Mammals (2024) s01e03 Episode Script
Water
1
The deep ocean.
For mammals,
it's one of the most
inhospitable places on Earth.
Can we move another
camera to channel three?OK.
Anything we've got. Yeah.
Survival in this alien world
..requires extreme adaptations.
We have only recently begun
to explore these depths.
So if you're watching on channel
one, the Supersampler isYeah.
The heck is that?!
Oh, my gosh!
Oh, my goodness, what is that?
Yet, some mammals
have been coming here
for millions of years.
It's a sperm whale.
Oh, my goodness.
Look at that shape.
Holy cow!
Wow!
Unbelievable.
Like all mammals,
sperm whales breathe air.
Yet, almost a mile underwater,
in the freezing darkness,
they seem completely at home.
They, like many mammals,
have overcome the challenges
of living in water
in the most remarkable ways.
Many mammals, encountering water,
prefer to do no more
than dip their toes into it.
Northern Sri Lanka,
late in the dry season.
A troop of macaques
are looking for what little fruit
is left in the forest.
Their search has brought them
to a jungle pool.
But there's more for them here
than just a refreshing drink.
Water lilies.
Enough to fill the empty stomachs
of the entire troop.
But the flowers
are just out of reach.
Got it!
But a single flower
merely whets the appetite.
For the real prize
..they must take the plunge.
For an animal that spends
nearly all of its time on land,
macaques are surprisingly
competent in water.
They're looking for
the lilies' juicy seed pods
which are packed
full of nutrients.
An excellent solution to the
macaques' seasonal food crisis.
Thanks to their natural curiosity
and willingness
to explore new opportunities..
..these macaques have discovered
that it can pay to jump into water.
Freshwater ponds in a jungle
may be few and far between.
In Central Canada, however,
water is everywhere.
Moist soil is easy to dig
..and just underground
there is a network of tunnels.
The work of a particularly
industrious little mammal.
A star-nosed mole.
Virtually blind,
he relies on his
super-sensitive nose.
It's not just for smelling.
It's also
for feeling.
And it is 100 times more sensitive
than our own fingertips.
To fuel his active lifestyle,
he must eat up to twice
his body weight every day.
And worms, as they burrow,
simply drop into his tunnels
of their own accord.
Life underground can be pretty good.
But every spring,
torrential rain saturates the soil.
Before long,
the mole's tunnels are flooded.
He can hold his breath
for little more than 30 seconds.
He must get out or he'll drown.
Made it!
But having taken a breath
..he dives straight back in.
Large feet, excellent for digging,
also make very effective paddles.
And his water-resistant coat
keeps him warm
..so he's well equipped
for swimming.
But, nonetheless, there's a problem.
How do you sniff out prey
underwater?
First, he blows bubbles
into the submerged leaves.
Smells pass into them.
And sniffing them with his nose
enables him to detect
something edible
so he can locate possible prey
even underwater.
Star-nosed moles
are one of the few mammals
that are just as at home in the
water as they are in soil.
Beyond land,
the oceans that cover
two-thirds of our planet
are full of possible food.
For most mammals, it's out of reach.
But that doesn't stop some
from trying to get it.
A female coyote,
patrolling the Pacific coast
of Mexico.
Living on the edge of a desert
means often relying
on the ocean for food.
This female would make a meal
of a sea bird
if only she could catch one.
She can't afford to keep failing.
Driven by hunger, she moves on.
The desert stretches 2,000 miles
along Mexico's Baja coast.
Coyotes living here
are forced to explore
tangled mangroves and deep creeks.
After a long day
under the desert sun,
persistence pays off.
A dead body cast up by the waves.
It's the carcass of a grey whale
rotting in the sun.
Enough to feed her for months.
But other hungry beachcombers
have found it, too.
They quarrel over the best bits.
But a 40-tonne whale is more
than enough food to go round.
The daily tides
provide so much food
that the Baja's Pacific coastline
supports up to 14 times
the number of coyotes
than occur inland.
But extending scavenging on shore
to hunting in the sea
requires very different skills.
Nonetheless, 50 million years ago,
the ancestors of marine mammals
started to do exactly that.
A bottlenose dolphin
and her two young
cruise the shallows of Florida Bay.
The coastal waters here
are full of fish.
But much of the bay
is less than a metre deep.
