Original subtitles

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Apex predators are usually on the offensive.

They have evolved tools to kill.

Then there are the animals, who've evolved to escape,

deceive and even poison these predators.

Don't underestimate the power of prey.

These cutting creatures are all masters of defense.

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In fields and gardens, it's common to spot wasps and bees.

But next time you see some, look closely.

They might be flies in disguise.

This isn't a wasp or a bee.

It's a hoverfly.

It's a species that mimics bees to fool predators

with relatives like these that mimic wasps.

For hoverflies like these, the best defense is a good pretence.

Without biting jaws or stingers,

they depend on illusion to survive.

Many hoverflies have bee-like stripes, coloring

and body hair;

all to trick predators into thinking

they're a dangerous snack to eat.

Bees and wasps have a defense that hoverflies don't.

Powerful stingers that predators avoid.

So the hoverfly has taken advantage of this strategy

and evolved to be a Batesian mimic.

Batesian mimicry is where you're a palatable species,

but to avoid being eaten by predators,

you evolve a similarity to an unpalatable species.

And that similarity is often morphological,

so it's in terms of your appearance.

But sometimes it can also be behavior.

For a hoverfly that behavior can mean

flying in a bee-like pattern, making stinging motions,

without actually having a stinger

and even moving like a bee.

Like all good mimics, the hoverfly knows

the most important part of the con game is confidence.

There's a certain swagger to many wasps and bees.

And they know they're well-defended

and they act like it too.

So they'll move around

and they'll quake their wings in a certain way.

When you look at the mimetic hoverflies,

a number of them also do that.

They have this little swagger as they walk around.

A sort of a cocky appearance, if you like.

Some species even mimic the long antennae of wasps.

So what do they do if they're perfect mimics,

their legs are the color of the bee or wasp antennae

that they're mimicking,

and they stick their legs out in front

and wave their legs like antennae.

Fantastic.

And when it comes to hoverflies, size definitely matters.

In many cases,

the bigger the hoverfly, the more convincing the mimicry.

The larger the species,

the better its mimicry of wasps or bees.

And the small hoverflies tend to be relatively poor

in terms of how closely similar they were

to the wasps or bees.

What we think is going on

is that if you're a big meal to a predator,

predators will take a very strong interest in you.

And so if you're going to gain from mimicry,

you really have to carry it off very well.

But despite their clever masquerade,

many hoverflies can easily be distinguished

from bees and wasps.

Bees and wasps have four wings.

The hoverfly only has two,

but can flap theirs about a 1,000 times a minute

to hover in mid-air.

A hoverfly wing also has what's called a vena spuria,

meaning false vein in Latin.

Embarking along its length it looks like a vein,

but it's not.

Bees and wasps, all have true venation in their wings.

If we look really closely, though,

we can tell the difference.

So how convincing are they to birds,

major predators of hoverflies

and the creatures they're actually trying to fool?

The answer may be found in the tiny hairs of the abdomen

of the hoverfly mimics.

Many bees and wasps have hairs on their abdomen

that are patterned.

But the patterns are only visible in UV light.

As it happens, many birds can see in UV.

So the hoverflies mimics the patterns

that the bees and wasps have on these hairs.

The UV markings are invisible to human eyes

with three types of cones in their retinas,

but visible to birds, who have four.

This means that to a bird,

they are able to see this whole new range of ultraviolet colors

that we are unable to imagine.

And so it's possible that these hoverflies

and wasps and bees have ultraviolet markings,

which are invisible to us.

So while the mimicry might be imperfect to humans,

it might, in fact, be perfect to birds.

And that's a good thing,

because hoverflies like their bee counterparts

are prodigious pollinators.

As adults, their diet consists of nectar and honey dew.

They're one of the few insects that can actually digest pollen.

They're as important as bees in many ecosystems,

particularly, as you go north in latitude

or south in latitude.

So towards the temperate regions,

flies become more important as pollinators than bees.

Approximately 6,000 species of hoverflies encompass the world.

That's a really big family of phonies.

Hoverflies are true survivors, masters of disguise

and some of nature's greatest pretenders.

As light and lovely as they seem,

butterflies are masters of defense.

It took millions of years of evolution for them

to blossom into the complicated creatures they are today.

Butterflies will entirely transform themselves

three times before reaching adulthood

in a 4-staged process known as complete metamorphosis.

These physical transformations

aren't the hardest part of a butterfly's life.

The biggest challenge to a tiny butterfly?

Staying alive long enough to make it to their final form.

Butterflies have some impressive tricks for staying alive.

Their first line of defense starts before they're even born.

Butterflies place their eggs on the underside of a leaf.

Placing them on the ridges of a leaf's vein

will help camouflage the eggs from would-be predators.

But that's about all the help

an infant butterfly is going to get from mom.

Once they've become caterpillars,

they're on their own.

But these small arthropods have a whole buffet of defenses

at their disposal.

Some caterpillars like this zebra,

have spines all along their bodies.

So these little spines make them quite unpalatable.

It'd be like chewing a lobster claw

without removing the claw.

