All language subtitles for Animal Empires - 01x06 - Gone Wild Eng

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NARRATOR: Donkeys stranded
on a desert island

conquer
the arid wilderness.

Pigs in paradise

sunbathe on
a Caribbean beach.

And off the east coast
of the United States

two herds of horses
share one island.

Animals gone wild

must adjust to life
on their own.

That means
unusual adaptations

and surprising
behaviors.

But their very
success

could be
their downfall.

NARRATOR: Inside
the different realms

of the wild kingdom

members of
a single species

assemble in droves.

One flock,

herd

or troop

reigns supreme.

These are
the world's great

These are
the world's great

NARRATOR: The small Dutch
island of Bonaire

lies off the northwest
coast of Venezuela.

Just over 100 square miles
in total area

this tiny island
of dry land

and sparse bush,
is the adopted home

of one the world's
most iconic beasts of burden,

the donkey.

Donkeys have been
living wild on Bonaire

for over 500 years.

Most of them have
distinctive stripes

that form a cross
down their back.

This has led to
a long association

between the donkeys
and Christianity.

Other than snakes,
donkeys are the only animals

that speak
in the Bible.

The cross is
actually a trait

inherited from
the Nubian wild ass,

one of two sub-species
from which

all domestic donkeys
are descended.

The donkey's ancestors
made their home

in the desert land
of Northeast Africa,

between Egypt
and Somalia.

Then over
5,000 years ago

humans
domesticated them,

and brought them across
the far reaches of Asia

and into Europe.

In the 16th century,

it was the Spanish
conquistadors

that brought donkeys
to Bonaire.

For centuries, donkeys were
used in Bonaire's salt trade,

alongside enslaved
African people.

When slavery was abolished
on the island in 1862,

the salt business
industrialized.

The donkeys
were set free.

Today, they are a reminder
of the island's history.

The feral donkeys
quickly adapted to Bonaire.

They are naturally suited to
desert environments like these.

In the 1950s, their population
exceeded 1,200.

There were 10 donkeys
for every square mile.

Their diet here
consists of grass,

shrubs and
desert plants.

The plants
also give the donkeys

most of the water
they need.

The thick hooves
protecting donkey's feet

actually benefit from
the rough and rocky ground.

Their hooves are the same
material as human fingernails,

and never stop growing.

Trekking across the hard
terrain files them down

protecting from
painful overgrowth.

To keep cool, the donkeys
kick up the desert dust

and cover
their bodies.

This insulates them
from the hot sun.

Male donkeys
are called jacks.

The dominant jack
will lead a herd

of around
20 individuals.

The herd includes a harem
of up to eight females,

their foals,
and often

a few subordinate
males too.

These days, the donkey's
desert home is changing.

Development on the island
and a growing tourism industry

have intensified
competition for territory

between jacks.

And, as humans move in
on the donkey's turf,

conflicts with their
new neighbors are inevitable.

NARRATOR: In the Bahamas,

the Exumas
are an island chain

about the length of
Long Island, New York.

This is
Big Major Cay.

One of
the 365 sandy isles

that make up
the chain.

It's home to some
surprising castaways.

Stranded here,

pigs in paradise.

These are the same
species of swine

that can be found on farmer's
fields across the globe.

But these ones
are feral.

Domesticated pigs are
descended from wild boars.

These pigs may live
in the Bahamas now,

but their ancestors
hail from Asia.

More than ten thousand
years ago,

people there started
capturing and breeding

wild boars
for food.

Today domesticated pigs
are found

on every continent
except Antarctica.

About one billion
domestic pigs

are alive
at any given time,

making them among
the most numerous

large animals in
the world.

But here, domestic pigs
have gone wild,

and live feral lives.

Whether it's a nursery rhyme
about pigs going to market,

a folk tale featuring
three little pigs

hiding from
the big bad wolf,

or a classic novel

where a well-meaning spider
named Charlotte,

tries to save
her barnyard buddy.

Stories about pigs

have been igniting
the imagination of children

for centuries.

Big Major Cay
is no exception.

The origin of these pigs
has become a local legend.

Some speculate
that they swam to shore

following a 16th century
shipwreck.

The truth is they were
actually brought here

as livestock from
the Bahamian capital, Nassau

in the 1990s.

At first, there were only
five juvenile pigs

and they were fed
and fenced in.

But when they grew larger,
they escaped.

The pigs survived on the island
for seven generations.

Now, the population
has grown to over 30.

They may technically be
domestic pigs,

but these boars
and sows

haven't lost their innate
ability to find food.

This behavior
is called rooting.

Pigs see the world

through a heightened
sense of smell.

