01x05 - Open Bay Islands

[bunniefuu]

[thrilling music]

[water splashes]

[water splashes]

[water splashes]

[calm music]
[pup squeals]

Narrator: A female fur seal

nudges the birth membrane apart

[pups squeal]

and her pup opens its eyes for the very first time

on New Zealand's wild west coast.

[dramatic music]
[waves crash]

Over the next month, up to 1,000 pups will be born

into this New Zealand fur seal rookery.

[pups coo]

From the moment of birth,

fur seal mothers lovingly nurture their pups,

[waves crash]

but they won't all survive their first months.

Life for an infant seal is filled with threats

from the ocean
[water sloshes]

and from the bull seals in its own colony,

[seals squealing]

they must learn early to fend for themselves.

[pups squeal]

For those that make it, this is an exceptional place.

Their home is known as the Open Bay Islands

or Moko Taumaka by the traditional Maori owners.

[bird squeals]

They are remnants of an ancient land.

The foundation is limestone thrust up by tectonic forces,

eroded by relentless wind and rain.

Once connected to the mainland,

constant geological changes

meant that over millions of years,

these two small islands

became isolated outposts,

cut adrift from New Zealand's south island.

A mere five kilometers from the mainland,

it may as well be 5,000.

So remote and rough are these waters,

but there's plentiful food in these waters,

[waves crash]

which attracts more marine wildlife than any other habitat

on the west coast.

[water splashing]

There can be up to 4,000 New Zealand fur seals,


gulls and terns,

which visit regularly from the mainland;

and even the occasional little blue penguin

all sharing these two rocky islands,

an area of less than 30 hectares.

[water sloshing]
[seal squeals]

[ominous music]

Below the ocean surface,

rocks are festooned with kelp and carpeted with soft algae,

food for this marble fish family,

which blend into their habitat

to avoid being eaten by other residents.

[hopeful music]

The southern ocean carries cold,

nutrient-rich water here,

where the continental shelf runs close to shore.

As a result, an expl*si*n of life is concentrated

in relatively shallow water,

a feature that's drawn fur seals to these islands

for thousands of years.

[ominous music]

A crayfish forages the undersea meadow,

watched by the resident octopus,

but the eight-legged hunter has its own predator to avoid.

[suspenseful music]

When the foraging cray falls into dangerous territory,

the octopus can't believe its luck.

[suspenseful music continues]

The crayfish has tough armor,

but as the octopus envelops its prey,

it injects a toxin through its bite

[sand swooshes]

that turns seafood flesh into soup.

Any bits that can't be digested are rejected.

This octopus senses when to hunt and when to hide,

but another makes a fatal mistake.

[water sloshing]
[tense music]

[water splashing]

The Open Bay Islands' underwater neighborhood

is both playground and 24-hour buffet

for these fur seals.

To fuel their dynamic acrobatics,

they must hunt fish continuously from dusk to dawn.

[water sloshing]

[ominous music]

But fur seals are not the top of the food chain here.

[ominous music continues]

Sevengill sharks are mostly after fish,

[water splashes]

but great white sharks prefer fatty seal blubber.

[dark music]

[seal squeals]
For Open Bay Island fur seals,

the ocean is as dangerous as it is bountiful.

[somber music]
[waves crashing]

It's a summer morning on the larger island of Taumaka,

[female seal squeals]

and this young female is just beginning her labor.

It should take her just a couple of hours

of contractions to give birth.

Unlike land mammals, seals have a more flexible pelvis

which means pups should slip out easily.

[female seal squealing]

Most of her colony sisters have already given birth

to their pups and are nurturing them with protein-rich milk.

[seal sputters]

The summer schedule here starts with hundreds of males

like this huge bull,

[tense music]

hauling the shore ready to fight for hundred square meters

he hopes will attract up to eight females.

[seals growling]

At 12 years old, he's been attracting females

to his harem for three to four seasons already.

[female seal squealing]

When the females come ashore,

their priority is to seek the best place to birth

and raise this year's pup.

[water sloshes]

That means easy access to the ocean when they need to hunt;

crevices and overhangs for protection and shade,

as they can overheat in their thick fur coats;

and proximity to the shallow enclosed nursery pool

where, over time, their pups will learn to swim.

[pup cooing]

Females will stay on Taumaka for around 10 months

before weaning their pups.

[pup coos]
[tense music]

In contrast, the males will be here for just 10 weeks

with just one goal.

