Original subtitles

(upbeat music) (birds chirping)

There are not many places in

the world with mangroves.

We tend to view them as hard to navigate.

Full of tangled roots, mosquitoes, and mud.

But they are so much more.

Mangroves are one of the most important habitats on Earth.

The safeguard and the wellbeing of humans.

Not to mention being vital to many of

the planet's most extraordinary, wonderful,

and endangered species.

Everything from shorebirds to sharks,

and monkeys to manatees.

Once we explore this unique landscape,

it's not just wildlife,

but us who are drawn

to the magic of mangroves.

(bugs trilling) (birds chirping)

(light dramatic music)

(wings flapping)

In the dense, dark, intimidating tangle of a mangrove

a killer is on the move.

This is a Burmese python,

a formidable reptile.

(dramatic music)

(leaves rustling)

One of the longest snakes on Earth.

(light dramatic music)

Seven meters of muscle.

(dramatic music)

(leaves rustling)

(water trickling)

Expert in climbing and swimming,

and able to stay submerged for up to 30 minutes.

It's very much at home in native mangrove forest.

(light dramatic music) (birds chirping)

But this isn't Burma.

Thanks to the exotic pet trade

and some careless or thoughtless owners,

this snake is on the other side of the world from its home.

(dramatic music)

These of the Florida Everglades.

But since the 1970s, pythons have set up shop here.

It's warm and wet, a home from home.

Ideal habitat that's packed with food.

A multitude of species that have never met a python before

and have no adaptations to deal with such a predator.

(light dramatic music)

Small furry mammals, like the raccoon,

have declined by 99%.

And foxes and rabbits have all but gone

thanks to this exotic invasion.

(light dramatic music) (leaves rustling)

There might be 150,000 or more pythons in the Everglades

munching their way through everything from birds,

(wings flapping)

to deer,

(light dramatic music)

and even alligators.

(dramatic music)

(water trickling)

They're having a massive impact on the entire ecosystem.

A reminder of how finely balanced nature is.

The giant snakes have knocked this ecosystem out of kilter,

and some ecosystems are more important than others.

(light dramatic music)

(light guitar music)

Though mangroves are found in more than 100 countries

across the tropical and subtropical regions of the world,

they cover just 137,000 square kilometers.

About the size of Greece.

And yet, as we'll see, perhaps more than

any other landscape, they're vital to human health,

as well as a unique animal and plant community.

(birds squawking)

Here, plant life from land dips its toes in the water,

creating a magical in between place that

has massive benefits for the surrounding ocean

and the habitats inland.

Mangroves are among the most productive

and complex ecosystems on Earth.

They're comprised of a unique family of trees,

about 60 species in all.

United by incredible adaptations to their surroundings.

(light dramatic music)

They will have networks of roots that spread out

to anchor them in the soft sediment of the coast,

and aerial roots that can rise above the soggy ground

to absorb oxygen.

(light music)

And special salt glands in their leaves

which can extract and expel the salt

taken in from the seawater.

(birds squawking) (water trickling)

The biggest area of mangrove on Earth

is along the coastline of Indonesia.

A lush coastal forest area twice the size of Jamaica

and home to one of the most bizarre faces on the planet.

Female and young proboscis monkeys look a little odd,

but it's the male, with his fist-sized schnoz

that draws the eye.

The primates live in small family groups

with one adult male.

Therein lies the key to his distinctive profile.

Apparently, for proboscis monkeys, size does matter.

The bigger his nose, the more girlfriends

a monkey is likely to have.

The supersize snout not only has visual appeal,

but also amplifies his voice.

The bigger his nose, the better his barking.

The quality of the sound warns other males

in the area that a big boy's in residence

and seems to be a major turn on for the females.

(monkeys squawking)

This troop lives high in the canopy of the mangroves

but makes a daily downhill migration.

(upbeat music)

(leaves rustling)

Mangroves undergo radical changes during the day

as the tide rises and falls.

(monkeys squawking)

With the water levels lower, the monkeys descend.

The male stands guard as his dozen lady friends

and their young make their way down.

(leaves rustling) (upbeat music)

He brings up the rear.

They are totally suited to life in the trees

and hardly ever go to the ground.

