Original subtitles

NARRATOR: At the mouth of the Mississippi River,

the last survivors of a rare breed of deer

fight for a future,

On Britain's rivers, the Queen of England's

very own flock of birds

gets the royal treatment,

And tunneling tortoises dig deep

as they compete for real estate

in southern Florida.

Throughout history,

thousands of species have faced extinction.

Some have been to the brink,

and back.

For others, the road to recovery

is just beginning.

NARRATOR: Inside the different realms

of the animal kingdom,

Members of a single species

assemble in droves,

And one flock,

herd,

or troop

reigns supreme.

These are the world's great

These are the world's great

NARRATOR: It's the start of another long hot summer

in the heart of the southern United States.

This is the great Mississippi River Delta,

the southern-most point

of the line that once defined

the American western frontier.

Vast marshes and swamps

formed by the delta support a rich

variety of wildlife,

Including one the world's rarest species,

known as Père David's deer.

These ruminant mammals live in large herds

and spend their time grazing on the grasses

and aquatic plants of the delta's wetlands.

This particular species

is known partly for its mix and match characteristics.

Its head is long and slender like a horse,

It has large and spreading hooves,

like an ox or cow,

allowing it to walk on the soft ground.

Its tail and body are similar to a donkey's.

And, of course, it has antlers,

though they're different than most deer.

They look like they're on backwards.

But it's not just the antlers

that make this species different.

Currently, David's deer live only in captivity.

The deer in this herd are refugees,

Brought here to Louisiana

to be one of the cornerstones

in the rebuilding of an animal empire

on the edge of extinction.

Evidence suggests that the species once ranged

throughout Central and Eastern China.

According to Chinese myth,

more than 3000 years ago,

a horse, a donkey, an ox and a deer

vowed to seek justice

against the tyrannical King Zhou.

They transformed themselves into one animal

that combined their strengths.

The Chinese called it the milu,

or "sze pu shiang",

which means "not one of the four".

Famed Chinese folk hero, Jiang Ziya

then rode this strange new creature into battle,

and won victory over the ruthless King.

Having fulfilled its vow,

the milu settled in the lower Yangtze River

and became a symbol of good fortune.

In the centuries that followed,

Chinese Emperors believed

that eating this extraordinary animal

would bring them everlasting life.

By the late 19th century,

hunting had taken its toll.

The milu had been slaughtered to near extinction.

The only remaining herd

lived in China's Royal Garden,

property of the Emperor.

In 1866, a French naturalist, Father Armand David,

heard about the rare and mysterious deer.

He had to see them for himself.

He convinced the Emperor to send a few deer

back to Europe,

where scientists named the species:

"Père, meaning Father, David's deer".

The Emperor also agreed to send

a few living deer to be showcased

in European zoos.

Though numbers were low,

the species seemed destined to survive

in these captive settings.

Then, tragedy struck.

In 1895, a flood destroyed

China's Imperial Garden walls.

Most of the deer escaped.

Starving peasants killed and ate the fleeing milu.

Just five years later, during the Boxer Rebellion,

soldiers occupied the palace

and killed the few deer that remained.

The empire of the milu had fallen.

Or had it?

There were still the few remaining deer

that had been sent to Europe.

For Père David's deer to survive,

the species depended on just six individuals,

whose genes would provide the building blocks

for a new empire, far from their native land.

Like the greatest of the Chinese dynasties,

the British Empire once ruled

far beyond the nation's borders.

At the height of its power,

it held sway over a quarter of the globe

and one fifth of the world's population.

Expansive palaces,

great stately manors

and lush gardens exist today

as a symbol of British royalty.

Part of that symbolism

is an animal with an empire of its own.

The mute swan.

Recent data suggests a half million mute swans

live throughout their native range

from western Europe through to Western Asia.

There are at least 22,000

in the United Kingdom alone.

in the United Kingdom alone.

The mute swan is one of six species of swan.

Like most swans, it's predominantly white

but can be identified by the orange trim

and distinctive large knob on its bill.

It's not technically mute;

a mute swan will hiss and grunt,

but its trachea is a simple straight tube

that goes directly into the lungs,

instead of the coiled looping windpipe

that produces the loud characteristic "honk"

of these trumpeter swans.

