Original subtitles

Sometimes in life,

to make it to the top you need to bend the rules.

To survive in this competitive world,

many animals have pushed the boundaries of possibility to the LIMIT.

They seem to test the very fabric of reality...

Compared to us,

they can see sharper,

stretch their bodies further

and perform feats that are just out of this world.

Rainforests...

..deserts...

..coasts.

Three hostile landscapes

each forging their own distinct mix of mavericks.

By capturing their lives in spectacular detail,

we reveal the secrets that allow these animals to achieve the impossible.

Deserts...

They are barren AND they are brutal.

In fact, by their very definition,

they lack the one thing that's most fundamental to all life.

Water.

They get less than 25 centimetres of rain a year.

Then there's the blistering, ROASTING heat.

The desert air can reach 55 degrees Celsius.

And the ground, where most animals live,

can be over 70.

That is hot enough to cause third-degree burns on human skin

in less than a second.

Finally, it's their sheer scale...

Covering a fifth of the earth's surface,

resources are spread desperately thin.

And finding food can mean travelling for HUNDREDS of miles.

So, how does anything survive?

Well, first things first,

you've gotta know how to handle the heat...

The Namib Desert in Southern Africa is so hot and dry,

surviving here would be mission impossible for most animals.

But there's one group of daredevils who seem to like it here.

Reptiles.

The feet of the shovel-snouted lizard

would COOK were it not for his unusual dance moves.

But his real superpower is his shovel-shaped head.

He can use it to dig...

..tunnelling safely away from the searing sun.

Another reptile, the web-footed gecko,

has an eye-opening solution to the desert heat.

The Namib might not get much rain,

but it gets a lot of fog.

Droplets collect on the gecko's giant eyeballs...

..and all that's needed to quench its thirst...

..is a flick of the tongue.

Of all the reptiles that live in the Namib,

there's one colourful character that really stands out...

The Namaqua chameleon.

A high-speed predator that can snatch a toktokkie beetle in a split second.

On a good day,

it can eat 200 of these fast-moving beetles,

so it needs to hit the ground running.

But desert mornings are cold...

..so it needs a little time to warm up.

Like many reptiles...

..it needs to soak up heat energy from the sun.

So, to get its body to running temperature,

it starts the day by sunbathing.

All chameleons can change colour

thanks to special chemical crystals hidden under their skin.

Now, the Namaqua goes one step further

by combining science with fashion.

When it's sunbathing, it prefers to wear black,

and that's because the darker the colour,

the more heat is absorbed

and the quicker the lizard can warm up.

To top it off, it has hinged ribs,

which means it can expand its skin like a sail,

stretching out the side facing the sun to catch the maximum number of rays.

And it can even make the other side of its body white,

so all that precious heat doesn't escape.

The Namaqua gains more and more energy with every passing second.

And once it's fully charged...

..it doesn't hang around.

At top speed,

the Namaqua chameleon can reach a BLISTERING three miles an hour...

What? Only three?

Come on, give them a break...!

I know that might not seem that impressive to you and I,

but at only 25 centimetres long,

that's practically greased lightning!

And if three miles an hour won't cut the mustard,

the Namaqua can always pull out its ballistic tongue.

At twice the length of its body,

it can fully extend in as little as three-hundredths of a second.

When it boils down to it,

being cold-blooded is a great way to deal with a hot climate.

By using outside sources to regulate their body temperature,

reptiles can warm up by basking in the sun

and cool down by crawling into the shade.

But what about warm-blooded creatures like mammals?

They have to stick to a very narrow internal temperature range.

Any more or less and it CAN end up being fatal.

So, for them,

the extreme desert heat presents a far greater challenge.

The heart of the Sahara,

one of the hottest and driest deserts on earth.

Hardly the place you'd expect to find a tiny furball

like this fennec fox.

He's the smallest dog on the planet,

about half the weight of a Chihuahua...

..and everything about him is miniature.

Well, almost everything...

With the sweltering sun beating down,

his body temperature would rise to deadly levels if not for his giant ears.

Each ear measures over a hundred square centimetres

and is cram-packed full of tiny capillaries.

When the fennec fox is in danger of overheating,

these swell up,

bringing more warm blood into contact with the cooler air,

allowing any excess heat to dissipate.

This turns him from a dangerously hot dog...

..into an impossibly cool canine.