For a large mammal with a tail
that beats up and down,
just moving around here
is a challenge.
But she has a simple solution.
She swims on her side.
But it's still a struggle
to keep up with a fish.
Let alone catch one.
And a single fish won't feed
a family.
But this intelligent mother
has another,
even more ingenious, solution.
Beating her tail,
she churns up the water
..creating a muddy barrier
..around a shoal of fish.
In a bid to escape
..the fish are forced
..to leap.
She's not the only one
that gets a meal.
Her young family can also feed.
But rings of muddy water
aren't the only way in which
dolphins hunt in Florida.
This family uses an S-shaped barrier
to spook the fish.
Why Florida's dolphins
use different shapes
remains a mystery.
But this ingenuity
enables marine mammals
to move far beyond the shallows.
Californian sea lions.
They may spend over 70%
of their lives out at sea.
They know the opportunities
offered by the open ocean
are endless.
The trick is how to make
the most of them.
The sea lions have spent
a lot of energy to get here,
and the sardines they seek are
widely dispersed beneath them.
The hunters need to round them up.
Striped marlin arrive.
Up to four metres long
and with a deadly spear
on their nose,
they, too, are hunting.
Watched by the sea lions
..the marlin go to work.
They herd the sardines
into a ball
..and then drive them
up towards the surface.
This is what the sea lions
have been waiting for.
Fast and flexible,
the sea lions take advantage
of the marlin's efforts
..and collect an easy meal.
These canny sea lions
have learnt how to let marlin
do the hard work.
But sea lions don't stay
permanently in water.
The Galapagos Islands.
Specks of land in the vast emptiness
of the Pacific Ocean.
Here, pregnant Galapagos sea lions
haul out on a beach to give birth.
Unable to swim
when it's newly born,
a pup relies completely
on its mother
for her care and her milk.
Within two weeks, thanks to the
richness of this milk,
it will be strong enough
to venture into the water.
But a newborn pup
is something of a shock
to its older brother.
For the last two years,
he's had his mother all to himself.
The new pup is a sure sign
that he must now find his own feet.
A sheltered inlet is a safe place
for pups and other juveniles
to build up their confidence.
Now, under the watchful eye
of a dominant bull
..the young sea lions acquire
the skills they'll need
for a life at sea.
But this is the time of year
when sea lions also mate.
While the bull's attention
is elsewhere
..the pup ventures beyond
the safety of the rock pool.
It's a mistake.
The waters surrounding the Galapagos
are patrolled by sharks.
The pup strays further
from the pool
..while the bull is preoccupied.
The pup can outmanoeuvre
the shark
..but not for long.
Alerted by the commotion
..the bull takes action.
Weighing a quarter of a tonne,
the bull is more than a match
for the shark.
Biting at its tail,
he chases it away.
For the pup, it's an important
lesson learned.
Many others
..are less fortunate.
Nearly half of these young sea lions
will not survive beyond
their second birthday.
This pup is safely back on land,
and not too old
for a reassuring cuddle.
One small group of mammals, however,
have completely cut their ties
with the land.
Humpback whale calves can swim
from the moment they're born.
The warm coastal shallows
off Western Australia
provide excellent nurseries.
In their first few days,
mothers and babies
form a strong bond.
Tucked gently under her fin,
this mother gives her daughter
an early lesson
in holding its breath.
But they won't stay here for long.
The reef may be an excellent
place to give birth
..but there's almost
nothing to eat here
..so mothers and young
must now make the long journey
to richer waters around Antarctica.
But once they've left the safety
of the shallow reef
they are vulnerable.
A pod of orca
..six strong,
patrols the migration route.
They are a formidable force.
But the humpback mother
puts her baby high on her back
to protect it
..and then goes on
the attack herself.
Slashing her powerful tail
and long five-metre fins,
she could easily kill an orca.
But the orca have a plan.
Some of the pod distract
the mother
..while others ram the calf.
Once it's separated
..they drown it.
Since 1986,
when commercial whaling
was largely banned,
humpback numbers have risen here
from a few hundred
to more than 35,000.
With so many calves on the move,
some orca have specialised
in hunting them.
A small pod - just three.
The humpback calf they're pursuing
has more than just its mother
at its side.
It also has
..a 40-tonne male.
This is a much bigger challenge.