(swans honk)

This makes it far less vocal

than its closest relative.

The image of this creature

has left its impression throughout history.

From cave drawings to Russian ballets,

Arthurian legends to the "the ugly duckling",

these elegant birds feature prominently

in a variety of cultures.

Aristotle, Plato and Socrates,

all wrote that a swan's singing

peaks as death approaches,

giving rise to the idea of the swan song,

or the final performance.

But being a status symbol comes with a downside.

The mute swan,

is among the largest waterfowl on the planet.

Its size, and royal stature,

made it a popular main course

for the banquet tables of medieval Europe.

Beginning in the 13th century,

mute swans were considered a valuable food source.

For the next 600 years, landowners and noblemen

captured and hunted them across the continent.

By the end of the 19th century,

the species was all but eradicated in the wild.

The regal mute swan

was on the verge of extinction.

For this empire to avoid

a final swan song of its own,

it would take an alliance with none other than

her Majesty, the Queen of England.

4,300 miles west across the Atlantic,

Florida was once at the bottom of a shallow sea.

Florida was once at the bottom of a shallow sea.

Over hundreds of thousands of years,

rivers transported sediment here

from the eroding Appalachian Mountains.

Eventually, water levels dropped

and the ocean floor was exposed,

leaving a thick layer of sand

surrounding what is now Naples, Florida.

It's this sand that makes a perfect home

for one of nature's expert diggers,

the gopher tortoise.

"Gopherus polyphemus"

is the only North American tortoise

native to areas east of the Mississippi River.

Its empire expands across the southeast United States.

Here in Florida, they can be found in every county.

Gopher tortoises inhabit uplands with deep

well-drained sandy soil

and desert-like conditions.

Several times a year, these expert diggers

build burrows up to 40 feet long

and 10 feet deep.

The burrows are not only home to the tortoise,

but also used by more than 350 other species.

Snakes, frogs, owls and crickets,

all lease burrow space

for feeding, reproduction, and protection.

Some live alongside the tortoises.

Others occupy abandoned burrows.

Both the gopher tortoise and its cohabitants

depend on the burrows for survival.

This makes the gopher tortoise

a keystone species,

a species critical to maintain the structure

of its ecosystem.

But that ecosystem is under siege.

60 million years ago,

23 species of tortoise lived in North America.

Then came European settlement.

Loss of habitat

began to take a toll on the tortoises.

During the depression,

they were even hunted as food.

In the years that followed,

development in fast growing South Florida

turned tortoise territory into hotels and housing.

Residents and tourists

were attracted to the same sandy soil

that gopher tortoises use to burrow.

Between 1990 and 2000 alone,

the human population in the southeast United States

rose by 20%.

By then, the gopher tortoise population

had fallen to 20% of its historical high.

In 2007 the State deemed the species threatened.

This empire is in need of rebuilding.

To reverse the decline,

the gopher tortoise must find a way

to defend its shrinking territory.

For Louisiana's herd of Père David's deer,

it was a long journey,

over many miles and many decades,

to their adopted home.

By the early 1900s,

the last of China's deer population

had been killed.

And not a single member of the species

was left in the wild anywhere in the world.

5,000 miles away in England,

the 11th Duke of Bedford received word

of the animal's extinction in its native land.

The duke tracked down the few

that remained in European zoos

and brought them under his protection

at his deer park at Woburn Abbey,

just outside London.

This became the only home

of a breeding herd of David's Deer

in the world.

Over the years, the deer reproduced

and the Woburn herd grew.

And soon,

there were enough David's deer

to disperse them to other zoos

and wildlife sanctuaries around the world,

like the Global Wildlife Center,

north of New Orleans, Louisiana.

Rebuilding an empire

starts with the right habitat.

David's deer are social animals.

They stay together in large herds

and prefer low lying grasslands

and reed beds, like coastal marshes

and flood plains.

They spend hours a day cooling off in shallow water.

And they have the mysterious habit

of sticking their heads in the water,

and digging up the marsh muck,

decorating their antlers.

Scientists are baffled by this unusual behavior.

But what is known is that these antlers

play a key role during the mating ritual

known as the "rut".

In June, about two months before the breeding season,

males feed intensively to build up strength.