Desert-dwelling animals have found some impressive ways of outfoxing the heat,

but that is just the start.

Next,

the ingenious methods animals use

to navigate the treacherous desert terrain.

The parched deserts of the world push life to the limit.

But for the animals that live here, heat isn't the only problem.

Deserts are vast,

and the terrain is SERIOUSLY hostile.

Jagged rocks as sharp as knives...

..dunes that tower 300 metres high...

And then, of course, there's that sand.

Lots and lots of sand...

Now, from a physics point of view,

sand doesn't act like a solid or a liquid,

but something in between.

If you've ever tried running on a sandy beach,

you'll have experienced this first hand as the sand shifts under your feet.

It can feel like you're tackling a full-on assault course.

Unless, that is, you have a clever solution.

For the sidewinder,

these giant dunes COULD be a massive problem...

If it slithered forwards like a normal snake,

its tiny body would quickly be buried in the loose sand.

So, instead...

..it skims over the surface sideways.

This strange diagonal wiggle

not only keeps the sidewinder afloat...

..but it also means only a tiny amount of skin

ever comes into contact with the sand.

But what does all this sand mean for animals with a need for speed?

Salukis are lean, athletic dogs,

bred for hunting in the desert by Arabian tribes.

But in order to chase down swift prey like hares and gazelle,

these canines have shifted their running up a gear.

The Saluki becomes fully airborne,

not once...but twice each stride.

First with its feet together,

then again when apart.

A running style called the double suspension gait.

This top gear of galloping

has seen Salukis clock an incredible 68 kilometres an hour.

And over distances of half a mile or more,

they leave even the fastest greyhounds for dust.

When getting around the world's deserts,

there are other challenges to overcome.

The spiny forests of Madagascar...

..look more like an alien world.

But they're still technically just as much of a desert as the Sahara.

This three-dimensional maze is an obstacle course for any creature.

Luckily, the sifaka,

a species of lemur,

has not one but two impossibly effective strategies.

First of all, it's an unrivalled arborealist...

..leaping up to ten metres between trees.

And what could be a skin-shredding landing on these needle-sharp plants...

..is ingeniously prevented thanks to thickly padded palms and feet

just like inbuilt safety gloves.

But when the sifaka hits the ground,

this maverick mover does something even stranger...

This sideways bouncing doesn't look like a sensible running style,

but appearances can be deceptive...

New science has shown that,

by stringing jumps together in a chain,

sifakas spend less energy than they would if they took individual jumps

one at a time.

And that's all down to momentum.

Each leap produces energy that's carried forward to the next jump.

It's sort of like bouncing a rubber ball.

Each bounce provides energy for the next.

And this is exactly what's happening when the sifakas jump in this way.

It might seem odd to you and I,

but this is a brilliant way of getting around in the desert.

From leaping through trees to galloping on the ground...

..they've got the spiky Madagascan habitat...

..nailed.

In the Sonoran Desert of Arizona,

one solution to vicious vegetation on the ground...

..is to take to the air.

For a Harris hawk, with a wingspan of over a metre...

..it's nothing but a breeze.

But all that thorny vegetation provides excellent cover

for lizards attempting to evade capture.

The hawk has no choice but to engage in an aerial pursuit.

Not OVER the obstacles...

But through them.

And to keep up,

there are some clever calculations going on in the cockpit.

Other raptors like peregrines and kestrels

use a guidance system a lot like a homing missile,

flying more or less in a straight line to intercept their prey,

cutting them off at the very last minute.

Now, that's great in open terrain,

but not so good if your flight path is full of spiky cacti.

The other option is an all-out pursuit,

chasing your prey, beak pointed directly at their tail.

This tactic requires a different flight path,

of actively manoeuvring around obstacles.

But the thing is, it's a lot slower.

What's special about hawks is that they use BOTH.

They stay right on the tail of their prey

whilst also predicting its path,

which gives the hawk the ability to make adjustments

and take shortcuts where it can.

Just like the sifakas that change tactics in different terrain...

..when the lizard goes to ground,

the hawk doesn't let being a bird hold it back.

It stalks its prey on foot.

A light build and long, thin legs...

..make this bird a formidable runner.

Plus,

Harris hawks have some of the best colour vision in the animal kingdom,

which could give it the edge in a deadly game of desert hide-and-seek.

But despite these advantages...

..this time the lizard is just out of reach.