These spines also release a small amount of acidic fluid

that irritates predators.

So if a bird or a lizard eats one caterpillar,

they're going to have that sensation of burning

and they'll learn very quickly not to eat another one.

When it's not on the defensive,

a caterpillar spends all of its time eating.

It needs to build up its energy levels

to begin its final transformation.

These fragile-looking structures are critically important

to the survival of a butterfly.

Chrysalises can come in all shapes and sizes,

every one designed to defend its inhabitants.

When a butterfly caterpillar has pupated

and it's in its chrysalis form, they have to blend in,

because they can't move and get away from any predators.

So they do this by primarily a type of camouflage.

So it can be either the color of the chrysalis

or the shape of the chrysalis.

So some chrysalis are shaped very much like a berry.

Some of them are shaped like the end of a branch,

so they look just like an extension of the plant

that they're sitting on.

There's also chrysalis that are brilliantly colored

and they actually reflect light off them.

Inside these tiny vessels,

a caterpillar's hard at work digesting its own body.

They use enzymes to break themselves down

into an oozy caterpillar soup,

only to rebuild and emerge as a magnificent butterfly.

Butterflies sometimes struggle to emerge from their capsules.

This one is having a difficult time.

Its head is stuck.

Eventually, it manages to break free.

Once each appendage is out,

a butterfly must get a good grip on its host plant.

This step is critical to the emergence process

because new adult butterflies are full of a heavy fluid.

If they drop, it's a fall to the death.

They use the fluid in their bodies to pump up wings.

Once it takes its maiden flight, a butterfly is truly an adult.

Adult butterflies have some defensive tricks of their own.

They use camouflage to blend in

and disruptive coloring to confuse predators.

Some species, like the owl butterfly,

use mimicry to pose as a larger animal than they really are

Often making themselves look

like a threatening predator themselves.

They have beautiful, beautiful large eyespots

as you can see here.

So this eyespot actually looks a little bit

like the eye of a predator.

Instead of somebody coming along and thinking this is lunch,

they're gonna think, "Maybe, I better run."

But even with all of these defenses,

scientists are still discovering new adaptations

that butterflies use to evade predators.

It's recently been brought to light

that many species actually have ears

that help them defend themselves from creatures on the hunt.

Most people actually don't realize

that butterflies have ears.

But most butterflies don't make sounds

and so people haven't really looked for their hearing organs

and we've been discovering that some butterflies have

actually really well-developed miniature hearing organs

at the bases of their wings.

Butterfly ears evolved millions of years ago

when nocturnal moths adapted ears

to evade bat predators at night.

After many species transitioned to be active during the day,

scientists now suspect that their ears are used

to evade daytime predators like birds.

With defenses like these, in each stage of their lives,

butterflies are well-equipped for survival.

If a butterfly can maintain its defenses

and live through the year,

it might finally get a little time to itself to rest

and start the cycle all over again.

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Yellow.

Red.

Yellow.

Black.

A warning sign to stay away.

A signal that danger has just crossed your path.

These are the colors of the coral snake,

a member of the elapid family of snakes

and one of the most deadly.

Cobras, mambas, kraits, those are elapids.

They have small, front-fixed fangs.

They're also far more toxic venom than vipers.

And they are therefore the most toxic species

of venomous snake in the Americas.

How dangerous is this coral snake?

If a bite is left untreated,

its venom can cause muscular paralysis,

eventually leading to full-on respiratory or cardiac failure.

Over time,

predators like bears, foxes, possums and hawks

have learned to stay away from the coral snake

by adapting the ability to distinguish

its bold color pattern from that of less-dangerous snakes.

Those would-be predators have learned

that if they are bitten by something

marked yellow, red, yellow, black, they will die.

If you think of it like a stop light,

right before you stop, the light turns yellow.

So the red and the yellow touch each other,

the yellow and the red slow down, stop.

So the red and yellow patterning on a coral snake

tells you that same thing.

Slow down.

Stop.

In terms of survival,

this coral snake's distinctive pattern

has proved to be a perfect defense mechanism.

Science has shown that a predator's reluctance

to attack this coral snake because of its iconic pattern

is sometimes imprinted in predators,

even in newborns that have never seen one.

So as a series of experiments

that had been done in Costa Rica and Panama,

where these baby birds that had never seen this pattern before,

would freak out and run to the other side of their cages.

But what about snakes that aren't so dangerous?

Snakes like this scarlet kingsnake

with no deadly bite to speak of,

it has no real way of defending itself.

It's an undefended prey species,

is one that has no means of deterring predators

from attackin' it.

Whereas a defended prey species might have noxious chemicals

or venom or something like that

to keep predators from wanting to bite it.

So if this scarlet king

is completely vulnerable to predators,

how does it survive?

By being a world-class impersonator.

A total fake.

A gun with no bullets.

Riding the coattails of the coral snake,

the scarlet king has adapted to look like its toxic cousin.

There's a lot of mimicry that goes on in the animal kingdom.

They want to trick predators into leaving them alone.

They try to fool predators into thinkin',

"Do you really wanna take a chance?