A male's need to mate means he won't eat or drink

the whole 10 weeks.

[bull growls]

The bulls perform rituals like this neck display

to establish dominance and territory,

[bulls growling]

because only bulls commanding the best real estate

will attract the females.

[tense music continues]

The advantage of ritual posturing means males

can avoid having to fight,

which saves valuable energy.

Although brawls do break out when a competing male

oversteps the line.

[bulls growling]

[bull whimpers]

[bull growls]

Females can weigh 40 to 50 kilograms when fully grown,

but males weigh up to 200 kilograms.

[tense music continues]

The bigger the neck, the bigger the bull

and the more females he gets to mate with.

[female seal squealing]

[relaxing music]

In stark contrast to the drama on the foreshore,

just in land, the juvenile males gather.

At age five, they're sexually mature,

but they're barred from the breeding grounds

by the dominant bulls who won't share females.

[relaxing music continues]

It'll be a few more years till they are big

and strong enough to challenge the older bulls

and start their own harem.

Until then, all they can do is practice postures

that threaten aggression.

[seals grunt]

[curious music]

They share this place with the weka or bush hen,

a bird that was introduced to the islands

as a food source for sealers.

The species can neither fly nor swim

and so has been marooned here for a century.

[tense music]

Weka are opportunistic and feed on leftovers

from the other locals.

Shellfish, insects,

slugs, anything at all.

Early summer is when the Fiordland crested penguins

on the Open Bay Islands molt.

Penguins are one of the few bird species

that lose all their feathers during this process.

It takes two to three weeks to grow new,

clean feathers that will keep them waterproof

in these cool waters.

During the molt, they can't enter the water at all,

which means they aren't able to eat.

[somber music]

Back on the beach,

the young female fur seal is still having contractions.

It's likely she's a first time mother,

and with the weather closing in,

the odds of her survival are diminishing by the minute.

[distressed music]

On Taumaka, the larger of the two Open Bay Islands,

the summer day turns grim as rain squalls move in.

[distressed music continues]

It's been over six hours now

since this female began contractions,

[female seal squeals]

an unusually long labor for a New Zealand fur seal.

It's possible she's trying to give birth to twins,

although fur seals tend to bear just one pup at a time.

The disc indicates she was tagged as a pup

by a scientist as part of a long-term population count.

[tense music]

If she can't deliver, her life will be in danger

and the pup will die.

[curious music]

Nearby are other newborns.

This one with the placental afterbirth still attached

are bonanza for the opportunistic weka.

Many mammals often eat the placenta.

It's a rich food source for a new mother,

but the weka is quick to stake its claim.

[gull squawking]

There's a hierarchy here in the birthing grounds.

The local gulls bully the weka,

[gull squawks]

who knows her place in the pecking order.

[gull squawks]

But the minute the gull's back has turned,

she scores her most nutritious meal all year.

[gull squawks]

At this time of year, everyone on Taumaka

has hungry mouths to feed.

[waves crash]

For the first week of a seal pup's life,

it feeds around the clock

[pup coos]

gaining weight rapidly,

which means the female's fat reserves diminish just as fast.

[pup coos]

This pup is one week old already

and becoming cautiously independent,

which means his mother can make her first trip out to sea

to replenish her milk supply.

[pensive music]

She'll need to repeat this demanding journey

once or twice a week over the 10 months that she'll nurse

and consume several kilograms of protein on each trip.

[pensive music continues]

In her search for squid and octopus,

she passes by the power precinct.

These ancestral mollusks

are among the most primitive of ocean creatures,

with a massive foot that grips the rocks,

able to withstand the constant powerful surge.

Its rasping tongue protrudes from its mouth to scrape algae

from the rocks.

Its tentacles detect approaching danger.

[tense music]

It's the starfish that is the Paua's ruthless enemy.

[tense music continues]

If the starfish can grab on with its tube feet,

it can break the Paua's hole on the rock.

The starfish will try to slip its stomach under the shell

to start dissolving Paua flesh,

but the Paua has a defensive strategy.

When under threat, it twists and secretes a slippery mucus

which breaks the starfish's stronghold.

[tense music]

Then comes a rapid crawl.

For an animal in the slug family,

it can move surprisingly quickly.

[suspenseful music]

In fact, the only thing it can't shake off is another Paua.

[water sloshing]

[female seal squeals]

Female seals, superbly equipped to hunt in these waters,

are now almost ready to return to their pups.