But rather than give up
..the orca bide their time.
The male humpback,
believing, perhaps,
that the orca have gone
..now dives.
The killers seize their opportunity.
They kidnap the calf.
They appear to mimic
the mother's behaviour,
putting the young calf
on their backs
and carrying him along
in the slipstream.
Young and naive,
the calf goes willingly with them.
Now, far from his mother
..the orca attack him.
During the months of migration,
the pod may kill as many
as five calves a day.
They catch so many
that sometimes they eat
no more than the tongue
..and leave the rest
for the sharks.
This is what can happen
when prey is so abundant
and hunters have such skill.
False killer whales are less
than half the size of orcas
..but they are equally clever.
They roam the ocean in groups
up to 50 strong.
Right now, they're on the hunt
for other mammals.
Ocean-going bottlenose dolphins.
But the false killers
aren't looking for prey.
These two groups
are old acquaintances.
In the waters around New Zealand,
they are almost always found
together.
Lifelong bonds within species
are common
..but they are rarely seen
between different species.
Such friendships
between bottlenose dolphins
and false killers
..have been documented
going back 20 years
..so it's entirely possible
that individuals of both species
recognise each other.
They team up not only to play
..but in order to hunt.
So, when one goes
..they all go.
A huge school of kahawai fish.
The false killers
swim under the shoal
..and drive it to the surface.
Here, the dolphins attack.
But despite helping,
the whales don't appear to feed.
For them,
the kahawai are just the bait.
The false killers know the commotion
will attract bigger fish.
Kingfish arrive.
They're up to ten times heavier
than the kahawai,
and one metre long.
Too big for the dolphins.
So, now it's the turn of the false
killer whales to feed.
They form small groups
and break up the school
..and then go after the fish
that get separated.
Not all the whales make a catch.
But they won't go hungry.
Extraordinarily, the successful
hunters share their food.
By helping one another
..they ensure that no-one
goes without.
Teamwork, intelligence
and cooperation
has enabled marine mammals
to flourish in the high seas.
But one part of the ocean is still
beyond the reach of most.
The deep.
Only a very few are capable
of venturing here.
A pod of sperm whales resting
near the surface.
They spend just 7%
of their lives asleep,
less than almost any other mammal.
But they're also waiting here
for another very special reason.
The birth of a baby.
Helped into the world
by supportive relatives,
the newborn is already
more than three metres long.
It will grow up surrounded
and protected by close family.
It thirsts for its mother's milk,
but the food the mother needs
in order to produce it
is 1,000 metres below,
far beyond the reach
of a young calf.
So, whilst the family
looks after the newborn
..the mother sets off
in search of a meal.
Adult sperm whales may remain below,
holding their breath, for an hour.
As they descend, their bodies
change in an astonishing way.
The increasing pressure
squeezes their lungs
until they collapse completely.
To save oxygen,
their digestion,
kidney and liver shut down.
A special camera records
a rare and privileged view
of a hunting sperm whale,
sending out a stream of clicks
to detect prey
in the pitch blackness.
At this depth, they start
to hunt for giant squid.
As the whale closes in,
their clicks speed up.
A puff of ink is released
by the fleeing squid,
but the sperm whale isn't fooled
..and the squid is eaten
in a last cloud of ink.
As this mother returns,
her calf, like all mammal babies,
has only one thing on its mind.
Milk.
It's growing faster now
than during its 16 months
in the womb.
And it will consume
up to 100 litres,
300,000 calories,
every day for the next two years.
To meet this demand,
its mother will have to dive
up to 15 times every day.
It is her ability to reach
such extreme depths
and turn what she eats
into rich milk
that will be the key
to her baby's success.
Today,
protected almost worldwide,
the outlook for this mother
and baby,
and all sperm whales,
is bright.
Even so, sperm whales
still face many threats.
Every year, enough fishing line
is lost in our oceans
to stretch to the moon and back
..together with 20 million traps,
and carrying 14 billion hooks.
The whales become entangled
in these so-called "ghost nets".
The lines cut into their bodies
..and the floats can prevent them
from diving.
Theirs is a slow
and agonising death.
We are now aware
of the threats we create.
Surely, we should now do everything
we can to prevent them.
The greatest challenge
for the Mammals team
was not only filming false
killer whales in New Zealand,
but trying for the first time
to place a data-recording
camera onto one.
