring ] And one cat... still lives just like they used to.

They are the most ancient type of cat alive today.

Their genetic blueprint is shared by all cats.

♪ This is the clouded leopard.

They are key to understanding how cats evolved and spread across the planet.

But they are now so rare, little is known about them.

WOOD: Good girl.

Oh, hi.

NARRATOR: Bill Wood is a clouded leopard expert at a special breeding center in Thailand.

WOOD: Oh!

Hey!

NARRATOR: His work could help save them from extinction.

WOOD: It's incredibly important to breed these cats in captivity because there's very little known about them in the wild.

We do know that the population is dwindling.

Most of their habitat has been destroyed.

And it's really a safeguard in case the worst did ever happen, as has happened to some cat species, that they become extinct in the wild.

At least we'll have some population here.

NARRATOR: All cats share the clouded leopard's razor-sharp canines... heightened senses... and their extreme agility.

WOOD: They've got short legs, so they've got a low center of gravity, close to the branch.

They've got incredibly long tails for balance.

The speed they move through the branches, sometimes you think they're more like monkeys than cats.

NARRATOR: Some of these abilities can be seen in the newest member of the cat family -- domestic cats.

They share retractable claws -- up to two inches long.

These claws are hooked and usually sharper at the front, helping them climb vertical surfaces.

But not all of the clouded leopard's adaptations are shared by domestic cats.

At the top, front-facing paws mean they can't climb down easily... [ Meowing ] ...which is why pets get stuck up in trees.

Clouded leopards can rotate their rear ankles.

They easily climb down trees headfirst.

But the similarities between clouded leopards and other cats outweigh any differences.

When they're young, clouded leopards learn how to be ambush predators through play.

It's a crucial time when they must develop the abilities that they'll need to survive in the wild.

Learning this way is a behavior they share with all cats.

[ Playful growling ] [ Chirping, purring ] Cubs and domestic kittens are driven to keep playing by dopamine, which is constantly released in their brains.

[ Purring ] [ Toy squeaks ] It's the same chemical that gives humans a euphoric feeling after intense exercise.

[ Soft meowing ] [ Playful growling ] They'll spend almost every waking moment mastering their skills and instincts, because cats have to grow up fast.

These clouded leopards are just three months old.

But in seven months, their mother will force them out of her territory.

[ Birds chirping ] They will then face the world as solitary predators.

Cats are hardwired to disperse every generation... ...to find their own territory... a safe place for them to hunt that can range from six square miles to 29 square miles in size.

This was one of the reasons that around 9 million years ago, ancient felines spread across Asia's forests and beyond.

As cats encountered new landscapes, they had to adapt.

They came down from the trees more often, in search of bigger prey.

One of those early felines was the leopard.

Leopards are nocturnal.

They can see up to seven times better than humans at night, thanks to a mirror-like layer in their eyes that amplifies light reaching the retina.

Sri Lanka is home to one of the world's largest concentrations of leopards.

To see in the dark like they do, we must use the latest thermal imaging and infrared cameras.

Leopards will eat anything, from small insects to large deer.

They are always looking for food, and this female has spotted a potential meal.

Civets are small tree-climbing mammals.

Their best line of defense is to run and hide.

But like clouded leopards, leopards are natural climbers, and she has no problem following, using her retractable claws.

♪ The civet makes a daring escape and survives the 65-foot drop.

Leopards can take down much larger prey.

And this female has another option for dinner tonight.

It's 8:00 p.m. She doesn't have far to go.

Yesterday's kill, a chital stag, still has plenty of meat left.

Crocodiles will walk hundreds of feet inland to scavenge a kill.

[ Hissing ] We think of leopards as big, powerful predators.

But being solitary makes them vulnerable.

Wild boar sense a chance to get some of her food.

[ Leopard growling, boar squealing ] She is outnumbered.

Buffalo, wild boar, and crocodile surround her.

