Original subtitles

NARRATOR: The cloud mountains of South Africa

contain natural enclaves of incredible beauty and diversity.

A lost world.

Swirling in silver mists.

The majestic realm of the Rain Queen.

Indigenous forests teem with life.

Giant prehistoric plants are a window

into the time of dinosaurs.

This is one of the last strongholds

of the ancient mountain forests of Africa.

♪ ♪

The mighty Drakensberg Mountains.

250 miles of jagged peaks

extending along the entire eastern side of South Africa.

They separate the arid heart of the country

from the moist air of the Indian Ocean.

In the very northern reaches of the range are the Wolkberg

or cloud mountains,

so named because they are often blanketed in fog.

A diverse landscape of grassy covered summits

and ravines cloaked in mountain forest.

One of the rarest types of forest in the world.

And across this ancient landscape,

three clever species of primates are adapting to the challenges

and opportunities found in these gardens in the clouds.

It is summer in the Wolkberg

and a troop of vervet monkeys are in search of breakfast.

Vervets are found throughout southern Africa.

Rarely seen out in the open,

they seldom leave the shelter of the trees.

They live in large families sometimes numbering

as many as 70 individuals.

Both males and females live according

to a strict pecking order,

which is often aggressively enforced.

But there is no need for aggression today, however.

It's December, mid-summer, and many of their favorite trees

are in fruit.

The troop is on the move across its territory.

The monkeys are heading

to the extraordinary Modjadji cycad forest,

which is also found in these mountains.

This contains the largest collection

of a single cycad species anywhere on earth.

Cycads are living fossils and evolved

before dinosaurs roamed the earth.

During the Jurassic, some 180 million years ago,

cycads were one of the most common plant types.

These forests not only have an ancient history,

each tree grows slowly and is long lived.

Some are more than 1,000 years old.

This forest has grown here for millennia,

but now it is threatened by an invasion of exotic trees.

Exotic forestry plantations now surround

these natural outposts.

During summer,

when the ancient forest is in fruit,

vervets have learned to visit every day

to gorge on the giant cones.

Another monkey is also making the most

of the summer fruits

in the enchanted mountain forests of this range.

Samangos are close relatives of vervets

but are even more reliant on these forests.

They are the only exclusive forest species in the region.

Thick fur guards against the chill,

and their characteristic white eyebrows keep rain

out of their eyes.

A long tail helps with balance.

Living 65 feet above the ground

in these threatened mountain forests,

every day is a balancing act.

Summer in the Wolkberg means food is plentiful.

But it also brings rain.

The clouds that blanket these mountains are born

310 miles to the east.

Easterly winds move in

over the coast from the warm waters of the Indian Ocean.

This moist air moving inland hits the Wolkberg.

Rising, it cools and condenses into clouds

and ultimately falls as rain.

This is the kingdom of the Rain Queen.

Local people believe that their tribal monarch

is able to control the rain.

Her powers are widely revered.

During summer, the open slopes of the cloud mountains

are regularly drenched,

creating perfect growing conditions for grasses.

More than 50 species thrive on these open plains,

adapted to the well-drained, nutrient-poor soil.

There are not enough nutrients in these soils,

so bushes and trees struggle to survive on these open slopes.

Plants here are also exposed to seasonal fires,

so forests can only survive in the wet ravines.

The resulting mix of forest and grass

is critical for a number of species.

Chacma baboons are the largest monkeys in the region.

Large males can weigh more than 110 pounds.

They are highly social and, like vervets,

their family life is strictly organized.

A dominant male is in charge.

He heads the troop and gets first dibs

on any food on offer.

He is experienced and knows all the best feeding spots.

Female society is also organized.

Females inherit their rank from their mothers,

while for males,

dominance is constantly changing.

This troop is foraging through the grass,

looking for underground bulbs and tubers.

Baboons are well adapted to survive in open grasslands

and they divide their time between grassy areas

and the surrounding forests.

A host of other species also make its home

in the open grassy plains.

Rocky outcrops are prime habitats for snakes

such as this berg adder.

The chilly evening has slowed its metabolism.

Like all cold-blooded reptiles,

it must warm up before it can get moving.

So it's recharging itself by sunbathing.

But it is a balancing act.

Sunny surfaces such as these are exposed to predatory raptors.