With only 150 individuals somewhere
within 4,500 square miles,
just finding them
will be hard enough.
Luckily, they have the help
of Jochen Zaeschmar,
who has been studying
this group of whales
for the last 20 years.
He has a directional hydrophone,
with which he can hear the false
killer whales' whistles
but only from less
than ten miles away.
Nothing.
I was kind of hoping
kind of hoping to hear something.
Cameraman Andre Rerekura
scans the horizon,
but picking out a fin in the open
ocean is no small feat.
The scale of the task ahead
is dawning on assistant producer
Kyle Swann.
Searching.
Searching, searching.
That's kind of the strategy,
but so far, no luck.
With only a brief few weeks
during which it's possible
to film them,
it's a disappointing start.
There's absolutely nothing.
Over the coming days,
the team search without pause.
Nothing.
Absolutely nothing.
Nothing again.
Still, keep trying.
They have spent 20 days
with no whales
..but Andre spots something
promising in the distance.
There's a few birds,
but nothing crazy.
Yeah, well, that's where I heard
some faint whistles there.
Worth a look while we're here.
Ah, I've got something!
Whoa! We have a haul.
Oh, my God, yeah.
It's promising.
It looks
I've seen a stumpy nose!
I think we've got falsies!
Whoa!
Falsies!
No way! Woohoo!
We have 'em!
But with the sun setting
and the whales capable
of covering 100 miles a day,
the team hop on their liveaboard
to follow the whales overnight.
The crew takes turns on watch,
using their eyes and ears.
Yeah, we've pretty much
done circles all night.
We're in the same spot we found
them yesterday afternoon,
so they don't go far.
Like Jochen says, they just sleep.
So they've probably had
more sleep than us!
Falsies off the bow!
Big old falsies off the bow.
Woohoo-hoo!
There's one just here.
Oh, my God,
this is just amazing.
They're in a good mood.
A new dawn presents a new challenge.
Back on the filming boat,
the team follow the false killers
as they hunt.
No-one has ever recorded them
creating a bait ball before.
But the whales can swim at 20mph,
so Andre has brought
a little extra propulsion.
The scooter's a game-changer.
You can free-dive down with,
you know, a full lung of air,
all your energy,
and hold your breath for a minute
and a half to two minutes with ease.
The scooter lets him
keep up with false killers
and helps propel him swiftly
into the heart of the action.
Once the feeding frenzy is over,
the whales turn their attention
to Andre.
This incredible interaction.
It justjust made me
realise how amazing
and intelligent these animals are.
It was really unique
and really special.
That was Woo!
I can't even explain that!
Having captured
this extraordinary behaviour,
the team switch to the most
difficult goal of the trip
..to place a suction tag on a whale.
For 20 years,
Jochen has studied this group
of false killer whales,
but this would be a first.
The tag contains a camera
and a data collector.
Combined, they will give Jochen
new insights
into how these animals
spend their time underwater.
Getting close enough to attach a tag
will take every ounce of Jochen's
expertise and understanding.
Here they are.
While they're just chilled,
I'll just go in there real slow.
Hope to Hope to get lucky.
OK, OK, OK, OK.
Beautiful, beautiful,
beautiful, beautiful.
OK.
No, no, no.
No. No, no, on the next one,
on the next one.
They're going down a bit.
We'll get them, we'll get them.
Trying to find
that perfect moment!
Heart's going through the roof!
This is a bunch of different males.
Let's see, though,
see how they like us.
They're all coming together now.
There's just so, so many factors.
The way the angle of the camera is,
where it comes up next to you.
I'm hopeful. It's hard work.
They're not making it easy.
As the wind drops,
the team have a brief
but perfect opportunity.
So I'm just going to
..ease my way over towards them.
Wait.
OK, this is it.
Yeah!
We did it! We did it!
We did it!
Well done!
Woooo!
We did it. We did it!
I'm so happy!
It's not just the achievement
of getting the tag on,
it's the promise
of what it will reveal.
And that turns out
to be astounding.
Intimate food sharing
and new hunting strategies
have been recorded
for the very first time,
giving us a new perspective
on mammals' lives underwater.
Next time -
we venture into the cold.
A vast and unforgiving world
..where mammals,
through sheer tenacity
and adapation
..have found a way to make it home.
