Nature (1982–…): Season 36, Episode 13 - Natural Born Rebels: Hunger Wars - full transcript
The complex science behind the behavior of animals that rebel, including and alpha chimpanzee, a manipulative crab and a dolphin with a pufferfish drug problem.
♪♪
All animals face
the same challenge.
They must find food...
if they're to survive.
So to get what they want,
some animals will
break all the rules.
When food is hard to come by,
being able to take what you
need can be essential for survival.
Meet the planet's
greatest rebels.
They'll steal...
deceive...
and even resort to brute force.
But could behaving like this
actually be the secret
to their success?
♪♪
We'll reveal new discoveries
and astonishing science...
as our rebels strive
to find their next meal...
and get ahead in
the Hunger Wars.
♪♪
♪♪
Every day, animals
face the same problem.
Finding food.
And getting your
share is never easy.
♪♪
Here on one of Australia's
most remote outposts,
one animal's search
for sustenance
is causing serious
trouble for the locals.
Well, when I first
arrived to the island,
in the middle of the night,
you'd hear knocks and scratches.
And some people think
the place is haunted.
I just left my bag on the ground
like you normally
would anywhere else.
Go for a walk that way. You
come back. Where's my bag?
He's gotten it open,
there's a camera
that's now over there,
and he's got my drink bottle.
He's, like, clawing at
the lid, just trying to get in.
The creature behind
this crime wave...
is the coconut crab.
♪♪
Equipped with
formidable armor...
claws powerful enough
to tear open a coconut...
and weighing in
at up to 9 pounds,
they may be the
world's largest land crab.
But they have a problem.
Here on Christmas Island,
there are over
a million of them.
That's 500 crabs
for every person.
And they all need to eat.
So to keep themselves fed,
these crabs have
turned to a life of crime.
In fact, to the locals here,
they're known as robber crabs.
We'd find the crabs
were stealing our lunch
every time we left it alone.
They can get into cool boxes,
they can cut through plastic,
they can cut through metal.
But it's not just food
they're making off with.
These daring thieves
are taking everything
that isn't tied down.
They pinch shoes off porches...
shiny things like cutlery.
There's even a story
of a coconut crab
taking a gun off
a military guard.
♪♪
But why would crabs
steal things they can't eat?
Coconut-crab expert Max Orchard
has been exploring
this outlandish behavior.
By setting a trap with
some everyday objects...
and motion sensor cameras...
he can document exactly
what these crabs get up to...
The next morning, he
returns to assess the evidence.
Ok.
Yep.
Well they've been here...
And the footage
reveals they've lived up
to their criminal reputation.
In total, 10 different crabs
came to check out the items.
♪♪
And under the cover of
darkness, one even stole a camera.
But what is this all about?
Max thinks he knows the answer.
Normally, when they
do obtain food in the wild,
they go off to an area
where they're privately
able to devour things
rather than having
to fight off other crabs
that might like to take
possession of the food
that they've picked up.
So the numbers of
crabs on the island
creates an intense
competition...
which means they'll
check out anything new
to see if they can eat it.
And when they take these
items somewhere safe
to investigate them,
we see it as theft.
But there's one thing
this doesn't explain.
Coconut crabs appear to
show up as if from nowhere
as soon as a new item appears.
Surely that's a
pretty surprising skill
for a crustacean.
So, how does a
crab hone in so well
on the items it's interested in?
Max has been helping
scientists find the answer.
The key is one of
their incredible senses.
He's positioned one
of their favorite foods,
a coconut, off the ground,
alongside some
empty control poles.
With the raised
bait harder to see,
do the crabs need to rely on
something other than sight?
It's only a matter of
minutes before they appear.
But how did they
find it so quickly?
The robber crabs
have four antennas
on the front of their head.
The ones on the outside
they use to orientate
themselves spatially.
The two in the
middle are actually
their equivalent of our nose.
They wave these
around in the air,
and that's their sense of smell.
As they evolved to live on land,
these crabs developed
an incredibly effective way
of detecting aromas in the
air as opposed to underwater.
The tips of their inner antennae
are covered with thin hairs
which detect chemicals given
off by any item with a scent.
The fact that they've
been able to pick up
these items' aroma
through the jungle
just proves how
strong a sense of smell
that these animals do have.
They can even detect
residual scent left on items.
So anything that's previously
come in contact with food,
or even other smells like
sweat, can catch their attention...
which is why they seem
to appear out of nowhere
for any old object.
They're the crab
equivalent of a bloodhound.
♪♪
So a highly developed
sense of smell,
combined with great strength
and impressive dexterity,
has led to their reputation
as the island's
resident kleptomaniacs.
♪♪
And it's not just these crabs
who have turned
to crime to find food.
Around the world, animal
thieves are wreaking havoc...
breaking and entering...
shoplifting...
and even mugging.
For some animals, stealing
has become a way of life.
- Watch out.
- Ooh!
Frigate birds can get
up to 40% of their food
by carrying out midair
shakedowns on their neighbors.
And in Zimbabwe, this gang
of baboons thrives on the spoils
from the steady stream of
people at a border crossing.
In fact, when food
is hard to come by,
being able to take what you
need can be essential for survival.
♪♪
The dizzying heights
of the Rocky Mountains.
Home to this little guy.
The pika.
A relative of the rabbit.
♪♪
It's August, and
summer is in full bloom.
♪♪
But the days of plenty
won't be here for long.
These slopes are only free
from snow for 10 weeks a year.
When winter comes, this pika
will be trapped in its burrow.
To survive, it needs
to stock up the larder.
But while home is up here,
the food is all the
way down there.
Every summer, pikas
must collect enough plants
to see them through
the tough times to come.
When planning ahead,
it pays to be picky.
The freshest flowers...
lush, new grasses...
and a few toxic plants in the
mix to act as a preservative.
Multiple trips are inevitable.
♪♪
And anyone living high up
on the slopes, like this female,
has their work cut out.
She may make over 10,000
trips in just one season.
And the grand result
of this frenetic activity?
A haystack.
These stockpiles of food
can weigh up to 60 pounds.
That's more than 180 times
a pika's own bodyweight.
