Our Big Blue Backyard (2014–…): Season 3, Episode 1 - The Snares Islands - full transcript
Deep in the Southern Ocean, the Snares Islands is one of the most pristine island wildernesses on the planet and a sanctuary for penguins and millions of other breeding seabirds.
(SEAGULLS CRY)
In the Southern Ocean,
a granite fortress
intersects the vast expanse
of sea and sky.
Caves deep beneath
tell of an ancient origin...
..which goes
all the way back to Gondwana.
This is one of the most
untouched places on our planet...
..where it's possible
to imagine a world
long before humans arrived.
But isolated
does not equal lifeless...
..in Tini Heke,
the Snares Islands.
(HIGH-PITCHED WHALE SONG)
(DEEPER WHALE SONG)
It's late spring...
..and the Southern Ocean's mood
is a little feisty.
Big swells
sweep up from Antarctica.
Northeast at 280 hectares is
the alpha of the seven-island group.
It's coated in a dense
primaeval forest of tree daisies.
Broughton is just 48 hectares...
..and the Western Chain is made up
of five small rocky outcrops.
On the cusp of a season change...
..the islands appear deserted.
(BIRD TWITTERS)
Almost!
(TWITTERS)
The summer residents arrive.
These penguins have been swimming
continuously for six months,
over 15,000 kilometres...
..chasing squid and krill
on one of the longest foraging trips
made by any animal on the planet.
(PENGUINS SQUAWK)
They are Snares crested penguins...
..a species found only here.
And every year
they return for the summer.
(PENGUINS SQUAWK)
There's no time to waste.
(PENGUINS CHATTER)
The hard graft of the summer's
breeding cycle must commence.
But the Snares
is not just an island of penguins.
A New Zealand sea lion arrives...
..one of the biggest carnivores
in the Southern Ocean.
(SEA LION SNORTS)
But the threat these marine mammals
pose to penguins
is usually in the water.
On land, there's a sort of
uneasy truce between both species.
(SEA LION SNORTS)
He is a youngish male,
probably around eight years old.
300 kilometres south
is a sea-lion breeding colony,
where beach master males
twice his size
fight to the death for
the right to mate with the females.
(SOFT VIBRATING GROWL)
He will have been turfed out
by these dominant males.
So he and his fellow bachelors
show up here at the Snares Islands
to make their own fun
for the summer.
(GROWLS SOFTLY)
(SNORTS)
The penguins begin the first
of many brazen treks they'll make
through the bachelor chill zone.
The standard drill
is to keep a respectful distance...
..but also push the boundaries.
All around Northeast Island,
thousands of penguins now begin
a gruelling climb up steep
- sometimes near-vertical -
cliffs...
..to their breeding colonies.
These stumpy little legs are driven
by a parental imperative...
..safety for
this year's offspring at all cost.
The well-worn pathway
into the forest
is more manageable.
Webbed feet march right over
the giant endemic earthworms...
..which can grow
up to 30 centimetres long
in the peat soil...
..provided
they stay out of the traffic!
It's estimated that there are
up to 50,000 Snares crested penguins
on Northeast Island.
Muddy Pool is
one of the major breeding colonies,
named so for an obvious reason.
Thousands of couples
will eventually squeeze in here,
making this one of the most
densely populated penguin nurseries
on the planet.
(PENGUINS CHATTER)
The party is just beginning.
Successful parents mate for life.
So many couples pick up just where
they left off last season.
Others are first-timers.
Choosing a mate
is a serious commitment
as this relationship
could last up to 15 years.
Make the wrong choice,
and there could be a divorce!
(PENGUINS CHATTER)
The bond is sealed with
what's called an ecstatic display.
(PENGUIN PAIR SQUEAK AND CHATTER)
(CALLS ACCELERATE)
(CALLS INTENSIFY)
(CALLS SUBSIDE)
Once that's done,
the couple build their nest.
When they're in sync,
a penguin bond is unbreakable.
(PENGUIN COLONY CHATTERING)
The penguins settle in for the first
night in their summer retreat...
..and all is calm.
But Tini Heke has another spectacle
waiting in the wings.
(SEABIRDS CRYING)
Five million more seabirds
arrive for the summer.