[calm music]

They're called fur seals

because two layers of fur keep them warm in water

that pulls heat from their bodies


[water sloshing]

They fly through the water powered by front flippers

and thick muscles,

while loose-moving vertebrae and rear flippers

enable them to perform fluid acrobatics.

[tense music]

[water sloshing]

Large eyes help seals see well in low light

and long whiskers feel for fish prey at night.

As she dives, the seal's nostrils automatically close

and the dive reflex kicks in.

Her heart rate slows by around 90%

and blood circulation almost stops.

But seals store oxygen in their muscles.

Of all 11 fur seal species around the world,

New Zealand fur seals dive the deepest,

up to 230 meters and the longest often over 10 minutes.

They are among the most masterful divers on the planet.

[seal huffs]

[pups cooing]

As each female returns from hunting,

she finds her pup by listening for its call.

[pups cooing]

All pups' lives depend on how efficiently

their mother can catch fish and return home.

[seal squeals]

If she's detained beyond several days,

this pup will starve.

More than a third of newborns do.

[pups coo]

[waves crash]

It's late afternoon

and while other mothers suckle their satisfied pups,

this female is still in distress.

[distressed music]

A closer look reveals the problem.

Her pup is breech and coming out flippers first.

[distressed music continues]

The little flippers move but seem unable to advance.

One gull watches like a vulture.

[female seal cries]

It's been at least 10 hours of labor so far,

an enormous stress on both mother and pup.

[bull grunts]

[female seal squeals]

The one visitor is a lusty male.

[bull growling]

But he soon realizes that she's unable to mate.

[female seal squealing]

The rain grows heavier, dusk approaches.

[rain pattering]

At last, more of the pups seems to be emerging,

but then the flippers go still.

[somber music]

[waves crash]

Weather on the Open Bay Islands worsens as dusk approaches.

[waves crash]

The stressed female is suddenly agitated.

[female seal squeals]

It seems like there's progress at long last.

[female seal cries]

After 11 hours of labor, it's a female.

[hopeful guitar music]

[pup coos]

The pup calls and her mother mouths her.

This crucial contact is establishing their connection,

which will last for up to a year.

[pup cooing]
[tense music]

[calm guitar music]

The gulls stand by as the female coaxes her new pup to feed.

They know the drill

and grabbed their chance,

as the new mother and pup bond.

[calm guitar music continues]

In the fur seal colony,

warm summer days pass

and the newborn pup nurses every couple of hours.

This female may be new to mothering,

but she knows not to let her pup stray

in her first vulnerable week.

There are dangers here, even in the safe haven of Taumaka.

[pups coo]

Seals are born for the water,

but it takes time to learn how to swim.

[tense music]

If a pup strays near the surging ocean,

at just one week old, it could drown.

[tense music continues]

The other threat comes from within the colony.

[female seal chirp]

The new mother is one of around eight females

in this dominant male's harem.

She's the last to deliver a pup.

One week after giving birth,

it's time for her to mate again.

The timing is crucial for next year's birth season

but not so great with young pups around.

[pup crying]

She must keep hers clear at the distracted bull

[pup crying]
[tense music]

or the pup could be accidentally trampled and suffocate.

[bull growling]
[pup crying]

[waves crashing]

After she mates, something remarkable happens.

When her egg is fertilized,

it enters a state of suspension for three months.

After that, the embryo starts to grow,

which means seals can time the birth of their pups

to the most favorable season:

[dramatic music]
summer.

[seals squealing]

On the eighth day of this new pup's life,

her mother prepares to leave her for the first time.

Feeding the pup has exhausted her energy reserves

and now she needs to feed herself.

[tense music]

The main exit to the ocean

all the Open Bay Islanders use is this surge channel.

[waves crash]

It's a wild ride

but deposits her right where she needs to be:

in deep water.

Most of the pups know to avoid this channel

until they've learned to swim in the safety

of the nursery pool.

[waves crash]

[pups coo]

[tense music]

When the female enters her territory,

the pressure is on for her to hunt, eat,

and return before anything happens to her pup

or to her.

[dark music]

The fur seal's main predator is especially active

around the Open Bay Islands at this time of year,

as seals are their favorite food.

[dark music continues]

The pup is left desolate.

She must remain at the birth side and not wander off

until her mother returns to this exact spot.