Digging with
their elongated snouts,

they can sniff out
edible roots

as far as three feet
underground.

Most of their diet
comes from roots,

but they also eat
wild cabbage and berries.

They get their water

from the island's
three inland springs.

By nature pigs are social,
gregarious creatures.

They travel in groups,
called sounders.

This one consists
of three mature sows,

one boar,
and their offspring.

A curious disposition
and a broad diet

means pigs can find food
in just about any range,

making them one of the world's
most adaptable animals.

But there's a downside
to their success.

With no predators,
the number of pigs here

will continue
to grow

until there's not enough food
and water for everyone.

Potentially devastating
the island's native ecosystem

in the process.

NARRATOR: Assateague
is a barrier island

running parallel to
the East Coast

of the United States,

from Maryland
to Virginia.

It's a narrow strip
of sand and sediment

almost 37 miles long.

Another island, with
another species gone wild.

Horses.

Assateague's horses
have free rein

over the island's
open meadows.

Worldwide the population of
domestic and feral horses

is estimated
to be 58 million,

with over nine million
in the United States alone.

There are so many horses
in the U.S.,

that if they were
to form their own state,

it'd be the eleventh
most populous in the country.

Prior to their
domestication,

horses roamed
the open plains

and grasslands of
the Eurasian steppes,

from Ukraine to
Mongolia.

First domesticated
as a food source,

humans eventually
realized that tame horses

made great workers.

Over thousands
of years,

people brought horses
with them across the globe,

just like pigs
and donkeys.

Assateague Island's horses
have been here

since before
the American Revolution.

But how they got here,
is a mystery.

Some say
that the horses arrived

when two Spanish galleons
crashed into the island

during the 1500s.

Others believed
that early colonizers

stashed the horses
on the island

to avoid paying
livestock taxes.

Regardless of
how they arrived,

they've been roaming free
for over three centuries.

Today 300 horses
live on Assateague.

Horses instinctively
form herds like this one

to protect one another
and act as lookouts.

Feral horse herds are
often called bands.

The bands are led
by a dominant stallion.

He's the herd's
protector

and enforcer of the band's
rigid hierarchy,

leading a harem
of up to eight mares.

In addition to
a dominant stallion,

every band has a lead-mare,
like this white horse.

She decides where to graze and
when to go find water.

Horses are
prey animals.

They grow anxious
and flighty when alone,

even here where
there are no predators.

The company and hierarchy
of the band

keep everyone
feeling secure.

With winter on
its way,

this horse has begun
shedding dead hair

and growing in
a thicker coat.

The horse's
pituitary gland

recognizes the shift
in daylight hours,

and produces
a hormone

that triggers
the increased hair growth.

It's an itchy process
for the horse.

Horses need to keep their coat
well groomed all year.

It regulates
body temperature

and protects against
the elements.

Horses also produce
pheromones

that make it possible to
identify other herd members

from as far as
400 feet away.

Of course,
there's always an itch

that you just can't reach
without a little help.

When animals clean
each other

its called
"allo-grooming."

It's a sign of an intense bond
between horses.

The more horses
an individual grooms,

the higher her social status
is within the herd.

Scientists have even
found that mares,

who are the most
gregarious groomers,

also produce
the most offspring.

Horses spend between
15 and 17 hours a day grazing.

Horses here eat the grasses
that grow in the salt-marsh

or on the beach.

This diet is
high in salt content,

so the horses drink
twice as much water

as other
wild horses.

All that water
makes them bloated.

The grasses are also
low in nutrients,

so the Assateague horses
are shorter and stockier

than other breeds.

Adult horses eat
21,000 calories each day.

Grazing the grass
and trampling the field

takes an enormous toll
on the island,

and increases erosion.

With no natural predators
to control the population,

these horses
could eat themselves

out of house
and home.

NARRATOR: In the 1950s,

there were 5500 people
living on Bonaire.

At the time, that meant
that for every five people

on the island,
there was one donkey.

But as the world changes
around them,

the donkeys are
starting to disappear.

These days it's tourism,
not salt,

that drives
Bonaire's economy.

70,000 people
visit annually,

most of them coming
to dive the clear blue water

and explore the coral reef
that surrounds the island.

16,000
human residents

now also call
the island home.

Development has encroached
on the donkey's former range,

meaning there's
less area to graze

and less food to
go around.

Many also believe,

the donkeys are throwing
the ecosystem out of balance

killing plants and,
like the Assateague horses,

eroding the island
with their non-stop grazing.

The donkey's
brave new world

is full of
unknown threats,

And their ancient instincts
never prepared them

for dangers
like these.