They are sooty shearwaters
- or titi - as named by
indigenous New Zealand Maori.
Every year, these avian athletes
spend six months foraging off Japan
or far-east Russia.
When it's time for them
to raise their own chicks,
they always return
to where they were born.
They too nest in the daisy forest
on Northeast Island,
where the dense canopy
presents a challenge.
Five million birds
must all somehow descend
with no landing strip.
(THUD)
(THUD)
Each bird now locates
its specific burrow
from last year...
..and its mate.
(COOING)
There's a lot to catch up on
before they begin their task
of producing a new generation.
At dawn,
those penguins who need to forage
make their way down the slope.
Eggs will be
in the nests any day now,
requiring weeks of incubation.
So it's best
to pack on body weight now.
When there's a roadblock
on the commute...
..some cheeky penguins
don't hesitate to run the gauntlet.
(WAVES CRASHING)
This is one of
the penguins' preferred launch pads
into the ocean.
The tide is quite low this morning.
So they had to time it just right.
Daredevil stunts are standard
for tough crested penguins...
..although
these two lose their nerve...
..at the sight
of a sea lion patrolling.
It's in the water that penguins
become prey for these predators.
But penguins can release
a turbo boost of bubbles
from their dense feathers
to increase speed
if they are attacked.
It's like a layer of lubrication,
which reduces drag as they fly.
For now,
the sea lions are in cruise mode.
But onshore
already
there are hints of the casualties
this season will bring.
It's early summer now,
and Tini Heke is silent...
..before the forest awakes,
as it does every morning.
The first of the sooty shearwaters
- or titi -
emerge from their burrows.
Some parents
stay behind to incubate eggs...
..while others stretch out
the night cramps from the wings.
These expert flyers
scurry around on the forest floor...
..because the dense canopy
on Northeast Island
also prevents the birds
from taking off.
Thousands flood towards launch pads
on the top of the steep cliffs.
(TITI SQUAWKS)
Early-rising sea lions
participate...
..as the heavy titi skim the surface
on their flight path.
(PENGUINS SQUAWK AND CHATTER)
In the penguin breeding colony...
..each nest is now a haven
for the Snares crested
parenting strategy.
Crested penguins
always lay two eggs.
The first egg
arrives just days after
the female returns for the summer.
She lays a second egg
around five days later.
It's always quite a lot bigger.
This second egg
always hatches first...
(CHIRPING)
..and the chick that emerges
is big and strong.
(CHICK CHIRPS TENACIOUSLY)
When the early egg hatches...
..the chick is much smaller
than its sibling.
(CHICK CHIRPS)
But this story has a further twist.
Crested penguins
usually only raise one chick.
When the small chick
joins its sibling,
both compete for food.
But the parents
only feed the larger one.
(ADULT PENGUINS CHATTER)
(CHICK CHIRPS)
In this family, the favoured chick
is starting to resemble
a beach ball...
(CHIRPS)
..while its sibling
is beginning to starve.
(CHIRPING)
In the natural world,
weaker chicks often die.
But there can be
an exception to the rule.
(SQUAWKING)
(CHIRPING)
Next door,
two eggs are hatching together.
One is a little ahead.
But it's possible these parents
can provide enough food for both...
..and successfully raise twins.
All around Tini Heke's coastline...
..the often tempestuous
Southern Ocean
eats into the granite foundation...
..creating coves and caves.
These islands
sit on the Campbell Plateau -
a great underwater shelf
that extends
from southern New Zealand
down into the sub-Antarctic.
This shelf is part of the recently
discovered eighth continent,
Zealandia,
which became submerged
around 25 million years ago.
Penguin Cove has also been
etched out of the rock...
..until it's become like
a natural amphitheatre...
..where the summer residents
can socialise.
It even has a spa pool,
constantly flushed
by the tides and swell.
This is a place
for rest and relaxation...
..away from the stress of parenting.
(AGGRESSIVE SQUAWKS)
There's always one who tries
to ruin it for everyone else.
(SQUAWKS)
(SQUAWKS)
He's an adolescent.
Males who haven't found a mate yet
often get pumped up on testosterone.
(SQUAWKS)
However, this spa
isn't designated penguins only.