It's exhausting work.
Perhaps there's another way.
An easier way.
Just down the slope,
another pika is getting
started on his haystack.
But he's being watched.
♪♪
It's daylight robbery.
But it's not just wanton theft.
By taking food that's
so much closer to home,
our pika is saving
precious time and energy.
♪♪
But...
she's caught red-handed.
♪♪
Every rebel needs
a good getaway plan.
♪♪
But unfortunately, she's not
the only thief on the mountain.
For animals like the pika,
having the skills to steal food
can mean the difference
between life and death.
And one creature in particular
has become renowned
for its light-fingered ways...
The rhesus macaque.
After humans, these are
the most widespread
primates on our planet.
A cross mainland Asia,
they've had to adapt to
life in urban environments...
and get their hands on
the mouthwatering food
in the open-air market.
The macaques time
their robberies perfectly...
using the element of surprise...
and making a swift exit.
But what's the secret to
being such expert thieves?
New science is
unraveling the answer,
and it's happening in the
most unlikely of places...
the Caribbean.
♪♪
On an island just off
the coast of Puerto Rico,
Laurie Santos has been studying
this troop of rhesus macaques
for over a decade.
These are the
descendants of a colony
brought here from
Calcutta in 1938.
And Laurie has had plenty
of first-hand experience
of these pilfering primates.
We ourselves on the island
have been duped by the monkeys.
You know, many of our
researchers have had this moment
of you, know, placing their lunch
down on the side and looking back.
You're like, "Wait.
Where'd it go?"
and realizing that a monkey
has stolen something from you
when you weren't
paying attention.
They must be cuing in to what
we can see and what we can't.
Otherwise, they wouldn't
be such great thieves.
To find out what makes
these macaques
so good at stealing,
Laurie's devised a test.
What we do is basically
give the monkeys
a chance to rip us off.
I would go out with
my research assistant,
we'd show the
monkeys a little grape
and put it on a
little foam platform
and place it on the ground,
and one of us is
gonna turn around...
so that the monkeys
have a chance to steal it.
The aim is to see if
the monkey understands
that the best
person to take from
is the one who can't see.
For the test to work,
Laurie needs to get one
macaque's undivided attention.
The lure of the grape
seems to work on this male.
Okay. Ready? Show.
See?
Down.
First, the macaque
checks who else is around...
then makes a beeline
straight for the
unguarded grape.
It's the outcome
Laurie anticipated.
And it's the same result
time and time again.
What does this tell us?
What we saw out there is
basically what we've seen
about 9 out of 10 times.
The fact that monkeys
steal the grape
from the person
who can't see them
shows that the monkeys
are taking another
person's perspective.
They realize that that
person who's turned around
can't see the same
thing as they do.
The test shows that
these rhesus macaques
are clever enough to imagine
what the person they're
stealing from is thinking.
That's known as
a "theory of mind."
When you live in a large
group of intelligent animals,
being able to watch and
interpret another's behavior
can be crucial.
And if you can
learn how to target
the right individual
to steal from,
it pays off.
Think about the
monkey we just tested.
He's this low-ranking guy who
doesn't have access to food.
But because he's
good at analyzing
when he has that one moment
to take something he's
not supposed to take,
that gives him access
to some critical food
that might help
him down the line.
♪♪
Laurie believes the
theory of mind in primates
may have evolved
in order for them
to cheat, deceive, and
steal from each other.
♪♪
And this ability can give them
the upper hand with us, too.
♪♪
Animals across the
world have discovered
that stealing can be the
easiest way to get a meal.
But others must
catch their food.
And that's much harder.
♪♪
From evasive maneuvers...
to chemical weapons...
and frightening facades...
the hunted have come
up with clever ways
to avoid being eaten.
And that's driven
predators to evolve
some seriously
underhanded tactics
to make their task
a little bit easier.
Even one of the world's
most notorious hunters
has to use every tool at
its disposal to succeed.
The tiger.
And one of its main
prey? A chital deer.
These deer have
finely tuned hearing...
an excellent sense of smell...
and are incredibly
fleet of foot.
The tiger needs to get close
enough to launch a strike...
Not easy for a 500-pound cat.
♪♪
Large paws allow the
tiger to move almost silently.
Approaching downwind
helps it evade detection.
And its unmistakable
stripes hide its outline
in the shadows of the forest.
But it tums out...
tigers have another
trick up their sleeve.
♪♪
Scientists John
Fennell and László Tálas
from Bristol University's
Camouflage Lab
are exploring how
the tiger's orange coat
could actually be giving
it an unfair advantage.
To put it to the test,
John needs to see the world
through the eyes of a deer.
And this pair of glasses
makes that possible.
Humans have trichromatic vision,
meaning we have three different
color receptors in our retina,
enabling us to see
the world in full color.
But deer, the main prey
of the tiger, are dichromats.
Their color vision comes
from just two color receptors,
so they can only
see greens and blues.
A filter in the glasses
blocks any red light
from reaching the eye,
allowing John to see
the world like a deer does.
Ready when you are, László.
Tálas: Okay.
Now all he needs to do
is see how quickly he
can pick out the tiger
in a series of images.
The big screen fills
John's field of vision.
What would take him less
than a second to spot normally...
Can't see that one at all.
Now becomes
significantly more difficult.
Looking right at me.
Viewing the world like a deer
means it takes John twice
as long to pick out the tigers.
And that gives these
predators the edge.
♪♪
It's an exciting new discovery.
In the context of
our experiment,
or the demonstration here,
the reaction times to
find the tiger would equate
to an advantage to the tiger
of around about 7
meters in an attack,
which is quite a
significant advantage.
And as a tiger can
leap nearly 20 feet
from a standstill,
getting that much closer
could make all the difference.
The obvious question to ask
is why are tigers bright-orange,
'cause that would seem to
be not an intuitively good color
to be to be camouflaged.
But once we take
into consideration
how a deer sees the tiger,
it puts it more
into perspective.
So while through our eyes
the tiger looks like this...
through the eyes of a
deer, it looks very different.
The tiger now blends
into the background.
Its bright-orange color
actually helps the tiger
get close to the deer
without being spotted.