Next,

we'll look at how some of the world's greatest animal athletes

have solved the problem of finding food in the desert.

Deserts are the least productive ecosystems on the planet.

Compared to rainforests, they produce just 5% of the food.

The lack of rainwater results in fewer plants...

..and fewer plants means fewer herbivores.

This continues all the way up the food chain to the apex predators of the desert.

So, no matter what you eat,

you're gonna need to beat some near impossible odds to bag yourself a decent meal.

At around five metres tall...

..giraffes are voracious vegetarians

that CAN spend 18 hours a day eating.

And in the barren Namib wilderness,

the need to satisfy this huge appetite...

..has driven them to extraordinary lengths.

To avoid the hottest part of the day,

they undertake marathon marches at dawn and dusk.

The range of desert giraffes is an astonishing 15 times larger

than their grassland cousins.

The Namib is also home to desert elephants.

Their quest for food is even more extreme.

Older members of the herd have the phenomenal ability

to remember the exact locations of food and water for decades.

A vital skill in a world where human activity is causing deserts to expand

and resources to become increasingly scarce.

They'll trek hundreds of miles

and their super sensitive trunks can smell water

even if it's buried underground.

When they finally find food,

these herculean animals have the power to tear down heavy branches...

..yet the precision to pluck single seed pods from the ground.

Because in the desert, every leaf counts.

The near impossible challenge of finding food in the desert

doesn't get any easier as you climb the food chain.

For carnivores who can't just top up their calories by grazing,

each kill can mean the difference between survival and starvation.

So, with such little food around,

you wouldn't think that the world's top apex predators,

big cats,

would be able to survive here.

Yet a few of these natural-born killers have found a way.

Most cheetahs make their home in Africa's grasslands...

..but they can also be found in the Sahara and Namib deserts.

Their black tear marks, called malar stripes,

reduce glare as they scan the surroundings for their next meal.

But when they spot their prey, that's when the real magic begins.

Within an instant,

the cheetah switches gears and goes from stealth to all-out speed.

When most animals start to run,

their heart rate increases gradually,

but a cheetah's heart rate more than doubles,

going from 120 to 250 beats per minute

in just a few seconds.

Its muscles are also four times more powerful than a human's,

and propels it to a level where it's able to cover seven metres in a single stride.

On top of that,

its ridged feet and permanently extended claws

give it the perfect amount of grip

to race its way to a blistering 120 kilometres an hour,

even on desert sand.

In the race for survival, there can only be one winner...

Deserts are found across the earth's surface,

and while they're always dry,

they aren't necessarily hot.

The arid lands of Mongolia are cold...

..and the predators that live here are just as mysterious.

The Pallas's cat seems more like a moggie than a mountain lion.

But this Central Asian wildcat...

..is a lean, mean...

..stealth machine.

And if you're a gerbil,

he might be the last thing you never see.

His unusually flat head and low-profile ears

allow him to get within metres of his prey.

And when it comes to the crunch...

..his powerful bite...

..is more than a match for a gerbil.

In the desert, it's an evolutionary arms race,

driving strategies and adaptations

that reward the rebels who take innovation to the extreme.

And one desert predator has raised the bar impossibly high.

The caracal is the ultimate desert hunter.

She may be one of the smallest wildcats in Africa...

..but she has a secret superpower.

These weaver birds have built their nests high enough to be out of harm's reach.

A fortress...

But that doesn't phase the caracal.

She knows that, as darkness approaches,

the weaver birds will make one final approach back to the nest.

And the caracal has an unexpected skill for a mammal.

She can fly...

..jumping an incredible three metres in the air from a standing start.

Mammals have three kinds of muscle fibres.

Slow, fast and REALLY fast.

The caracal's muscles are overwhelmingly more than 70% of the third kind,

AKA the type of really fast muscle fibre

that's linked with the explosive speed needed for sprinting and jumping.

Sprinters who train for years trying to increase this type of muscle

still don't even come close to the caracal.

All that power would be nothing without precision.

Next, the ultimate fight for life

as animal mums and dads battle to raise their young in the desert.

In the desert, only the strongest survive.

It's hard enough to stay alive as an adult

when you only have yourself to look out for...

So, imagine just how impossible it must be to raise an entire family here.

Heat, hunger and drought are constant problems.

Predators see infants as an easy meal,

but animal babies DO survive here.

