Original subtitles

(THEME MUSIC)

(GENTLE MUSIC)

NARRATOR: During the wet season,

most of northern Australia becomes a tropical seasonal wetland.

These vast swamps support

the world's largest breeding colony of magpie geese.

They also provide a habitat for the Top End's top predator -

the prehistoric saltwater crocodile.

If you think this well-armoured warrior is big,

just give him a few more decades to pump himself up

and rise through the ranks.

By the time he's the boss croc around here, he'll be well over 5m long.

Saltwater crocodiles,

or salties as they're affectionately known in Australia,

are the world's largest living reptiles.

The biggest in captivity today is over 6m...

and weighs just over a tonne.

Saltwater crocodiles never actually stop growing

and they can live for 70 years.

Once hunted for their skin and meat, they are now protected in Australia,

and populations throughout the north are healthy, to say the least.

In the Northern Territory alone,

there are estimated to be at least 100,000 salties

lurking just beneath the surface, ever ready to take down prey.

It's almost impossible not to fear these prehensile creatures.

But they command in equal measure our respect.

Millions of years of evolution

have finetuned them into the ultimate wetland predator.

The forward orientation of their eyes

allows them to expertly judge the distance of unsuspecting prey.

And a third transparent eyelid means

they can see as well underwater as above.

They can slow their heartrate down to a couple of beats per minute...

a very Zen-like skill that helps them to hold their breath underwater

for up to an hour.

(TENSE MUSIC)

A saltie's jaws contain 64-68 dagger-like teeth...

with a bite force to rival that of a great white shark.

Their jaws contain an additional joint

that helps to spread the full force of their powerful bites

so they don't lose their grip in the middle of an attack.

Crocodiles cannot chew, but will manipulate their prey

to move it closer to the back of their throats before swallowing.

The safest way to encounter saltwater crocodiles is from a distance.

Wildlife guides are experienced

in knowing exactly when it's appropriate to move in for a close-up

and when it's better to slowly back away.

(JAZZY MUSIC)

For a closer encounter still,

consider swimming with these notorious maneaters.

But make sure you're well protected by a cage such as this,

or you'll risk being eaten alive.

Salties are the largest reptilian predators on the planet.

But even they lack the size and strength

to take down this gargantuan beast.

Water buffalos grow to 1.8m at the shoulder,

and have lethal horns up to 2m wide.

A young one would be fair game for a croc,

but once they reach their adult size, they are pretty much invincible.

Water buffalo are not native to Australia.

They were introduced from Asia by settlers in the 1800s...

who brought them here to ensure they had a reliable source of meat.

Then, slowly but surely, they took over the seasonal wetland,

and the entire character of this landscape was altered.

They trampled vegetation, eroded the soils...

created deep channels and interfered with the quality of the water.

Their habit of wallowing muddied the water,

making it difficult for certain aquatic plants and fish to survive.

As they degraded the habitat,

they disrupted the nesting activity of magpie geese and crocodiles.

So even these normally prolific species were compromised.

At the height of their domination,

some 350,000 buffalos roamed the nation's Top End,

but culling has now reduced their population considerably.

Here in Kakadu National Park, they number in the low hundreds.

It's ironic

that these impressive animals need to be kept in check in Australia...

for in their native homelands across Asia they are a species at risk.

Without the protection afforded by nature reserves and national parks

in India, Nepal and Thailand...

their survival in the wild would be completely compromised.

And with access to some form of boat or land-based hide...

birdwatchers can have a field day

adding sightings of various species of herons and cranes

to their endless checklists.

All wading birds have long thin legs

that help them to forage in deep water.

And long agile toes that aid their balance

when the ground beneath them is unstable.

Many wading birds have long bills,

shaped according to how they hunt and what they eat.

One special place tailor made for waders

is the Birds of Eden sanctuary in South Africa.

A huge dome covering several hectares

affords the birds here a measure of protection

and yet the freedom to fly.

A walkway through the enclosure

makes it easy to view some of Africa's most iconic wading birds.

Including these magnificent and aptly named spoonbills.

One of the more spectacular species visitors can encounter here

is the scarlet ibis, whose native habitat is half a world away.

To see these beautiful birds in the wild

you'll need to head to Los Llanos, in Venezuela.

A vast landscape of plains, rivers and swamps

stretching from the Andean mountains to the Caribbean Sea...

Los Llanos provides sanctuary to a strange collection of animals.

Primeval birds with claws on their wings.

Rodents the size of sheep.

And snakes the length of five people.

In total, Los Llanos covers over 500,000 square kilometres.