Unlike horses, who instinctively
flee nearby threats,

these frightened donkeys
freeze in the face of danger,

stopping to
investigate threats.

It's an impractical
defense

when your range
extends across roadways.

Donkeys stay close
to the road for a reason.

It's quite resourceful and
efficient for grazing.

The asphalt
repels water,

which means that during
the rainy season,

runoff from the road

spills over
onto the curbside,

cultivating some of the island's
most luscious greens.

In recent years,
up to 60 donkeys annually

have been killed in
motor vehicle accidents.

Even though their numbers
are declining,

there are still
too many donkeys

and not
enough space.

So measures have been
put in place to control

Bonaire's remaining population
of wild donkeys.

Jacks
have been gelded,

and then released back
into the wild.

Meanwhile mares are being
relocated to a protected area,

safe from
the island's development.

Limiting the number of free
roaming donkeys on the island

means fewer
car accidents,

and more space
for the donkeys to graze.

But population control
may just be the straw

that finally breaks
the donkey's back.

It might mean the long
history of the donkeys'

wild life on Bonaire

could be coming
to an end.

NARRATOR: The wild pigs'
colonization

of the Bahamas'
Big Major Cay

has been
so successful

that the locals
now refer to this spot

as Pig Beach.

To avoid the hot sun,
the island pigs

spend the hottest hours
of the day

in the shade.

They save their foraging
for the early morning

and late afternoon.

Pigs don't have sweat glands
to help them keep cool.

They're susceptible
to heat exhaustion,

sunburns and
even skin cancer.

Wallowing in sand,

while not as effective
as a mud bath,

cools them, and
also helps the pigs

by shielding them
from harmful UV rays.

And when things get
really hot,

these pigs have another
trick up their snouts.

Out on the ocean,
a commotion sounds.

The pigs
storm the sea.

And then, an even
more curious behavior,

they piggy paddle
out to the waiting boats.

They weigh between
100 and 200 pounds each,

and they're not exactly
hydrodynamic.

But what these pigs
lack in speed

they make up for
in determination.

In the last 10 years,
the legend of Pig Beach

has spread far beyond
the Bahamas.

They've become the biggest
single attraction

in the Exuma Cays.

The sight, sounds and smells
of boats and humans

draw the pigs
out of the bush,

and into the water.

This isn't the first time
stories of swimming pigs

have amazed humans.

During a World War I
naval battle,

an attacking British vessel
rescued a pig

swimming away from
a sinking German ship.

He was nicknamed Tirpitz,
and became the official mascot

of the HMS Glasgow.

In 1946, 200 pigs were brought
to the Marshall Islands

to test the effect
of nuclear fallout

from an atomic bomb
detonation.

After the explosion,
they found Pig Number 311

swimming safe and sound
in the Pacific Ocean.

She lived out her remaining
days at Smithsonian's

National Zoological Park
in Washington, D.C.

Swimming is actually
instinctual in pigs,

and can be traced back
to their ancient ancestors.

Wild boars are
exceptional swimmers.

In 2013, a wild boar
swam seven miles

into the English Channel,

and was found on an island
off the coast of France.

So if pigs have always
been able to swim,

why is it
such a rare sight?

For the most part,

domestic pigs just have
no reason to swim.

So what makes
Big Major Cay's pigs

take to the sea?

Food naturally!

From the same humans
who come to see them swim.

Widely considered amongst
the smartest animals

on the planet, pigs
have similar brainpower

as elephants, dolphins
and chimpanzees.

Pigs have excellent
long-term memories

and exhibit extraordinary
problem-solving skills.

Both qualities
help them exploit

what's become a dependable
supplementary food source.

Locals were
the first to discover

Big Major Cay's
swimming pigs.

But in the age of
social media,

word spreads quickly.

By the mid-2000s,
photos of the pigs

began popping up
online.

Before long,
the pigs went viral.

They've made
international headlines,

partied with
pop stars,

been photographed
with swimsuit models,

and even appeared on
reality television shows.

Hashtag
pigs in paradise?

Not so fast.

The daily visits
and supplemental feeding

are beginning to
blur the line

between wild and
domesticated once again.

Although the pigs here
are being fed,

there's no one
directly responsible

for their well being.

If left unchecked, feral pig
populations grow rapidly.

One sow can birth
over 20 piglets annually.

The number of feral pigs
in the United States

has tripled
in the last 25 years,

from two million
to six million pigs.

An island like this one
could quickly become overrun,

devastating the local
flora and fauna.

In the past,
population control for swine

meant
the slaughterhouse.

Nobody seems keen to take
these little piggies to market.

But If left alone,

the number of pigs
living in this hog heaven

could go hog wild.