♪♪
It's what their prey sees
that's driven the evolution
of a highly effective
means of concealment.
But, of course, tigers
aren't the only predators
that need to stay one
step ahead of their prey.
Others have evolved
an arsenal of sneaky
adaptations to catch their food.
♪♪
The panther chameleon
of Madagascar.
It harbors a concealed weapon...
that packs one powerful punch.
Its tongue shoots out at
up to 16 feet per second.
So fast, its prey
rarely sees it coming.
In Australia's
Great Barrier Reef,
this cone snail is one
Machiavellian mollusk.
The fish it hunts are fast...
so it waits until
they're asleep.
Sneaking up, it releases
an invisible chemical weapon.
Once paralyzed, the
fish are eaten alive.
♪♪
But perhaps one of the
ocean's most unusual predators
is the thresher shark.
Whipping its tail forward
at speeds of up to
50 miles an hour,
it strikes its fish
before it eats them.
♪♪
Being armed and dangerous
is a surefire way to catch prey.
What do you do if
your prey can kill you?
♪♪
The tropical rainforests
of Queensland.
Home to a hunter
who's small but deadly.
The jumping spider.
Rather than spinning a web,
this predator uses stealth.
But the food it most
desires seems out of reach...
an ant's nest, full
of delicious larvae.
♪♪
The problem is, they're guarded
by a vicious army of adults.
These green tree ants
dominate the treetops.
Each colony can contain as
many as half a million workers.
They use a chemical
code to identify each other.
At the first sign of an
intruder who smells strange,
they're hardwired to
retaliate with violence.
Armed with formidable jaws,
the ants could kill the
jumping spider with ease.
Getting ahold of the ant larvae
might look like a
mission impossible,
but these spiders have
evolved some remarkable tricks
to get what they need.
In fact, it's thought that
about 300 species of spider
can cunningly mimic ants.
Predators all over the
world disguise themselves
as something else
to dupe their dinner.
By pretending to be
a harmless branch,
this African vine snake
tricks its prey into
thinking they're safe...
when they're about to be eaten.
In Hawaii, a fly
out for a stroll
is in for a shock...
from a carnivorous
caterpillar in a leafy costume.
And while it may look
just like an alluring flower,
this orchid mantis is
actually a stealthy assassin.
Compared to these
magnificent masquerades,
the spider's disguise
doesn't look that convincing.
Its color is a good match.
It has a decidedly
un-spider-like waist,
just like an ant.
But surely, no one
would mistake one...
for the other.
Nevertheless, it
heads for the nest.
♪♪
Mission impossible turns
into mission accomplished...
right under the ants' noses.
But was it the spider's
appearance that did the trick?
Well... no.
It's actually mastered a far
more complex impersonation.
The spider carries the
ants' chemical code.
In fact, like all of its kind,
it was born in a green ant nest.
Its mother laid her eggs there.
It's fed on the ant
larvae from birth,
and it smells just like them.
Now that it's hacked
into their security,
it can rob the nest
whenever it likes...
like a bank robber
with a key to the vault.
It's an incredibly
impressive con.
It can take creative thinking
to get the food you need.
Some animals will even work
with another species to do it.
These arrangements
should be mutually beneficial.
One species gets the food...
and the other gets
a service in return.
It works for the agama
lizard and the lion.
But the hunger
game can be ruthless.
And not every animal
upholds its side of the bargain.
♪♪
This pygmy falcon is
about to become a dad.
Like all parents,
he and his mate
need to provide for
their new arrivals.
While he's just 8 inches
tall, the size of a parakeet,
this bird of prey
is a skillful hunter.
What he's not good at...
is art of building a nest.
Construction is not
the falcon's forte.
Fortunately, here in
the southern Kalahari,
our pygmy falcons
have some master
builders on their doorstep.
A colony of insect-eating
social weavers.
Welcome to Weaverville...
a luxury condominium of a
hundred individual apartments.
The biggest avian
constructions in the world.
♪♪
It's the perfect pad...
for the falcons.
And they've moved in...
kicking out the current
occupants in the process.
For the weavers,
it's surely a disaster.
Not only have one
pair lost their home,
now they have a predator
living on their doorstep.
But the falcons aren't
just idle neighbors.
They make the weavers an
offer they simply cannot refuse.
♪♪
Protection.
♪♪
The apartment complex
is regularly plagued
by unwelcome visitors...
like mongoose...
and cobras.
Cue security.
♪♪
The weavers' luxury residence
now has its own live-in bouncer.
It seems like a good deal.
But don't forget, the
pygmy falcon is a predator.
♪♪
It's not long before both
the weavers and falcons
have new mouths to feed.
♪♪
The new falcon chicks
need to eat nearly half
their bodyweight in food...
daily.
And as the summer dry
season reaches its peak,
the adults have to work harder
to find enough to feed them.
♪♪
What they need is
something easy...
something close to home.
♪♪
A weaver chick.
It appears to be a
shocking betrayal.
For the weavers, the
falcons have become...
the neighbors from hell.
But the falcons
must tread a fine line.
If they take too many chicks,
the weavers might
desert the colony,
leaving behind a huge house...
no caretakers...
and an empty larder.
But this pair of falcons
have played it just right.
♪♪
They have fledged two chicks.
♪♪
And despite their losses,
the weavers are thriving, too.
♪♪
By developing a
clever protection racket,
these birds have found
the perfect shortcut
to feeding their family.
♪♪
♪♪
At least the pygmy falcon
gives something back in return.
On the opposite
side of the world,
another brazen bird
has found a way to violate
one of the most long-standing
arrangements on the planet.
The cloud forests of Ecuador,
home to over 130 different
species of hummingbird...
including the wedge-bill.
But behind those innocent looks
lies one of the biggest
crooks in the rainforest.
To get its food,
this little bird does
something truly outrageous.
What could drive it
to such bad behavior?
Hummingbirds are capable
of spectacular
feats of aerobatics.
Their wings can beat at
up to 80 times a second,
allowing them to break,
turn, and hover in mid-air.
But this impressive
ability comes at a price.