All they're after are the lower branches

that can be out of reach at high tide.

(light music)

There are plenty of mangrove leaves here for them to eat.

But even the freshest young chutes they gather

are tough to digest.

Which is why proboscis monkeys

are unlikely to win bathing suit competitions.

Their rather portly stomachs are basically

big fermentation chambers to break down the tough foliage.

They waste no time in bingeing before the tide turns.

(light dramatic music)

Proboscis monkeys are good swimmers.

They even have partially webbed feet.

But they still prefer to avoid the deeper

water below the trees.

You never know what might be lurking there.

(monkeys screeching) (light dramatic music)

Crocodiles have learned to wait under the monkey's

favorite feeding spots.

(light dramatic music)

And the crocs of Australasia are the biggest in the world.

Salt water crocodiles.

The great reptiles get their name

because they can tolerate seawater

and move freely between rivers and the coast.

(birds chirping) (water bubbling)

The mangrove in between is an excellent place to hunt.

Ambush predators.

They try to get as close as possible,

ready to launch their attack.

A large family means many eyes to spot danger,

(dramatic music) (water splashing)

but this time the alarm call came too late.

(dramatic music) (water splashing)

The rest of the troop watches in horror from a safe height.

(somber music) (water splashing)

Time to go.

(monkeys squawking)

They need some downtime after breakfast anyway,

to let their big bloated bellies do their thing.

(light music) (birds chirping)

(water splashing)

The rise and fall of the tide

can transform coastal mangroves.

Asian mangroves, like these in Japan,

can see big shifts in water level.

As the tide retreats,

(light dramatic music)

tiny armies march into action.

Soldier crab maneuvers have military precision

as they invade the mud.

(light music)

Moving in squads, they're less likely

to be picked off by predators.

With safety in numbers, they scan the sand,

snatching up any edible detritus left by the sea.

Fiddler crabs, on the other hand, don't like company.

(playful music)

They prefer to dine alone.

But space on the mudflats is in short supply.

With a single enlarged claw, they beckon

like traffic wardens giving directions

for the neighbors to back up.

Anyone ignoring the message might resort to an arm wrestle

to settle the score.

The beach cleanup crew don't have time to argue.

In just a few short hours the tide seeps back

into the mangroves and the crabs must return to the mud.

(birds squawking)

The reason the crabs have adopted this lifestyle

is because the mud beneath the mangroves

offers a good living.

(water bubbling) (light dramatic music)

With food both washed out from the land

and washed in from the sea.

(light dramatic music)

But they make sure they're safely tucked away

ahead of the returning tide

because it's not only food that the sea can bring in.

(dramatic music)

Lemon sharks.

This time cruising in the waters of Florida's mangroves.

(water bubbling)

The deeper water allowing them to get

right in under the trees.

(light dramatic music)

They forage by nuzzling under rocks looking for shellfish.

(dramatic music)

Horseshoe crabs draw their eye.

(light dramatic music) (water bubbling)

But they're too big.

(light music)

These sharks are tiddlers, baby sharks,

using the mangrove as daycare.

Sharks don't look after their babies,

but their mother was careful to give birth in the mangroves.

So that from the word go, the pups could take shelter

in the tangle of roots.

(light music)

As sharks go, they're pretty cute and friendly,

and have allowed researchers to study them closely.

Revealing that they have individual personalities,

make friends with each other, and can even be taught tricks.

(light music) (water bubbling)

They'll hang out here, learning the ropes,

until they're 10 to 15 years old.

Big enough to head offshore and stand up for themselves.

Sharks are not the only fish to cash in

on the protective root systems of mangroves.

Warm and sheltered, the waters are ideal

places for young life.

(birds chirping)

The roots make fantastic playpens for a myriad of baby fish.

(water bubbling)

Some fish species spawn in the mangroves,

laying eggs so the young hatch here.

While others spawn at sea, but their planktonic babies know

to make their way here for safety.

(water bubbling)

(birds chirping)

Many commercially important marine fish begin

their days here in the mangroves.

And the colorful fish life on coral reefs,

so loved by human divers, is dependent on

the mangroves for child rearing as well.

(light music) (water bubbling)

Coral reefs that are close to mangroves

have 25% more fish on them than those that are not.