Like the clouded leopard, her safe place is in the treetops.

[ Growls ] [ Boar squealing ] Losing large kills like this is so common for leopards, they've developed a unique behavior.

They've learned to drag prey weighing up to 200 pounds up trees.

But this time, it's too heavy.

[ Boar grunting ] [ Boar squealing ] [ Leopard growling ] Having food stolen is a real fear that runs through all solitary cats.

And as big cats evolved, they came up with ingenious ways of hanging on to their kills.

This is a Bengal tiger.

This female is white because of a rare genetic mutation.

She can hunt animals weighing up to 1,000 pounds, but she'll usually only eat up to 80 pounds of meat a day.

Like a leopard, she has to hide food or face losing it to scavengers.

She left this ribcage here several days ago.

Bengal tigers have been known to drag prey 1,500 feet before feeding on it.

Burying the meat will force her two nine-month-old cubs to search for their dinner.

♪ All young cats go through this vital step in predator training.

Tigers are the only cats with vertical stripes -- perfect for blending into the reeds.

Camouflage is an integral part of the feline blueprint.

In every terrain, cats have evolved markings and colors to fit their surroundings.

Ancient clouded leopards have cloud-like patterns that give them their name... and help hide them in the dappled light of the jungle.

Recent research has found a cat's markings are more than fur-deep.

They're also tattooed on their skin.

So in theory, if you took away their fur, they'd still be able to blend into their surroundings.

And scientists have now discovered that camouflage is linked to hunting techniques.

And this also applies to domestic cats.

Lighter, solid-colored cats prefer to hunt in grass, moving slowly to blend in.

Whereas spotted cats are forest predators, often hunting at dawn and dusk.

Changing their camouflage helped cats hunt in new terrains.

It was essential to adapt, as early felines were living in a constantly changing world.

[ Thunder crashing ] Millions of years ago, the rainfall in Asia was double what it is today.

Wetlands became havens for wildlife.

And underwater was a whole new hunting opportunity.

One cat evolved to be semi-aquatic.

It faced new dangers in wetlands.

So the fishing cat adapted its camouflage to stay hidden.

They're so difficult to find, scientists are still learning about how the fishing cat lives.

In Sri Lanka, one pioneering researcher has got closer than ever to this elusive cat.

RATNAYAKA: The first time I saw a fishing cat, I was floored.

It was not anything I expected, really.

Because growing up, everyone's drilled on the whole "Big cat, big cat, big cat" thing.

The way it moved, the way it play-hunted and just general interaction was just amazing.

Kind of felt like somebody was keeping a really big secret from me for a long time, so that's when I realized to start working with the small guys.

NARRATOR: Anya Ratnayaka is the first researcher in the world to satellite-collar a fishing cat.

She's been tracking a 7-year-old male for a year, finding out where he goes and discovering that despite their name, fishing cats don't only eat fish.

RATNAYAKA: So we found old scat with bone and then there are beaks.

And feathers and fur.

There's a high possibility of it being fishing cat.

NARRATOR: Fishing cats, like all felines, will eat whatever they can catch.

But they specialize in hunting aquatic species.

They've been recorded diving into water to catch prey, using their webbed paws to swim.

Anya's data shows they hunt more often from the banks of waterways.

Their markings enable them to blend into wetlands, and they have adapted the cat blueprint for this style of hunting.

In rainforests, clouded leopards use their whiskers to help navigate around the treetops.

They have nerve endings that are sensitive to wind speed, air pressure, and touch.

Fishing cats use them to detect which direction prey is moving.

Then their claws hook in their target.

Anya's research is revealing how fishing cats can swim long distances across rivers.

For early cats, this ability would give them access to new places in Asia.

Combined with the need to have their own territories, cats pushed farther north into the highest mountain range on Earth.

The Himalayas reach up to 29,000 feet into the sky.

Life is so tough up here, cats had little competition.

And one feline species still dominates.

