All language subtitles for Natures.Strangest.Mysteries.Solved.Series.1.05of10.Unscrambling.Eggs

Narrator: What if...

Woman:
That is enormous.

...Elusive deep-sea fish could
help us predict earthquakes?

[ screaming, gasping ]

What exactly are they detecting?

Narrator: And what is the point
of this pointy egg?

Okay, that's a big question.

Narrator:
Nature is awe-inspiring,

But sometimes it just
doesn't make sense.

Man: I have never, ever seen
anything like this.

Our team of experts investigate
the weirdest animal behavior.

That's amazing.

And the most
unexpected events...

What is causing that?

...Ever caight on camera.

Woman: My god.

These are nature's
strangest mysteries...

"solved."

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

Captions paid for by
discovery communications

Narrator: Planet earth --
300 million years b.C.

The dinosaurs are already using
an incredible delivery system

For bringing their young
into the world.

Perfect for incubation,

Eggs are strong on the outside
and safe within.

And now 300 million
and some 2,000 years later,

The dinosaurs' descendants,
birds, are still laying them.

But there is one question

Scientists haven't
quite unscrambled --

Why are birds' eggs
such different shapes?

The shape of eggs
has excited speculation

For hundreds of years.

♪

We tend to think of eggs
as being egg shaped,

But the variation that we get
across different species

Is remarkable.

[ birds chirping ]

Hummingbirds have these little
tiny bullet-shaped eggs.

Birkhead: Others like waders
produce rather pointed eggs.

Of course, the most extreme end,
you have the kiwi,

Which gives birth
to a very large oval egg.

The human equivalent
of giving birth to a 4-year-old.

Narrator: There are around
18,000 species of bird,

And amazingly,
almost as many varieties of egg.

And that really throws up
a question of, "why?"

It's a mystery.

Narrator: Some eggs are round,
some are long,

And others are in between,

But why is each kind of egg
a different shape,

And what exactly determines
the shape of an egg?

It was a puzzle no one
could solve until 2017,

When scientists thought
they'd finally cracked it.

Researchers found a correlation
between the shape of an egg

And the flight performance
of a bird.

Narrator:
The scientists examined photos

Of nearly 50,000 eggs,

And compared them
with the birds' lifestyles.

Birkhead:
The main conclusions were,

Birds that spent
a lot of time in the air

Tended to produce
rather elongated eggs,

And birds that didn't spend
a lot of time in the air

Produced rather squatted,
dumpy eggs.

When I first heard this,

It sounded a little bit
bizarre to me,

A little bit like
the ancient study of phrenology,

When the shape of one's head

Indicated your likelihood
of criminal behavior.

It was all a bit weird.

Narrator:
It might sound weird,

But there was method
to the madness.

If a bird is going to fly well,
it needs to be,

Well, aerodynamic.

And that means having a thin
and streamlined body.

So any eggs growing inside them
must expand lengthways

So the eggs end up narrower,
or pointy at one end.

Got it?

Good flyers, thinner birds,
thinner eggs.

Easy.

But did the theory stand up?

♪

Greive: So swifts,
as the name implies,

Are very gifted flyers.

Their eggs are
incredibly elongated,

Consistent with
the researchers' theory.

On the other hand,
you have birds like owls

Who only fly very short
distances occasionally,

And their eggs are almost
perfectly spherical --

Again, consistent
with the theory.

♪

Narrator:
So one of the biggest mysteries

In the avian world
had been solved.

Well, maybe, because one egg
defied the theory completely.

There's an exception
to the rule, as always.

And this is the egg of a bird
called the guillemot.

♪

Narrator: Known as guillemots,
or mirrors,

In the breeding season,

These sea birds congregate
on cliffs

In groups
of as many as 5,000

Because they need to be
stimulated by a noisy crowd

If they're to mate successfully.

The guillemot belongs to a
family of birds, the auk family.

Actually, I'm getting off
on a tangent now.

I'll come back again.
[ laughs ]

It has a very elongated egg.

One end is very pointy,

And the other end
is very rounded.

Narrator: Scientists found that
the pointiest eggs --

Call them asymmetric
if you want to be fancy --

Tended to come
from the top flyers,

But the guillemot
was going against the grain.