The deep ocean.
For mammals,
it's one of the most
inhospitable places on Earth.
Can we move another
camera to channel three?OK.
Anything we've got. Yeah.
Survival in this alien world
..requires extreme adaptations.
We have only recently begun
to explore these depths.
So if you're watching on channel
one, the Supersampler isYeah.
The heck is that?!
Oh, my gosh!
Oh, my goodness, what is that?
Yet, some mammals
have been coming here
for millions of years.
It's a sperm whale.
Oh, my goodness.
Look at that shape.
Holy cow!
Wow!
Unbelievable.
Like all mammals,
sperm whales breathe air.
Yet, almost a mile underwater,
in the freezing darkness,
they seem completely at home.
They, like many mammals,
have overcome the challenges
of living in water
in the most remarkable ways.
Many mammals, encountering water,
prefer to do no more
than dip their toes into it.
Northern Sri Lanka,
late in the dry season.
A troop of macaques
are looking for what little fruit
is left in the forest.
Their search has brought them
to a jungle pool.
But there's more for them here
than just a refreshing drink.
Water lilies.
Enough to fill the empty stomachs
of the entire troop.
But the flowers
are just out of reach.
Got it!
But a single flower
merely whets the appetite.
For the real prize
..they must take the plunge.
For an animal that spends
nearly all of its time on land,
macaques are surprisingly
competent in water.
They're looking for
the lilies' juicy seed pods
which are packed
full of nutrients.
An excellent solution to the
macaques' seasonal food crisis.
Thanks to their natural curiosity
and willingness
to explore new opportunities..
..these macaques have discovered
that it can pay to jump into water.
Freshwater ponds in a jungle
may be few and far between.
In Central Canada, however,
water is everywhere.
Moist soil is easy to dig
..and just underground
there is a network of tunnels.
The work of a particularly
industrious little mammal.
A star-nosed mole.
Virtually blind,
he relies on his
super-sensitive nose.
It's not just for smelling.
It's also
for feeling.
And it is 100 times more sensitive
than our own fingertips.
To fuel his active lifestyle,
he must eat up to twice
his body weight every day.
And worms, as they burrow,
simply drop into his tunnels
of their own accord.
Life underground can be pretty good.
But every spring,
torrential rain saturates the soil.
Before long,
the mole's tunnels are flooded.
He can hold his breath
for little more than 30 seconds.
He must get out or he'll drown.
Made it!
But having taken a breath
..he dives straight back in.
Large feet, excellent for digging,
also make very effective paddles.
And his water-resistant coat
keeps him warm
..so he's well equipped
for swimming.
But, nonetheless, there's a problem.
How do you sniff out prey
underwater?
First, he blows bubbles
into the submerged leaves.
Smells pass into them.
And sniffing them with his nose
enables him to detect
something edible
so he can locate possible prey
even underwater.
Star-nosed moles
are one of the few mammals
that are just as at home in the
water as they are in soil.
Beyond land,
the oceans that cover
two-thirds of our planet
are full of possible food.
For most mammals, it's out of reach.
But that doesn't stop some
from trying to get it.
A female coyote,
patrolling the Pacific coast
of Mexico.
Living on the edge of a desert
means often relying
on the ocean for food.
This female would make a meal
of a sea bird
if only she could catch one.
She can't afford to keep failing.
Driven by hunger, she moves on.
The desert stretches 2,000 miles
along Mexico's Baja coast.
Coyotes living here
are forced to explore
tangled mangroves and deep creeks.
After a long day
under the desert sun,
persistence pays off.
A dead body cast up by the waves.
It's the carcass of a grey whale
rotting in the sun.
Enough to feed her for months.
But other hungry beachcombers
have found it, too.
They quarrel over the best bits.
But a 40-tonne whale is more
than enough food to go round.
The daily tides
provide so much food
that the Baja's Pacific coastline
supports up to 14 times
the number of coyotes
than occur inland.
But extending scavenging on shore
to hunting in the sea
requires very different skills.
Nonetheless, 50 million years ago,
the ancestors of marine mammals
started to do exactly that.
A bottlenose dolphin
and her two young
cruise the shallows of Florida Bay.
The coastal waters here
are full of fish.
But much of the bay
is less than a metre deep.
