The animal world is full of spectacle and wonder.
But what's it like to be right in the heart of the action?
To find out, our team of spy creatures goes undercover.
They not only look like the animals they film...
..they behave like them, too.
Armed with the latest camera technology...
..they are heading across the globe.
From the heat of the tropics...
..to the lands that lie in the north.
From the islands of the Southern Seas...
..to the snow and ice of the frozen poles...
..our spies reveal the astonishing variety of life that thrives there
from inside their world.
On this assignment, our spy creatures
reveal how life thrives on the islands of the Southern Hemisphere.
Far from the mainland,
these isolated places
have given rise to some of the most unique animals on Earth.
The Galapagos Islands of the Pacific Ocean.
A barren archipelago
formed by underwater volcanoes
over three million years ago.
This landscape of lava is home
to a remarkable fauna
found nowhere else in the world.
One of the most intriguing
is the marine iguana.
Before they can become active,
these cold-blooded lizards
must bask in the sun.
Their black skin absorbs the heat,
raising their core temperature
to a toasty 40 degrees.
To film these highly protected animals,
Spy Iguana has special permission
to go closer than any human is allowed.
To succeed, it has to be totally convincing.
Once they are hot enough,
they start to move.
Spy Iguana
now witnesses something remarkable.
Cliff jumping for lizards.
They are after the seaweed
that flourishes just off shore.
They're on borrowed time.
The water's cold.
And in less than an hour,
their body temperature will halve
and they'll have to return.
Now, another spy takes over.
Lava Cam can track the iguanas
wherever they go.
At this time of year, the females
are laying their eggs on the beach.
The sand is baking hard,
but a metre down
it's the perfect temperature for incubation.
Spy Iguana joins them
for a closer look.
Digging the nest can take an hour.
Hard work in the hot sun.
When they take a break,
they have a self-styled sun hat.
Even our spy.
Competition for the best nest sites is intense.
Those digging must be prepared to hold their ground.
Head bobbing is a challenge for ownership.
The winner is decided
by a test of strength.
The owner wins.
She's free to finish her work.
Along the tide line,
the others are returning
from their underwater feast.
Chilled through by the cold sea,
they must sunbathe once more.
As Spy Iguana joins them,
another surprise is in store.
They sneeze snot.
Special glands in their nose
remove excess salt,
which is expelled spectacularly.
Whatever they can do,
our spies can do, too.
Oh...perhaps not.
As the day ends,
iguanas show their more affectionate side.
Even our spy has an admirer.
Snuggling together
preserves precious warmth,
as the sun sets
over the Galapagos Islands.
Over 8,000 miles away,
off the southern coast of Australia,
Kangaroo Island is another unique wildlife haven.
Cut off from the mainland
for 10,000 years,
it even has its own variety of kangaroo.
Koalas are here, too.
But they are relative newcomers.
Introduced here 100 years ago,
they now survive
in unrivalled numbers.
Among them is a new koala,
fresh from the mainland.
It's here to film
their breeding behaviour.
The timing's perfect.
They're just waking up.
Yawning pumps oxygen to the brain.
Even wide awake,
he needn't go far.
His favourite food is all around him.
Eucalyptus.
But their leaves are not only tough,
they are poisonous,
so koalas have powerful digestive juices
that neutralise the toxins.
Just digesting their food saps energy,
so they sleep up to 23 hours a day.
But today, this koala
is breaking the habit.
In the breeding season,
he must step up a gear.
One of our mobile spy cams
must rise to the challenge.
Koalas rarely come to the ground
or show such a turn of speed.
But he now has a territory to defend.
KOALA BELLOWS
He bellows to announce he's in charge.
A warning to other males.
HE BELLOWS
Koalas scent mark the ground
to tell each other who's been passing through.
He's caught the scent of a female.
But this one already has a baby.
No point chasing her.
But she's not the only female here.
And our spy is now keeping her company.
The male's enthusiasm may be short-lived.
A rival has found her first.
He will have to challenge for possession.
HE BELLOWS
He announces his arrival
with a warning.
HE BELLOWS
Spy Koala is witnessing
something rarely filmed.
A fight in the treetops.
SCREECHING
The only injury...
..a loss of dignity.
The loser makes his retreat.
While the challenger gets the girl.
