♪♪
-The oceans are full of wonder,
an alien world waiting to be explored.
A place of extraordinary life-forms
with intriguing social lives
and incredible intelligence.
[ Dolphin squeaking ]
To reveal their secrets,
a hidden team goes undercover.
Spy creatures.
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The most innovative undersea robots in the world.
They not only look like the animals they film,
they interact with them as no human can.
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Equipped with hidden cameras...
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...they reveal their astonishing lives.
As our spies join their undersea world,
they shed light on some of the mysteries of the deep.
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Last time, our spies looked at how ocean creatures think.
This time, they explore how they feel.
As we dive into the world of animal emotions,
we can't help but be moved,
for their feelings aren't that different from our own.
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Surfing dolphins certainly seem to be having fun.
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Proving it is another matter.
To investigate what they're feeling,
a new spy will join them.
Spy Dolphin will be surfing with the best.
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It not only swims like a dolphin,
extra thrust helps it power through the waves.
[ Squeaking ]
Dolphins are famed for their intelligence,
but how they feel may be just as important.
To find out more, Spy Dolphin will join them in the waves,
its camera eye capturing what they experience.
Not bad for the first attempt.
Dolphins will play like this for hours.
But our spy is struggling to keep up.
♪♪
A wipeout.
[ Dolphins squeaking ]
Well, there's always another wave.
Like human surfers, dolphins wait for the big one.
And like us, surfing is a communal event.
By playing and having fun, they learn social skills
and get to know what others are feeling.
All while trying to catch the perfect wave.
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For Spy Dolphin, it's a chance to try again.
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For real dolphins, it's a chance for some tricks.
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What dolphins feel when surfing
may not be that far from what we feel.
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When we surf, we feel a surge of endorphins --
feel-good hormones found in other animals,
including dolphins.
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Endorphins help build friendships too.
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And what could be better than surfing with friends?
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No longer a newbie, our spy is now a surfing pro.
But it takes a real dolphin to experience the joy.
♪♪
French Polynesia is the next destination
for our surf-loving spy.
This time he's investigating the emotional life
of humpback whales.
Each winter, they travel over 3,000 miles from Antarctica
to reach these warmer waters.
They come to this safe haven to find a mate
or nurse their young.
But this is a humpback like no other.
One that can film.
Together they'll investigate the playful nature of young whales.
A lively duo on a mission.
They needn't wait long.
A calf, just two months old.
This is how a whale calf plays.
[ Whale singing ]
To find out more, our spy must make its acquaintance.
[ Whale singing ]
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Whales are inquisitive,
their young the most curious of all.
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He certainly seems welcoming. A promising sign.
[ Singing continues ]
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Just when the encounter seems over,
he comes back for more.
Again, another close pass,
ending with a playful swish of his tail.
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Play is an important part of a young calf's life.
[ Singing continues ]
So, what will happen when he meets Spy Whale...
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...a spy creature his own size?
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Already the calf is reacting differently.
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His approach is slower.
And he rubs alongside, as he would another calf.
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He also shows off by rolling and flashing his belly.
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Slapping his fins is an invitation to join in.
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Twisting and rolling suggests he wants more than to play.
He wants to be friends.
Adults make the same welcoming gestures.
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Through play, he learns the skills he'll need later in life.
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Then, as quickly as it started, introductions are over.
But there's plenty more for our spies to see.
Spy Whale captures the moment the calf's mother returns.
[ Whale singing ]
He dives down to greet her.
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After all that play, perhaps the strongest emotion of all --
the love between a mother and her young.
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It's this deep connection that will keep the calf safe
on their long journey back to Antarctica.
[ Singing continues ]
♪♪
Off the coast of Australia,
there are more emotions to explore.
Giant cuttlefish are never ones to hide their feelings.
In fact, they're clear for all to see.
Their ever-changing moods are displayed on their skin.
To find out more, a doppelganger has infiltrated the gathering.
One of the most sophisticated spies ever made.
Its back conceals a screen that can replay the patterns
expressed by the cuttlefish.
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How will this imposter be received?
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It's already attracting attention.
The skin of the cuttlefish shows his emotional state.
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Linked to his brain,
thousands of pigment cells expand and contract.
These chromatophores show what's on his mind.
Our spy's screen responds in kind...
...playing the patterns displayed by males.
A first contact with an alien mind.
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He turns to check if rivals are watching.
As he does, the patterns switch to his other side,
the one that faces our spy.
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Then a clue to what he's feeling.
He approaches our spy from the side.
It's something he'd only do to another male.
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It seems our spy is displaying a provocative message,
that of a rival male.
By approaching from the side, he avoids a danger
he's expecting -- a male's sharp mouthparts.
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As our spy isn't aggressive, the cuttlefish is intrigued.
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The spy then changes its display
to the more neutral patterns of a female.
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The male is even more curious.
In female guise, our spy gets a very different reaction.
He now dares approach from the front.
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A sure sign he knows he's not with a male.
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But a female cuttlefish attracts many admirers.
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Ones he must keep at bay.
He returns to our spy.
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A unique relationship has been formed...
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...one that will reveal more about the emotional lives
of these extraordinary creatures.