For a large mammal with a tail
that beats up and down,
just moving around here
is a challenge.
But she has a simple solution.
She swims on her side.
But it's still a struggle
to keep up with a fish.
Let alone catch one.
And a single fish won't feed
a family.
But this intelligent mother
has another,
even more ingenious, solution.
Beating her tail,
she churns up the water
..creating a muddy barrier
..around a shoal of fish.
In a bid to escape
..the fish are forced
..to leap.
She's not the only one
that gets a meal.
Her young family can also feed.
But rings of muddy water
aren't the only way in which
dolphins hunt in Florida.
This family uses an S-shaped barrier
to spook the fish.
Why Florida's dolphins
use different shapes
remains a mystery.
But this ingenuity
enables marine mammals
to move far beyond the shallows.
Californian sea lions.
They may spend over 70%
of their lives out at sea.
They know the opportunities
offered by the open ocean
are endless.
The trick is how to make
the most of them.
The sea lions have spent
a lot of energy to get here,
and the sardines they seek are
widely dispersed beneath them.
The hunters need to round them up.
Striped marlin arrive.
Up to four metres long
and with a deadly spear
on their nose,
they, too, are hunting.
Watched by the sea lions
..the marlin go to work.
They herd the sardines
into a ball
..and then drive them
up towards the surface.
This is what the sea lions
have been waiting for.
Fast and flexible,
the sea lions take advantage
of the marlin's efforts
..and collect an easy meal.
These canny sea lions
have learnt how to let marlin
do the hard work.
But sea lions don't stay
permanently in water.
The Galapagos Islands.
Specks of land in the vast emptiness
of the Pacific Ocean.
Here, pregnant Galapagos sea lions
haul out on a beach to give birth.
Unable to swim
when it's newly born,
a pup relies completely
on its mother
for her care and her milk.
Within two weeks, thanks to the
richness of this milk,
it will be strong enough
to venture into the water.
But a newborn pup
is something of a shock
to its older brother.
For the last two years,
he's had his mother all to himself.
The new pup is a sure sign
that he must now find his own feet.
A sheltered inlet is a safe place
for pups and other juveniles
to build up their confidence.
Now, under the watchful eye
of a dominant bull
..the young sea lions acquire
the skills they'll need
for a life at sea.
But this is the time of year
when sea lions also mate.
While the bull's attention
is elsewhere
..the pup ventures beyond
the safety of the rock pool.
It's a mistake.
The waters surrounding the Galapagos
are patrolled by sharks.
The pup strays further
from the pool
..while the bull is preoccupied.
The pup can outmanoeuvre
the shark
..but not for long.
Alerted by the commotion
..the bull takes action.
Weighing a quarter of a tonne,
the bull is more than a match
for the shark.
Biting at its tail,
he chases it away.
For the pup, it's an important
lesson learned.
Many others
..are less fortunate.
Nearly half of these young sea lions
will not survive beyond
their second birthday.
This pup is safely back on land,
and not too old
for a reassuring cuddle.
One small group of mammals, however,
have completely cut their ties
with the land.
Humpback whale calves can swim
from the moment they're born.
The warm coastal shallows
off Western Australia
provide excellent nurseries.
In their first few days,
mothers and babies
form a strong bond.
Tucked gently under her fin,
this mother gives her daughter
an early lesson
in holding its breath.
But they won't stay here for long.
The reef may be an excellent
place to give birth
..but there's almost
nothing to eat here
..so mothers and young
must now make the long journey
to richer waters around Antarctica.
But once they've left the safety
of the shallow reef
they are vulnerable.
A pod of orca
..six strong,
patrols the migration route.
They are a formidable force.
But the humpback mother
puts her baby high on her back
to protect it
..and then goes on
the attack herself.
Slashing her powerful tail
and long five-metre fins,
she could easily kill an orca.
But the orca have a plan.
Some of the pod distract
the mother
..while others ram the calf.
Once it's separated
..they drown it.
Since 1986,
when commercial whaling
was largely banned,
humpback numbers have risen here
from a few hundred
to more than 35,000.
With so many calves on the move,
some orca have specialised
in hunting them.
A small pod - just three.
The humpback calf they're pursuing
has more than just its mother
at its side.
It also has
..a 40-tonne male.
This is a much bigger challenge.
But rather than give up
..the orca bide their time.