Are you feelin' lucky?"

Like the hoverfly,

the scarlet king's crafty con job

is another case of Batesian mimicry.

One type of mimicry is Batesian mimicry,

where you have a dangerous animal,

which is nonetheless a prey species

and it is sometimes mimicked by a non-venomous animal.

But how does the scarlet kingsnake

come to mimic the coral snake in the first place?

How does it physically evolve and change its skin patterns?

Snakes produce coloration through these cell groups

that are called chromatophores.

And the scarlet kingsnake and the coral snake

and all other snakes, in fact,

use the same suite of pigments to produce their colouration.

Natural selection is the driving force behind this mimicry.

If the scarlet kingsnake resembles a coral snake

more than others in the area,

then it will stay alive longer

and will be better able to reproduce.

Then that resemblance will very quickly spread

throughout the population,

because often times, one animal will be so much better defended

than all the rest of the population

that quickly its offspring will come to dominate that spices.

But as far as impersonators go,

this scarlet kingsnake is far from perfect.

They try their best to copycat but can't beat the original.

Like a cheap knock-off,

it's managed to resemble the original.

But a closer look reveals that the scarlet king's pattern

is slightly different.

So the coral snake has its rings

in the order yellow, red, yellow, black.

And then the scarlet kingsnake has its rings

in the order black, red, black, yellow.

And that's like something that is very obvious to a human

if the human has, you know, both snakes to look at

side by side.

And to remind us of this key difference,

there is even a riddle that some use

to keep themselves out of danger.

Red and yellow, kill the fellow.

Red and black, friend of jack or venom lack.

As well, whereas the tip of the coral snake's nose is black,

this scarlet king's snout is red.

So what good is imitation if it is not perfect?

Apparently, when it comes to telling

the real thing from the fake,

the scarlet king has its enemies totally fooled.

Predators apparently don't care about the difference.

I did a huge experiment

where I put out hundreds of clay snakes

all throughout North Carolina.

And if you have something that has a phenotype of a coral snake

or a phenotype of a king snake.

So the same colors but different patterns,

predators actually don't care about the difference.

Predators just don't have time

or the cognitive capacity to perform that discrimination.

They just do a quick-snap judgement.

They say,

"Okay, that snake has the right amount of red and black.

I'm not gonna touch it."

And that's all that engenders them with protection.

And while this scarlet kingsnake

poses little threat to predators and humans,

it has gotten by fooling many,

pulling off a most daring and devilish facade.

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At first glance, frogs seems pretty friendly.

There is a reason they're used as kids' toys

and famous Muppets.

But these frogs are not for children or adults.

One drop of their venom can kill a person.

They are poison dart frogs.

They're about the size of a paper clip

and come in a crayon box assortment of vivid colors.

But their brightly-colored skin oozes toxic venom.

They got their name because

indigenous tribes used this poison

to soak deadly blowgun darts for hunting.

But the frogs don't use it for hunting.

They use it solely to defend themselves against predators.

The toxins help protect the frog.

When the predator comes along and tries to eat it,

the toxins can actually paralyze or even kill the predator

that's trying to come at it.

The toxin is called "lipophilic alkaloid".

It kills by going straight to the muscles

stopping them from flexing.

This means when it gets to critical muscles

like the heart and the diaphragm,

the victim can't breathe and blood can't flow.

Scientists aren't sure where the poison dart frogs

get this venom in the first place,

they think that the frogs poison is created

by eating a specific type of native arthropod,

since frogs raised in captivity never develop the poison.

But the frogs would rather their enemies never even try it.

That's where this incredible coloring comes in.

Poison dart frogs come in a rainbow's worth of colors.

It changes depending on where exactly the frog lives.

The coloring serves as a warning to predators

that they're deadly, so stay away.

These frogs evolved this bright colouration

to advertise the fact that they're very well-defended.

There have been a number of experiments

done by other researches

where they have put out replicas of frogs

of various color patterns

and they've shown that if you have the right color pattern

that matches the local morph of poison frog,

then you're well-defended from predators.

Certain poison dart frogs have strange unique patterns as well.

That's also to help them hide from predators

by making their features difficult to distinguish.

Frogs are masters of breaking up their facial features.

They can have stripes across their eyes.

They can have bands that run down the length of the head

and down their back.

And this all helps to break up

their characteristic face feature's

making it difficult for things like birds and snakes

to recognize them.

There are 100 different species of poison dart frogs,

but this one is the most deadly.

The golden poison dart frog.

In fact,

it's considered one of the most poisonous animals on Earth.

The golden poison dart frog is from the Amazonian rainforests

in Colombia.

It's isolated to about five locations

and it's pretty crazy because it has enough poison in it

to kill 15 to 20 humans, just one frog.

This incredible defense system seems to be working quite well.

Only one snake has come up with immunity to the venom.

These frogs are nowhere near as innocent as they look.

They may be little,

but they pack a lethal punch that makes predators beware.

Staying alive is job one for these masters of defense.

With clever adaptations

like mimicry and poison on their side,

they continue to outwit predators to survive.

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