Cuttlefish aren't the only sea creatures
to wear their feelings on their skin.
The colors of octopus also change with their moods.
Spy Octopus couldn't possibly compete,
but it may find someone who can.
♪♪
The mimic octopus is the trickster of the ocean.
He not only changes his skin color with his emotional state.
He changes to match his surroundings too.
But our spy discovers that's just the start.
It even re-creates the grains of sand...
...raising its skin to match the texture.
That's not all.
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Among sea grass, he'll even mirror its shape and movement.
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A trick to fool his enemies.
But as impersonations go, he's just warming up.
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For his next trick, he needs inspiration.
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Hidden in the sand is another vanishing act.
A poisonous flatfish.
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Impersonate this, and he can avoid being eaten.
Not bad at all.
But will it fool the real thing?
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By staying in character, the mimic has gained an admirer.
The flatfish is looking for a mate.
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This relationship is dead in the water.
But the mimic has plenty more tricks to pull.
Constantly changing persona confuses predators.
New inspiration is never far away.
The deadlier the better.
A lionfish, armed with 18 venomous spines.
But is octopus up for the challenge?
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He'll certainly give it a go.
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He flattens his tentacles to mimic the lionfish spines.
And changes his shape and color too.
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Enough to fool an enemy.
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But it's not the end of his repertoire.
Sea snakes are among the world's most venomous snakes.
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Even though they're surprisingly docile,
their banded appearance still keeps danger away.
It's certainly worth mimicking.
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So far, over 15 different impersonations
have been discovered.
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But has he another to add to the list?
A passable imitation of our very own spy.
[ Birds squawking ]
In New Zealand, it's an emotional time
for a colony of fur seals.
[ Seals barking ]
The pups are three months old,
and they've just left their mother's side.
Their playground is a rock pool, safe from the ocean waves.
At this sensitive time, Spy Seal is here to find out
what they might be feeling.
[ Seals barking ]
Like us, their emotions are influenced by hormones,
the same as those that govern our own feelings.
Spy Seal watches as they learn the social skills
that will help them later in life.
But not all are ready for play school.
This pup is a few weeks behind the others.
He has yet to leave his mother's side.
♪♪
But that's about to change.
[ Seals barking ]
The fear of missing out makes him want to join the other pups.
His first tentative steps towards independence.
It's the sign his mother was waiting for.
She slips away unseen.
He'll be left alone for days.
♪♪
It's a worrying time.
He's never felt loneliness before.
But Spy Pup is near and welcoming.
A comfort for a pup whose mother has gone.
[ Seals barking ]
His next step is to join the playgroup.
First, he must summon up the courage.
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As the youngest pup, he's the most vulnerable.
And the weather is changing for the worse.
Our spy is first to feel its force.
And this is just the start.
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Those more experienced head to the shore.
[ Barking ]
But the young pup has yet to learn the dangers.
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He's now at the mercy of the waves.
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He's not the only one.
Spy Seal joins him in the surf.
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But waves wash both ways.
And the pup makes it out as well.
But his playmates have abandoned the beaches to head inland.
He'll struggle to catch up with them now.
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They're heading upstream for somewhere safer to play.
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He's alone once more.
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[ Barks ]
Although not completely alone.
[ Barks ]
A companion to raise his spirits.
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But it's the real pups he needs to find.
Where he's going, our spy can't follow.
The pup will struggle on alone.
To cover the challenges he faces,
rock cams take over filming duties.
They're hidden all along the way.
[ Barking ]
♪♪
The pup is undaunted,
despite facing one hurdle after another.
[ Barking ]
♪♪
The first trial is over,
but his emotions will soon be tested once more.
The feelings we share with other life
are found among all marine mammals,
including a visitor to the coral reefs of the Caribbean.
A manatee.
They come here purely to socialize,
having spent most of their day out feeding.
It's somewhere where friends and acquaintances can meet.
A very special visitor is about to join them.
A spy creature seeking company.
But what will the real manatee think?
♪♪
It's clear he's curious.
Spies based on youngsters usually go down well.
♪♪
Inspection over, Spy Manatee is off to a good start.
The manatees closest living relatives are elephants.
[ Manatees singing ]
It appears they share their emotional side too.
Our spy soon finds out how affectionate they really are.
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Mouths formed to graze on sea grass
here offer a gentle caress.
And even a slobbery kiss.
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Why they enjoy these touchy-feely moments
soon becomes clear.
Hairs that cover their body are highly sensitive to touch.
♪♪
Who they groom and for how long
depends on the strength of their relationships,
whether they are close friends or looking for a mate.
Often they enjoy just hanging out together.
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When socializing's over, they take it up a notch.
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For a youngster, a game of chase.
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But the manatee's favorite pastime is just chilling out.
When our spy does the same, it attracts attention again.
♪♪
This time it receives an affectionate once-over.
♪♪
And even a manatee kiss.
It's the ultimate sign of acceptance.
Just what we wish for our spy.
Back in Australia,
emotions are still running high among the cuttlefish.
As before, our spy is being guarded by the jealous male.
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It's still displaying the subdued patterns of a female.