Snow leopards evolved the blueprint to hunt at high altitudes.

They have large chests and powerful lungs so they can make the most of the thin air.

Like the clouded leopard, they have long tails, which help them balance, and they've been known to use them as a scarf when temperatures drop.

Recent DNA research has discovered these big cats are more closely related to tigers than they are to leopards.

It was long thought they were the only feline that could survive in the harsh conditions of the Himalayas.

But recently, a team of scientists in Nepal made an incredible discovery.

They had been tracking a female snow leopard living at 20,000 feet above sea level.

This is no easy task.

MAN: Oh, this is a good place.

NARRATOR: Gathering clues and using remote cameras, they've gained unique insights into her life.

They believed she was the only cat that had a territory at this altitude.

♪ Ganga Ram Regmi is one of the lead researchers.

The snow leopard was captured by several cameras as she marked her territory.

Like all cats, they have scent glands all over their bodies and in their paws.

Rubbing them releases powerful pheromones that usually warn other animals to stay away.

But, remarkably, the team recorded a mysterious cat in snow leopard territory.

It turned out to be a little-known, very rare feline called the Pallas' cat.

♪ REGMI: [ Laughs ] NARRATOR: A cat's sense of smell is about 14 times more sensitive than a human's.

It's such a powerful sense, they can use smells to communicate.

Scientists have discovered that scent marking allows cats to keep track of each other.

Pheromones can tell them who's in the area, when they were last here, and when they might return.

Ancient clouded leopards used scent to divide territories in jungles.

It's such an important part of the feline blueprint, it's still used by domestic cats today.

So it's not surprising they often scent-mark furniture using their paws and body.

When two cats live together, like their wild relatives, they'll use pheromones to share the couch.

It's hard to believe a cat the same size as a domestic cat could survive in the same place as a snow leopard.

But Pallas' cats have learned to cope with mountain life.

They often live in rock dens, which keep them well-protected.

But out in the open, these nine-pound cats are vulnerable to attack from eagles and wolves.

So they move with extreme caution.

They hunt insects, small rodents, and birds by using rocks for cover.

[ Bird squawking ] Their fur is the perfect camouflage.

To say warm in the mountains, Pallas' cats have the longest fur of any cat.

It helps them to survive in sub-zero temperatures.

♪ After adapting to Asia's mountains, cats pushed farther north.

They were already well-equipped for one of the harshest environments on the planet.

Siberia endures the world's lowest temperatures outside of Antarctica... with extreme lows of -50 degrees Fahrenheit in some areas.

♪ To survive here, cats had to adapt the blueprint in a big way.

Siberian tigers are the largest cats in the world.

[ Squealing ] Adult males can grow up to 11 feet long and weigh over 600 pounds... ...12 times heavier than a clouded leopard.

This male is an instinctive ambush predator.

♪ [ Squealing ] His size has severely compromised his stealth, but it's the reason he can survive in extreme cold.

A two-inch layer of fat keeps him so warm that after a burst of activity, he needs to cool down on a nearby log.

By adjusting to their environments, cats had conquered Asia, its jungles, rivers, mountains, and now the frozen forests.

But around 8 million years ago, a new world opened up to them.

♪ Sea levels dropped 200 feet below what they are today.

And land bridges connected Asia to Africa via the Red Sea.

It led to the most dramatic changes in the feline blueprint so far.

Africa was full of varied habitats and teeming with prey.

It's still home to a quarter of all cat species.

Cats evolved to fill every niche, taking full advantage of each ecosystem.

One small cat conquered one of the toughest places.

Sand cats are a solitary species that only live in deserts.

At night, the chilling reason for their success is revealed.

They can go without water longer than a camel because as well as eating their prey, they drink its blood to survive.

They hunt snakes, geckos, and rodents.

They also adapted the blueprint to give them thicker fur on their feet, protecting them from heat and stopping them from sinking into the sand.