For more than half the year,

these plains receive almost no rainfall at all

and sizzle under drought conditions.

(THUNDER RUMBLES)

But when the rains fall, they totally transform the landscape.

(JAZZY MUSIC)

The grassy plains - where the local cowboys, or Llaneros, hold court,

rounding up their cattle on horseback -

become inundated with water.

Los Llanos becomes a wetland wonderland.

It's Venezuela's greatest treasury of wildlife,

and its animals are some of nature's crown jewels.

Believe it or not, this capybara is a kind of guinea pig...

but it towers over every other rodent on the planet.

Despite their fearsome size, capybaras are gentle creatures,

spending most of their time grazing or napping.

They're well adapted to living in water.

In fact, they even have webbed feet,

and their eyes, ears and nostrils are all near the top of their heads

so they can hide their bulk underwater.

Apparently, capybara meat tastes delicious.

So much so, the Spanish colonialists who arrived here in 1500s

appealed to the Catholic Church

to have the capybara classified as a fish

so they could eat it on Fridays

and other occasions when religious fasting needed to be observed.

Despite the fact that capybaras are quite clearly mammals,

the Church conceded to the argument

that an animal with webbed feet that lives mostly in the water

could be called a fish.

Another oversized animal

that frequents the swampy backwaters of Los Llanos

is the giant green anaconda, the largest snake in the world.

Just seeing one of these huge reptiles up close

gets the adrenaline going.

So spare a thought for these scientists

charged with extracting boas from the field

in order to study them more closely.

Despite their intimidating looks, these snakes are not venomous.

They hunt by coiling themselves around prey

and squeezing until it's asphyxiated.

The largest anaconda ever measured

was just over 8.5m long with a 1m girth.

This one is considerably smaller,

but still a handful for these scientists to contend with,

as they attempt to collect and record

data that will help them to determine its growth rate and overall health.

(MAGICAL MUSIC)

Another extraordinary place

to encounter the best of South America's wetland animals

is the Pantanal.

Indeed, it's the largest tropical wetland in the world...

awash with lakes, waterfalls and crystal-clear rivers.

Covering a daunting 181,000 square kilometres...

it contains one of the highest concentrations of wildlife

on the continent.

The jaguar's share of this UNESCO World Heritage site is in Brazil.

And a key access point for exploring some of its amazing biodiversity

is Bonito.

A short trek leads animal lovers through the jungle

that lines the Rio da Prata.

It's possible to encounter capybaras here.

And if you're really lucky, armadillos and tapirs.

Despite their pig-like looks...

tapirs are closely related to horses and rhinos.

Jaguars sit at the top of the food chain here...

and despite the fact that they are excellent swimmers,

there's no need to fear an unexpected encounter here.

The water is so clear, you'd see them coming for miles.

What you will see below the surface of the water, however,

will completely blow you away.

A swirl of orange-tipped fish.

(MAGICAL MUSIC)

The whole experience is quite surreal.

And it's heartening to know

that a place this pristine still exists in the wild.

NARRATOR: The Pantanal is truly a remarkable wetland,

but it's far from the most well-known eco region in this part of the world.

That honour belongs to the Amazon, South America's most iconic river.

Nearly 6,500km long, it snakes its way across seven countries.

The rainforests on either side of the Amazon...

hold a greater diversity of life than any other place on Earth.

20% of the world's oxygen is made by the plants of the Amazon.

And the number of different animals here is simply phenomenal.

Hundreds of mammals...

thousands of birds and fish...

and millions of creepy-crawly insects.

During the wet season, the Amazon floods

and the width of the river expands.

In some places, it can be over 190km wide.

One of the most amazing creatures of the Amazon

spends its life underwater.

And thanks to Hollywood's horror movie heavyweights,

its reputation is unfairly tarnished.

Scientists dispute the whole Hollywood myth

that a school of piranha can devour a person in a matter of seconds.

They believe it would take 300-500 of the tiny fish

a good five minutes to consume a fully grown human.

So really, why all the fuss?

Lurking beneath the water hyacinths, growing to nearly 3m long...

the manatee is one of the Amazon's largest animals.

Notoriously shy,

even expert guides would count themselves lucky to see one.

Fortunately for animal lovers the world over,

there's a rescue centre in Peru

where sightings of these curious creatures are 100% guaranteed.

The Amazonian manatee is one of only four manatee species in the world.

It's slightly slimmer than the other manatees,

and unlike its Caribbean and African cousins,

has no nails on its flippers.

Sometimes called sea cows, manatees are gentle creatures.

They are herbivores that only eat two types of plant in the wild -

water lettuce and hyacinth.