That's the quality of childcare the forests offer,

sheltering and feeding the little ones

and keeping them out of the reach

of the bigger predators of open water.

But there are hunters that have learned to cash in.

A lava heron uses the aerial roots as a handrail

to lower itself carefully into place.

(upbeat music)

It's a spear fishermen.

(water bubbling)

But here in the mangroves of the Galapagos Islands,

it's got competition.

(light dramatic music)

These fish face attack from both above

and below the surface.

(suspenseful music) (water trickling)

In both cases, from birds,

(light dramatic music)

Galapagos penguins.

(light dramatic music)

The birds are critically endangered

and depend on the rich pickings in the mangroves.

(light music)

Small and maneuverable torpedoes in tuxedos.

(light music) (water splashing)

They can dash in around the tree roots.

(water bubbling) (light music)

The fleeing fish reward the herons' patience as well.

(water bubbling) (light music)

Despite the occasional avian invasion,

mangroves remain a safe haven for many.

Green turtles are long distance travelers.

After months of ocean crossing journeys,

many seek the chance to rest and warm up,

preparing themselves for the breeding season.

(water bubbling)

The mangrove trees absorb the impact of waves

on the coastal side, but further into the forest,

create lagoons where the water is still and safe.

Shallow and protected, the water is warmed by the sun.

A hot bath for chilly turtles.

(light music)

These warm water spas are a vital stopoff

for many marine species.

Especially important here in the Florida Everglades,

manatees are three meter long gentle giants.

The only vegetarian marine mammals,

they have to munch through 10%

of their body weight every day.

And the mangroves supply a smorgasbord.

But it's more important than just a snack bar.

Truly marine, manatees can roam out to sea,

ranging from the north coast of South America

across the Caribbean islands and Central America

and along the Southern Atlantic coast of the USA.

But this marks the end of their habitat.

The limiting factor: cold.

During winter, North America's manatees

can suffer from hypothermia if they don't seek

warm water sanctuaries.

(light music)

As the salinity changes,

barnacles and other pests acquired at sea fall off,

and over time, algae grows.

The mangrove fish are more than happy

to give them a body wash.

(light music) (water bubbling)

With solid bones as ballast,

manatees can spend hours resting in

the shallows enjoying the warm.

(birds chirping)

(water bubbling)

It's even more important to this mother,

giving her a place to raise her young calf.

(calf squeaking)

In deep waters it might be at risk of shark attack,

but here it can safely follow her around

and enjoy her rich milk.

(light music)

The mother will look after this little one for two years

safely in the mangrove's custody.

It's not just marine creatures that depend on mangroves,

everything from monitor lizards

to monkeys

and even cassowaries.

(light music) (ground rustling)

The huge flightless birds live in the tropical forests

of Australasia and wade into the mangroves

to look for fallen fruit.

(water splashing)

Their sensitive hearing picks up on every splash.

(water splashing)

And their eyes are drawn to bright colorful objects,

helping them locate the ripest fruits.

(water splashing)

(light music)

(gargling)

The birds prefer to forage alone.

Females might rendezvous with males briefly,

but they don't stick around.

(ground rustling) (birds chirping)

Cassowaries are always raised in single parent families

with a protective dad who shows them how

to find their way around the mangroves.

(light dramatic music)

Many birds thrive in these unique forests.

(suspenseful music) (birds chirping)

Ospreys are widespread and often feed

and breed in mangroves.

In many regions, they're migratory,

but the warm, rich mangroves can provide

for them year round.

(birds squawking)

Pairs often use the same nest year after year.

Adding branches with each use, building huge platforms.

They're among the most accomplished fish catchers.

(bird squawking)

Which is just as well.

The appetite of their chicks is unending.

The secretive, skulking, yellow crowned night heron

waits patiently

for the tide to retreat.

(light music)

At first the mud banks look barren,

but all it takes is a falling leaf.

A knock on the door, home delivery.

(light music) (rustling)

It's enough to tempt a blue land crab from its burrow.

But the wary crustacean isn't going to give

up without a fight.

(light country music)

(ground rustling)

(bird squawking)

(water splashing)

During the summer, fish can be concentrated

in shrinking pools in the Everglades

at the back of the mangrove,

making them easy for white ibis to pick off.