Adders are part of the viper family

that have long, hinged fangs to inject venom.

And when they feel threatened, they let you know.

They resort to hissing loudly

and puffing themselves up in threat.

The triangular-shaped head allows room

for large venom glands located behind the upper jaw.

They are ambush predators,

lying in wait for prey such as frogs, rodents, and lizards

on these rocky islands

in the sea of grass.

But this one is not yet warm enough to hunt.

Rocky outcrops are not the only breaks

in the uniform grasslands.

Small seeps and streams crisscross these slopes

that are home to a number of plants and animals

not found elsewhere.

The entire Wolkberg forms a giant water catchment.

The mountains act like a sponge,

retaining water and slowly releasing it

into myriad streams,

which are the birthplace of the rivers

that will ultimately carry this water back to the ocean.

Once the stream is formed, it burbles downhill,

cutting into the topsoil until it reaches bedrock.

This abundance of water brings life.

Mosses thrive on the moist banks.

Algae coats the rocks,

fed by nutrients dissolved in the water.

The larvae of net-winged midges

cling to the smooth, rocky surface.

Blackfly larvae filter algae from the water.

It's a precarious existence.

Plants and animals are constantly blasted by water.

Floods can wash both algae and invertebrates

from the rocks and, during extreme dry conditions,

little streams can run dry.

Mountain wagtails hunt bugs along the banks.

Breeding pairs can hold territories

along streams such as this for life.

They defend their boundaries against intruders.

In this, two wagtails are better than one

and pairs that share territories gain significantly more food

than if they live alone.

Mountain wagtails are the longest lived of all wagtails

and can survive longer than 12 years.

Wagtails get their name from their habit

of flicking their tails repeatedly.

It is thought that this deters predators by telling them

that the wagtail is aware of its surroundings and any danger.

As the stream flows into the mountain forests,

life changes in the water.

Less sunlight hits the surface,

and so less algae grows on the rocks.

The food chain is now fueled by falling leaves,

rather than growing plants photosynthesizing in the water.

And a different suite of animals patrols the shallow waters

specially adapted to consume fallen leaves.

Minnows patrol deeper pools.

The shadowy habitat is also perfect for frogs.

Nearly all frogs must return to water in order to breed.

This male Queckett's river frog has attached himself

to his partner's back to mate.

His specially thickened thumbs enable him to keep hold

of her slippery skin.

He's not letting go.

When she's ready, the female will lay hundreds of eggs.

This is costly, and so the females are much larger

than the males, due to the reproductive effort required.

With her partner aboard,

the female searches for a safe place to lay her eggs.

The main stream contains many predators

that will eat her eggs and tadpoles when they hatch.

So she's looking for a small pool away from the danger.

Males have no say, they must just hang on.

His only role is to fertilize the eggs once laid

and prevent interlopers from displacing him.

A single male tries to muscle in on the action.

He's persistent,

doing all he can to split the courting couple.

But she's happy with her chosen partner

and the single male is left out in the cold.

Put in his place, he heads off

to find a more accommodating female.

The streams merge to form bigger and bigger rivers.

These gather energy, cutting deep into the landscape

as they flow downhill.

Where rocky outcrops resist the erosive power of the water,

waterfalls form.

A natal green snake is hunting along the edge of the river.

While they resemble deadly green mambas, they are harmless.

Active during the day,

he's searching the shallows for frogs.

Snakes are surprisingly good swimmers,

but currents in the steep mountain streams are strong.

If he's misjudged the water, he risks being washed downstream.

The rocks are wet and slippery, and he battles to gain traction.

♪ ♪

He's made it.

The rivers flowing through this landscape

provide an abundance of water,

the lifeblood of its ancient forests.

(birds singing)

Entering Africa's mountain forests

is like going back in time.

Many ancient trees thrive on the abundance of water.

Across the Wolkberg, rainfall is supplemented

by mist rolling over the landscape.

Drops of moisture form on everything it touches.

With sufficient water,

forest giants tower above the ground.

These forests are sustained by water and light.

Here it's every tree for itself

as they strive to raise their leaves high

above their neighbors to gather sunlight.

Leaves act like solar panels,

capturing light energy so it can be converted into food

so the plants can grow,

ultimately feeding the entire forest.

Below the canopy, the forest is dark and moist,

shaded from above.