With each 300-plus kilo animal

needing to consume 8% of its body weight every day,

they sure put a dent in the salad bar.

To help them contend with all that chewing,

manatees have quite unique teeth.

They're the only mammals

that constantly replace their worn-out molars

with new teeth that grow at the back of their jaw,

moving forward when needed.

Manatees once lived throughout the Amazon basin...

but thanks to high demand for their meat and oil,

these lovely creatures are in serious decline.

But with careful human intervention,

the Amazonian manatee population is slowly recovering.

North America's wetland is a complete contrast to the Amazon.

It has very few trees

and is dominated by one slow-flowing river...

nearly 80km wide.

They call it the Everglades,

and it takes up most of the southern tip of Florida, in the USA.

It's easy to see why

this unique combination of shallow water and prairie

is often called a river of grass.

It too is home to a manatee, the West Indian species,

a larger relative of the Amazonian one.

It's not only possible to encounter Florida's manatees underwater -

here in the Kings Bay Wildlife Refuge, it's actively encouraged.

These gentle giants are mesmerising to watch...

curious and comfortable in the presence of humans.

There are more manatees here in the Crystal River during winter,

as most migrate in the summer,

travelling as far as Mexico or Massachusetts.

Not far from the city of New Orleans, on the southern coast of America,

are the swamplands of Louisiana...

a wetland brimming with opportunities

to encounter the state's top predator, the American alligator.

Alligators are not as big as saltwater crocodiles

but they're still a lot of primeval reptile to contend with,

growing up to 4m long.

Needless to say,

everyone in Louisiana treats them with a healthy respect.

Alligators are well-armed apex predators,

with a preference for eating fish, snakes and small mammals.

An opportunist, an adult gator will also go for carrion,

the occasional pet dog and sometimes their two-legged masters.

By the mid 1900s, they'd been hunted to the brink of extinction.

But effective protection, coupled with habitat preservation,

and a reduced demand for alligator products,

have allowed the species to recover.

The wild alligator population

is now estimated to be over a million and growing.

The Great Rift Valley, a series of cracks in the earth,

threatening, in time, to pull the continent apart,

is best known as the place where mankind was thought to have evolved.

But we humans are just one species to have made a home for ourselves

in this magnificent part of the world

awash with the wonder of wetlands.

Many of the Rift's great trenches now contain lakes,

and these lakes are a haven

for an astonishing concentration of wildlife.

Lake Naivasha, in Kenya, is one of the easiest to get to,

a mere 100km from the capital, Nairobi.

The animals you're most likely to encounter here

are impressive to say the least.

This giant resident needs both water and grass to survive,

so it's settled in well to Naivasha.

The hippopotamus can eat 1.5 times its body weight in a single day.

And when you consider

that a full-grown male weighs around 3.5 tonnes,

that's clearly a lot of food.

The hippos around Lake Naivasha

feast mainly on the papyrus grasses fringing the swamps.

They have to spend at least five hours a day eating just to survive.

But they generally do this at night.

By day, hippos tend to while away the hours cooling off in the water...

or resting in the shade, trying to keep out of the sun.

Hippos do not have sweat glands, so they can overheat quite quickly.

Their thick skin can crack if it's exposed to the air for too long.

Fortunately, however, they secrete a special oil

to protect themselves from the sun's harmful rays.

Despite its alarming red colour, it doesn't contain any blood.

It forms a kind of varnish that keeps the hippos' skin moist.

It also acts as an antibiotic, and heals infections effectively.

The hippos' proportions are daunting,

but it's hard to get past that remarkable jaw-dropping mouth.

Tusks in a male can get to 50cm long.

And while they do wear down, they never actually stop growing.

Male hippos fight terrible battles

when it comes to winning the right to mate.

Females will fiercely protect their young.

And males are very territorial,

so any encounter needs to be from a safe distance.

Hippos cause the most human fatalities

of all the animals in Africa,

so visitors to Lake Naivasha need to remain vigilant at all times.

Despite their land-loving ways,

a hippo's closest living relatives are whales.

Their ears and nostrils close completely when they're submerged,

and they have a strange way of hearing underwater

that's similar to that of a dolphin.

They use their lower jaws to pick up sounds,

which are then transmitted to their ears via fatty tissue.

As wild habitats throughout the Great Rift Valley continue to diminish,

hippo numbers continue to fall.

But for the time being, at least, protection appears to be working

for those lucky enough to have chosen Naivasha as their home.

(INTRIGUING MUSIC)

Two hours' drive from Lake Naivasha

is one of the most hostile wetlands on earth...