Greive:
The egg itself is asymmetric,

Indicating that the guillemot

Must be an exceptionally
gifted flyer,

But in fact,
they're absolutely rubbish.

[ chirping ]

They spend almost their entire
lives bobbing about

Like a feathered cork
on the ocean

And seldom fly at all.

And when they do,
they don't do it very well.

[ birds chirping ]

Birkhead: Guillemots are
pretty awful flyers.

You know, they flap like crazy
just to stay up.

Narrator:
They're no soaring eagle.

♪

In fact, the sea bird's wings
are more adapted for diving.

They reach depths of 600 feet,

Where those stubby wings
make perfect flippers.

It's a great way to catch fish.

And they only need
to move off the sea

And up the cliffs when it's time
to raise their young.

But the chicks don't
hang around for long.

Burke:
The chicks will stay on that
cliff ledge for a few weeks,

But as soon as they're
strong enough and big enough,

They take this incredible
leap off the cliff.

♪

Narrator: These chicks are even
worse flyers than their parents.

At just three weeks old,

They hurl themselves off
the cliff and hope for the best.

♪

They go into a phase
where we call them jumplings,

And as a paratrooper,
I especially appreciate

This suicidal urge
to leap from the cliff

Into the void,
where they land

Hopefully in the sea,
and not the rocks.

Narrator: Some jumplings

Need a little
parental encouragement.

♪

[ squawking ]

So it seems safe to say
guillemot's pointy,

Or asymmetric, eggs

Aren't related to their strong
flying technique.

With that in mind, why on earth
would the guillemot

Have such an exceptionally
asymmetric egg?

Pfft.
[ laughs ]

Okay, that's a big question.

Burke: One explanation is

That the shape of the egg
prevents them

From rolling off the cliff edge.

They balance their eggs
in a small space,

And obviously an egg rolling off
is a very real risk.

Narrator: Guillemot parents take
turns to incubate their eggs,

And changeover is a risky time.

They're just one clumsy move
and one cracked egg away from

"worst parent of the year"
award.

[ squawking ]
emperor penguins also have

A precarious
nesting arrangement.

They have pointy eggs, too,
and for a very good reason.

Greive: The eggs are perfect
for being balanced on the feet

To be kept above
the frozen ice and snow.

Narrator: So with that in mind,
could guillemots lay pointy eggs

To stop them rolling off
the cliff edge?

Tim has been studying
these birds for 46 years

And wanted to find out.

If you take a guillemot egg
and roll it on a smooth surface,

It will indeed roll
in an arc.

But that arc is quite big

Relative to the width
of the bank

On which these birds breed.

Narrator: Which means the egg
would roll right off the edge.

So that pointy shape
should be a disadvantage.

Clearly, stopping them
from rolling off the cliffs

Is not the answer.

So, they're not stopping them
rolling off cliffs.

They're not helping them fly.

Why are their eggs pointy?

[ insects chirping ]

[ insects chirping ]

Narrator: For centuries,
scientists have wondered

Why the guillemot egg
is such a pointy shape.

Most birds that lay pointy eggs
are excellent flyers,

But not guillemots, so how come?

♪

Greive: Is the shape
inherently stronger?

One of the things
that guillemot eggs face

Is the risk of being broken
by a clumsy guillemot

Coming in and crash landing
on an incubating bird,

So I wondered whether
this particular shape

Would minimize the risk
of the egg being broken

If another bird landed
on top of it.

Narrator: But it turns out,
this pointy egg

Isn't actually
the strongest shape.

A perfect sphere,
a perfect round object

Is the strongest structure
in nature.

It's why we've designed deep-sea
submersibles the way they are.

It evenly distributes
the pressure

Across the entire surface.

The largest egg we know of,
the ostrich egg,

Is almost perfectly round
and is strong enough

To support the weight
of a human being standing on it.

But in the case
of the guillemot,

The eggs are the opposite
of spherical.

Therefore, we have to imagine

There's some other virtue
to this unique design.

♪

Narrator: Sometimes,
solving a science problem

Must feel like scaling a cliff.

But then, after hundreds
of hours on the rocks,

Tim finally had a breakthrough.