The wedge-bill, and
all other hummingbirds,
have to eat more than
twice their bodyweight
in food each day.
They burn through
calories so quickly
that if they were the
size of an average human,
they'd need 3 cans of energy
drink every minute to survive.
Through years of evolution,
they've struck up a bargain
with the surrounding
plants to get what they need.
The plants produce
flowers rich with nectar.
In exchange, the
hummingbirds act as pollinators.
Moving pollen between flowers,
they enable the
plants to reproduce.
But each flower
has only a limited
supply of nectar a day,
which means the hummingbirds
must compete for it.
♪♪
Each species has a
unique ploy to get their prize.
The green violetear is
one pugnacious little bird.
Engaging in aerial combat,
they prevent all others from
getting close to their flowers.
The booted racket-tail
uses agility and speed
to outmaneuver the opposition.
♪♪
And the tiny
purple-throated woodstar
makes up for what it lacks
in size with a clever trick.
Most hummingbirds
are terrified of bees.
Just one sting could be fatal.
So the woodstar mimics the
sound of a bee with its wings,
scaring other hummingbirds off
just long enough
to get the goods.
While these birds
are full of tricks,
at least they hold up their end
of the bargain with the plants.
The wedge-bill, however,
has a far more rebellious plan.
While the other
hummingbirds fight it out,
it makes its move.
The wedge-bill doesn't
reach inside the flower.
It goes straight to the base...
and pierces a hole where
the nectar is created,
tapping into the very source.
It's gotten the food it needed,
but it hasn't
pollinated the plant.
This blatant
shirking of the rules
is what scientists
call "floral larceny."
By reneging on its
deal with the plants,
the resourceful
little wedge-bill
has dodged the competition...
and found an easy way to
access any nectar it chooses.
And it's not the only
nectar thief out there.
Here in Madagascar,
baobab trees are
plagued by another bandit.
The trees' magnificent
blooms open only at night.
Just what this tiny mouse
lemur has been waiting for.
It scampers out to steal
the flowers' precious nectar.
♪♪
Then, the lemur catches and
eats the tree's true pollinator,
a giant hawk moth.
But now the tables are turned
to the baobab's advantage.
The lemur becomes
dusted in pollen
and becomes a pollinator itself.
When it moves to take
from yet another flower,
this little rebel inadvertently
ends up helping the plant.
We've seen how animals
steal, trick, and cheat
their way to a meal.
But sometimes, to
get the food they need,
brute force is the only answer.
With over 150 individuals,
this is one of the largest
communities of
chimps ever recorded.
That's a lot of mouths to feed,
so they must secure as
many resources as possible
if they're to survive.
♪♪
The target in this case
is a fig tree full of fruit.
But there's another group in it.
A patrol sets out
into the forest.
The chimps move with purpose...
and in silence.
Signs of the rival group
confirm they're nearby.
Now they're in
dangerous territory.
The patrol edges forward.
The way the chimps approach
is so deliberate, so coordinated,
that some scientists consider
this to be an act of warfare.
Loud calls announce
the start of battle.
The aim is to
terrorize, to intimidate.
This is a numbers game,
and they need to show
they're a formidable group.
♪♪
In such a frenzied
situation, it's all too easy
for the innocent to
become the victims.
♪♪
One female is brutally attacked.
She escapes.
But chimps can easily
be killed in fights like this.
Resorting to
violence has worked.
Now they can feast on
the best fig tree in the area.
To get the resources
they need for the group,
chimps must expand
their territory...
by any means possible.
If it means all the
family get to eat,
it's a risk worth taking.
When it comes
to fighting for food,
these chimps show
that being one of a group
can have its advantages.
But if the group gets
too big, it can collapse.
Then it's every
animal for itself.
♪♪
The picture-perfect
Greek island of Naxos.
♪♪
A popular destination
for tourists...
and for the Aegean wall lizard.
At just 3 inches long,
these little reptiles
have made the island's
stone walls their playground.
Between basking in the sun...
and plenty of insects to eat...
life here is pretty sweet.
♪♪
But less than a mile
off the coast of Naxos...
lies a much smaller island,
where things are very different.
This is Parthenos.
There are no people living here.
Just an ever-increasing
population of wall lizards.
♪♪
No predators ever
made it to the island.
And while you might think that
would make it a lizard heaven,
this is the place of nightmares.
The island is
overrun by lizards.
Their numbers here are 5
times denser than on Naxos.
♪♪
In the parched summer months,
food is increasingly
hard to find.
So how can a hungry lizard
beat its rivals and
find itself a meal?
These islanders
have had to adapt.
They've had to take any
opportunity that's at hand.
Any opportunity.
♪♪
Scientists studying
these island lizards
have made a grisly discovery.
When we've flushed the
stomachs of these lizards,
we've actually
found tail tissue...
and bits of fingers from
the same species of lizard,
so we know they're
eating each other.
These lizards are cannibals.
Some even catch and
swallow their victims whole.
Well, we would expect
cannibalism to evolve
only in extreme
ecological conditions.
This island is exactly that.
But this scandalous
hunting strategy
isn't an easy option.
It's hard work to
hold a struggling lizard
nearly your own size.
And they're evolving
in response to this
somewhat gruesome lifestyle.
Lizards from small islands
have evolved larger body size,
larger head size
relative to their body size,
and, really interestingly,
they can bite much harder
than lizards from the mainland,
sometimes twice as hard.
On a tiny island where
there aren't a lot of resources
and lizards are eating each
other, it'd be advantageous
to evolve to be bigger, stronger
so you can compete and survive.
♪♪
These wall lizards
have rewritten
the rulebook when it
comes to dining etiquette.
But in the dog-eat-dog
world of Parthenos,
cannibalism is a surefire
way to get much-needed food...
and eliminate your
rivals at the same time.
All animals need
food to survive.
So it's no wonder that need
drives them to some
seriously underhanded tactics...
♪♪
From theft...
to predatory tricks...
broken promises
and even brute force.
When you consider the
immense challenges animals face,
it's no wonder these
rebels have evolved
some extraordinary strategies
to get themselves a meal.
♪♪
Next time, we meet
nature's survivors.