One of this Dracula cat's favorite victims is a small rodent called the jerboa.

♪ Jerboas can leap 10 feet with each stride.

But sand cats can sprint at 24 miles per hour.

This time, the jerboa outruns the bloodthirsty sand cat.

[ Growling ] One of the first cats to evolve in Africa is an example of how much felines had to adapt their senses to catch prey.

The serval is known as Frankencat... ...because it looks like a cat made up of spare parts.

They're actually a perfectly designed specialized hunter.

They have super hearing... [ Chirping ] [ Rustling ] ...because their ears are the biggest in the cat family.

And they can rotate them 180 degrees for surround-sound hearing.

[ Chirping ] [ Rustling ] It's even thought they can hear prey moving deep underground.

Another close relative of the serval also uses its keen sense of hearing to hunt.

But it's not their most well-known attribute.

This is a caracal.

Their ears have tufts to guide sound waves towards them.

But it's their back legs that are their killer asset.

They can jump so high, this female can catch birds in midair.

[ Birds chirping ] All she has to do is wait for the perfect moment.

This is an ability they share with the clouded leopard, who also has powerful back legs to pounce from trees.

These legs are such a key part of the blueprint, it's one of the things that makes cats such successful hunters... ...including the domestic cat.

The secret behind their explosive leaps are fast-twitch muscles.

They propel some cats more than 12 feet.

But despite this power and skill, there's no guarantee of success.

Most cats like caracals only catch their target 10% of the time.

She will have to keep searching for food and hope that she catches something soon.

Failure is the harsh reality for most solitary cats.

Cheetahs often face starvation.

And predation is a real danger for their little ones.

90% of cheetah cubs die before they are three months old.

♪ Cheetahs are often thought of as invincible hunters because they're the fastest cats on the planet.

Their claws aren't retractable because they act like running cleats.

They can reach zero to 60 miles per hour in less than three seconds.

♪ But their sprinting prowess comes at a price.

They have become so specialized, they don't have the muscle to defend what's theirs.

[ Chirping, barking ] Hyenas outnumber her and steal the kill.

This mother is powerless.

She will lose up to a quarter of her food this way.

Being solitary makes life difficult and stressful for most cats.

But in Africa, one feline found that working together was better.

Lions changed the feline blueprint in such a drastic way, no other cat is like them.

One man in South Africa has an insight into how beneficial it is for lions to be social.

Kevin Richardson is known as the lion whisperer.

He's spent two decades getting as close as possible to a lion pride.

RICHARDSON: The reality is most people will see me interact with a lion like this and say, "You're completely insane."

I'm definitely part of this group, accepted as an individual amongst them.

However, they obviously know I'm not a lion.

They tone down the way they play with me.

There you go, Mako.

And it's almost like just an acceptance of this -- this is a funny little creature with two legs that's part of this group.

Becoming part of a lion pride is a lengthy process.

It doesn't just happen overnight.

It's based on trust and a buildup of trust over time.

NARRATOR: Lions can live in prides made up of 30 individuals.

And trust is an important part of their lives.

Unlike their solitary ancestors, these cats have learned to divide roles and share responsibilities.

So while most of the females of this pride are surrounding prey... a nanny is protecting their youngest and most valuable members.

Females in a pride often lactate at the same time.

So cubs can be fed even when their mom isn't around.

They have the numbers to ensure that cubs are almost never left alone.

So if they get into trouble, an adult is usually around to help.

[ Cub mewing ] It's not just domestic cats that get stuck up in trees.

[ Mewing continues ] Lions have lost the need and ability to hunt in the trees, so it's not going to be an elegant rescue.

After a bumpy landing, the cub is okay.

While females look after young and hunt... ...males are on patrol, protecting the territory.

One of the ways they do this is by roaring.

[ Roaring ] Strengthened vocal cords make them the loudest big cat.

[ Roaring continues ] Calls can travel for over five miles.