Tini Heke is a magnet
for sub-Antarctic visitors.
It's a leopard seal...
..a youngish female,
but she still weighs
around 350 kilograms...
..and she is
nearly three metres long.
Her face smiles...
..but it's an illusion.
Her mouth is shaped this way.
And she's not named leopard
just for her spots.
She is a fierce predator...
..and penguins
are a staple of her diet.
(SEAL GRUNTS)
At the northern edge of the cove,
a large fur seal also hauls out...
(GRUNTS)
..followed by
one of the male sea lions.
Three predators
taking over the spa...
..is just not acceptable.
It's the nimble fur seal
who makes a half-hearted charge.
(PENGUINS CHATTERING)
One rebel takes a stand...
..and others join.
What the predators
really seem to want
is a nap.
The one-legged penguin
has reason to be cautious.
It's possible it was
a leopard seal who took his foot.
His staunch attitude depicts just
how fearless these penguins are.
So far,
this summer on bachelor island
has been fairly relaxing
for the sea lions.
(SEA LION BARKS)
Barking at penguins
keeps them entertained...
..but there's also plenty of time
for long naps in the forest.
(SNORES)
The blow flies are pesky.
(FLIES BUZZING)
But this 400-kilogram
sack of blubber
has an unlikely friend
to take care of him.
(BIRD PEEPS)
The Snares Island fernbird
is found only here.
Because this place
is so isolated and untouched,
these tiny birds
have no fear of large mammals.
A mutually beneficial relationship
has evolved.
An all-you-can-eat buffet...
(FLIES BUZZING)
..with central heating
on a cold day...
..in exchange
for pest extermination.
(BIRD TWEETS)
An endemic Snares tomtit
is also
in the pest-removal business.
There's plenty of real estate
to share...
..and client satisfaction
is guaranteed.
(SNORES)
(CHICK CHIRPS)
Up in Muddy Pool,
the growing chicks
demand food around the clock.
Most of the nests
now just have one mouth to feed.
The beach ball's frail sibling
is nowhere to be seen.
This nest is the exception.
For now,
the twin chicks are both being fed.
If their parents can keep this up,
they may both
have a chance to survive.
It's the height of summer now...
..and the bachelor sea lions
make the most
of the sub-Antarctic resort.
It's usually only marine mammals
who get to explore
the underwater wonderland
beneath Tini Heke.
Lush kelp forests...
with their robust holdfasts
endure everything
the Southern Ocean throws at them.
Mosaics
of the more fragile bryozoans...
..and jewelled anemones
cling to steep walls...
..and inhabit caves to shelter
from the constant surge...
..while zoanthids or soft corals
thrive in vast underwater gardens.
The water column is festooned
with plankton feeders...
..a clear sign
the currents which circulate here...
..are so nutrient rich.
(SNORTING)
When their daily circuit
of the islands is complete...
..the bachelors
entertain themselves.
(GROWLS)
Play fights
double as domination practice
for the day
they can challenge bigger males
for a harem of their own.
A stranger enters the game.
Her light colouring
identifies her as a female...
..probably another absconder from
the breeding colony further south.
The males don't mob her.
She's playful...
..and they just take turns
swimming with her.
(PENGUINS CHATTER)
It's around eight weeks
since the new generation
of Snares crested penguins
hatched...
..and they're now enduring
a major milestone...
..the moult.
All that fluffy down
that kept them warm has to go...
..as their adult plumage grows in.
At this stage, chicks
often hang out together in a creche.
Older chicks
babysit the younger ones.
Adults also moult
their swim feathers once a year.
It's a miserable time as they can't
go to sea to hunt for three weeks.
So they itch...
on top of an empty stomach.
The swell is up today...
..and it coincides
with a batch of fledglings
heading to sea for the first time.
Despite the odds,
the twin chicks who hatched together
have both been successfully
raised by their parents.
They're agile in their eagerness
to meet the ocean.
(BARKS)
The well-fed beach-ball-sized chick
has finished her moult,
and attempts her first descent.
(SQUAWKS)
(SQUAWKS)
(CHITTERS)
Down in the cove, the relaxing spa
has transformed into a surge pool.
The giant swell
is creating conditions
not ideal for first-timers.