(water splashing)

Pelicans don't mind hunting in the more open water

on the front side of the forests.

(water splashing)

Scooping with their big beaks to snag fish,

though they don't mind taking advantage

of a visitor from the coast.

(water bubbling) (dolphins screeching)

Bottle nosed dolphins frequent the edge of the mangrove,

knowing the treasure trove of fish it attracts.

They can work together to drive fish into tight balls

and chase them into each other's mouths.

(water splashing)

They can even force them to the shore,

trapping them against the bank.

The pelican can make sure it's in the right place

at the right time.

(dolphin chittering)

Mangroves don't just provide food,

but safe nesting places for birds.

Different species cram close together.

They are safer in a busy community

with many pairs of eyes to spot danger.

Though the best spots are in short supply,

so neighborly disputes compete with the racket

from chicks begging for food.

(leaves rustling) (birds squawking)

Though they live together,

each of the birds has its own niche,

so they might compete for space, but not food.

(light dramatic music) (birds squawking)

The lightening fast dagger beaks of egrets

and herons snatch small fish.

(light music)

Woodstocks go for larger fish.

The biggest birds, lords of the colony,

they tend to snatch the best spots high up in the branches.

It's mostly the male birds that build the meter-wide nests,

both parents brood eggs and young.

The chicks are never alone

for their first three weeks of life.

(light dramatic music)

White ibis tweeze smaller prey with delicate jaws.

Their scowled heads contrasting

with their snow white feathers.

Though it's the rosy spoonbills who steal the show.

A lot of the stunning pink comes from their food.

Like the rosy turns of flamingos.

The spoon bill enables it to sift little shrimps

and other invertebrates that are abundant

in the waters of the mangrove.

The broad spoon is covered in tiny receptors

that can detect the movement of prey

that would be impossible to see in mud and murky water.

(wings flapping) (birds squawking)

(upbeat music)

All of the birds tirelessly ferry food to their hungry young

creating an endlessly moving noisy throng.

By building their colonies in trees over

hanging waterways, they're out of the reach

of land predators and the creatures of the water.

Mostly.

(light dramatic music) (birds squawking)

There's one hunter here that has developed

a rather clever skill.

Alligators are rare in the mangroves.

Unlike all other crocodiles, they lack salt glands,

and so only occasionally come into the brackish water.

But this one's brought a tool.

Everglades alligators have been observed waiting patiently

with sticks on their heads under the bird colonies.

(light dramatic music)

It's bait.

The gator can simply wait for an egret

to spot the stake, perfect for completing its nest.

(water splashing) (dramatic music)

(light dramatic music) (water splashing)

The creatures of this unique landscape exhibit skills

and adaptations as special as the mangroves themselves.

(light music)

Just as mangrove bridges the gap between water and land,

so does one of its liveliest inhabitants.

(water splashing)

Fish with lofty ambitions.

(bell dings)

Like our ancestors that crawled from

the water nearly 400 million years ago,

here are fish that prefer to feel terra firma

beneath their feet, or at least beneath their fins.

Mudskippers.

(water splashing)

Several dozen species of these specialist gobies

make a living in mangroves, seeking the best of both worlds.

Humans take a mouthful of air before diving into water.

Mudskippers do the opposite.

A mouthful of water that will sit in their gills,

a mini oxygen tank allowing them to breathe.

They're actually happier out of the water than in it,

but must find puddles from time to time to dunk their gills.

Strong fins enable crawling and even some impressive hops,

helping them to navigate the mud.

(water splashing)

During high tide, they hide in their burrows on the sea bed

safe from marine predators.

But when the water retreats, they rule the beaches.

(light dramatic music)

Marching across the mud to nibble on algae

and invertebrates the sea left behind.

They're not the friendliest fish.

Each ready and willing to defend its patch.

Flying their flags, ready to wage war.

(light dramatic music)

Fights can't go on for too long,

because sooner or later, the water will seep back in

and the free roaming fish of the land

will need to hide away.

(light dramatic music)

Mangroves have some of the most diverse

animal communities on the planet.

They have virtually everything, even their own deer.