Kevin Richardson has made new discoveries on how lions react to roars in their territory.

[ Roaring ] RICHARDSON: They're very astute and listening very carefully.

And you'll hear, as soon as lions roar in this park, they all listen and, "Oh, okay, I know who those lions are."

We've done experiments where we've played them familiar roars or the lions that they're used to.

[ Lion roaring ] A big male lion doesn't even react.

'Cause he know it's his -- he knows who they are, he knows that they're not a threat.

Play them an unfamiliar roar... [ Lion roaring ] And suddenly, he's -- you can see his hair bristle.

And if it's a one male lion, he's after it like a shot.

He goes in the direction of that sound.

But if you play three roars, unfamiliar, he's very quiet.

And suddenly, he goes in a kind of benign, to maybe avoid them.

So it's very interesting roaring.

We're still learning a lot about it.

[ Roaring ] NARRATOR: Cats are divided into ones that roar and ones the purr.

[ Purring ] No cat can do both.

Bigger cats like jaguars, tigers, and lions roar.

[ Roaring ] Whereas smaller cats like cheetah, serval... and domestic cats purr.

[ Purring ] Purrs are made by vocal cords that vibrate at up to 150 times per second.

The sound reverberates through their bodies.

And recent studies have shown the constant vibrations help to strengthen bones and even repair fractures.

[ Purring continues ] And when lions are injured, prides have been known to keep feeding them and looking after them.

Kevin has seen firsthand how important personal relationships are in a pride.

RICHARDSON: They've definitely got that more bonded, friendly, kind of interactive side to them, where they're always touching each other.

And on a day that's 45 degrees in the shade, you see a pride of lions all lying on top of each other.

And, you know, I've seen it myself when I'm with a group.

You'll see on a day where it's hot and you're lying amongst them, and you do a little test where you take your leg away from where you were touching them, and then you see this paw go... and feel for where your leg is and then touch you again and knowing that you're there.

Obviously, there's advantages to being social in terms of having tenure over territories.

[ Roaring ] Having the ability to hunt as a group and bring down larger prey to feed the group.

Having almost sentinels that stand back and look out, call for danger.

Or look after the cubs in a crèche.

NARRATOR: The reason behind lions' social nature has been the subject of fierce debate.

But the latest theory is that it's all about territory.

Like all cats, lions were once solitary, competing with other felines for food.

But then early lions figured out that if they worked together, they could hold the best territories with the most prey.

From that point on, they evolved the most sophisticated social order of any cat.

Whatever the reason, Kevin thinks this change has led to lions being smarter than other cats.

RICHARDSON: There has been experiments done on the cognitive ability of lions -- or of animals that are social -- showing that maybe there's a higher level of intelligence being social.

Because you need to know who your peers are, you need to know what their function is, you need to know what I can get from them or what I must do, what I mustn't do.

You know what I'm saying?

Whereas when you're a solitary animal, you don't need to worry about all of that.

You need to worry about me, me, me, and me.

NARRATOR: Lions are unique among cats, but the feline blueprint still runs through them, as it does through all felines.

Agility... super senses, and instinct are shared by the pioneering cats that spread across Asia... ...by the unique species that conquered Africa... ...and by domestic cats today.

This blueprint is the reason cats are one of the most widespread carnivores on the planet.

[ Growls ] Next time we discover how cats conquered the Americas... ...and ultimately gave rise to the most successful cat of all... ...our humble house cats.

[ Cat meows, baby babbles ] [ Purring ] -They're the greatest predator since the dinosaur, and one may be living in your home.

So what makes a cat a cat?

And how have they thrived in nearly every landscape on Earth?

-They're our last remaining large carnivore in the mountains, surviving next to one of the largest urban areas in the world.

-This is the story of cats, an 11 million-year evolutionary journey into our homes.

♪ Do ♪ To learn more about what you've seen on this "Nature" program, visit pbs.org.