NARRATOR: The sand that makes up
Assateague Island's beaches

comes from the ancient
eroded rock

of the nearby
Appalachian Mountains.

Waves pounding against
the shore, move the sand,

and keep
this barrier island

in a state of
constant flux.

But man-made barriers
also shape life on this island,

for both people,
and horses.

A state border runs
across the island,

separating it
into two parks.

The northern section
of the island

is Maryland's

Assateague Island
National Seashore.

The southern part
is in Virginia,

where
the horses live

on the Chincoteague
National Wildlife Refuge.

A fence separates
the two parks

and divides
the island's horses

into two
distinct herds.

This is one of
the Maryland horses.

Now in his fourth year,

he's just beginning
to reach sexual maturity.

He's on his own.

The leader of his band,
probably his own father,

chased him away
when he got old enough

to become a threat to
the stallion's dominance.

For horses, this is
an instinctual prevention

against inbreeding.

Stallions
form their own band

by drawing in females
that have also been cast out,

Or by attracting
a mare

that's left her band
to give birth.

The Assateague Island horses
are one of the few

wild roaming herds
in the United States.

They're the subjects of
ongoing studies by scientists

striving
to understand

the secrets of
wild horse herds.

They've found that
individual horses

form close bonds
with each other,

but these relationships are
so prone to fall-outs,

that researchers have
compared life in the herd

to a soap opera.

The horse's reign
on Assateague Island

faces a similar
set of threats

as the donkey's empire
on Bonaire.

The horses are drawn
to the rich grasses

on the side of the road;

humans are drawn
to the majestic horses.

It's a dangerous and
potentially deadly combination.

Since 1982,

traffic accidents have killed
29 horses on the island.

But the horses
themselves

may be
their own worst enemy.

By pulling up
the grass,

the hungry horses are weakening
the island's foundation.

This salt marsh is regularly
flooded by the tides.

Assateague
is a barrier island

and, like all barrier islands,
it's made from sand.

The grass is the glue
that keeps the island

from washing away.

When this area was made
a National Park in the 1960s,

there were
only 28 horses

living on the Maryland
side of the island.

A nor'easter had
decimated their numbers,

and the park sought
to protect the small herd.

By 1997, the herd's numbers
had risen to 165,

and the park faced
the opposite problem.

The horse population
was too high.

To protect the horses
and their home,

the United States
National Park Service

put in place a plan
to control the population.

Most of
the female horses

on the Maryland side
of the island

are now
on birth control.

Mares who have
given birth at least once

are shot with
a dart gun

containing a state-of-the-art
equine contraceptive.

For the first few years
of the program,

the population
continued to grow.

But officials were
patient

and in 2014 the Maryland
horse population

dropped to a sustainable
100 horses,

with no cull or
relocation necessary.

The female horses that receive
the contraceptive

even live longer because
they're spared the stress

of pregnancy and
nursing.

The future of the Maryland
horses has been secured.

On the Virginia
side of the island,

the horses' appetite
poses the same threat

to the Island's
foundation.

But officials there

are trying
a different solution

to manage
the population.

NARRATOR: Worldwide,
95% of donkeys

are still
domesticated workers.

In places like Latin America,
the Middle East,

India and
Sub-Saharan Africa,

they remain a valuable
beast of burden.

There are an estimated
44 million donkeys

around the globe, and
their numbers are growing.

In industrialized countries
it's a different story;

donkeys are
in steep decline.

Affordable cars and trucks
mean donkeys get left behind.

Donkey Sanctuary Bonaire
exists to ensure the future

of the next generation
of the island's donkeys.

It was established in 1993
to help care for

the island's sick and
injured donkeys.

Displaced by development,
and killed by cars,

before the sanctuary,
the donkeys' island empire

was on the road
to extinction.

The donkeys here are fed
three times a day,

a diet of horse pellets,
vegetables

and as much hay
as they can eat.

These days its far safer
for Bonaire's donkeys

to live
in the sanctuary

than it is to try
and survive in the wild.

This foal was brought
to the sanctuary

when she was
just two weeks old.

She was hit
by a car

and was found
with a broken leg.

Without Donkey
Sanctuary Bonaire

she would have died.

Here on-site veterinarians
provide regular check-ups.

The foal's two months old now,
and still healing.

They line her legs
with wooden stints

to keep
the bone straight.

Donkeys' bones grow
until they're 3 years old.

This is a critical time.
If her bone doesn't set right,

she'll face a life
of constant pain,

and will need to be
euthanized.

But so far the young foal
is doing well,

and if she continues
to recover,

she could live
to be 40.

Today close to half
of the island's donkeys

live in the safety of
the sanctuary.