Doing field work,
I had the opportunity

To simply place the guillemot
egg on a sloping bit of ledge.

I was staggered to see that
a guillemot egg just stayed put.

Narrator:
Tim had discovered

That only the most
asymmetrical eggs

Could stick to
the most extreme cliff faces.

Birkhead: We tested
this very rigorously,

And it's true --
the more pointed the egg shape,

The steeper the slope
that it can sit on.

It made me realize that
stability was the explanation

For why the guillemot egg
is this shape.

Narrator: So the reason
the guillemot egg

Breaks all the rules --

It helps them cling
to their precarious nests.

It's a perfect example
of natural selection in action.

Less pointed eggs rolled
off the cliff,

So the birds that laid them
lost all their chicks.

Birds that laid pointy eggs
saw their chicks survive,

So their genes
are still going strong today.

[ insects chirping ]

♪

Narrator: Mexico --
April 2014.

Kayakers looking for adventure

Get a bit more
than they bargain for.

-Uh-oh.
-Oh, my gosh.

Woman: My god, look at the size
of the thing.

-It's going under your boat.
-Oh, my gosh.

And I'm taking
a movie of it.

Narrator: And this little movie
went viral,

With over
6 million views online.

Oh, boy. Oh, boy.

It was quite a shock
for the woman with the camera.

Woman: That is enormous.

♪

Narrator: The kayakers had
stumbled across an oarfish,

An animal rarely seen by humans

Despite the fact it lives
in all warm oceans.

♪

It is normally hidden away
in the deep,

3,000 feet below the surface.

Conley: Normally
when we find these guys,

You're gonna find them in a
vertical position in the water,

Their head toward
the surface of the water

And their tail
towards the deep.

And they sort of undulate
and sort of swim

In a vertical manner.

Narrator:
Oarfish are huge.

In fact, the giant variety
is the longest bony fish alive.

Conley: They're so long,
they can get up to

56 feet long, 600 pounds.

They're very large fish.

Narrator:
Only a few videos exist

Of an oarfish in its natural
deep-sea habitat.

More people have seen earth
from space

Than witnessed this rare
aquatic species in the wild.

Just hear how excited
this deep-sea diver is

To finally see one.

Man: There it is.
There it is.

♪

This is incredible.

This is absolutely incredible.

♪

Narrator:
Yet, in the last few decades,

Dozens of oarfish have washed up
on beaches all around the world.

This one was found

By u.S. Navy seals

On a san diego beach,

And measured 23 feet long.

So what are these
rarely seen

Denizens of the deep
doing in the shallows?

Well, there are some
surprising possibilities.

Some of the sightings
have coincided

With looming natural disasters.

Nosal: What's interesting
is that sometimes a string

Of these oarfish will wash up
right before an earthquake hits.

[ gasping, screaming ]

Some people think that
they are sensing

These impending large events.

Woman: Baby, the water's
coming to an end!

Narrator: In 2010, dozens of
oarfish beached themselves

Before earthquakes
in both chile and haiti.

At least a dozen more were found
on the shores of japan

In the months before the
devastating tohoku earthquake

In 2011.

♪

In which case, could our oarfish
have swum up to a mexican beach

Because it senses
an impending earthquake?

Moser:
Earthquake scientists have

Amazing types of instruments

That are doing everything
they can

To detect very minute
ground shakings.

And you know, we as human beings
still can't predict earthquakes,

And so it would be
really incredible to think

That these fish seemingly
have learned this trick.

Narrator: These recent beachings
aren't the first time oarfish

Have caught our imagination.

♪

There are a lot of stories
from ancient history of mariners

Finding strange
mythical creatures,

And one of those turns out
to be the oarfish.

When you go back
into ancient japanese folklore,

These oarfish were known
to let the people know

That an earthquake
might be coming.

Narrator: So could this
ancient myth be right?

♪

Do these deep-sea dwellers

Hold seismic-sensing powers?

Nosal: If oarfish were somehow
detecting earthquakes,

How would that work
mechanistically?

What exactly are they detecting?

[ insects chirping ]

[ insects chirping ]

Narrator: In April 2014,

Kayakers stumbled
across an oarfish

By a beach in mexico.

