Original subtitles

Narrator: Why does this elephant look like it's smoking?

This behavior is completely unique.

Narrator: How is the brazilian rainforest

Suddenly submerged?

Why are fish swimming through the trees?

Narrator: And what has happened

To this snake's most defining feature?

Nelson: It's a rattlesnake without a rattle.

I don't know if that's even a rattlesnake anymore.

Narrator: Nature is awe-inspiring,

But sometimes it just doesn't make sense.

Man: I have never seen anything like this.

Our team of experts investigates the weirdest animal behavior...

That's amazing.

...And the most unexpected events...

What is causing that?

...Ever caught on camera.

My god!

These are...

-- Captions by vitac -- www.Vitac.Com

Captions paid for by discovery communications

Jardim, brazil, February 2018.

Overnight, a forest footpath in an ecopark

Takes on a slightly surreal and soggy look.

What you're looking at is not a crystal-clear aquarium,

So why are fish swimming through the trees?

Riskin: So, this is a weird one.

It looks like some kind of alien world

Where everybody lives underwater,

But there are walkways, but it's not.

This is nature, so why is it like that?

Narrator: The question is, where did all this water come from

And why is is so perfectly crystal clear?

Clues may lie on the other side of the globe.

Every year, green lake in austria

Is transformed into a scuba divers' playground.

The park's trees and benches are totally submerged.

So, green lake floods every spring and summer

When the glaciers melt,

So it's that clean, clear runoff from glacial melt,

And the streams and the rivers all adding to green lake,

Which is why it's so clear.

Narrator: Could the flooded ecopark in brazil

Be the result of something similar?

This is like that, but it can't be the same thing

Because green lake is water that comes from a glacier.

It's fresh, clear water with nothing in it

Because it comes from snow.

Narrator: The jardim area doesn't get any snow.

The ecopark is in a rainforest and it gets really hot here

In February -- up to 85 degrees fahrenheit.

If this water is not from snow, could it be from a recent flood?

Riskin: Maybe the river swelled up.

It's a big flood and now everything's underwater.

Narrator: Flooding does happen in other parts of brazil.

Nearly 100,000 square miles of amazon rainforest

Are submerged every year as the famous river spills its banks

And rises by 30 feet.

Yellow-spotted river turtles swim through the trees,

While caiman become temporary forest dwellers,

And arboreal animals like sloth have to swim

Rather than climb through the branches.

So, is something similar happening in jardim?

This isn't part of the amazon.

This is south of that, so that shouldn't be happening here.

Narrator: The amazon is over 1,000 miles north of jardim,

But the source of the amazon's floods may still hold clues

To what's happening here.

Riskin: Another possibility

Is that there's just been a lot of rain.

Narrator: Well, in early 2018,

The area was indeed hit by a deluge of heavy rain.

Increased rainfall could cause flooding in the area.

Narrator: But normally, heavy rain transforms a river

Into a murky mess,

The opposite of the crystal-clear water of jardim.

In reality, it can't just be

The run-of-the-mill flash flooding

Because very quick flooding

Really always brings in a lot of sediment.

You would really expect the water

To be much more cloudy and murky and full of debris,

But that was definitely not the case here.

Riskin: It's almost like this water's been filtered.

There's something else going on.

The region is made up of bedrock

That is comprised of porous limestone,

And that filters mud and sand and silt beautifully.

Narrator: Usually, the water comes up through springs

That supply the famously transparent rio de prada,

Which makes this river

And its amazingly transparent tributaries

A snorkeler's paradise.

But heavy rains overloaded the system.

All the extra water filtered down

Through the limestone bedrock, supercharging the springs,

And causing the river level to rise from below.

The result -- a crystal-clear filtered flood.

But there's one more thing.

So, the underlying bedrock of the area acts as a water filter,

Making the water the nice clear that we see,

And on top of that, the limestone particles

In the water actually refract the light

And make it this nice blue color.

Narrator: But the phenomenon is short-lived.

Within a day or two,

This submerged dream world disappears,

Taking the fish with it as the flooding subsides

And the water flows back down the river.

It's incredibly rare for this to happen.

The rainforest only gets transformed

About once every four years,

Turning a walk in the park into a swim.

♪

Isla santa catalina, sea of cortez.

A scientific expedition

Stumbles upon a strange species of rattlesnake.

It's a rattlesnake without a rattle.

I don't know if that's even a rattlesnake anymore.

Riskin: So, here's a mystery -- you've got a snake

That looks like a rattlesnake.

It's got the head of a rattlesnake,

It's got the body of a rattlesnake,

It even shakes its tail like a rattlesnake,

But there's no rattle.

So what's going on?

Narrator: Animal planet host

And wildlife biologist forrest galante is also curious.

All other living species of rattlesnake

Have an active rattle.

That's why they're called rattlesnakes.

But this one doesn't.

Why?

Narrator: With no rattle, how do we even know

The santa catalina rattler is a rattlesnake to begin with?

Well, aside from a rattle,

Rattlers have a triangle-shaped head and vertical pupils,

Just like our catalina rattler.

They also share the same type of venom

And give birth to live young -- another check.