For all, that's quite enough activity for one day.
Christmas Island in the Indian Ocean.
Home to a creature
found almost nowhere else on Earth.
Every year, the monsoon rains
sweep the island
and trigger a mass awakening.
Spy Crab is ready to capture
what's about to unfold.
The real crabs have been sealed
in their burrows for months,
avoiding the worst
of the yearly drought.
Now they emerge en masse.
Each female carries thousands
of eggs in a protective pouch
beneath her belly.
United by a common goal,
they begin their march to the sea.
A few soon become an army.
They haven't eaten for months
and are hungry for anything they can find.
Sometimes even each other.
But a robotic crab
won't satisfy anyone's hunger.
All in working order,
Spy Crab rejoins the march to the sea.
Since human settlers arrived,
the crabs have faced hurdles
never found in nature.
The smallest try to squeeze through.
The rest have just one option.
To climb.
No problem with six powerful legs to help.
Once down, an even greater challenge awaits them.
Many roads close in the migration season, but not all.
There are always some
that never make it.
But here it's a case
of waste not, want not.
Now it's Spy Crab's turn.
Against the odds,
most make it to the coast.
They assemble in the shade,
waiting for the perfect moment.
High tide triggers the final push.
Then, in their thousands,
they release their eggs.
A victory dance speeds the process.
Each crab may release 100,000 eggs,
all swept out
by the retreating tide.
In four weeks' time,
their hatchlings will return to the island.
Madagascar.
Bizarre baobab trees
are a remnant of the island's
ancient connection to Africa,
now 300 miles west.
It was once connected to Asia, too.
Separated from both
for millions of years,
life here has taken
its own evolutionary course.
In the island's spiny forest,
95% of plants
exist nowhere else on Earth.
And the animals are equally unique.
A sifaka lemur.
One of over 100 different species
found only here.
Madagascar is also home to half the world's species of chameleon.
One of the most beautiful
is the panther chameleon.
This one's a spy.
He's eyeing up a warty chameleon.
To their own kind,
they are fiercely territorial.
But not, it seems, to our spy.
While our chameleon is otherwise preoccupied,
another takes over.
It's soon spotted by another lemur.
The ringtail.
They spend more time on the ground
than any other.
They're also intelligent and curious.
Anything new demands a second look.
Lemurs are sun-worshippers.
Adopting the lotus position
helps raise their body temperature.
Vital for an animal
with a low metabolism.
They're very good natured -
even to those that steal their sun.
After half an hour's meditation,
the day begins.
They live in large groups
up to 30 strong.
Their tail acts as a flag,
making sure no-one gets lost.
While ringtails spend
most of their time on the ground...
..sifakas spent most of theirs
in the trees.
Their powerful legs
and stabilising tails
help them leap up to ten metres.
Adapted for jumping
from tree to tree,
they have trouble
walking on all fours.
They have a unique solution.
They pogo.
How better to cross open ground?
It may not be conventional,
but it's surprisingly quick.
In just a few seconds,
they can be gone.
Leaving our spy with those
who prefer life in the slow lane.
Back on Kangaroo Island,
it's now the breeding season
for the animals that gave the island its name.
This type of the western grey kangaroo
is smaller and stockier
than its mainland relatives.
They, too, hang around in groups
known as mobs.
Each consists of up to ten females
and their babies, called joeys.
Every mob has an adult male,
known as a boomer,
keeping an eye out for them.
Now there's a newcomer in their ranks.
The boomer checks out
any new member of his gang.
She looks the part.
That's good enough for him.
Inside the mob,
females often act as aunties
to each other's joeys.
One joey has taken a shine to Spy Roo.
He seems to regard her
as an auntie, too.
Then, as the ultimate sign of acceptance,
he even tries to suckle.
Despite the apparent harmony,
there are dangerous rivalries here, too.
Competing males are everywhere,
hoping to steal a female.
Their liaison is no longer a secret.
It's something no boomer would tolerate.
First, a bit of shoving,
Then, the claws are out.
His mob can only watch from the sidelines.
Now for the big guns.
The kick can deliver
a blow over of two tonnes.
Victory for now.
But the boomer must always stay on guard.
Meanwhile, peace returns.
And the joey's adopted auntie
is the centre of attention once more.
Just off the coast of South Africa
lies a small outcrop
known as Seal Island.