A thick layer of plicanthus shrubs survives

in the shadows.

The forest is not uniform, but a mosaic of patches.

Young trees struggle to gain a foothold

on the dark forest floor.

Sometimes it's simply down to being in the right place

at the right time.

Eventually, even the mightiest trees fall.

This creates gaps allowing light to penetrate

into the lower reaches of the forest.

And in these gaps, new, up-and-coming trees

get a precious chance to grow.

Birds and other creatures prefer the mix of light

and shade found in these gaps.

A Wolkberg dwarf chameleon is relishing the sunlight.

Insects too are drawn by the warming rays.

The chameleons are careful in the open areas,

wary of bird predators who can attack without warning.

Contrary to popular belief, chameleons change color

primarily to communicate with each other

rather than match their background.

They rely more on their characteristic gait

for camouflage, mimicking swaying branches and leaves,

thereby avoiding detection

by both their predators and their prey.

Chameleons are not able to lap from pools of water.

They can only drink from droplets on leaves and branches.

Like all reptiles, chameleons are cold-blooded

and sunlight provides the warmth they need

to fuel their metabolism.

Sunlight is so precious in these forests

that some plants are ruthless in their pursuit

of sufficient light to grow.

While most forest trees invest heavily in reaching

for the light by building strong trunks,

there are some species that cheat the system.

Strangler figs parasitize other trees,

using them as scaffolding to carry their leaves aloft.

Eventually, once the host has served its purpose,

the strangler slowly suffocates it,

conveniently eliminating the competition in the process.

The gnarled shape of the strangler's trunk

traps leaf litter and water,

creating a microcosm all of its own.

Epiphytic plants grow in the cup-like folds

of the strangler fig.

Unlike the parasitic fig, these do not harm the tree

and only live on its surface, using the tree's cracks

and crevices to reach up into the sunlight.

Another opportunistic plant crisscrosses the forest.

Lianas root themselves in the ground

but use established trees to climb into the light

of the forest canopy rather than investing heavily

in their own trunks.

Affected trees grow more slowly

and have lower reproductive success.

Lianas form forest highways for a number of species,

enabling them to cross the open spaces between trees.

While this is good for many species of animals,

for the trees, it allows parasites and herbivores

to access the canopy.

Trees that remain free of lianas have a terrific advantage.

For the Wolkberg dwarf chameleon,

streams and rivers are impassable barriers

in the forest...

unless the liana highway bridges the gap.

This spiny liana links discreet forest patches,

allowing small animals to cross the streams

that thread through these forests.

Wolkberg dwarf chameleons live only in the forests

of this area,

one of 17 dwarf chameleons unique to South Africa.

He's made it to the other side, thanks to the liana bridge.

Afromontane forests contain many species that occur nowhere else.

Tragically, the surrounding landscape is ideal

for forestry, and these forests have been destroyed

to make room for exotic plantations.

The Wolkberg's valleys are an important refuge

for Africa's mountain forests,

usually referred to as Afromontane forests.

Only half a percent of South Africa is suitable

for indigenous Afromontane forest.

These are some of the last fragments in the country.

The warming of the continent after the last ice age

caused forests to recede drastically.

And, more recently, what was left has been decimated

by agriculture and forestry.

They are surrounded by plantations

of Australian eucalyptus and American and European pines,

species exotic to this region.

These plantations are uniform and biologically sterile...

large areas with few native species of plant and animal

compared to the rich diversity within the natural forests.

Within the plantation, super trees tower above the canopy.

This 105-year-old Sydney Gum stands 265 feet high

and is believed to be the largest planted tree

anywhere on earth.

The Woodbush Forest Reserve to the north of the Wolkberg

is the second largest continuous patch of indigenous forest

in South Africa.

Fed by the rain and mist that cover the mountains...

it is an ideal habitat for a number of bird species

including rare Cape parrots.

They're looking for yellowwoods growing in the forest.

The cones of these trees are an important source of food.

While there is plenty of other food,

a compound found only in these cones

is particularly important to parrots.

If they can't find enough,

they rapidly lose condition and will eventually die.

Samangos also enjoy yellowwood cones,

but they are less particular.

They eat fruit and seeds, flowers and even fungi.

Leaves and insects also feature on the menu for protein.