Lake Nakuru.

The water here is so caustic it could burn human skin.

The soda lake contains so many salts and minerals

it repels most of Africa's animals.

But one creature positively thrives here.

Over 1.5 million flamingos live in and around Lake Nakuru.

They're perfectly adapted

to survive conditions that would prove fatal to most.

Tough scaly skin on their legs prevents them from burning.

They have special glands in their heads

to remove salt from the water when they're drinking,

which then drains out through their nasal cavities.

They eat cyanobacteria, an organism that grows here in vast pink drifts.

It's a highly toxic creature

that would destroy the liver and nervous systems of lesser animals.

But the flamingo can eat it with gusto.

The only visible effect it seems to have on the flamingos

is evident in their feathers.

All that pink algae is the cause of their scintillating colour.

Flamingos feed by sweeping their bill upside down through the water.

Filters within catch the microscopic algae floating in the water and mud.

Flamingos can fly fast and travel far...

up to 1,500km.

So one wonders

why they would've chosen such a hostile niche for themselves

in the first place.

Certainly flamingos in other parts of the world

have settled into less extreme places

and adapted well to less challenging lifestyles.

But in adapting to this particularly toxic environment,

Africa's flamingos find themselves with very little competition

and a measure of protection from predators.

When hyenas, jackals or eagles attempt an attack,

all a flamingo need do is wade into the caustic water to stay safe.

NARRATOR: Africa's most famous wetland

lies in the middle of the desert...

and it floods just as the land around it begins to dry up.

This is the Okavango Delta...

a massive body of water in northern Botswana.

The water that fills it each year

comes from seasonal rains in the highlands of Angola,

ultimately flooding 15,000 square kilometres of land.

Seeing this landscape and all the animals drawn to it from the air

is an unforgettable experience.

The delta is a lifesaver for animals from far and wide...

a seasonal home to over 500 different bird species...

300 mammals and reptiles and countless insects.

But the most impressive to see on the move

are those that have come to this wetland oasis from the plains...

great herds of zebra and impala, giraffes and elephants.

This is a dynamic environment.

Every year, the layout of the wetland is different,

thanks to a range of pressures.

Sediment and vegetation block certain channels,

while seismic activity and movements of hippos

open up completely new ones.

Eventually the Okavango Delta peters out,

with the water evaporating into the tropical air

or sinking into the thirsty desert sands.

(MAJESTIC MUSIC)

The Okavango is not the only wetland in Botswana

where water-loving animals congregate.

This remarkable country

has 17% of its land devoted to wildlife protection.

But its very first national park was Chobe.

The land around the Chobe River, in north-eastern Botswana,

has been a haven for wildlife since 1968.

Decades of tireless conservation

have allowed Chobe to build a veritable menagerie of wild animals -

including the largest elephant population in Africa, 120,000 strong.

Getting close to these remarkable animals

is a powerful, life-affirming experience...

especially during the dry season, between April and October,

when they tend to congregate along the Chobe River.

African elephants are the largest land animals on earth.

A full-grown bull can be 4m tall at the shoulder and weigh 6 tonnes.

Bull elephants tend to lead semi-solitary lives,

wandering alone or in loose-knit bachelor herds.

If you encounter a large herd of elephants of all ages and sizes,

they're probably all females and their young.

Female elephants will spend their entire lives in herds such as these,

living as one big extended family -

mothers, grandmothers, aunts and sisters

plus an assortment of their offspring.

When a baby is born,

every member of a herd will help to raise the young elephant.

Female elephants will only carry one calf at a time,

and since each pregnancy lasts for nearly two years,

they will likely only calve four times in their lives.

Young calves are not fully independent

until they are around 13 or 14 years old,

and reach their full size around 20.

Both males and females have tusks,

a major tool in their quest for survival.

Each tusk is an overgrown incisor...

but unlike human teeth, they never stop growing.

Another standout feature of African elephants is their trunks.

They contain 100,000 muscles and tendons, and can stretch out to 3m.

The finger-like tip of the trunk can perform delicate tasks

like picking a berry or selecting a single juicy leaf.

These massive animals are herbivores,

so they have no interest in attacking humans unless they feel threatened.

Grass and leaves do not contain a huge amount of nutrition...

so an elephant needs to eat over 100 kilos a day to stay alive.

They also need to drink up to 200 litres of water.

Despite their bulk, elephants are able to swim.

They can also walk on river bottoms using their trunks as snorkels.

Those enormous ears also have a range of uses beyond hearing.

They are excellent cooling devices...

and an important means of communication.