The male humpback,
believing, perhaps,
that the orca have gone
..now dives.
The killers seize their opportunity.
They kidnap the calf.
They appear to mimic
the mother's behaviour,
putting the young calf
on their backs
and carrying him along
in the slipstream.
Young and naive,
the calf goes willingly with them.
Now, far from his mother
..the orca attack him.
During the months of migration,
the pod may kill as many
as five calves a day.
They catch so many
that sometimes they eat
no more than the tongue
..and leave the rest
for the sharks.
This is what can happen
when prey is so abundant
and hunters have such skill.
False killer whales are less
than half the size of orcas
..but they are equally clever.
They roam the ocean in groups
up to 50 strong.
Right now, they're on the hunt
for other mammals.
Ocean-going bottlenose dolphins.
But the false killers
aren't looking for prey.
These two groups
are old acquaintances.
In the waters around New Zealand,
they are almost always found
together.
Lifelong bonds within species
are common
..but they are rarely seen
between different species.
Such friendships
between bottlenose dolphins
and false killers
..have been documented
going back 20 years
..so it's entirely possible
that individuals of both species
recognise each other.
They team up not only to play
..but in order to hunt.
So, when one goes
..they all go.
A huge school of kahawai fish.
The false killers
swim under the shoal
..and drive it to the surface.
Here, the dolphins attack.
But despite helping,
the whales don't appear to feed.
For them,
the kahawai are just the bait.
The false killers know the commotion
will attract bigger fish.
Kingfish arrive.
They're up to ten times heavier
than the kahawai,
and one metre long.
Too big for the dolphins.
So, now it's the turn of the false
killer whales to feed.
They form small groups
and break up the school
..and then go after the fish
that get separated.
Not all the whales make a catch.
But they won't go hungry.
Extraordinarily, the successful
hunters share their food.
By helping one another
..they ensure that no-one
goes without.
Teamwork, intelligence
and cooperation
has enabled marine mammals
to flourish in the high seas.
But one part of the ocean is still
beyond the reach of most.
The deep.
Only a very few are capable
of venturing here.
A pod of sperm whales resting
near the surface.
They spend just 7%
of their lives asleep,
less than almost any other mammal.
But they're also waiting here
for another very special reason.
The birth of a baby.
Helped into the world
by supportive relatives,
the newborn is already
more than three metres long.
It will grow up surrounded
and protected by close family.
It thirsts for its mother's milk,
but the food the mother needs
in order to produce it
is 1,000 metres below,
far beyond the reach
of a young calf.
So, whilst the family
looks after the newborn
..the mother sets off
in search of a meal.
Adult sperm whales may remain below,
holding their breath, for an hour.
As they descend, their bodies
change in an astonishing way.
The increasing pressure
squeezes their lungs
until they collapse completely.
To save oxygen,
their digestion,
kidney and liver shut down.
A special camera records
a rare and privileged view
of a hunting sperm whale,
sending out a stream of clicks
to detect prey
in the pitch blackness.
At this depth, they start
to hunt for giant squid.
As the whale closes in,
their clicks speed up.
A puff of ink is released
by the fleeing squid,
but the sperm whale isn't fooled
..and the squid is eaten
in a last cloud of ink.
As this mother returns,
her calf, like all mammal babies,
has only one thing on its mind.
Milk.
It's growing faster now
than during its 16 months
in the womb.
And it will consume
up to 100 litres,
300,000 calories,
every day for the next two years.
To meet this demand,
its mother will have to dive
up to 15 times every day.
It is her ability to reach
such extreme depths
and turn what she eats
into rich milk
that will be the key
to her baby's success.
Today,
protected almost worldwide,
the outlook for this mother
and baby,
and all sperm whales,
is bright.
Even so, sperm whales
still face many threats.
Every year, enough fishing line
is lost in our oceans
to stretch to the moon and back
..together with 20 million traps,
and carrying 14 billion hooks.
The whales become entangled
in these so-called "ghost nets".
The lines cut into their bodies
..and the floats can prevent them
from diving.
Theirs is a slow
and agonising death.
We are now aware
of the threats we create.
Surely, we should now do everything
we can to prevent them.
The greatest challenge
for the Mammals team
was not only filming false
killer whales in New Zealand,
but trying for the first time
to place a data-recording
camera onto one.