So the santa catalina snake is indeed a type of rattlesnake.

Question is, how and why did it become rattleless?

Nelson: So, it might be as a form of camouflage.

Being camouflage means you can't be seen in the environment.

Narrator: Unlike other rattlesnakes,

The santa catalina rattler's tail is camouflaged,

Just like the rest of its body.

So, did the catalina rattlers lose their rattles

In order to become more stealthy in pursuit of their prey?

Perhaps not.

But this wouldn't make sense because every other rattlesnake

Everywhere else in the world is a very efficient predator.

Narrator: They can strike in just 50 milliseconds.

So fast that if you blink, you really would miss it.

So, why would a rattlesnake need to lose his rattle

To be a good predator?

Doesn't make sense.

Narrator: If losing your rattle

Doesn't make you a better hunter,

Maybe we need to go back to the reason

That rattlesnakes have rattles in the first place.

Galante: They're a snake that has evolved itself

An entirely unique defense mechanism --

An object on the end of its tail that it can shake like crazy

And rattle to send off a warning signal to say,

"hey, I'm venomous, I'm dangerous.

Leave me alone."

Narrator: Most animals avoid tangling

With these snakes' venom-filled fangs,

But there may be a downside

To the rattlesnakes' early warning system.

Could the rattle actually attract unwanted attention?

[ bird screeches ]

So, perhaps in this instance,

When the isla catalina rattlesnake rattles its tail,

It's actually alerting predators to its whereabouts.

It's creating a beacon, saying,

"I'm right here, come and eat me."

Riskin: So, maybe it's possible that predators are the reason

That these snakes have lost the rattle.

There are predators that do eat snakes.

Things like hawks --

All kinds of animals that will go after an easy meal,

And that rattle might be a way of attracting predators.

Narrator: Isla santa catalina, sea of cortez.

A scientific expedition encounters

A rather unusual reptile.

Of the 36 species of rattlesnake,

The santa catalina snake has no rattle.

Why?

Well, despite their fearsome reputation,

Some animals will prey on rattlesnakes,

So maybe the rattle was lost to avoid detection.

On catalina, one of those predators is a surprise.

The rattlesnakes coexist with feral pigs.

Narrator: So, one theory is...

Galante: Because pigs harass rattlesnakes, that over time,

The rattlesnakes have lost their rattles.

This would enable them to hide better from these pigs

That are messing with them.

So could it be that pigs have literally scared

The rattle out of rattlesnakes?

This is an interesting theory because --

Well, pigs, they love to eat snakes.

They will search out rattlesnakes,

Stomp them, eat them.

It would be a good meal for a little pig.

Narrator: Pigs are only one of a handful of mammals resistant

To snake venom and they can survive snake bites.

So, if pigs are not scared of attacking snakes,

Could this be why the santa catalina rattlers

Lost their rattles?

Maybe, but...

It's doubtful, though, that pigs are the whole story.

There just aren't enough pigs

Where there are these rattlesnakes.

Narrator: In fact, there are very few predators

Of any kind living on this island,

Making santa catalina a pretty safe place

For the snakes to call home.

So instead, could this lack of predators

Have caused the snakes to shed their rattles?

Riskin: Places where there are dangerous animals,

That rattle really comes in handy to ward them off,

But on this island, there were no animals to worry about.

So, it's not all that big of a benefit to have the rattle.

Narrator: But why are the island's missing predators

Important to our mystery?

The answer may lie in how a rattlesnake's rattle

Is normally made.

So, what I have here is

One of the most beautiful rattlesnake species on earth.

This is the spectacled rattlesnake and look at him go.

Listen to that rattle hum away,

And when you look at that rattle,

You realize there's a little tiny bead in every single ring.

So what you can assume is that the body's genes

Are telling it to make that little bead.

Narrator: A new bead or rattle segment

Is added every time the snake sheds its skin.

The distinctive rattle sound is made

Whenever these segments smash into one another.

Galante: Now, in an area with very few predators, over time,

What happens is the snakes stop wasting

That valuable biological energy to create this bead.

Narrator: Since arriving on santa catalina,

These snakes have gradually evolved

To stop growing the one body part

They simply don't need anymore.

Over time, more snakes continued to lose their rattle

Because it wasn't having an adverse affect on them.

Now you have an entire population

Of rattleless rattlesnakes.

A rattlesnake without a rattle. How cool is that?

♪

Narrator: April 2016.

Nagarhole national park, india.

Scientists from the wildlife conservation society

Are on a safari when they stumble upon something strange.

Okay, so, it's putting something in its mouth

And it's puffing it out.

Smoking, not good.

Narrator: April 2016.

Nagarhole national park, india.

Scientists encounter an elephant acting strangely.

I have never seen this behavior before.

To see an elephant blow out a plumage of smoke,

That was very interesting.

Narrator: The elephant seems to repeat this action

Again and again.

This indian elephant is picking something up off of the ground,

Clearly chewing on it, and then on his exhale,

This huge cloud of smoke

Is coming out either side of his mouth

And just engulfing his whole head,

And then he chews, picks up another piece,

And does it again.