They eat grass, reeds and bushes

found in and around the wetlands.

At the same time,

females break off from the larger herd,

and form small mating harems.

At the start of the rut,

a stag will rub his antlers

on trees or shrubs.

It was once believed this was

to prep the antlers for fighting.

But recent studies suggest

it's to mark their territory.

They rub their scent to demonstrate

to other bucks and does

that they're ready to mate.

When a stag is ready,

he approaches one of the groups of females.

But he's not the only eligible bachelor.

He must establish dominance,

by force.

by force.

The stag uses his antlers

to butt heads with his opponent.

He'll also bite and even

rise up on hind legs and box.

When the fight is over,

the winner claims the right

to mate with the harem.

To increase his odds of reproduction,

he mounts as many of the does as possible.

For about the next two months, the stag's focus

is entirely on mating.

He doesn't even eat, and loses weight rapidly.

But he's not done fighting.

He must continue to defend his harem

from other males.

from other males.

By November, the rut is complete.

The stag leaves the harem,

begins to feed again,

and quickly regains his weight.

He also sheds his summer antlers.

Unlike most other deer,

a second set sometimes grows in

over the winter months,

and falls off a few weeks later.

Scientists believe this second rack is only possible

due to the amount of supplemental feeding

the deer get in captivity.

Meanwhile, the pregnant females

return to grazing on the grasslands,

feeding the unborn calves they now carry.

Breeding within the confines of the park

has its risks.

A shallow genetic pool and the spread of disease

can decimate a captive population.

But David's deer have no choice.

The survival of this species

depends on a new generation

born into captivity.

Sometime in the 13th century,

mute swans became so popular

on the banquet table of British noblemen,

that the Monarchy took special interest.

Too many birds were disappearing from the wild.

A Royal Decree was sent out,

the owners of swans were now duty-bound

to mark their feathered property.

Much like branding cattle, swan owners

were required to mark their birds

with signature nicks in their beaks.

To conserve the population, any unmarked birds

became property of the ruling monarch

and could not be hunted or captured.

Swans were given the title of "Royal Bird".

Many believe that if it weren't for this law,

swans would now be extinct in Britain.

800 years later, the royal bird is thriving.

Across the country,

swans now flourish in their preferred habitat,

ponds, estuaries, and streams.

Even in urban areas they thrive

in the shallow lakes and slow-flowing rivers

of parks and gardens.

Most of Britain's mute swans

stay in the same territory all year.

In winter, they're joined by other migrating mute swans

from further north,

who come looking for warmer waters.

These calm bodies of water provide the mute swans

with a venerable all-you-can eat buffet.

They use their long necks to dip under the surface

and take mollusks that cling to vegetation.

They also eat plants, insects and snails,

small fish, frogs and worms.

And they'll also graze on grassy fields.

They'll eat just about anything to survive.

With an ample supply of food,

the swans turn their attention to breeding.

The male and female birds,

known as the cob and pen,

will attempt to mate for life.

However, if one or the other dies

an adult bird will seek another mate.

After mating, the pair works together

to construct a nest.

It's a huge mound of dried grasses

and assorted plants and sticks.

The male supplies the materials for the nest.

The female builds it.

In the wild, the pair builds near the water's edge.

From late April to early May

she'll lay up to seven eggs

in a single clutch.

Both parents will take part in incubating them.

For the next month,

they will watch over their un-hatched brood,

with the hopes that they will survive long enough

to help preserve the lineage

in what is now a thriving empire.

Finding enough suitable habitat

is crucial for the survival of any species.

Especially those in need of rebuilding their population.

The gopher tortoises of southwest Florida

have a strong preference when it comes to choosing a home.

The habitat must have sandy soil for digging.

And it must also have plenty of food plants,

and open sunny areas for nesting and basking.

Open canopy woods,

like long leaf pine forests, are ideal.

But Florida has lost all but about 4%

of its pine forests, in the last quarter century

to development.

Simply put, the restoration of this keystone species

requires a helping hand.

In response, starting in the 1970s,

conservationists began fighting to protect

the gopher tortoise.

State laws were introduced

outlawing the harvest and disturbance

of tortoises in the wild.

And sanctuaries were built to provide safe havens.