Samangos live in families

of between 14 and 30 individuals consisting of one adult male

and a number of females and young.

Males leave the troop around six years old

and either seek out a new family for themselves

or join a bachelor troop.

Within the indigenous forest,

exotic oak trees from the Northern Hemisphere

have gained a foothold.

Samangos are clever opportunists and make the most of the acorns.

On the other side of the forest, other opportunists

are taking advantage of the seasonal windfall.

During summer, the Modjadji cycads explode in cones.

It's a feast not to be missed.

For three months there's plenty of food for everyone

and the monkeys make this a daily stop

on their foraging trips through the forest.

While cycads are inedible to humans and are often poisonous,

the vervets devour the starchy seeds with impunity.

They're not the only species relishing a forest feast.

Crowned eagles patrol riparian forests

along the river courses, hunting small mammals.

They are the most powerful raptors in Africa.

Capable of capturing prey weighing as much

as 75 pounds, they can pluck a monkey out of the trees.

Even though they are formidable hunters,

their efforts are outdone by a much more lowly predator.

In these forests, spiders are more prolific killers.

Incredibly, the weight of butterflies eaten by spiders

in a year in these forests is more than the weight

of all the monkeys consumed by crowned eagles.

Surrounded by forest giants,

it is easy to overlook smaller species.

(buzzing)

Potter wasps collect mud for their nests.

In the natural world,

small creatures often have big impacts.

Spiders have existed for 100 million years,

during which time they've perfected the art of capture.

Many create elaborate webs of silk.

This is made from protein and spun into thread

by their spinnerets.

By weight, spider silk is one

of the strongest substances on earth.

Spiders are classified by the webs they spin.

Tangle or cobwebs, funnel webs, sheet webs,

and the largest of all, spiral orbs

such as those spun by golden orb spiders.

The webs are death traps

for flying insects.

Once they become entangled, there is usually no escape.

And the spider is able to inject a lethal cocktail

of venom to paralyze its victim, before wrapping it in silk

to store for later.

Another group of ancients

inhabits one of the oldest forests on earth,

a forest that has been rooted here for millennia.

Giant modjadji cycad trees are the largest cycad species

in the world, growing to over 40 feet in height.

They are prehistoric looking.

Their fruit looks like a giant pineapple.

These are cones similar to pine cones, only much bigger--

weighing 75 pounds or more, the weight of a large monkey.

There are male and female cones.

Usually cone-bearing plants are wind pollinated,

because cone-bearing plants,

called gymnosperms, evolved before flowering plants.

When flowers evolved, they enabled plants

to attract animal pollinators, such as insects and birds.

Cycads don't have colorful flowers,

and yet many of them are, nonetheless,

pollinated by insects.

Researchers speculate that animal pollination

may be older than we think because cycads were doing this

before flowering plants evolved.

(thunder)

For generations,

the Rain Queen of the Lobedu people

has protected this ancient forest.

Outside of Modjadji,

cycads are one of the world's most endangered plant groups,

threatened by habitat destruction

and the exotic plant trade.

With so much on offer in Modjadji,

there's less pressure on the vervet family

to search for food in the surrounding forests.

There's also time for other important things,

like feeding the little ones.

Female vervets remain with their family for life.

But when males reach maturity,

they migrate to neighboring families,

helping to broaden the gene pool.

Grooming is important in building cohesion.

High-ranking females receive the most grooming,

usually by subordinate females to curry favor.

Male grooming is less common and some males never groom.

Male dominance relies on their prominent blue genitals

and sizing each other up.

But with so much to eat,

the males seem more interested in food than showing off.

For youngsters it's not so easy.

They still need to learn how best to tackle

the bountiful cones.

But persistence does pay off eventually.

The cycads of Modjadji only fruit once a year,

but are a valuable resource,

enabling these monkeys to overcome the challenges

brought on by their ever-shrinking forest homes.

The ancient plants and animals of the cloud mountains

of South Africa have long captured people's imagination.

It's a landscape defined by weather

and threatened on all sides by invaders.

Indigenous forest fragments survive against the odds...

Providing homes for an incredible array

of plants and animals.

But these mountains are not only a vibrant sanctuary

for life in the present.

They also offer a fascinating window into our past.

Captioned by Media Access Group at WGBH, access.wgbh.org