And it looks like he's smoking.

Narrator: But could this elephant really be smoking?

I mean, when you look at it at first,

It looks like it's pulling on a cigarette

Or something like that, but there's too much smoke

And there's no cigarette.

This is something else.

Narrator: The local forestry department

Recently burnt areas of the jungle

In an attempt to prevent future forest fires from spreading.

This left behind burnt wood and ash.

In this case, the elephant is not foraging its typical diet,

But it is in fact picking up with its trunk

And chewing on and eating charcoal.

Narrator: So, the elephant isn't smoking,

It's blowing the ash off pieces of charcoal and chewing it.

This is new.

Until this video,

No one else had ever seen an elephant eating charcoal.

Narrator: The mystery is,

Why eat charcoal in the first place?

Perhaps it's using the charcoal to help clean its teeth.

There's actually a lot of different instances of animals

Using tools as dental tools to aid in hygiene.

Narrator: And charcoal is something

That can be used to clean and even whiten our smiles.

So, is the smoking elephant caring for its teeth?

Well, perhaps.

Daly: Teeth are a vital part of an animal's life.

If a tooth was to become loose or if it was to become sore,

That could really impede the feeding of that animal

And they could also be in pain.

It's so important, actually, that in some species,

They use tools to actually help clean and maintain those teeth.

Galante: Long-tailed macaques live in thailand,

And these animals are very adaptable.

They live near a shrine where people often frequent.

Narrator: These monkeys have adopted

A strangely familiar routine

For their dental care -- flossing.

Galante: They've learned that if they collect human hair,

They can actually use it as dental floss.

They sit around and actually floss with human hair,

And just like you're human,

Kind of check it out and then discard it.

Be like, "yeah, my teeth are clean."

Narrator: So, is this elephant using charcoal

To clean its ivories?

To find out, we need to understand

How elephants' teeth work.

Elephant teeth are not like our teeth.

They're weird.

New teeth come in at the back of the mouth

And then everything shifts forward

And then old teeth fall out the front,

And they just keep rotating through.

Daly: Elephants have six sets of teeth

To keep up with the sheer amount of food

That they're going through.

Narrator: With new teeth growing all the time,

Elephants don't have the same oral-hygiene concerns as we do,

So tooth care is ruled out.

So, we need to consider something else.

Narrator: Perhaps there's something inside the charcoal

The elephant is after.

After all, wood ash does hold some minerals.

Maybe the charcoal contains nutrients

That are in short supply,

And so maybe it's just trying to fill out its diet.

It's like a vitamin.

Narrator: One of the most sought-after minerals

In the natural world is salt.

Elephants have been known to go to extreme lengths

To get salt in their diet.

Narrator: In kenya's mount elgon national park,

Some exceptional elephants have become experts

In harvesting salt from the earth itself,

And they've passed the knowledge

Of how to reach it down through generations.

Every evening, they descend deep into dark cave tunnels

For six-hour shifts, mining the salt-rich rocks.

These are the only elephants in the world to do this.

The elephants will dig into soft rock with their tusk,

Wearing down their tusk while they do it,

Just to break up the dirt so that they can eat it

And get the salt.

Narrator: They have been mining like this

For thousands of years,

And in that time, they've extended the entire cave

By over 170 meters into the mountainside.

Such is the importance to elephants of salt.

So, if there's salt in this charcoal that the elephants

Are picking up, it would make total sense

For them to be putting it in their mouth.

Narrator: So, could this elephant be after salt

In the charcoal?

Galante: I'm not convinced.

Charcoal does contain some salt but not that much.

Not enough that an elephant would be chewing on it.

Narrator: As the largest land mammal,

An elephant would have to eat a lot of charcoal

To supplement its diet.

So, if not for the salt, why else are they eating it?

Might the charcoal contain chemicals

That could benefit the elephants' health?

Narrator: April 2016.

Nagarhole national park, india.

Scientists record never-before-seen behavior --

An elephant eating charcoal.

Why is it doing this?

Is it possible the elephant is using it as a type of medicine?

Animals across the world use a variety of plants

And materials to help stave off infection

Or protect themselves from disease.

Narrator: Many animals have been seen chewing charcoal.

Maybe they hold the answer to the smoking elephant.

Red colobus monkeys in zanzibar

Have been seen to ingest charcoal,

Which is meant to help with settling their stomachs.

What charcoal can do is it can treat poisoning

If an animal has ingested toxins.

It can also act as a laxative and it can help with digestion.

Narrator: So, it seems that eating charcoal

Is not for tooth care

Or to consume the salt minerals it contains.

Instead, it's a medicine that will neutralize toxins

In the elephant's stomach.

Until now, we've seen colobus monkeys eating charcoal

To presumably settle their stomachs,

And now we have this elephant footage

Showing that they may do exactly the same thing.

It's pretty special.

Galante: Charcoal is a natural filter.

It helps with stomach problems,

And, in fact, human beings will buy charcoal pills

When they're having upset stomachs.

Narrator: So, this puffing pachyderm

Has raided nature's medicine cabinet

To treat indigestion.