The delinquents...
the deceivers...
and the downright thugs...
doing whatever it
takes to stay alive.
♪♪
♪♪
♪♪
All animals face
the same challenge.
They must find food...
if they're to survive.
So to get what they want,
some animals will
break all the rules.
When food is hard to come by,
being able to take what you
need can be essential for survival.
Meet the planet's
greatest rebels.
They'll steal...
deceive...
and even resort to brute force.
But could behaving like this
actually be the secret
to their success?
♪♪
We'll reveal new discoveries
and astonishing science...
as our rebels strive
to find their next meal...
and get ahead in
the Hunger Wars.
♪♪
♪♪
Every day, animals
face the same problem.
Finding food.
And getting your
share is never easy.
♪♪
Here on one of Australia's
most remote outposts,
one animal's search
for sustenance
is causing serious
trouble for the locals.
Well, when I first
arrived to the island,
in the middle of the night,
you'd hear knocks and scratches.
And some people think
the place is haunted.
I just left my bag on the ground
like you normally
would anywhere else.
Go for a walk that way. You
come back. Where's my bag?
He's gotten it open,
there's a camera
that's now over there,
and he's got my drink bottle.
He's, like, clawing at
the lid, just trying to get in.
The creature behind
this crime wave...
is the coconut crab.
♪♪
Equipped with
formidable armor...
claws powerful enough
to tear open a coconut...
and weighing in
at up to 9 pounds,
they may be the
world's largest land crab.
But they have a problem.
Here on Christmas Island,
there are over
a million of them.
That's 500 crabs
for every person.
And they all need to eat.
So to keep themselves fed,
these crabs have
turned to a life of crime.
In fact, to the locals here,
they're known as robber crabs.
We'd find the crabs
were stealing our lunch
every time we left it alone.
They can get into cool boxes,
they can cut through plastic,
they can cut through metal.
But it's not just food
they're making off with.
These daring thieves
are taking everything
that isn't tied down.
They pinch shoes off porches...
shiny things like cutlery.
There's even a story
of a coconut crab
taking a gun off
a military guard.
♪♪
But why would crabs
steal things they can't eat?
Coconut-crab expert Max Orchard
has been exploring
this outlandish behavior.
By setting a trap with
some everyday objects...
and motion sensor cameras...
he can document exactly
what these crabs get up to...
The next morning, he
returns to assess the evidence.
Ok.
Yep.
Well they've been here...
And the footage
reveals they've lived up
to their criminal reputation.
In total, 10 different crabs
came to check out the items.
♪♪
And under the cover of
darkness, one even stole a camera.
But what is this all about?
Max thinks he knows the answer.
Normally, when they
do obtain food in the wild,
they go off to an area
where they're privately
able to devour things
rather than having
to fight off other crabs
that might like to take
possession of the food
that they've picked up.
So the numbers of
crabs on the island
creates an intense
competition...
which means they'll
check out anything new
to see if they can eat it.
And when they take these
items somewhere safe
to investigate them,
we see it as theft.
But there's one thing
this doesn't explain.
Coconut crabs appear to
show up as if from nowhere
as soon as a new item appears.
Surely that's a
pretty surprising skill
for a crustacean.
So, how does a
crab hone in so well
on the items it's interested in?
Max has been helping
scientists find the answer.
The key is one of
their incredible senses.
He's positioned one
of their favorite foods,
a coconut, off the ground,
alongside some
empty control poles.
With the raised
bait harder to see,
do the crabs need to rely on
something other than sight?
It's only a matter of
minutes before they appear.
But how did they
find it so quickly?
The robber crabs
have four antennas
on the front of their head.
The ones on the outside
they use to orientate
themselves spatially.
The two in the
middle are actually
their equivalent of our nose.
They wave these
around in the air,
and that's their sense of smell.
As they evolved to live on land,
these crabs developed
an incredibly effective way
of detecting aromas in the
air as opposed to underwater.
The tips of their inner antennae
are covered with thin hairs
which detect chemicals given
off by any item with a scent.
The fact that they've
been able to pick up
these items' aroma
through the jungle
just proves how
strong a sense of smell
that these animals do have.
They can even detect
residual scent left on items.
So anything that's previously
come in contact with food,
or even other smells like
sweat, can catch their attention...
which is why they seem
to appear out of nowhere
for any old object.
They're the crab
equivalent of a bloodhound.
♪♪
So a highly developed
sense of smell,
combined with great strength
and impressive dexterity,
has led to their reputation
as the island's
resident kleptomaniacs.
♪♪
And it's not just these crabs
who have turned
to crime to find food.
Around the world, animal
thieves are wreaking havoc...
breaking and entering...
shoplifting...
and even mugging.
For some animals, stealing
has become a way of life.
- Watch out.
- Ooh!
Frigate birds can get
up to 40% of their food
by carrying out midair
shakedowns on their neighbors.
And in Zimbabwe, this gang
of baboons thrives on the spoils
from the steady stream of
people at a border crossing.
In fact, when food
is hard to come by,
being able to take what you
need can be essential for survival.
♪♪
The dizzying heights
of the Rocky Mountains.
Home to this little guy.
The pika.
A relative of the rabbit.
♪♪
It's August, and
summer is in full bloom.
♪♪
But the days of plenty
won't be here for long.
These slopes are only free
from snow for 10 weeks a year.
When winter comes, this pika
will be trapped in its burrow.
To survive, it needs
to stock up the larder.
But while home is up here,
the food is all the
way down there.
Every summer, pikas
must collect enough plants
to see them through
the tough times to come.
When planning ahead,
it pays to be picky.
The freshest flowers...
lush, new grasses...
and a few toxic plants in the
mix to act as a preservative.
Multiple trips are inevitable.
♪♪
And anyone living high up
on the slopes, like this female,
has their work cut out.
She may make over 10,000
trips in just one season.
And the grand result
of this frenetic activity?
A haystack.
These stockpiles of food
can weigh up to 60 pounds.
That's more than 180 times
a pika's own bodyweight.
It's exhausting work.
Perhaps there's another way.
An easier way.
Just down the slope,
another pika is getting
started on his haystack.