Here at the Christopher Smith Preserve near Naples,

70 gopher tortoises make their home

on seven acres of scrub land.

The Conservancy of Southwest Florida

protects and maintains the habitat.

Still, real estate is at a premium.

And when space is limited,

territorial battles are inevitable.

These reptiles have a reputation

for being slow-moving and docile.

But when it comes to defending its home,

a tortoise can be fierce.

A test of strength and leverage ensues

with one turtle trying to flip the other over.

If it succeeds, the loser gets a death sentence.

A tortoise on its back is a dead tortoise.

It has no way to right itself.

Luckily, this conflict is settled without casualty.

The loser retreats,

in search of another place to start a home.

Once territory is established,

gopher tortoises spend most of their time

burrowing in the sand,

sometimes digging several yards deep

in a single day.

They have shovel-like front legs that help them to dig,

and their back legs are strong and sturdy.

Each burrow has a single opening.

They're easy to spot in the landscape

because of the characteristic mound

of loose sand at the entrance,

known as an "apron".

The width of the burrow is approximately equal

to the length of the tortoise.

This way, the tortoise is able to turn around

within the burrow.

Consequently, you can pretty much tell

the size and age of the tortoise

based on the width of his burrow.

The burrow is an ideal refuge,

a place for its occupant to hide from predators.

It also remains at a fairly constant temperature

and humidity year-round,

offering an escape from extreme temperatures,

drought and fire.

There's another reason an open canopy forest

is crucial to the gopher tortoise.

It's an ideal spot for its preferred food.

It feeds mainly on the leaves, stems

and flowers of slow-growing grasses,

cactus, pawpaw, berries, and other fruits,

all of which require abundant sunlight to grow.

The tortoise doesn't have teeth,

but uses its sharp beak to tear away foliage,

then pulls the food into the mouth with its tongue.

From these herbaceous plants,

the tortoise gets the nutrients it needs

for a busy day of burrowing.

It also gets most of its water from this food.

It rarely needs to find a drink.

All that greenery is hard to digest.

So it depends on worms and bacteria

in the intestines to break down the plants.

It helps spread the seeds of these plants with its droppings,

acting as a kind of gardener

that supports new growth throughout the habitat.

This dietary process is another reason the gopher tortoise

is such an important part of the ecosystem.

Starting in the early spring, it's time to breed.

During May and June, females lay

one clutch of 3-15 eggs,

either in a sandy mound in front of the burrow,

or in a sunny place nearby.

The eggs need heat to incubate.

But being out in the open poses a risk.

Tortoise eggs are a favorite snack

for raccoons, foxes, and snakes.

Hatching a full nest is rare.

With hungry predators lurking,

an individual female tortoise

will be lucky to produce a successful clutch

once every 10 years.

It's another challenge to the future of this species.

For the next three months,

the clutch will be especially vulnerable.

And the next generation of tortoises must survive

if this empire is to have a chance

to continue rebuilding.

Back in southern Louisiana,

nine months have passed at the Global Wildlife Center

and this female Père David's deer

has given birth to a healthy female fawn.

has given birth to a healthy female fawn.

Now the future of the empire is in the hands of the newborn.

Several aunts watch over the fawn,

also known as a calf,

in a group called a 'creche'

Like most species of deer,

the young doe can be identified by her spotted coat.

Though little is known about the species life in the wild,

the spots are likely a throwback

to their days in the marshes of China,

serving as camouflage from predators, like tigers.

Here, while the herd lives amongst

other animals in the wildlife center,

it is safely protected from potential threats.

The doe has a good chance of a long and healthy life.

And at about two years of age,

she will reach sexual maturity

and be eligible to start a family of her own.

Despite the genetic bottleneck of the captive herd,

disorders caused by inbreeding have been rare.

The world's David's deer population has grown.

So finally in 1986,

it was decided to reintroduce the species

to its native land.

22 deer were flown from Woburn Abbey in England

to Beijing, China,

where they were released into a wildlife sanctuary

in the area of the Old Imperial Park,

the same place where they were discovered

over 120 years before.

The transition was successful,

and the herd expanded.

To cope with newest inhabitants,

additional reserves were set up

in other neighboring parts of China.

But there was one more step

to the rebuilding of this empire,

their return to the wild.

