Shark Vs. Whale

The great white shark!

Focus.

Power.

Purpose.

Seals are their usual prey of choice.

But what about something bigger?

Much bigger.

South Africa's Coast is shark infested.

Massive tigers.

Marauding bulls.

And gangs of blacktips.

They're all here.

It's a predator's playground.

Roughly two million seals live at the southern tip of Africa,

which is why one of the highest concentrations of great whites

on the planet hunt these waters.

Other giants are here, too.

It's the beginning of winter in the Southern Hemisphere.

Great pods of humpback whales like this are heading north.

For four months,

they fed on nutritious krill off Antarctica,

building up blubber reserves for this journey.

Over 30,000 humpbacks make this annual migration.

Their destination, Mozambique,

to give birth to their calves in warm tropical waters.

The ocean off southern Africa is too cold for baby whales.

It's dangerous, too.

Great white sharks dominate these southern waters.

The humpback migration routes

take them right through white shark territory.

So what happens when humpback whales and white sharks

run into each other?

Wow.

Away from the boat, away from the boat, away from the boat.

There we go.

Ryan Johnson is a shark scientist

based in Mossel Bay, South Africa.

He's been studying the white shark population here

for over 20 years.

Whoa, there we go!

Oh, she went for it!

In February 2017 he was flying his drone

during a shark survey when the phone rang.

The phone call came in

from the National Sea Rescue Institute

that they had been alerted that there was a whale out at sea.

It looked like it had been wrapped up in longline.

The whale wasn't moving.

Was it dead?

And then the whale breathed and it blew,

and I realized that this whale was still alive.

Then, Ryan saw something else.

A 14 foot great white shark

headed straight for the young whale.

And it did the unexpected.

It attacked.

I know the science and I know the literature,

and I know this has never been seen before.

It bit the tail,

then it rolled the weakened whale

as if trying to drown it.

This was not some random meeting.

It was a methodical attack on a whale by a great white shark.

A shark that seemed to know just what to do.

Ryan is the first person ever to witness this shark behavior.

He played the drone footage over and over

and suddenly recognized the shark.

He tagged her for research back in 2012.

Her name is Helen.

Dorsal fin came up out of the water,

and you could clearly see the satellite tag remnants on her,

plus that distinctive dorsal fin.

Now that she is that shark that hunted a humpback whale,

a living humpback whale, she has sort of marked her place

in the sharks' hall of fame forever,

and she's always gonna be remembered for that.

Ryan had serious questions.

Is this shark attack a one time only event,

or do white sharks really hunt living whales

and we just never see it?

To get some answers, Ryan decides to dig deeper.

He sets off to follow

the 4,000 mile migration route of the humpbacks.

Are there specific places where white sharks ambush the whales?

Do attacks follow a pattern?

And why hunt whales at all

when there are plenty of seals available?

Ryan goes back to what he already knows

about the great white.

11 million years of evolution has made them fast...

Agile...

And calculating.

Most shark species are cold blooded

and have to stay in warmer waters.

Great whites are one of only seven species

that can raise their internal body temperature.

Being warm blooded, they keep their edge in cold water,

which is why no seal is safe

off the coast of southern Africa.

For them, white sharks are an almost unbeatable foe.

So, why would white sharks turn to whales?

Off the coast of South Africa,

the sharks have plenty of seals to eat.

Resident colonies of Cape fur seals dot the coastline.

Half of a seal is blubber or fat.

That's what white sharks are after.

A white shark's liver is like a giant fuel tank

where it stores the calories from fat.

Combine enormous energy reserves with warm blood,

big teeth, hydrodynamic shape,

and sharks' super senses,

and you've got a feeding machine.

Spectacular breaches on seal decoys

show just how these sharks have been hunting

for millions of years.

They know how to hunt seals.

So, the question Ryan really wants to answer is,

why would they hunt something much bigger

and much more dangerous?

Ryan begins his research at Seal Island

just off Mossel Bay, South Africa.

It's a well known hot spot where great whites hunt seals,

and it's just three and a half miles

from the site of the humpback whale attack.

Seals and humpback whales are as different

as they can possibly be.

What connects them in a shark's brain?

It's well known that their diet is mostly marine mammals.

But just how selective is the great white?

Ryan runs an experiment

with two different sized seal decoys.

Which one will the sharks attack?

For me, this experiment is all about

that cognition of a shark, that decision making process,

when it weighs up the pros and cons of attacking a prey.

Does it go from that extreme level of success,

that big reward but high risk,

or is it going to be more conservative?

Because this feeds right into the decision making

Helen had to go through

when she was faced with a whale nine, ten times her size.

She had to be assessing the risk;

the chance of her getting injured;

the chance that she would be unsuccessful;

the chance that her life as a predator could end.

Do the sharks display

a simple species preference,

or is there something more to their selection?

Make this turn as tight as you can,

because there's no swell,

and we just head right up the edge of that island.

Nice one.

A little shark, but hit the little decoy,

hit the little juvenile pup.

Nice, that's what we're looking for.

First breach, number one.

Baby seal.

Okay, decoy back in.

Wow!

Big shark, big breach!

That was massive!

Can you believe it?

And on a juvenile seal.

There we go, we thought so!

Again, small decoy.

Look, we swapped the small seal over to this side,

got the hit on it.

This is getting conclusive now.

Every breach is on the smaller decoy.

The small seals are low risk

and an almost guaranteed reward.

The sharks make a clear choice.

They're very discerning, which suggests that Helen's attack

on the humpback whale was discerning, too.

At Seal Island, the pickings are easy,

but not all hunting grounds are the same.

Just how adaptable are great white sharks

when conditions are not in their favor?

To find out, Ryan moves from Mossel Bay

to Robberg Nature Reserve 80 miles east along the coast.

Just offshore, the humpbacks are migrating.

The sharks pay no attention.

Like at Seal Island, they're after the pups.

But the sharks can't ambush from the deep here;

the water's too shallow and clear.

Then how do they get the job done?

They're incredibly adaptable.

Hiding behind the adults, pups flounder in the surf.

Ryan has never before had the opportunity

to watch white sharks tested like this.

There's no chance of surprising a seal here.

A shark patrols the cliff face

engaging the prey in plain sight.

It's looking for a single small seal.

But the sharks aren't the only adaptable species here.

The larger seals gang up.

Attack is the best form of defense.

But only to a point.

And the cat and mouse game begins.

Ryan Johnson is at Robberg Nature Reserve