[pensive music]

As night falls, squid and other fur seal favorites rise

through the water column.

[pensive music continues]

The female fur seal will cover many kilometers

and use all her diving prowess to consume several kilograms

of food as she forages in the Tasman Sea.

The local Open Bay Islands octopus is also on the hunt.

[dark music]

He's after an easy meal tonight.

His specialized skin cells change color,

camouflaging him, as he tracks his prey.

Cray pots are a common site down here

and the highly intelligent octopus knows it.

Unlike other invertebrates,

the octopus has short and long-term memory

stored in separate parts of its brain just like humans.

It can solve complex problems,

so finding a way into this cage

should be a walk in the park.

It's likely this is a scenario he's played out

many times before.

[dark music continues]

His next trick is to encircle the crayfish.

[cage rattling]

Crayfish are covered with sharp, thorny spikes,

but this meal is worth a few scrapes.

The assassin's sharp beak bores through

the cray fish's tough shell,

injecting its toxic saliva,

and he feasts once again.

[dark music fades]

[bright music]

Early the next day,

there's no sign of the fur seal mother

who went to sea to feed.

[bright music continues]

Dawn reveals her pup weathered the first night alone

by staying put like she was supposed to.

[bulls growl]
[pup coos]

But as the day heat's up,

her caution is overtaken by curiosity.

[pup coos]

Her attention is attracted

by other pups down in the nursery pool.

They're mostly several weeks older than she is,

but the late born pup is drawn to join them.

With their mothers absent from such an early age,

the more confident a fur seal pup,

the more likely it is to survive.

[tense music]

She has no idea what to expect.

[water sloshes]

[pup coos]

At nine days old, she's right on track

to give swimming a try,

but first she checks out this new world.

[curious music]

Seals see better underwater than on land.

It's thought they can see colors, although not proven.

This is just a first taste of the underwater world

she will experience for the rest of her life.

[curious music continues]

Seal pups swim instinctively

once they're brave enough to try.

She makes a thorough survey of the nursery pool.

She will spend many hours here

over the next few months

socializing with her colony cousins.

[pup coos]

Fur seal pups form loosely-knit pods

of usually four to five others,

which come together whenever their mothers

are out at sea hunting.

[pups coo]

The young pups play boisterously constantly in motion.

Everything they do is rehearsal for adult life.

Opportunistically, they pick up skills along the way,

like how to chase a fish.

[bright music]

Once she's weaned by 10 months old,

she should be capable of catching it.

[bright music continues]

But for now, her hunger pangs are growing

and there's no way to know when her mother will return.

The next few days will be the longest

of this pup's short life.

[pups coo]

[bright music continues]

The Open Bay Islands off New Zealand's Wild West Coast

sparkle on this summer afternoon.

[birds squawking]

It's an idyllic day for most of the pups

socializing in the nursery pool.

[pup coos]

But this young pup is weak now

and starting to lose body weight,

as her mother has not yet returned

from her feeding trip at sea.

[water sloshes]

She lingers at the edge of the nursery pool

as she waits for her mother.

[tense music]

As she swims close to the rock gap,

a road wave hits and sucks her out to the other side.

[waves crash]

The open ocean is no place for a 10-day old pup.

[tense music continues]

She's drifting away from the pool entrance,

when a familiar figure shoots in from the deep.

[bright music]

A moment of recognition,

and the pup can now follow her mother back to safety.

[bright music fades]

As summer yields to autumn,

the crested penguins have finished their molt

and grown back waterproof feathers.

And weka still steal any food they can.

[birds squawking]

[curious music]

The bull seals returned to sea for months of feeding.

And now it's just females and pups bonding in peace.

[pensive music]

At three months old, our pup is growing

and becoming used to her mother's absences.

[waves crash]

The female is now fully pregnant with her embryo developing

after its three-month delay,

and she needs lots of food to prepare

for this birth next year.

[waves crash]

The surge channel has been violent enough

to keep the pup from following her mother to sea,

but today she's ready to give it a try.

[tense music]

This is a huge milestone.

Over the coming months

she'll begin to explore her big blue backyard,

meet all the locals,

and eventually extend out her hunting grounds

for thousands of kilometers.

It will be a year or more

before she's ready to dive the deeper ocean

and several more before she herself

will mate and give birth.

[pups squealing]

But for the rest of her life,

the Open Bay Islands will be her home.

[thrilling music]

[waves crash]

[thrilling music continues]