Cape gulls are common here,
but this one has a camera
in its eye and belly.
Below are the Cape fur seals
that gave the island its name.
Over 60,000 of them.
They feed on the vast fish stocks
that thrive in the cold Antarctic currents.
At this time of year,
they gather to raise their young.
Among them is a spy.
He can sneak right up close
without raising suspicion.
Touching noses shows
they are totally at ease.
All around, the pups are growing fast.
Fed on their mother's full-fat milk,
they quickly outgrow
their island home.
Everyone is squabbling over space.
Soon they must venture into the water,
including our spy.
Female seals are known to adopt orphans.
Perhaps this is why Spy Seal
is creating interest.
He's also a welcome playmate
to the younger seals.
But in nature,
danger is never far away.
Spy Gull is patrolling the waters
around the island.
Below, the ocean's greatest predator.
A great white shark.
Each year, over 40 gather here
to hunt the young seals.
Spy Seal is the first
to see the shark approach.
But one young seal
is still blissfully unaware.
Seen from above,
a game of cat and mouse unfolds.
The seal may be young,
but he's quick and manoeuvrable.
From above,
something remarkable becomes clear.
The seal pup can turn faster than the shark.
He deliberately gets behind it,
out of sight.
Whenever the shark turns,
the seal stays right on its tail.
Until finally...
..he makes his escape.
Our spy is now the only seal remaining.
The shark begins to circle...
..checking out yet another likely target.
Sharks can detect
minute electric fields.
Spy Seal has plenty of those.
At every pass, it gets closer.
The first bite is exploratory.
Testing if it's a worthwhile meal.
This wasn't what it was looking for.
Battered and bruised,
Spy Seal is left alone.
But it's a long way
back to the island.
Over 5,000 miles away,
off the coast of Western Australia,
is Rottnest Island,
home to one of the most photogenic creatures on Earth.
Meet the quokkas,
the only native mammals to live here.
These marsupials
have no other living relatives
and exist only in a few places in Australia.
They have a friendly reputation.
So our spy should fit right in.
It's all going to plan.
As few predators are found on the island,
they are curious and welcoming.
Spy Quokka's mission is to find out
how they raise their young.
Quokkas are vegetarians
and tea tree is one of their favourites.
Behind their cute smile
are some razor-sharp teeth.
And they use their five-fingered hands for grasping.
Quokkas eats so much vegetation,
they rarely need to drink.
But this is what our spy has come to see.
A baby quokka.
A joey, just three months old.
All marsupials
carry their babies in a pouch.
Quokkas are no exception.
For the last three months,
he's relied on his mother's milk.
Now he's trying solid food.
But, as a result,
he's getting too big for his pouch.
Withholding food is one way
to deal with the problem.
It's already quite a squeeze to get out,
but there's a big, wide world to explore.
He's going to need a lot of looking after.
Our spy now witnesses
another sight of quokka life.
For all their cuteness,
quokkas will fight over food,
especially tea tree.
Even the joey's mother
isn't keen to share.
With all this competition,
Spy Quokka is on dangerous ground.
A peace offering.
That seems to have done the trick.
For the baby, it's been quite enough
adventure for one day.
Across the Indian Ocean,
on the remote island of Komodo,
the east winds are blowing.
They bring the dry and harsh conditions
that trigger the breeding season
for the infamous Komodo dragon.
Unique to these tiny Indonesian islands,
they are the largest lizard in the world.
Up to three metres in length.
The forked tongue is used
to detect odours.
This male is seeking a mate.
Spy Dragon looks just like the real thing.
Certainly worth a closer inspection.
He rakes his claws over the skin
to try to release pheromones
to reveal its sex and age.
Then checks with his tongue.
She may look the part,
but she doesn't smell the part.
There's nothing of interest here.
He heads to the water hole -
always a good meeting place
at this time of year.
Here, Spy Pig is also on duty.
As wild pigs are often eaten by dragons,
it soon attracts interest.
Again, he uses his tongue to check its scent.
But there is something
far more interesting on the wind.
A real female dragon.
Some wooing is required.
His advances captured by a mud cam.
She stops to show she's interested.
This time, raking the skin
gives off all the right signals.
Our spy captures what must be
the closest reptiles get
to a tender moment.
