Natural World (1983) s30e05 Episode Script

This is the highest, widest mountain range in southern Africa.
Named for its brooding and unpredictable nature.
The Drakensberg, or Dragon Mountains.
Some say they're a friend only to vultures.
It's an uncompromising place to produce new life.
Yet eland antelope have found a way to eke out an existence on these slopes, despite the hardship.
All the animals here must constantly negotiate a living with this beast of a mountain.
The Drakensberg present an almost mythical set of challenges, but every year, eland prepare to meet the mountains head-on, as they start their long climb to the very top of this world.
Mountains are hostile places, and the Drakensberg has a particularly dark reputation.
It's far, far older than the creatures it dominates, its birth the most violent imaginable.
160 million years ago, as Gondwanaland split into the continents we know today, lava poured out across the Drakensberg region, and cooled into layers of resistant basalt rock.
The toughest basalt still caps the Drakensberg peaks, while softer sandstone has succumbed to aeons of erosion.
Our story lies at the heart of this thousand-mile stretch of soaring mountaintops and precipitous ravines.
There's often a 2,000 metre drop to the valley floor.
Vultures fly so high that local legend says they can see into the future.
Flight is one of the few ways to cross these mountains.
Not for nothing have Zulu people called it Ukhahlamba - the barrier of spears.
The steep valleys of sandstone propping up vertiginous basalt escarpments might seem the last place to find these animals.
Eland antelope are more usually at home in Africa's deserts and savannah.
They seem like trespassers on the Drakensberg's lower alpine pastures.
In fact, they are no strangers to these dizzying heights.
The artists who painted these images were San Bushmen, who revered the eland as a source of nourishment and strength.
The paintings are 2,400 years old.
The eland's struggles with the Dragon Mountains go back way further.
Eland don't look like natural mountaineers.
They're Africa's largest antelope.
Bulls can weigh as much as 800 kilograms.
Even so, they will soon need to climb even higher.
The newborn calves have no idea of the ordeal that lies ahead.
For now, they are insulated by motherly love.
Many eland are born in spring, as adults gather in advance of their remarkable expedition.
It's also when the grass carpeting the lower Drakensberg slopes is most nutritious.
It helps the mothers produce plenty of milk.
Calves take their first steps within the hour.
But it'll be a while before they are strong enough to escape from predators, or to run with the herd.
To stay out of harm's way, the calf lies low in the meadow, waiting patiently for its next feed, and allowing its mother to stay with the herd.
Eland are instinctively wary of predators, so they prefer not to graze alone.
As the calves get stronger, and as spring grass shoots appear on higher slopes, the Dragon Mountains will tempt them upwards.
Above the gathering eland herds, but below the basalt escarpment, live chacma baboons.
Born small but smart, baboons rely on intelligence to deal with the difficulties of mountain life.
They also depend on each other, not only for affection.
Within their extended families, they learn everything.
How to find food, even in hard times What is smart behaviour .
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and what might lead to trouble.
An infant's family is its safety net.
The adults are always on full alert.
Jackals are persistent, but they are no match for full-grown baboons.
Jackals roam up and down the slopes looking for anything small and defenceless.
But the calf has an effective deterrent - its mother's sharp horns.
Predators may be the least of the elands' concerns.
The higher they climb, the more exposed calves will be to the Dragon Mountains' violent moods.
Within minutes, the middle Drakensberg experiences a catastrophic drop in temperature.
The only way baboons can avoid exposure is to huddle up against the mountain's flanks.
Below them, the eland have no shelter at all.
This is the calves' first experience of the Drakensberg's fickle nature.
A break in the clouds is just a tease.
From here on, the mountains will not just dictate the weather, but control where the eland can feed.
Generally in Africa, the rainy season is a long-awaited blessing.
Up here, there's a heavy price to pay.
The rain can be incessant, bringing not just cold, but hunger, too.
It dilutes the nutrients in the soil, and the grass loses its goodness.
It turns too sour to eat.
The longer it rains, the greater the need to find new pasture.
The adults have fat reserves to help keep them warm.
But the smaller, leaner calves will suffer.
When the conditions turn against them, the herd faces a long trek.
Better grass will be spouting higher up, but that means starting the calves on their gruelling climb.
This first year of life will be touch and go.
The mountain's scavengers are ever-alert for those too weak to move.
Today, one little calf has lost its battle with the cold.
Cape vultures specialise in cleaning up the carcass.
A jackal might have better luck here.
Baboons and mother elands send jackals packing, but not vultures.
A bearded vulture is last on the scene.
But that's because it's not going to waste its energy competing for the meat.
It's waiting for the leftovers.
90% of the bearded vulture's diet is bone marrow.
However, their beaks are not strong enough to crack the bones open.
This darker-faced juvenile needs to use the powerful thermals to help with that.
Bearded vultures deliberately drop bones from a great height.
Once they've shattered, the birds can get to the marrow inside.
They can even eat the bone itself.