(CHICK CHIRPS)
The adults' response
is quite unexpected.
They plunge headlong
into the surf...
..take a ride...
..and do it again.
No-one is in a hurry to hunt...
..not when the surf is this good.
Adult moulters is must stay dry...
so they stoically observe
the fun from above.
(SQUAWKING)
(CHITTERING)
It's too rough
for a 200-kilogram sea lion.
But it takes more than just
a tempestuous Southern Ocean swell
to intimidate
Snares crested penguins.
The biggest threat to
this year's new generation of chicks
has not yet arrived at Tini Heke.
The next morning,
it's a fur seal
who disrupts the commute.
Unlike the big, heavy sea lions,
fur seals are agile climbers,
which makes them more of a threat.
But one of
this year's fully moulted chicks
has never seen a fur seal,
and she bravely stands her ground.
(SEAL SNORTS)
(PENGUIN CHITTERS)
On the waterfront,
another batch of chicks
is ready to try the ocean today.
The twins from the special two-chick
family appear ready to go...
..especially this one.
These flippers
are primed to perfection.
(CHICK CHIRPS)
(SEAGULLS CRY)
The sea is still a little rough
after yesterday's big surge party...
..and there's something out there.
A gang of monstrous birds...
..with bills shaped like gut hooks.
(PENGUINS SQUAWK)
The adults have seen this before.
They are giant petrels.
(PENGUINS SQUAWKING)
(CHITTERING)
Panic spreads.
The penguins stream ashore together.
Safety in numbers
is a defence tactic.
(AGGRESSIVE SCREECHING)
Giant petrels are
ferociously aggressive predators,
who spend the summer
island-hopping in the sub-Antarctic,
hunting penguins.
Chicks and juveniles
are the easy targets.
The parents wisely escort
their twin chicks back to safety.
These assassins have a hierarchy
when in attack mode.
The biggest adult male
approaches first.
Giant petrels
are smart and ruthless.
They have even been known
to kill huge adult albatross.
(PENGUINS CHITTERING)
True to form, there's always one
with a stroppy attitude...
..even when in danger.
The assassin, however, is patient.
His strategy is well-rehearsed.
(PETREL SCREECHES)
It's the chick
who stood up to the fur seal.
(SCREECHES)
The giant petrel
will hold her underwater
until she drowns.
But conflict in the ranks
creates a lucky break.
The penguin is gravely injured...
..but these staunch birds
are the ultimate survivors.
(SCREECHES)
The petrel immediately
snatches a new target.
Another courageous chick survives.
(SEAGULLS CRY)
The attackers regroup.
(PENGUINS CHITTERING)
The assassins claim a victim.
(PETREL SCREECHES)
Nothing goes to waste.
In the aftermath of the massacre...
..everyone takes stock.
Penguins seek out their mates.
(PENGUINS CHATTER)
This bond is unbreakable.
(SEABIRDS CRY)
Offshore,
thousands of Cape petrels,
Buller's albatross...
..and titi are gathering.
(SEABIRDS CRYING)
This can only mean one thing.
Opportunistic fledglings
take the plunge.
But flying underwater
for the first time...
does require some skills.
Even the experts
have their moments.
It's this phenomenon that has
summoned all the oceanic hunters.
A giant krill swarm.
It's a super-organism
made up
of trillions of tiny crustaceans.
The keystone food species
for all the residents
of the Southern Ocean.
The hunters
have specialised strategies.
If all the seabirds dived at once,
the krill swarm might disperse.
Instead, groups of birds dive...
..eat their fill...
..and then fly
to the back of the queue
to wait their turn again.
When the penguins arrive,
they hunt beneath the swarm.
This drives the krill
closer to the surface...
..which benefits the seabirds.
Inside the swarm,
the krill respond to the threat.
They pulse light from bioluminescent
cells on their bellies
to distract...
..and as one...
..switch direction.
To defend itself,
this intelligent organism
becomes the ultimate shapeshifter.
The sub-Antarctic summer
draws to a close...
..and the seasonal visitors
will soon depart.
Up in Muddy Pool,
a remarkable ritual is underway.
The breeding season is over...
..but this male is deliberately
building another nest.