And it's down to more than just luck...

When it come to the problems of desert life...

..this tiny African sengi has one go-to solution.

Speed.

Everything's done in fast-forward...

..including parenting.

Baby sengi can also run swiftly just one hour after birth...

..and can have babies themselves in less than two months.

Now that is a seriously fast learner!

But when it comes to being an early developer,

one desert animal has got the jump on everyone else.

Thirty-five percent of Australia is classified as desert.

This is home to the mighty red kangaroo.

These backcountry bruisers are well-known for their phenomenal jumping ability.

They're also brutally efficient boxers...

..who balance on their tails

to deliver a lightning-fast two-footed kick.

Adult roos punch well above their weight,

but when it comes to athleticism,

it's the baby roos that scale new heights.

Compared to the size of an adult,

kangaroos give birth to the smallest babies of any mammal.

They are TINY,

100,000 times smaller than an adult male kangaroo.

And the first thing this jellybean-sized baby has to do after being born

is haul its way up its mother's fur and into the pouch.

For an animal this size, it's like climbing Mount Everest

when you've only just entered the world.

Once inside the pouch,

it'll suckle for four more months

and then it's mum that does something really impressive...

While one joey develops in the pouch,

incredibly, she can already be pregnant with the next one.

But don't be fooled, these mums are in TOTAL control,

because if desert conditions get really tough,

they have the astonishing ability to put their pregnancy on pause.

Now, I know a few mums and dads out there who would love to have that option,

but for life in the desert, this isn't just a perk.

This ability is crucial to their survival.

When you're trying to raise a happy, healthy family

where no one else can,

timing is everything.

If punishing desert conditions

make raising one, two or even three babies in the desert difficult,

then imagine trying to raise 20 in such a brutal world.

If you want to have a large family, it makes sense to get some help...

LOTS of help.

Meerkats...

Amazingly,

there's often only one mum in a meerkat mob.

The matriarch.

She can have up to 20 pups a year,

a tough task for any mother...

And it's getting even tougher,

as the changing climate is reducing pup survival rates.

But she's not alone.

She has the help of her extended family,

a whole team of dedicated babysitters.

The pups will learn all of life's vital skills from them.

Welcome to meerkat training camp.

They have a lot to learn...

..from how to dig up grubs and insects...

..to safely mastering how to deal with a scorpion...

..and understanding when it might just be best to back down.

Just like a lot of big families, squabbles are fairly common...

But somehow, in true soap opera style...

..they make it work.

For youngsters in the desert, every day is a schoolday,

and these lessons WILL make the difference between life and death.

But some species have to overcome the most impossible odds before they're even born.

Or in this case, before they've even hatched...

When it comes to the bird world, ostriches don't play by the rules.

They have two toes instead of the normal four,

three stomachs

and eyes that are bigger than their brains!

And their parenting skills are even weirder...

Hatching the world's largest egg is definitely a slow process.

To stop them from hard-boiling in the hot desert sun,

these giant ostrich eggs are white to reflect light...

..making them really obvious to desert predators...

..and that means 42 days of peril before they even hatch.

The alpha female has a cunning strategy

to give her offspring the best chance of survival.

When another female approaches, you'd think there'd be a standoff.

But instead, it's a stand up...

Bizarrely, the newcomer's welcomed

to lay her eggs in the dominant female's nest.

This might LOOK like generosity,

but really it's a case of safety in numbers.

The dominant female is a street-smart mother in waiting.

She can recognise exactly which eggs are her own

by tiny differences in their size, shape

and the texture of the surface.

She then takes great pains to shift her own eggs to the middle of the clutch...

..and pushes the other female's eggs towards the outer edge.

But why does she do this?

Well, if a hungry jackal comes along looking for an easy meal,

the chances are it's more likely to take an egg from the outside edge of the nest.

And BOOM, her eggs are perfectly safe...

Once the nest is rearranged,

males and females share incubation duties around the clock.

After 42 days of surviving fearsome predators...

..and soaring temperatures...

..their eggs finally hatch.

For them,

the challenge of desert life has just begun.

Raising young in the barren and brutal desert

can at times seem like a futile resistance.

Yet it's one that happens every single day...

..because by breaking the rules, defying convention

and going further than their competitors

by being taller...

..faster and WIERDER...

..these incredible desert mavericks...

..have made the impossible POSSIBLE.

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