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