(PENGUINS CHATTER)
It's a symbol
of commitment to his mate.
The taller the nest,
the greater his intention...
..to meet her next spring
to do it all over again.
In the Southern Ocean,
a granite fortress
intersects the vast expanse
of sea and sky.
Caves deep beneath
tell of an ancient origin...
..which goes
all the way back to Gondwana.
This is one of the most
untouched places on our planet...
..where it's possible
to imagine a world
long before humans arrived.
But isolated
does not equal lifeless...
..in Tini Heke,
the Snares Islands.
(HIGH-PITCHED WHALE SONG)
(DEEPER WHALE SONG)
It's late spring...
..and the Southern Ocean's mood
is a little feisty.
Big swells
sweep up from Antarctica.
Northeast at 280 hectares is
the alpha of the seven-island group.
It's coated in a dense
primaeval forest of tree daisies.
Broughton is just 48 hectares...
..and the Western Chain is made up
of five small rocky outcrops.
On the cusp of a season change...
..the islands appear deserted.
(BIRD TWITTERS)
Almost!
(TWITTERS)
The summer residents arrive.
These penguins have been swimming
continuously for six months,
over 15,000 kilometres...
..chasing squid and krill
on one of the longest foraging trips
made by any animal on the planet.
(PENGUINS SQUAWK)
They are Snares crested penguins...
..a species found only here.
And every year
they return for the summer.
(PENGUINS SQUAWK)
There's no time to waste.
(PENGUINS CHATTER)
The hard graft of the summer's
breeding cycle must commence.
But the Snares
is not just an island of penguins.
A New Zealand sea lion arrives...
..one of the biggest carnivores
in the Southern Ocean.
(SEA LION SNORTS)
But the threat these marine mammals
pose to penguins
is usually in the water.
On land, there's a sort of
uneasy truce between both species.
(SEA LION SNORTS)
He is a youngish male,
probably around eight years old.
300 kilometres south
is a sea-lion breeding colony,
where beach master males
twice his size
fight to the death for
the right to mate with the females.
(SOFT VIBRATING GROWL)
He will have been turfed out
by these dominant males.
So he and his fellow bachelors
show up here at the Snares Islands
to make their own fun
for the summer.
(GROWLS SOFTLY)
(SNORTS)
The penguins begin the first
of many brazen treks they'll make
through the bachelor chill zone.
The standard drill
is to keep a respectful distance...
..but also push the boundaries.
All around Northeast Island,
thousands of penguins now begin
a gruelling climb up steep
- sometimes near-vertical -
cliffs...
..to their breeding colonies.
These stumpy little legs are driven
by a parental imperative...
..safety for
this year's offspring at all cost.
The well-worn pathway
into the forest
is more manageable.
Webbed feet march right over
the giant endemic earthworms...
..which can grow
up to 30 centimetres long
in the peat soil...
..provided
they stay out of the traffic!
It's estimated that there are
up to 50,000 Snares crested penguins
on Northeast Island.
Muddy Pool is
one of the major breeding colonies,
named so for an obvious reason.
Thousands of couples
will eventually squeeze in here,
making this one of the most
densely populated penguin nurseries
on the planet.
(PENGUINS CHATTER)
The party is just beginning.
Successful parents mate for life.
So many couples pick up just where
they left off last season.
Others are first-timers.
Choosing a mate
is a serious commitment
as this relationship
could last up to 15 years.
Make the wrong choice,
and there could be a divorce!
(PENGUINS CHATTER)
The bond is sealed with
what's called an ecstatic display.
(PENGUIN PAIR SQUEAK AND CHATTER)
(CALLS ACCELERATE)
(CALLS INTENSIFY)
(CALLS SUBSIDE)
Once that's done,
the couple build their nest.
When they're in sync,
a penguin bond is unbreakable.
(PENGUIN COLONY CHATTERING)
The penguins settle in for the first
night in their summer retreat...
..and all is calm.
But Tini Heke has another spectacle
waiting in the wings.
(SEABIRDS CRYING)
Five million more seabirds
arrive for the summer.
They are sooty shearwaters
- or titi - as named by
indigenous New Zealand Maori.
Every year, these avian athletes
spend six months foraging off Japan
or far-east Russia.