But he's being watched.
♪♪
It's daylight robbery.
But it's not just wanton theft.
By taking food that's
so much closer to home,
our pika is saving
precious time and energy.
♪♪
But...
she's caught red-handed.
♪♪
Every rebel needs
a good getaway plan.
♪♪
But unfortunately, she's not
the only thief on the mountain.
For animals like the pika,
having the skills to steal food
can mean the difference
between life and death.
And one creature in particular
has become renowned
for its light-fingered ways...
The rhesus macaque.
After humans, these are
the most widespread
primates on our planet.
A cross mainland Asia,
they've had to adapt to
life in urban environments...
and get their hands on
the mouthwatering food
in the open-air market.
The macaques time
their robberies perfectly...
using the element of surprise...
and making a swift exit.
But what's the secret to
being such expert thieves?
New science is
unraveling the answer,
and it's happening in the
most unlikely of places...
the Caribbean.
♪♪
On an island just off
the coast of Puerto Rico,
Laurie Santos has been studying
this troop of rhesus macaques
for over a decade.
These are the
descendants of a colony
brought here from
Calcutta in 1938.
And Laurie has had plenty
of first-hand experience
of these pilfering primates.
We ourselves on the island
have been duped by the monkeys.
You know, many of our
researchers have had this moment
of you, know, placing their lunch
down on the side and looking back.
You're like, "Wait.
Where'd it go?"
and realizing that a monkey
has stolen something from you
when you weren't
paying attention.
They must be cuing in to what
we can see and what we can't.
Otherwise, they wouldn't
be such great thieves.
To find out what makes
these macaques
so good at stealing,
Laurie's devised a test.
What we do is basically
give the monkeys
a chance to rip us off.
I would go out with
my research assistant,
we'd show the
monkeys a little grape
and put it on a
little foam platform
and place it on the ground,
and one of us is
gonna turn around...
so that the monkeys
have a chance to steal it.
The aim is to see if
the monkey understands
that the best
person to take from
is the one who can't see.
For the test to work,
Laurie needs to get one
macaque's undivided attention.
The lure of the grape
seems to work on this male.
Okay. Ready? Show.
See?
Down.
First, the macaque
checks who else is around...
then makes a beeline
straight for the
unguarded grape.
It's the outcome
Laurie anticipated.
And it's the same result
time and time again.
What does this tell us?
What we saw out there is
basically what we've seen
about 9 out of 10 times.
The fact that monkeys
steal the grape
from the person
who can't see them
shows that the monkeys
are taking another
person's perspective.
They realize that that
person who's turned around
can't see the same
thing as they do.
The test shows that
these rhesus macaques
are clever enough to imagine
what the person they're
stealing from is thinking.
That's known as
a "theory of mind."
When you live in a large
group of intelligent animals,
being able to watch and
interpret another's behavior
can be crucial.
And if you can
learn how to target
the right individual
to steal from,
it pays off.
Think about the
monkey we just tested.
He's this low-ranking guy who
doesn't have access to food.
But because he's
good at analyzing
when he has that one moment
to take something he's
not supposed to take,
that gives him access
to some critical food
that might help
him down the line.
♪♪
Laurie believes the
theory of mind in primates
may have evolved
in order for them
to cheat, deceive, and
steal from each other.
♪♪
And this ability can give them
the upper hand with us, too.
♪♪
Animals across the
world have discovered
that stealing can be the
easiest way to get a meal.
But others must
catch their food.
And that's much harder.
♪♪
From evasive maneuvers...
to chemical weapons...
and frightening facades...
the hunted have come
up with clever ways
to avoid being eaten.
And that's driven
predators to evolve
some seriously
underhanded tactics
to make their task
a little bit easier.
Even one of the world's
most notorious hunters
has to use every tool at
its disposal to succeed.
The tiger.
And one of its main
prey? A chital deer.
These deer have
finely tuned hearing...
an excellent sense of smell...
and are incredibly
fleet of foot.
The tiger needs to get close
enough to launch a strike...
Not easy for a 500-pound cat.
♪♪
Large paws allow the
tiger to move almost silently.
Approaching downwind
helps it evade detection.
And its unmistakable
stripes hide its outline
in the shadows of the forest.
But it tums out...
tigers have another
trick up their sleeve.
♪♪
Scientists John
Fennell and László Tálas
from Bristol University's
Camouflage Lab
are exploring how
the tiger's orange coat
could actually be giving
it an unfair advantage.
To put it to the test,
John needs to see the world
through the eyes of a deer.
And this pair of glasses
makes that possible.
Humans have trichromatic vision,
meaning we have three different
color receptors in our retina,
enabling us to see
the world in full color.
But deer, the main prey
of the tiger, are dichromats.
Their color vision comes
from just two color receptors,
so they can only
see greens and blues.
A filter in the glasses
blocks any red light
from reaching the eye,
allowing John to see
the world like a deer does.
Ready when you are, László.
Tálas: Okay.
Now all he needs to do
is see how quickly he
can pick out the tiger
in a series of images.
The big screen fills
John's field of vision.
What would take him less
than a second to spot normally...
Can't see that one at all.
Now becomes
significantly more difficult.
Looking right at me.
Viewing the world like a deer
means it takes John twice
as long to pick out the tigers.
And that gives these
predators the edge.
♪♪
It's an exciting new discovery.
In the context of
our experiment,
or the demonstration here,
the reaction times to
find the tiger would equate
to an advantage to the tiger
of around about 7
meters in an attack,
which is quite a
significant advantage.
And as a tiger can
leap nearly 20 feet
from a standstill,
getting that much closer
could make all the difference.
The obvious question to ask
is why are tigers bright-orange,
'cause that would seem to
be not an intuitively good color
to be to be camouflaged.
But once we take
into consideration
how a deer sees the tiger,
it puts it more
into perspective.
So while through our eyes
the tiger looks like this...
through the eyes of a
deer, it looks very different.
The tiger now blends
into the background.
Its bright-orange color
actually helps the tiger
get close to the deer
without being spotted.
♪♪
It's what their prey sees
that's driven the evolution
of a highly effective
means of concealment.