That means 600 donkeys

don't have to worry about
car accidents.

The jacks
are more aggressive,

so they still roam free
on the outside.

Most are tagged,
chipped and gelded

to limit
population growth.

Meanwhile, the island
is still looking for ways

to make the wild
safer for donkeys.

Like these
street signs

that have been placed
across the island,

warning motorists to look out
for crossing donkeys.

The next step is a scientific
study to determine

the number of donkeys
the island can support.

When the carrying capacity of
the island is determined,

and measures are put in place
to keep wild donkeys

away from
human development,

Bonaire will be safe
for donkeys once again.

Until then, the Sanctuary
will continue providing

the highest quality
of life possible.

That includes plans to deepen
the island's gene pool

by artificially
inseminating mares.

So when the time comes for
the donkeys to live free again,

Bonaire's donkeys
will have

the best possible chance
of survival.

The donkey's
long reigning empire

may soon be ready
to rise again.

NARRATOR: On a second sandy
and deserted island

in the Bahamas,

the burgeoning empire
of Bahamian pigs

is growing.

These pigs were born
on Pig Beach,

about 55 miles away from
Big Major Cay.

They were
relocated here

because its closer
to the Exuma's capital,

and therefore more
accessible to tourists.

This sounder is comprised of
three separate litters,

each with
about 4-7 piglets.

Like all piglets, they were
born highly developed;

they could see
and hear at birth,

and walk
within minutes.

The youngest pigs
are just six weeks old,

but a life-long "pecking order"
already exists among siblings.

It was established
the day they were born,

as the piglets competed
to suckle from teats.

The piglets will nurse
for up to five months,

but even
after they've weaned

they'll remain close to
their mother and siblings.

Unlike the pigs
on Big Major Cay,

these pigs can't survive
without human help.

Because there's no freshwater
spring on this island,

their drinking water
is shipped here daily.

The pigs here have been
domesticated once again.

Their new fence
is the Caribbean sea.

It's an odd combination of
agriculture and tourism.

The spread
of this pig empire

could spell disaster
for both pigs

and their adopted lands.

Across the Bahamas
other introduced species

like cats and mice, have
decimated island ecosystems.

Left free the highly
adaptable pigs

could eventually
outcompete native species,

and wipeout local plant life
in the process.

The unregulated nature
of this bizarre phenomenon

means
there's currently

no population
management plan.

But for the pigs,
life in the Bahamas

beats life
on the farm.

Most of those pigs don't
make it to their first birthday.

As long as they have food,
shelter and water they need,

these pigs could live
for another 20 years.

NARRATOR: The Chincoteague
National Wildlife Refuge

in Virginia, is on
the southern side

of Assateague Island.

Though these horses
are left to roam free,

each one is branded
with the year of their birth

so the herd's numbers
can be monitored over time.

There are a few differences
between the northern

and southern
Assateague horses.

One difference is
their name.

Down here people call them
Chincoteague ponies.

Genetically a horse
and a pony are the same.

The difference
is in the height.

Horses are taller;

island life has made these
short and stocky over time,

so by equestrian standards,
the Assateague horses

are, in fact,
also ponies.

The Chincoteague ponies'
relentless grazing

poses the same threat
to the island

as their
northern cousins.

When unmanaged,
feral horse populations

can double
every four years.

But even though 70 new foals
are born each year,

the effect on
the ecosystem here

hasn't been
as severe.

To prevent
overpopulation

this herd has been managed
for nearly a century.

But it's done
differently

than it is for
their northern cousins.

Each spring,
once foals are weaned,

they're rounded up
and auctioned off,

sent to new homes
off the island.

Today there are over a thousand
Chincoteague ponies

living on
the mainland.

The breed is highly valued
for their calm demeanor

and a hardy nature.

Every year, a few foals
are kept back

to make sure the wild
population stays strong.

There are now a manageable
150 horses

on this side
of the island.

That number
falls firmly in line

with the ecologist's
recommendations.

The two herds
are both considered

conservation
success stories.

With proper
population control

the hope is the sun
will never set on the empire

of the Assateague
Island horses.

NARRATOR: Thousands
of years ago

animals like donkeys,
pigs and horses

became reliant
on their owners.

Likewise, humans came
to rely on them,

bringing them with us
as we traveled the globe.

But when animals are abandoned
in strange new lands,

the consequences
are unpredictable.

Controlling the population
of feral species

remains an ongoing
challenge

for conservationists
around the globe.

These empires
gone wild

struggle with
depleted ecosystems

and new relationships
with humans.

As these herds,

bands

and sounders

continue to
try to find harmony

for their

for their
animal empires.

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