When it's time for them
to raise their own chicks,
they always return
to where they were born.
They too nest in the daisy forest
on Northeast Island,
where the dense canopy
presents a challenge.
Five million birds
must all somehow descend
with no landing strip.
(THUD)
(THUD)
Each bird now locates
its specific burrow
from last year...
..and its mate.
(COOING)
There's a lot to catch up on
before they begin their task
of producing a new generation.
At dawn,
those penguins who need to forage
make their way down the slope.
Eggs will be
in the nests any day now,
requiring weeks of incubation.
So it's best
to pack on body weight now.
When there's a roadblock
on the commute...
..some cheeky penguins
don't hesitate to run the gauntlet.
(WAVES CRASHING)
This is one of
the penguins' preferred launch pads
into the ocean.
The tide is quite low this morning.
So they had to time it just right.
Daredevil stunts are standard
for tough crested penguins...
..although
these two lose their nerve...
..at the sight
of a sea lion patrolling.
It's in the water that penguins
become prey for these predators.
But penguins can release
a turbo boost of bubbles
from their dense feathers
to increase speed
if they are attacked.
It's like a layer of lubrication,
which reduces drag as they fly.
For now,
the sea lions are in cruise mode.
But onshore
already
there are hints of the casualties
this season will bring.
It's early summer now,
and Tini Heke is silent...
..before the forest awakes,
as it does every morning.
The first of the sooty shearwaters
- or titi -
emerge from their burrows.
Some parents
stay behind to incubate eggs...
..while others stretch out
the night cramps from the wings.
These expert flyers
scurry around on the forest floor...
..because the dense canopy
on Northeast Island
also prevents the birds
from taking off.
Thousands flood towards launch pads
on the top of the steep cliffs.
(TITI SQUAWKS)
Early-rising sea lions
participate...
..as the heavy titi skim the surface
on their flight path.
(PENGUINS SQUAWK AND CHATTER)
In the penguin breeding colony...
..each nest is now a haven
for the Snares crested
parenting strategy.
Crested penguins
always lay two eggs.
The first egg
arrives just days after
the female returns for the summer.
She lays a second egg
around five days later.
It's always quite a lot bigger.
This second egg
always hatches first...
(CHIRPING)
..and the chick that emerges
is big and strong.
(CHICK CHIRPS TENACIOUSLY)
When the early egg hatches...
..the chick is much smaller
than its sibling.
(CHICK CHIRPS)
But this story has a further twist.
Crested penguins
usually only raise one chick.
When the small chick
joins its sibling,
both compete for food.
But the parents
only feed the larger one.
(ADULT PENGUINS CHATTER)
(CHICK CHIRPS)
In this family, the favoured chick
is starting to resemble
a beach ball...
(CHIRPS)
..while its sibling
is beginning to starve.
(CHIRPING)
In the natural world,
weaker chicks often die.
But there can be
an exception to the rule.
(SQUAWKING)
(CHIRPING)
Next door,
two eggs are hatching together.
One is a little ahead.
But it's possible these parents
can provide enough food for both...
..and successfully raise twins.
All around Tini Heke's coastline...
..the often tempestuous
Southern Ocean
eats into the granite foundation...
..creating coves and caves.
These islands
sit on the Campbell Plateau -
a great underwater shelf
that extends
from southern New Zealand
down into the sub-Antarctic.
This shelf is part of the recently
discovered eighth continent,
Zealandia,
which became submerged
around 25 million years ago.
Penguin Cove has also been
etched out of the rock...
..until it's become like
a natural amphitheatre...
..where the summer residents
can socialise.
It even has a spa pool,
constantly flushed
by the tides and swell.
This is a place
for rest and relaxation...
..away from the stress of parenting.
(AGGRESSIVE SQUAWKS)
There's always one who tries
to ruin it for everyone else.
(SQUAWKS)
(SQUAWKS)
He's an adolescent.
Males who haven't found a mate yet
often get pumped up on testosterone.
(SQUAWKS)
However, this spa
isn't designated penguins only.
Tini Heke is a magnet
for sub-Antarctic visitors.
It's a leopard seal...
..a youngish female,
but she still weighs
around 350 kilograms...