With only 150 individuals somewhere
within 4,500 square miles,
just finding them
will be hard enough.
Luckily, they have the help
of Jochen Zaeschmar,
who has been studying
this group of whales
for the last 20 years.
He has a directional hydrophone,
with which he can hear the false
killer whales' whistles
but only from less
than ten miles away.
Nothing.
I was kind of hoping
kind of hoping to hear something.
Cameraman Andre Rerekura
scans the horizon,
but picking out a fin in the open
ocean is no small feat.
The scale of the task ahead
is dawning on assistant producer
Kyle Swann.
Searching.
Searching, searching.
That's kind of the strategy,
but so far, no luck.
With only a brief few weeks
during which it's possible
to film them,
it's a disappointing start.
There's absolutely nothing.
Over the coming days,
the team search without pause.
Nothing.
Absolutely nothing.
Nothing again.
Still, keep trying.
They have spent 20 days
with no whales
..but Andre spots something
promising in the distance.
There's a few birds,
but nothing crazy.
Yeah, well, that's where I heard
some faint whistles there.
Worth a look while we're here.
Ah, I've got something!
Whoa! We have a haul.
Oh, my God, yeah.
It's promising.
It looks
I've seen a stumpy nose!
I think we've got falsies!
Whoa!
Falsies!
No way! Woohoo!
We have 'em!
But with the sun setting
and the whales capable
of covering 100 miles a day,
the team hop on their liveaboard
to follow the whales overnight.
The crew takes turns on watch,
using their eyes and ears.
Yeah, we've pretty much
done circles all night.
We're in the same spot we found
them yesterday afternoon,
so they don't go far.
Like Jochen says, they just sleep.
So they've probably had
more sleep than us!
Falsies off the bow!
Big old falsies off the bow.
Woohoo-hoo!
There's one just here.
Oh, my God,
this is just amazing.
They're in a good mood.
A new dawn presents a new challenge.
Back on the filming boat,
the team follow the false killers
as they hunt.
No-one has ever recorded them
creating a bait ball before.
But the whales can swim at 20mph,
so Andre has brought
a little extra propulsion.
The scooter's a game-changer.
You can free-dive down with,
you know, a full lung of air,
all your energy,
and hold your breath for a minute
and a half to two minutes with ease.
The scooter lets him
keep up with false killers
and helps propel him swiftly
into the heart of the action.
Once the feeding frenzy is over,
the whales turn their attention
to Andre.
This incredible interaction.
It justjust made me
realise how amazing
and intelligent these animals are.
It was really unique
and really special.
That was Woo!
I can't even explain that!
Having captured
this extraordinary behaviour,
the team switch to the most
difficult goal of the trip
..to place a suction tag on a whale.
For 20 years,
Jochen has studied this group
of false killer whales,
but this would be a first.
The tag contains a camera
and a data collector.
Combined, they will give Jochen
new insights
into how these animals
spend their time underwater.
Getting close enough to attach a tag
will take every ounce of Jochen's
expertise and understanding.
Here they are.
While they're just chilled,
I'll just go in there real slow.
Hope to Hope to get lucky.
OK, OK, OK, OK.
Beautiful, beautiful,
beautiful, beautiful.
OK.
No, no, no.
No. No, no, on the next one,
on the next one.
They're going down a bit.
We'll get them, we'll get them.
Trying to find
that perfect moment!
Heart's going through the roof!
This is a bunch of different males.
Let's see, though,
see how they like us.
They're all coming together now.
There's just so, so many factors.
The way the angle of the camera is,
where it comes up next to you.
I'm hopeful. It's hard work.
They're not making it easy.
As the wind drops,
the team have a brief
but perfect opportunity.
So I'm just going to
..ease my way over towards them.
Wait.
OK, this is it.
Yeah!
We did it! We did it!
We did it!
Well done!
Woooo!
We did it. We did it!
I'm so happy!
It's not just the achievement
of getting the tag on,
it's the promise
of what it will reveal.
And that turns out
to be astounding.
Intimate food sharing
and new hunting strategies
have been recorded
for the very first time,
giving us a new perspective
on mammals' lives underwater.
Next time -
we venture into the cold.
A vast and unforgiving world
..where mammals,
through sheer tenacity
and adapation
..have found a way to make it home.