But, of course, tigers
aren't the only predators
that need to stay one
step ahead of their prey.
Others have evolved
an arsenal of sneaky
adaptations to catch their food.
♪♪
The panther chameleon
of Madagascar.
It harbors a concealed weapon...
that packs one powerful punch.
Its tongue shoots out at
up to 16 feet per second.
So fast, its prey
rarely sees it coming.
In Australia's
Great Barrier Reef,
this cone snail is one
Machiavellian mollusk.
The fish it hunts are fast...
so it waits until
they're asleep.
Sneaking up, it releases
an invisible chemical weapon.
Once paralyzed, the
fish are eaten alive.
♪♪
But perhaps one of the
ocean's most unusual predators
is the thresher shark.
Whipping its tail forward
at speeds of up to
50 miles an hour,
it strikes its fish
before it eats them.
♪♪
Being armed and dangerous
is a surefire way to catch prey.
What do you do if
your prey can kill you?
♪♪
The tropical rainforests
of Queensland.
Home to a hunter
who's small but deadly.
The jumping spider.
Rather than spinning a web,
this predator uses stealth.
But the food it most
desires seems out of reach...
an ant's nest, full
of delicious larvae.
♪♪
The problem is, they're guarded
by a vicious army of adults.
These green tree ants
dominate the treetops.
Each colony can contain as
many as half a million workers.
They use a chemical
code to identify each other.
At the first sign of an
intruder who smells strange,
they're hardwired to
retaliate with violence.
Armed with formidable jaws,
the ants could kill the
jumping spider with ease.
Getting ahold of the ant larvae
might look like a
mission impossible,
but these spiders have
evolved some remarkable tricks
to get what they need.
In fact, it's thought that
about 300 species of spider
can cunningly mimic ants.
Predators all over the
world disguise themselves
as something else
to dupe their dinner.
By pretending to be
a harmless branch,
this African vine snake
tricks its prey into
thinking they're safe...
when they're about to be eaten.
In Hawaii, a fly
out for a stroll
is in for a shock...
from a carnivorous
caterpillar in a leafy costume.
And while it may look
just like an alluring flower,
this orchid mantis is
actually a stealthy assassin.
Compared to these
magnificent masquerades,
the spider's disguise
doesn't look that convincing.
Its color is a good match.
It has a decidedly
un-spider-like waist,
just like an ant.
But surely, no one
would mistake one...
for the other.
Nevertheless, it
heads for the nest.
♪♪
Mission impossible turns
into mission accomplished...
right under the ants' noses.
But was it the spider's
appearance that did the trick?
Well... no.
It's actually mastered a far
more complex impersonation.
The spider carries the
ants' chemical code.
In fact, like all of its kind,
it was born in a green ant nest.
Its mother laid her eggs there.
It's fed on the ant
larvae from birth,
and it smells just like them.
Now that it's hacked
into their security,
it can rob the nest
whenever it likes...
like a bank robber
with a key to the vault.
It's an incredibly
impressive con.
It can take creative thinking
to get the food you need.
Some animals will even work
with another species to do it.
These arrangements
should be mutually beneficial.
One species gets the food...
and the other gets
a service in return.
It works for the agama
lizard and the lion.
But the hunger
game can be ruthless.
And not every animal
upholds its side of the bargain.
♪♪
This pygmy falcon is
about to become a dad.
Like all parents,
he and his mate
need to provide for
their new arrivals.
While he's just 8 inches
tall, the size of a parakeet,
this bird of prey
is a skillful hunter.
What he's not good at...
is art of building a nest.
Construction is not
the falcon's forte.
Fortunately, here in
the southern Kalahari,
our pygmy falcons
have some master
builders on their doorstep.
A colony of insect-eating
social weavers.
Welcome to Weaverville...
a luxury condominium of a
hundred individual apartments.
The biggest avian
constructions in the world.
♪♪
It's the perfect pad...
for the falcons.
And they've moved in...
kicking out the current
occupants in the process.
For the weavers,
it's surely a disaster.
Not only have one
pair lost their home,
now they have a predator
living on their doorstep.
But the falcons aren't
just idle neighbors.
They make the weavers an
offer they simply cannot refuse.
♪♪
Protection.
♪♪
The apartment complex
is regularly plagued
by unwelcome visitors...
like mongoose...
and cobras.
Cue security.
♪♪
The weavers' luxury residence
now has its own live-in bouncer.
It seems like a good deal.
But don't forget, the
pygmy falcon is a predator.
♪♪
It's not long before both
the weavers and falcons
have new mouths to feed.
♪♪
The new falcon chicks
need to eat nearly half
their bodyweight in food...
daily.
And as the summer dry
season reaches its peak,
the adults have to work harder
to find enough to feed them.
♪♪
What they need is
something easy...
something close to home.
♪♪
A weaver chick.
It appears to be a
shocking betrayal.
For the weavers, the
falcons have become...
the neighbors from hell.
But the falcons
must tread a fine line.
If they take too many chicks,
the weavers might
desert the colony,
leaving behind a huge house...
no caretakers...
and an empty larder.
But this pair of falcons
have played it just right.
♪♪
They have fledged two chicks.
♪♪
And despite their losses,
the weavers are thriving, too.
♪♪
By developing a
clever protection racket,
these birds have found
the perfect shortcut
to feeding their family.
♪♪
♪♪
At least the pygmy falcon
gives something back in return.
On the opposite
side of the world,
another brazen bird
has found a way to violate
one of the most long-standing
arrangements on the planet.
The cloud forests of Ecuador,
home to over 130 different
species of hummingbird...
including the wedge-bill.
But behind those innocent looks
lies one of the biggest
crooks in the rainforest.
To get its food,
this little bird does
something truly outrageous.
What could drive it
to such bad behavior?
Hummingbirds are capable
of spectacular
feats of aerobatics.
Their wings can beat at
up to 80 times a second,
allowing them to break,
turn, and hover in mid-air.
But this impressive
ability comes at a price.
The wedge-bill, and
all other hummingbirds,
have to eat more than
twice their bodyweight
in food each day.