..and she is
nearly three metres long.
Her face smiles...
..but it's an illusion.
Her mouth is shaped this way.
And she's not named leopard
just for her spots.
She is a fierce predator...
..and penguins
are a staple of her diet.
(SEAL GRUNTS)
At the northern edge of the cove,
a large fur seal also hauls out...
(GRUNTS)
..followed by
one of the male sea lions.
Three predators
taking over the spa...
..is just not acceptable.
It's the nimble fur seal
who makes a half-hearted charge.
(PENGUINS CHATTERING)
One rebel takes a stand...
..and others join.
What the predators
really seem to want
is a nap.
The one-legged penguin
has reason to be cautious.
It's possible it was
a leopard seal who took his foot.
His staunch attitude depicts just
how fearless these penguins are.
So far,
this summer on bachelor island
has been fairly relaxing
for the sea lions.
(SEA LION BARKS)
Barking at penguins
keeps them entertained...
..but there's also plenty of time
for long naps in the forest.
(SNORES)
The blow flies are pesky.
(FLIES BUZZING)
But this 400-kilogram
sack of blubber
has an unlikely friend
to take care of him.
(BIRD PEEPS)
The Snares Island fernbird
is found only here.
Because this place
is so isolated and untouched,
these tiny birds
have no fear of large mammals.
A mutually beneficial relationship
has evolved.
An all-you-can-eat buffet...
(FLIES BUZZING)
..with central heating
on a cold day...
..in exchange
for pest extermination.
(BIRD TWEETS)
An endemic Snares tomtit
is also
in the pest-removal business.
There's plenty of real estate
to share...
..and client satisfaction
is guaranteed.
(SNORES)
(CHICK CHIRPS)
Up in Muddy Pool,
the growing chicks
demand food around the clock.
Most of the nests
now just have one mouth to feed.
The beach ball's frail sibling
is nowhere to be seen.
This nest is the exception.
For now,
the twin chicks are both being fed.
If their parents can keep this up,
they may both
have a chance to survive.
It's the height of summer now...
..and the bachelor sea lions
make the most
of the sub-Antarctic resort.
It's usually only marine mammals
who get to explore
the underwater wonderland
beneath Tini Heke.
Lush kelp forests...
with their robust holdfasts
endure everything
the Southern Ocean throws at them.
Mosaics
of the more fragile bryozoans...
..and jewelled anemones
cling to steep walls...
..and inhabit caves to shelter
from the constant surge...
..while zoanthids or soft corals
thrive in vast underwater gardens.
The water column is festooned
with plankton feeders...
..a clear sign
the currents which circulate here...
..are so nutrient rich.
(SNORTING)
When their daily circuit
of the islands is complete...
..the bachelors
entertain themselves.
(GROWLS)
Play fights
double as domination practice
for the day
they can challenge bigger males
for a harem of their own.
A stranger enters the game.
Her light colouring
identifies her as a female...
..probably another absconder from
the breeding colony further south.
The males don't mob her.
She's playful...
..and they just take turns
swimming with her.
(PENGUINS CHATTER)
It's around eight weeks
since the new generation
of Snares crested penguins
hatched...
..and they're now enduring
a major milestone...
..the moult.
All that fluffy down
that kept them warm has to go...
..as their adult plumage grows in.
At this stage, chicks
often hang out together in a creche.
Older chicks
babysit the younger ones.
Adults also moult
their swim feathers once a year.
It's a miserable time as they can't
go to sea to hunt for three weeks.
So they itch...
on top of an empty stomach.
The swell is up today...
..and it coincides
with a batch of fledglings
heading to sea for the first time.
Despite the odds,
the twin chicks who hatched together
have both been successfully
raised by their parents.
They're agile in their eagerness
to meet the ocean.
(BARKS)
The well-fed beach-ball-sized chick
has finished her moult,
and attempts her first descent.
(SQUAWKS)
(SQUAWKS)
(CHITTERS)
Down in the cove, the relaxing spa
has transformed into a surge pool.
The giant swell
is creating conditions
not ideal for first-timers.
(CHICK CHIRPS)
The adults' response
is quite unexpected.
They plunge headlong
into the surf...
..take a ride...
..and do it again.