But pheromones travel far.
Another male is also on the scent.
With testosterone raging,
a fight is inevitable.
The female has a vested interest in the outcome,
so follows behind.
They test their strength by wrestling.
The victor pins his rival to the ground.
And finally sees him off.
But with everyone in a fighting mood,
Spy Pig is no longer quite so safe.
The other dragons are showing interest, too.
He may be down,
but he keeps on filming.
At nearly 100kg,
these dragons are ten times heavier
than their victim,
and they've hardly even started.
For the first time ever,
a view inside a dragon's mouth.
One laden with venom
and toxic saliva,
dosed with over 50 types
of deadly bacteria.
But as Spy Pig doesn't taste edible,
he's soon abandoned.
Anyway, the Dragons still have
romance on their mind.
Spy Pig's days are well and truly over.
While our friendly dragon survives unscathed.
In the middle of the South Atlantic,
the Falkland Islands
become the focus of another spectacular event.
Rockhopper penguins
have arrived to breed.
Here, too, is Spy Penguin.
Part of an army of penguin cams
ready to provide total coverage.
While the mothers are fishing out at sea,
the males are left
on parenting duties.
One is already in trouble.
His chicks have hatched,
and his partner is yet to return with food.
Just off shore, another spy
also awaits the penguins' return.
They arrive without warning.
Just getting ashore is difficult enough.
Another penguin cam is there
to film their achievement.
Many more will be needed
to cover the huge challenge ahead.
To reach their chicks,
somehow the penguins must scale
this 100-metre cliff.
Just reaching the first level
is tricky enough.
But rockhoppers will never let
one mishap get in their way.
Even though at every step
they risk going back to the start.
With a little fancy footwork,
this female is faring best of all.
However, she still needs
to reach the next level up.
But they're not called rockhoppers for nothing.
Although a little practice is required.
Or, perhaps, an easier route.
But nothing here is ever that easy.
Next, this aquatic bird
must become a climber,
with beaks and bills
acting as crampons.
Fortunately, a thick layer of fat cushions her fall.
She follows an ancient route.
The sides carved out by the beaks and claw marks
of generations before her.
For some, the intensity of the climb brings out a competitive streak.
But our heroine avoids getting involved.
Instead, she finds some welcome relief.
A natural shower.
A quick freshen up before meeting her partner.
Just one more level to complete what's known in the trade
as a chimney climb.
Now it's just a matter of finding her mate.
Not so easy when everyone here is equally feisty.
The reunion will be short.
to go fishing.
They will each take shifts over the next six weeks,
until the chicks are ready for a life at sea.
Back in the Galapagos Islands, the moss-shrouded mountains
of Santa Cruz set the scene for another remarkable gathering.
Boulder-cam is on a mission to find this rare and secret event.
It's not long before it finds the first hopeful sign.
A giant Galapagos tortoise.
Unique to these islands, at nearly two metres head to tail,
they are the biggest in the world.
In these moist mountain valleys, there is plenty for them to eat.
But it's so tough and fibrous, they must feed for eight hours a day
just to get enough nutrients.
It's not the only tortoise here.
There's a spy in disguise.
It's the breeding season.
Spy Tortoise could be just what he's looking for.
Although he's never come across a female like this before.
With 400 kilos on her back,
it's a good job her shell is reinforced.
Well, that was never going to work.
But he soon picks up the scent of a real female...
..with both spies hot on his heels.
He would have smelt her from over a mile away.
A useful skill in such a dense forest.
It's now just a case of following the sound.
TORTOISE GROANS
Mating can last for hours.
TORTOISE GROANS
It never ends gracefully.
Finding a mating pair is quite an achievement.
But our spies have yet to complete their mission.
But this is a hopeful sign.
In fact, Galapagos tortoises are everywhere.
And here it is...
..their Shangri-La.
An incredible gathering of over 30 giant tortoises.
All enjoying the fresh water
found in just a few mountain pools.
It's a haven for other wildlife, too.
The Galapagos pintail duck.
For the tortoises, the pools not only offer a place
to drink and chill, but to absorb the food they've eaten.
Our spy's mission is finally complete.
Leaving the tortoises to digest their high-fibre meal.
Next time, our spy creatures venture to the Poles to find
the extraordinary animals that thrive in a world
of ice and snow.