Strong stomach acids will digest it.
Pound for pound, bone is more nutritious than meat.
So far from being the poor relations of the vulture world, these birds can exploit a valuable resource.
Despite this, they are very rare birds.
It may be a tough place to live, but the Drakensberg is a guardian to many.
Without such vast, open spaces, bearded vultures would be in serious decline.
Above all, this is the region's most important watershed.
The 800-metre drop of the Tugela Falls, the world's second highest waterfall, turns the stream into a veil of rainbows.
The Drakensberg's huge mass influences the weather, and therefore all life around it.
The water flowing off the Dragon's back is the source of South Africa's largest and longest rivers.
By the time spring turns to summer, the eland will have climbed many hundreds of metres to the mid-Berg, where they skirt the slopes in their search for fresh grass.
It offers adults and calves the chance to build up body fat.
Capricious weather at these altitudes doesn't just affect the quality of grass.
Flowering plants must be tough to survive the mountains' demanding regime of rain and frost.
Wind is another great enemy, sucking moisture from every leaf and flower, so most plants huddle close to the ground.
Pollination is the greatest challenge of all .
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which is why one flower times its opening to the emergence of this beetle.
A protea flower has cast its spell on the scarab beetle.
As the beetle roams through the petals, it collects a dusting of pollen, which it will carry to the next flower.
Summer won't last long at this height.
Flowers can't just rely on insects to help them set seed.
Sugarbirds can do the job too.
But it's the protea's sweet nectar which draws them in.
The feathers on their heads will transfer the precious pollen to the next bloom.
During these fleeting summer months, the eland will mate.
The females release an enticing scent which encourages dominant bulls to make advances .
.
only to be rejected.
The females aren't ready just yet.
But that won't stop the males thrashing about in the vegetation, checking out the field .
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or putting on an eye-catching display.
In these middle ranges, the grass has set seed, providing a highly nutritious feast for the baboons.
They might spend all day harvesting and eating.
But the Drakensberg is never generous for long.
Now these middle altitude meadows are at the mercy of the frequent summer storms, whipped up by the mountains.
They drain the grass of its food value.
Once again, the eland will have to move on.
They'll need to find still higher slopes where heavy rain has not yet leached the goodness from the grass.
The baboons in the mid-Berg are hardened to this.
The grass may no longer taste very good, but they can eat other things.
There are roots worth digging for.
It means the baboons can stay put, while the eland are always forced on.
As the summer rains continue, the grasses pull their remaining nutrients back to their roots.
What's left is no better than straw.
For the wandering eland, opportunities to find pasture close off behind them.
As a last resort, they seek out valleys where they can browse on the leaves of trees known as ouhout, or "old wood".
Even the smallest calves can reach the lower leaves.
But the old wood comes with a bite.
Fire ants nest along the branches.
They can sting as painfully as wasps, and will surge out to defend their homes against browsers like eland.
The ants are the warrior-herdsmen of their world, and have livestock to guard - aphids.
The ants milk the aphids for their honeydew secretions.
The aphids, in return, gain the fire ants' protection.
The leaves also flourish, thanks to the ants.
Even the hungriest eland doesn't like being stung in the mouth.
It serves to move the whole herd on.
There is little rest and not much food.
The Dragon Mountains all too easily claim another young victim.
Not all eland calves are born in spring.
Those dropped now are especially vulnerable.
The mothers are struggling to feed themselves, let alone produce milk for four months.
Many newborns won't survive this journey, and there are many creatures waiting to benefit from their demise.
The jackal must decide whether the scraps are worth a tussle with the vultures.
But on this occasion, the vultures appear determined to have the last of the carcass for themselves.
The slopes have never seemed more desolate.
But the eland cannot retreat.
There's nothing to eat at lower altitudes.
Their only option is to carry on up the mountains, and the river courses are the easiest routes there.
Along the banks there is some respite.
This long march in search of food is particularly taxing for the hungry calves.
But, day by day, their stamina is increasing, and they become better able to withstand hardship.
Rainfall is so high in the Drakensberg that the thin soils are readily stripped of what richness they contain.
Mountain streams benefit.
The wide-mouthed frog makes a good living here, by hunting almost everything else.
There's an abundance of crabs, which thrive on decaying plants and animals.
And the wide-mouthed frog lives up to its name.
It can't be the easiest of meals.
But nothing on this mountain is straightforward.
Soon it becomes clear why the eland have staked everything on their upward climb.
The higher they go, the cooler it is, and the later the seasonal change.
At 2.
5 kilometres above sea level, the grass is only now springing up.
The herds also become more concentrated - up to 300 strong.
Even the heaviest males will make the assault on the Dragon Mountains' steep upper slopes.
To the baboons that live all year round at these incredible heights, the eland are a travelling sideshow, worth little more than a moment's curiosity.
Arriving on these high altitude pastures is like entering a second spring.
The air may be a little rarefied, but so is the elands' palate.