Throughout history,
these deep-sea fish

Have often washed ashore
before earthquakes.

So, could it be detecting
an imminent quake?

Moser:
There are actually multiple
different types of waves

That propagate
from an earthquake,

And some of those waves actually
propagate through liquid.

Nosal: The oarfish might be able
to hear certain sounds

Or to feel certain vibrations

That certainly would be
transmitted through the water.

♪

Narrator: If so, they wouldn't
be the first animals to be found

To have a seismic sixth sense.

Some animals can detect
earthquakes

Right before
they're about to happen.

Some birds are known to do this.

Dogs are known to do this.

Narrator: Eureka, california --

January 2010.

This dog has sensed something.

It's out the door.

[ rumbling ]

And sure enough,
the earth starts to move.

[ clattering ]

So if an oarfish
washes ashore,

Would you be right
to run for the hills?

[ rumbling, clattering ]

These animals are probably
detecting

The very minute vibrations

Right before
the major shaking starts,

So we're talking about
predicting earthquakes

On the order of seconds,
not hours or days.

Certainly I don't think
that oarfish would be able

To predict an earthquake
days before one occurs.

Narrator: Even if,
like many other animals,

Oarfish can detect earthquakes,

It seems unlikely they could
do it far enough in advance

To swim all the way up from
the depths to reach the shore.

So why are they swimming
in the shallows?

Could there be something
in their biology

That might explain it?

Narrator: October 13, 2013.

One oarfish that entered

The shallow waters off
catalina island

In southern california

Was found to be a female
full of thousands of eggs.

In which case, could she have
come here to reproduce?

Most of the oarfish that have
washed ashore are females.

When we open them up, we find
that they're full of eggs,

But the eggs are at
different developmental stages.

So could there be some behavior
associated with spawning?

Narrator: Spawning,
a.K.A. Fish sex.

♪

Spawning near the shore
is actually quite common

For many species of fish.

Every summer, capelin throw
themselves out of the water

And onto the beaches
of the north atlantic

And north pacific coasts
in their millions.

The females lay their eggs
in the sand,

Where the males fertilize them
before returning to the sea.

It's a capelin beach party.

Might oarfish be doing
something similar?

♪

Oarfish have been observed

Spawning off the coast
of mexico.

And in fact, our amazing
footage of the oarfish

That startled the kayakers
was shot in mexico, too.

It's thought the fertilized eggs
stay at the surface of the ocean

Until the baby fish hatch

Before eventually swimming down
to their deep-sea home.

So it's possible,
since these guys

Are sometimes found in pairs,

But the problem
is they're very elusive,

We don't really know much about

The reproductive
history of this fish.

Narrator: So if they're not
coming ashore to spawn,

And they're not detecting
impending earthquakes,

Just what is driving
these fish out of the deep?

The answer might lie
in the motion of the ocean.

[ insects chirping ]

[ insects chirping ]

♪

Narrator: Kayakers in mexico
got a startling sight,

An oarfish in shallow water,

And there have been
other reported cases

Of these deep-sea fish

Washing ashore
all around the world.

They're not predicting
earthquakes

Or coming up to spawn,
so what else could be going on?

The answer may well lie with the
very waters they're swimming in.

Warming of the waters
often changes the currents,

It changes the direction
of the currents,

It changes the swiftness
of the current,

So it's very likely
that the currents changed

And ended up washing

Some of those oarfish
too close to shore,

And they were unable
to swim back

Because they are
such weak swimmers.

♪

Narrator: It may seem weird
for a fish to be a bad swimmer,

But in the ocean depths
where oarfish live,

There are hardly any currents.

That means they don't build up
much muscle mass,

And so lack the strength
to cope in turbulent waters.

♪

And oarfish are not

The only ones
to be swept away.

Ocean currents can be so strong
that even whales

And turtles
can be pushed off course.

So, is this what happened
to our oarfish?

Kind of being at the wrong place
at the wrong time,

They end up washing ashore.

Narrator: So the solution is
as simple as ocean currents

Driving oarfish to shore.

Perhaps this one's hoping
the tide will change

And whisk it back to the deep

And away from
the curious crowds.

[ insects chirping ]