(grass rustling) (bugs chirping)

The key deer of the Everglades

is a miniature version of the white tailed deer

more familiar across the United States.

Thousands of years ago, a small population of deer

were cut off by the rising sea levels

and evolved in isolation.

(water trickling) (birds squawking)

Land bridges reformed along the Florida peninsula,

rejoining the mainland.

(baby deer squawking)

But the little dog-sized deer remained unique.

They only live on the little islands of the Florida Keys

and have many adaptations to their unusual lives.

They are excellent swimmers.

(water bubbling)

Useful for a bit of island hopping.

They love to eat the mangrove leaves,

and can even tolerate the odd sip of salt water.

But despite their adaptations, the key deer is endangered.

(light dramatic music)

In the 1950s, only about 25 deer remained.

(ground rustling)

They became one of the first animals ever protected

by the Endangered Species Act.

But even today, hunting, human disturbance,

and loss of habitat keep the deer's population

down below 1,000 individuals.

The deer remain vulnerable, and so do mangroves themselves.

(dramatic music)

(bugs chirping) (birds chirping)

Threats include dredging, filling in,

pollution from farming, increasing boat traffic,

and the development for waterfront homes.

(light dramatic music) (water trickling)

When mangroves are destroyed

they release a lot of carbon dioxide.

This adds to the impact of greenhouse gases.

Changing global climate conditions.

Mangrove destruction is madness.

(flies buzzing) (light dramatic music)

Mangroves are vital, not just to the animals that live

in them, but to human populations all over the world.

(wind whistling)

During major storm events, like hurricanes and tsunamis,

that are ever more severe thanks to climate change,

they have proven to directly prevent billions of dollars

of flood damage and have protected millions of human lives.

(water bubbling) (light dramatic music)

Their dense tangles of branches along the coast

take the power out of storm surges

and absorb the impact of waves.

(light music)

They stopped coastal erosion,

and thanks to their roots that bind and collect silt,

they can actually build up and repair the coast.

Their roots filter out nitrates, phosphates,

and other pollutants, improving water quality.

The plants capture huge amounts of carbon dioxide

and greenhouse gases from the air

and lock them into their carbon-rich soils for millennia.

(water bubbling) (light music)

Therefore they're critically important

in climate stabilization.

Probably moreso than rainforests.

In some regions they're four times more effective

in removing carbon than jungles.

The mangroves also create nurseries for wildlife,

including many species of fish that are vital

to fishing economies and that feed local communities.

Especially in countries with mangroves where half

of the fish harvest is dependent on the forest.

(light music) (birds chirping)

They also provide livelihoods.

The timber from mangrove trees is water resistant,

ideal for houses, boats, pilings, and furniture.

(light music)

It's also burned for fuel and used to make charcoal.

Tannins for making leather and dyes

can be extracted from its bark.

The leaves are used to make teas, medicines,

livestock feed, and a tobacco substitute.

And that's not to mention the good they do us

by creating green spaces.

Where we can go snorkeling, kayaking, paddleboarding,

and get some free relaxation therapy from nature.

(light music)

(dramatic music)

35% of the world's mangroves have been lost

in the past 40 years.

(engine rumbling)

And still, 1% is lost every year.

One in six mangrove species is threatened with extinction.

(light dramatic music)

Without them, coasts are barren.

The productivity held there by mangrove roots

is washed away, fisheries collapse,

water becomes polluted,

(thunder rumbling) (rain pattering)

and communities are vulnerable to storm damage and flooding.

With sea levels rising, more than one billion people

in lowland areas are at risk.

It's thought mangroves could provide one trillion dollars

worth of sea defense if properly managed and protected.

(light music)

Mangroves have an estimated value to a nation

of 30 to $60,000 per hectare.

Surely worth protecting.

But if current trends continue,

they'll be gone by the end of the century.

We need this beautiful bio shield.

It's much more effective than any human-built sea defense

and does so much more besides.

(wings flapping) (light music)

Given a chance, mangroves grow fast and spread like weeds.

They can rebuild even around cities and protect us.

(engine rumbling)

Their rich animal communities can thrive,

and we'll be able to enjoy the benefits and the magic

of mangroves for many years to come.

(light dramatic music)

(water bubbling)

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