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But in the breeding season,
many other males are also looking for a mate.
It's a full-time job keeping them at bay.
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But some are ready to take him on,
carefully avoiding his sharp mouthparts.
Eight arms soon toss him away.
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But he comes back for more...
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...and is dealt with just as decisively.
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The male returns to our spy.
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To calm things down, it switches its display to that of a male.
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That takes him by surprise,
giving our spy the chance to leave him to it.
The cuttlefish are left fighting it out among themselves.
Even they have testosterone,
the hormone that charges our own aggression.
♪♪
Across the reef, tensions are rising.
Wherever our spy goes,
it finds females jealously guarded by males.
The cuttlefish hides her beneath his flowing mantle...
...always just out of view.
But she's a reluctant partner and tries to get away.
By squirting ink she creates a cloud of confusion.
She escapes unseen.
With so much rivalry, the cuttlefish find crafty ways
to come out on top.
Younger, smaller males use a sneaky trick.
Male tentacles are longer than females,
so he tucks them away to disguises his sex.
His skin patterns also mimic those of a female.
In this way he sneaks in unnoticed
to fool the dominant males.
As they fight it out,
the imposter hovers on the sidelines,
waiting for his chance.
When the female wriggles free, his moment arrives.
Just what he was hoping for.
He makes his move...
...slinking past the bigger male
and stealing his female.
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It's a kidnap in plain sight.
♪♪
Beneath their embrace,
he gives her a present to fertilize her eggs --
a spermatophore she'll keep for later.
But the female can be sneaky too.
She'll mate with others and keep their gifts of sperm as well.
She will choose which she'll use to father the next generation.
Among cuttlefish, it seems all's fair in love and war.
Everywhere, courtship is a time of heightened emotions.
The tidal mudflats of Japan are the mating grounds
of some very odd fish.
Ones that spend most of their lives on land.
This fish out of water is a blue-spotted mudskipper.
♪♪
He breaths by gulping air
and absorbing oxygen through his mouth.
By keeping wet, he can even breath through his skin.
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His courtship rituals are as bizarre as his looks.
It takes a very special spy to film them.
Mud is an occupational hazard,
so its camera has a built-in lens cap.
As the day warms up,
it spies a female venturing from her burrow.
She's on the lookout for an eligible partner.
The bigger the better.
Our spy fits the bill.
Waving her fin like a flag is another good sign.
Our spy waves back.
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But this is where it all goes wrong.
There are plenty more males to choose from.
Spy Mudskipper has serious competition.
And their flag-waving is far more seductive.
But to really impress, flagging alone is not enough.
He must show what else he can do.
As emotions soar, it's now a competition.
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There's one yet to take its turn.
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Hardly a serious contender!
She's after the one that leaps the highest.
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She approaches the two best contestants.
Our spy is cast aside.
There can only be one winner.
To decide, they must fight it out among themselves.
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The female awaits the result.
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Finally, the loser is driven away.
She has her champion.
He leads her back to his burrow.
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They'll spend the season together
in his underground mud nest.
Our spy's flagging performance
was no match for the high-flying males.
♪♪
Back in New Zealand,
there's still one lost baby far from his mother.
Spy Albatross is tracking the path of the lonesome seal pup.
It follows the mountain stream the pup was left climbing.
His destination is a waterfall high in the hills.
But the pup is still trying to reach it.
He tries to press on...
[ Grunts ]
...but it doesn't get any easier.
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And the journey so far has taken its toll.
He's dispirited and exhausted.
[ Cries ]
But once more he's not alone.
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[ Spy chitters ]
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Spy Pup invites him to play...
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...and has the perfect plaything.
[ Spy and seal calling ]
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How better to raise his spirits?
Play releases endorphins, just as it does with dolphins.
[ Calling continues ]
♪♪
It's just the boost he needs.
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But he still has one last hurdle to climb.
[ Barking ]
[ Seals barking in distance ]
Then, finally, what all the climbing was for.
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A lagoon filled with the pups that went before.
His quest is finally over.
All he needs to do is take the plunge.
Reunited with the pups he last saw in the ocean.
Here he can play without a care in the world.
But has he forgotten someone?
His companion and playmate.
♪♪
With a new toy to play with.
One to be shared with everyone.
But there's still one who's missing out --
a spy that's now a friend.
With some encouragement, it too takes the plunge.
With a full team, the games begin again.
Passing the stick is a lesson in working together.
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Vital when hunting fish shoals as a team.
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It also builds strength for life in the ocean.
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The pup will enjoy this mountain paradise for a week or so
before returning to the sea.
He's had an emotional journey to get here,
but he's now better equipped for adult life.
[ Seals barking ]
♪♪
By befriending our spy,
the pup gave us insights into his inner feelings.
Whoever he meets in the future,
he'll never make a friend quite like his first one.
Next time, our spies will discover
the extraordinary relationships found throughout the oceans...
...and how working together is always the better way.
[ Dolphins squeaking ]
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[ Whales singing ]
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[ Seals barking ]
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[ Mudskipper croaks ]
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To learn more about what you've seen
on this "Nature" program,
visit pbs.org.
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