In a fitting coincidence, a flood in 1998

allowed a handful of deer to escape

from a reserve south of Beijing.

They crossed the Yangtze River

to settle in adjacent marshlands,

where they remain in the wild today.

Lack of genetic diversity

still remains a long term concern.

Recently, 16 more deer were released

to join those in the wild in Hubei,

With the hope that the new additions

will boost the population.

There are now some 3,000 David's deer in China.

While the wild herd is growing,

most remain in protected sanctuaries.

Captivity has helped them bounce back

from the brink of extinction.

But it is up to these wild herds

to prove this species

can survive once again on its own.

Back in the UK, it's been just over a month

and the mute swan's eggs have hatched.

Young swans, or cygnets, come in two colors:

gray and white.

The white are known as "polish" chicks.

The gray, or "royal" chicks

eventually turn gray-brown and then white.

The young cygnets stay with their parents

for four or five months,

sometimes riding on their parents' backs

across the calm water.

These young chicks are especially vulnerable.

They need help foraging for food,

and can't fly until they're four months old.

Which makes them particularly attractive to predators.

So swan parents are very attentive.

By autumn, the cygnets' plumage is predominantly white,

and it's time for these young swans

to fend for themselves.

In about two years,

these young birds will begin breeding.

these young birds will begin breeding.

Today, mute swans are thriving.

In fact, in North America,

where they were introduced in the late 1800s,

they are so numerous and potentially damaging

to their adopted habitats

that they're culled in some states.

Here in Britain, even with their healthy numbers,

they remain protected.

But they're still illegally poached.

And water pollution is an ongoing threat.

For now, officials will continue to monitor

Britain's mute swans,

to ensure that the demise of the royal bird

is never repeated.

is never repeated.

While Britain's swan population has successfully bounced back,

and Père David's deer are on their way,

Florida's gopher tortoises continue to struggle.

The species' future lies in the hands

of the few remaining mating pairs.

For gopher tortoises,

the waiting game for new hatchlings

is much longer than it is for swans.

Eggs that escape hungry predators

hatch in about 90 days,

nearly three times as long as mute swan eggs.

The sex of a hatchling

depends on the temperature of the nest.

The warmer the sand,

the more chance the new tortoises will be female.

Once hatched, young gopher tortoises

may share an adult burrow

or dig a small burrow of their own.

It's crucial they get to burrowing as soon as possible.

They're born with a soft shell,

and are vulnerable to predators like raccoons, snakes,

black bears, and hawks, until the shell hardens

at about six to seven years of age.

Gopher tortoises have a relatively long life expectancy.

They can live more than 60 years.

They develop slowly.

Female tortoises reach adulthood

at 10 to 15 years of age.

If a tortoise doesn't make it to breeding age,

it won't have a chance to preserve its lineage,

and add to the population.

Those that do survive

must still find a home and a mate;

and they don't have many options.

In contrast to the mute swans and David's deer,

the gopher tortoise population remains in decline.

Development continues to put pressure

on the tortoise habitat.

On average, 1,000 new human residents

move to Florida each week.

The Florida Fish and Wildlife Conservation Commission

requires developers to relocate tortoises.

But relocation brings its own set of issues.

Moving sick individuals to new colonies

can unintentionally help spread disease.

Attachment to their burrows also means

that many try to find their way back home

after being moved.

Others search for a new habitat,

often drawn to the open, grassy lanes

next to busy roadways.

As a result, road kill

is one of the major causes of death

for Florida's tortoises.

And so, the gopher tortoise population

increasingly depends on sanctuaries

like the Conservancy of Southwest Florida.

Fences keep wandering tortoises

from the busy roads nearby.

Staff help rescue and care for those

that may be sick or injured.

And along with other conservation groups,

they are doing their best to give these rare reptiles

a chance to survive,

working to put a stop to the decline

of this animal empire.

Few species have stared extinction in the face,

and lived to tell the tale.

Père David's deer

and mute swans can make that claim.

They are the survivors of the wild kingdom.

For the gopher tortoise of the southern United States,

the struggle continues.

Threats loom for all three species.

The rebuilding process is ongoing.

They must continue to fight for their very existence

if there is to be a future

for their

for their animal empires.

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