What guides them in their wanderings is simply the quality of grass.
But up here, close to the spine of the Dragon Mountains, they are exposed to its most terrifying force.
The baboons seem to know what's coming.
The Dragon Mountains have a habit of turning lightning into fire.
The smell of burning is new to the calves.
Instinctive fear makes them flee.
After an electric storm, there's no rain to quench the flames.
These dry lightning fires can sweep up the mountain at incredible speed, and eland are in danger of becoming trapped.
The fire-breathing mountains have laid waste to the vegetation.
Few trees survive a scorching like this.
But in time, the grasses will return.
They have dealt with this fury many times before.
Having nested high above the fire-line, the bearded vulture can survey the blackened mountain side.
There may be casualties, bones to be picked over.
But this time, the eland mothers have successfully guided their calves away from the inferno.
They may be temporarily disorientated, but they will do what they've always done - travel in search of new pastures.
The baboons have no option but to remain here and make the best of the seared earth.
But somewhere across this brooding giant of a mountain range, grassland will once again spring into existence.
Beneath the blackened soil, a crop of tubers has survived the fire.
Baboons have both clever minds and the hands to take advantage of this timely resource.
Like humans, they produce babies with large brains and small bodies.
That means months of physical vulnerability and dependency.
Mothers need to stay close, especially in this unpredictable place.
Within days of the fire, underground moisture works its magic on the charred land.
The new grass has been fertilised by the ash of the old thatch.
But in this early stage of regrowth, it's thin on the ground.
Eland, especially the males, are big animals, so to find enough to eat they must stay on the move.
Their mobility and stamina is proving to be their core strength.
The calves will be more robust now, which is just as well.
A sudden cold snap shows just how treacherous these mountains can be.
Billowing in from the south, the air temperature drops lower and lower, until it's barely above freezing.
A mother baboon is looking for her baby.
A vulture has spotted the missing infant.
But the father gets there first.
The mother still doesn't know what's happened.
The baby could have strayed too far from its mother's warmth.
Or it could have been killed by another male, in a fit of jealousy.
Whatever the reason, the vulture won't get the body just now.
Baboons can carry dead infants for days, not wanting to let go.
Mother's still waiting.
She's finally realised what's wrong.
There's little room for ceremony.
The baboons will grieve .
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and the master of these mountain spaces will have to look elsewhere for a meal.
Despite the rigours of such high, cold places, there is evidence - tracks worn into the hard basalt rock by countless generations of hooves - that eland long ago conquered the Dragon Mountains' summit.
They may have evolved on the plains and savannah, but each year, eland use these ancient pathways to chase the summer right up to the roof of their world.
How and when they found this good pasture, on the very highest plateau, is lost in time.
But it will keep the mothers in good condition and allow them to finish nursing their young.
Eland don't form close friendships.
They drift in and out of herds as they please.
Although it looks like they're grooming each other, they're licking off each other's sweat for the minerals it contains.
But there may be useful side-effects.
It might discourage parasites.
Perhaps they gain some reassurance.
The calves that have made it to the top will reap the reward for completing the climb of their lives - a last rich stream of milk.
However, the gathering clouds are a reminder that, at this height, summer is like borrowed time.
Others are already preparing for the worst.
Ice rats can only survive up on the Dragon's back thanks to their snug burrows, which they must now stockpile with seeds.
Gathering this harvest exposes them to more than just bad weather.
Servals depend on ice rats up here, but they have to be quick.
The serval's large ears can detect their movement underground.
But the ice rats are out of reach.
3,000 metres up, the grass is tender, just as the elands' noses told them it would be.
But the air is cooling fast.
It's now a perilous place to be.
The winds have changed, bringing with them a deadly dose of winter.
This is something their cousins in the deserts and savannahs will never see.
But the Drakensberg eland know it's time to retreat.
Antarctic chill is streaming into southern Africa, and some won't make it down the mountain for the spring.
These bones are too big to be anything but an eland's.
Snow, in Africa, is something extraordinary.
But not in the Drakensberg.
Ice rats have carved out their very own niche up here.
They're found nowhere else.
Their fast pace of life helps them stay warm.
But they need constant refuelling.
And now there's very little to eat above ground.
As ruthlessly as any predator, the mountain weeds out the weak from the strong.
At lower altitudes it's much warmer, but the eland herds need to keep descending, back to the lower slopes where so many of their calves were born, to find fresh green grass again.
Less than half the eland calves survive this first year and arrive back where they began.
But these survivors are tougher for their ordeal.
The elands' remarkable ascent of the Drakensberg is legendary.
The yearlings will continue that story.
Following ancestral paths, they'll lead new generations of eland back to the summits.
Their stamina and resilience is defiantly etched along the flanks of the Dragon Mountains - time-worn journeys through famine, snow and fire.
This is one of the most gruelling places to live in Africa.
But in constantly pushing the creatures that exist here to the limits of endurance, the Drakensberg also reveals their true strength.