No-one is in a hurry to hunt...
..not when the surf is this good.
Adult moulters is must stay dry...
so they stoically observe
the fun from above.
(SQUAWKING)
(CHITTERING)
It's too rough
for a 200-kilogram sea lion.
But it takes more than just
a tempestuous Southern Ocean swell
to intimidate
Snares crested penguins.
The biggest threat to
this year's new generation of chicks
has not yet arrived at Tini Heke.
The next morning,
it's a fur seal
who disrupts the commute.
Unlike the big, heavy sea lions,
fur seals are agile climbers,
which makes them more of a threat.
But one of
this year's fully moulted chicks
has never seen a fur seal,
and she bravely stands her ground.
(SEAL SNORTS)
(PENGUIN CHITTERS)
On the waterfront,
another batch of chicks
is ready to try the ocean today.
The twins from the special two-chick
family appear ready to go...
..especially this one.
These flippers
are primed to perfection.
(CHICK CHIRPS)
(SEAGULLS CRY)
The sea is still a little rough
after yesterday's big surge party...
..and there's something out there.
A gang of monstrous birds...
..with bills shaped like gut hooks.
(PENGUINS SQUAWK)
The adults have seen this before.
They are giant petrels.
(PENGUINS SQUAWKING)
(CHITTERING)
Panic spreads.
The penguins stream ashore together.
Safety in numbers
is a defence tactic.
(AGGRESSIVE SCREECHING)
Giant petrels are
ferociously aggressive predators,
who spend the summer
island-hopping in the sub-Antarctic,
hunting penguins.
Chicks and juveniles
are the easy targets.
The parents wisely escort
their twin chicks back to safety.
These assassins have a hierarchy
when in attack mode.
The biggest adult male
approaches first.
Giant petrels
are smart and ruthless.
They have even been known
to kill huge adult albatross.
(PENGUINS CHITTERING)
True to form, there's always one
with a stroppy attitude...
..even when in danger.
The assassin, however, is patient.
His strategy is well-rehearsed.
(PETREL SCREECHES)
It's the chick
who stood up to the fur seal.
(SCREECHES)
The giant petrel
will hold her underwater
until she drowns.
But conflict in the ranks
creates a lucky break.
The penguin is gravely injured...
..but these staunch birds
are the ultimate survivors.
(SCREECHES)
The petrel immediately
snatches a new target.
Another courageous chick survives.
(SEAGULLS CRY)
The attackers regroup.
(PENGUINS CHITTERING)
The assassins claim a victim.
(PETREL SCREECHES)
Nothing goes to waste.
In the aftermath of the massacre...
..everyone takes stock.
Penguins seek out their mates.
(PENGUINS CHATTER)
This bond is unbreakable.
(SEABIRDS CRY)
Offshore,
thousands of Cape petrels,
Buller's albatross...
..and titi are gathering.
(SEABIRDS CRYING)
This can only mean one thing.
Opportunistic fledglings
take the plunge.
But flying underwater
for the first time...
does require some skills.
Even the experts
have their moments.
It's this phenomenon that has
summoned all the oceanic hunters.
A giant krill swarm.
It's a super-organism
made up
of trillions of tiny crustaceans.
The keystone food species
for all the residents
of the Southern Ocean.
The hunters
have specialised strategies.
If all the seabirds dived at once,
the krill swarm might disperse.
Instead, groups of birds dive...
..eat their fill...
..and then fly
to the back of the queue
to wait their turn again.
When the penguins arrive,
they hunt beneath the swarm.
This drives the krill
closer to the surface...
..which benefits the seabirds.
Inside the swarm,
the krill respond to the threat.
They pulse light from bioluminescent
cells on their bellies
to distract...
..and as one...
..switch direction.
To defend itself,
this intelligent organism
becomes the ultimate shapeshifter.
The sub-Antarctic summer
draws to a close...
..and the seasonal visitors
will soon depart.
Up in Muddy Pool,
a remarkable ritual is underway.
The breeding season is over...
..but this male is deliberately
building another nest.
(PENGUINS CHATTER)
It's a symbol
of commitment to his mate.
The taller the nest,
the greater his intention...
..to meet her next spring
to do it all over again.