Flapping ears are known to signify aggression or joy,

depending on the circumstances.

Elephants have amazing hearing.

They can pick up sounds from 10km away.

With a brain three or four times bigger than a human,

elephants are capable of intelligent communication,

and are known to have exceptional memories.

They also show a complex range of emotions,

expressing compassion, joy and grief.

The elephant's capacity for sadness is well documented.

They are known to mourn the loss of a loved one in a very human-like way.

(POIGNANT MUSIC)

Small wonder we find these huge animals so fascinating and endearing.

NARRATOR: Australia's largest lake usually contains no water at all.

Most of the time,

it's just a shimmering saltpan stretching as far as the eye can see.

When water does trickle into Lake Eyre,

or Kati Thanda as it's known to the local aboriginal people,

it comes from the rivers of Australia's central deserts.

It only rains sufficiently here to fill the lake occasionally,

perhaps once every eight years.

Even when it buckets down, the water behaves somewhat erratically.

The channels feeding into the Kati Thanda basin

decrease their flow as they move downstream.

The flat nature of the land and the hot air that passes above it

conspire to force the flow to either spread out or evaporate.

Any water that actually reaches the lake tends to be very salty.

The lake bed is the lowest point in Australia, 15m below sea level.

So when rain falls, Kati Thanda is totally transformed.

Central Australia's vast floodplains turn into wetlands,

brimming with life.

News travels fast in the natural world,

especially when there's food around.

Birds normally found living by the seaside

suddenly descend on central Australia.

Pelicans arrive in their tens of thousands.

The Australian pelican has a wingspan of nearly 3.5m.

And as you might expect, they're impressive travellers.

They can soar thousands of metres into the sky

and stay airborne for 24 hours.

Between 30 and 50,000 pairs

will arrive to take advantage of this instant inland bounty.

Many will have flown halfway across Australia,

so there's no doubting they're hungry.

Pelicans can fit 13 litres of water in their bills,

but here, they're more interested in fish,

supplemented by the odd turtle or frog.

They're big birds with big appetites.

And once they're refuelled,

it's on to the important business of mating and nesting.

Incredibly, scientists now believe

that pelican chicks communicate with their parents from inside the egg...

indicating when they're too hot or too cold...

which in this harsh landscape could be crucial to surviving incubation.

The chicks in their eggs have also been listening to

the unique sound emitted by their parents.

When they emerge, they recognise them straight away,

despite their uniform appearance.

Hatching happens after 35 days,

and both parents take care of their young.

The entire pelican community

contributes to the wellbeing of the chicks,

corralling them into boisterous creches.

Parents can leave to find food

knowing their offspring are well taken care of.

Chicks need to grow fast.

They need to start their flying lessons

when they're only three months old.

Kati Thanda will not remain a lake for long,

and when it dries out,

the young pelicans must be ready to make the 1,500km journey

back to the coast.

Nestled in the southeast of Australia,

the Great Otways National Park

is a diamond of land wedged between the mountains and the sea

200km west of Melbourne.

It provides a haven for some of Australia's strangest animals.

A carnivorous beast with a fierce nature and striking spots.

A spiky ant-eating ball of weirdness

with a tongue half as long as its body.

And this strange creature patrolling the main waterways.

A shy, secretive animal with venomous spurs on its heels,

a bill like a duck, and a fur coat that's thicker than an otter's.

It owes its existence to the evolution of mammals and birds

as they began to diverge 280 million years ago.

But of the many species of egg-laying mammals, or monotremes,

that developed at that time,

only two now remain in Australia - the echidna and the platypus.

They use their bizarre bills to dig for food underwater,

scooping up shellfish and worms, mud and gravel from the riverbed.

They store everything in special cheek pouches

until they return to the surface to eat.

Without the benefit of teeth,

a platypus makes good use of the gravel it's collected

to help grind the food it has found.

It is becoming increasingly difficult

to encounter shy animals, such as the platypus, in the wild.

River otters are faring a little better in North America.

But the Asian small-clawed otter

is now locally extinct in many areas of its range.

Fortuitously, these aquatic mammals breed well in captivity,

where encounters are actively encouraged.

(MYSTICAL MUSIC)

While zoos all over the world

do their best to provide enriching visitor experiences...

by far the most satisfying way to observe any wetland animal

is in its natural habitat...

living as nature intended...

in some of the most remarkable places on earth.

Lying between dry land and deep water...

the profusion of plant life that continues to thrive,

where conservation is valued and protection has been assured...

will continue to support and shelter

a watery ark of truly extraordinary animals.

Captioned by Ai-Media ai-media.tv