They burn through
calories so quickly
that if they were the
size of an average human,
they'd need 3 cans of energy
drink every minute to survive.
Through years of evolution,
they've struck up a bargain
with the surrounding
plants to get what they need.
The plants produce
flowers rich with nectar.
In exchange, the
hummingbirds act as pollinators.
Moving pollen between flowers,
they enable the
plants to reproduce.
But each flower
has only a limited
supply of nectar a day,
which means the hummingbirds
must compete for it.
♪♪
Each species has a
unique ploy to get their prize.
The green violetear is
one pugnacious little bird.
Engaging in aerial combat,
they prevent all others from
getting close to their flowers.
The booted racket-tail
uses agility and speed
to outmaneuver the opposition.
♪♪
And the tiny
purple-throated woodstar
makes up for what it lacks
in size with a clever trick.
Most hummingbirds
are terrified of bees.
Just one sting could be fatal.
So the woodstar mimics the
sound of a bee with its wings,
scaring other hummingbirds off
just long enough
to get the goods.
While these birds
are full of tricks,
at least they hold up their end
of the bargain with the plants.
The wedge-bill, however,
has a far more rebellious plan.
While the other
hummingbirds fight it out,
it makes its move.
The wedge-bill doesn't
reach inside the flower.
It goes straight to the base...
and pierces a hole where
the nectar is created,
tapping into the very source.
It's gotten the food it needed,
but it hasn't
pollinated the plant.
This blatant
shirking of the rules
is what scientists
call "floral larceny."
By reneging on its
deal with the plants,
the resourceful
little wedge-bill
has dodged the competition...
and found an easy way to
access any nectar it chooses.
And it's not the only
nectar thief out there.
Here in Madagascar,
baobab trees are
plagued by another bandit.
The trees' magnificent
blooms open only at night.
Just what this tiny mouse
lemur has been waiting for.
It scampers out to steal
the flowers' precious nectar.
♪♪
Then, the lemur catches and
eats the tree's true pollinator,
a giant hawk moth.
But now the tables are turned
to the baobab's advantage.
The lemur becomes
dusted in pollen
and becomes a pollinator itself.
When it moves to take
from yet another flower,
this little rebel inadvertently
ends up helping the plant.
We've seen how animals
steal, trick, and cheat
their way to a meal.
But sometimes, to
get the food they need,
brute force is the only answer.
With over 150 individuals,
this is one of the largest
communities of
chimps ever recorded.
That's a lot of mouths to feed,
so they must secure as
many resources as possible
if they're to survive.
♪♪
The target in this case
is a fig tree full of fruit.
But there's another group in it.
A patrol sets out
into the forest.
The chimps move with purpose...
and in silence.
Signs of the rival group
confirm they're nearby.
Now they're in
dangerous territory.
The patrol edges forward.
The way the chimps approach
is so deliberate, so coordinated,
that some scientists consider
this to be an act of warfare.
Loud calls announce
the start of battle.
The aim is to
terrorize, to intimidate.
This is a numbers game,
and they need to show
they're a formidable group.
♪♪
In such a frenzied
situation, it's all too easy
for the innocent to
become the victims.
♪♪
One female is brutally attacked.
She escapes.
But chimps can easily
be killed in fights like this.
Resorting to
violence has worked.
Now they can feast on
the best fig tree in the area.
To get the resources
they need for the group,
chimps must expand
their territory...
by any means possible.
If it means all the
family get to eat,
it's a risk worth taking.
When it comes
to fighting for food,
these chimps show
that being one of a group
can have its advantages.
But if the group gets
too big, it can collapse.
Then it's every
animal for itself.
♪♪
The picture-perfect
Greek island of Naxos.
♪♪
A popular destination
for tourists...
and for the Aegean wall lizard.
At just 3 inches long,
these little reptiles
have made the island's
stone walls their playground.
Between basking in the sun...
and plenty of insects to eat...
life here is pretty sweet.
♪♪
But less than a mile
off the coast of Naxos...
lies a much smaller island,
where things are very different.
This is Parthenos.
There are no people living here.
Just an ever-increasing
population of wall lizards.
♪♪
No predators ever
made it to the island.
And while you might think that
would make it a lizard heaven,
this is the place of nightmares.
The island is
overrun by lizards.
Their numbers here are 5
times denser than on Naxos.
♪♪
In the parched summer months,
food is increasingly
hard to find.
So how can a hungry lizard
beat its rivals and
find itself a meal?
These islanders
have had to adapt.
They've had to take any
opportunity that's at hand.
Any opportunity.
♪♪
Scientists studying
these island lizards
have made a grisly discovery.
When we've flushed the
stomachs of these lizards,
we've actually
found tail tissue...
and bits of fingers from
the same species of lizard,
so we know they're
eating each other.
These lizards are cannibals.
Some even catch and
swallow their victims whole.
Well, we would expect
cannibalism to evolve
only in extreme
ecological conditions.
This island is exactly that.
But this scandalous
hunting strategy
isn't an easy option.
It's hard work to
hold a struggling lizard
nearly your own size.
And they're evolving
in response to this
somewhat gruesome lifestyle.
Lizards from small islands
have evolved larger body size,
larger head size
relative to their body size,
and, really interestingly,
they can bite much harder
than lizards from the mainland,
sometimes twice as hard.
On a tiny island where
there aren't a lot of resources
and lizards are eating each
other, it'd be advantageous
to evolve to be bigger, stronger
so you can compete and survive.
♪♪
These wall lizards
have rewritten
the rulebook when it
comes to dining etiquette.
But in the dog-eat-dog
world of Parthenos,
cannibalism is a surefire
way to get much-needed food...
and eliminate your
rivals at the same time.
All animals need
food to survive.
So it's no wonder that need
drives them to some
seriously underhanded tactics...
♪♪
From theft...
to predatory tricks...
broken promises
and even brute force.
When you consider the
immense challenges animals face,
it's no wonder these
rebels have evolved
some extraordinary strategies
to get themselves a meal.
♪♪
Next time, we meet
nature's survivors.
The delinquents...
the deceivers...
and the downright thugs...
doing whatever it
takes to stay alive.
♪♪
♪♪
♪♪