- 1 day ago
Two billion years ago, a giant meteorite crashed into southern Africa's interior plateau, forming a six-mile-deep crater. Today, the site of this cataclysmic event is the Vredefort Dome--a dazzling and rich ecosystem of unique plant and animal life.
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00:00Two billion years ago, a giant meteorite collided with Earth, releasing enough energy to vaporize
00:18solid rock. A site of total devastation. Its effects rippled throughout Africa.
00:30But over the course of time, life conquered the barren lands, and today the crater's past is all but forgotten.
00:48This ancient landscape creates a haven for the unique plants and animals of the Freer de Fort dome.
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01:06Lying in the grasslands of southern Africa's interior plateau is a little known wonder.
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03:26Mountains of ancient rock lie in rich, fertile grasslands, whilst rivers and wetlands provide
03:37the water needed for life to flourish.
03:40Today, the mountains of the Freer de Fort Dome are the most prominent feature on the landscape.
03:52Surrounded by seas of undulating grassland, they hold clues to the craters past.
03:58Rounded granite boulders embedded in a black, glassy, obsidian layer are the result of colossal
04:12forces exerted during the impact, liquefying rock.
04:16These outcrops were once the giant canvas for some of the world's first artists.
04:27Ancient engravings left by bushmen who once sheltered here tell of a landscape rich in life.
04:32It is thought the Freer de Fort Crater may have played an important role in human evolution.
04:44Some even believe that without the major evolutionary changes the impact caused, we would not be here today.
04:54However the crater links to our past, we have been drawn to it for shelter, food and in the search for wealth.
05:03These tunnels were dug by gold prospectors decades ago.
05:11When the meteor struck, it fractured rock deep beneath the surface of the earth, pushing South Africa's gold reserves deep underground.
05:20Here the gold was preserved from erosion, laying the foundation for South Africa to become the world's biggest exporter of the precious metal.
05:31Abandoned as unproductive, these tunnels now offer shelter.
05:42Horseshoe bats have taken up residence.
05:49Hunting on the wing, they consume flying insects from the night sky.
05:54And they are not the only ones making the most of the tunnels' refuge.
06:07Cave toads also shelter in the darkness.
06:12From the very base of the mountains, life is provided for.
06:15The Freer de Fort Crater's unique mix of landscapes and vegetation make it a special place for wildlife.
06:35Grasslands dominate South Africa's high interior plateau.
06:40It is here that the mountains of ancient rock form islands rich in species not normally found on the open plains.
06:57Higher up the mountainside, a pair of mocking cliff chats are calling.
07:01The territorial birds defend sections of the rocky hillside.
07:10And this pair have a reason to be protective.
07:14They have a couple of new arrivals.
07:17Their recently fledged chicks are getting a feel for life outside the nest.
07:27The rising hills provide shelter for flowering plants and trees to grow.
07:31Attracting a new cast of creatures.
07:32From long-horned beetles.
07:33To kudu.
07:34These majestic antelope are browsers.
07:35Feeding on trees and bushes.
07:36Feeding on trees and bushes.
07:37The rising hills provide shelter for flowering plants and trees to grow.
07:38The rising hills provide shelter for flowering plants and trees to grow.
07:39Attracting a new cast of creatures.
07:40From long-horned beetles.
07:41To kudu.
07:42These majestic antelope are browsers.
07:43Feeding on trees and bushes.
07:44But rarely found out on the open grasslands.
08:09They are drawn here by food.
08:12And they are not the only ones tempted away from the plains below.
08:24At over 16 feet tall, giraffes have the pick of the canopy.
08:32Being able to eat from all levels of the tree gives them a valuable edge when conditions
08:38are poor.
08:45The mountain vegetation provides food for the largest and for the smallest of creatures.
08:57Chafer beetles feed, moving from flower to flower.
09:03Along the way, they transfer pollen, pollinating the plants in the process.
09:10It's a win-win scenario for both the beetles and the flowers.
09:17But the chafers are looking for a bigger meal.
09:21And around here, they don't need to go far.
09:23The flowers of the sugarbush protea are famed for their abundant sweet nectar.
09:34And the chafers seem to agree.
09:41This plant is more than just a source of food for the local insects.
09:45It is part of a unique relationship.
09:50Growing out of the rough barked stems is a parasitic mistletoe.
09:56It grows directly from the sugarbush, taking the nutrients it needs from its host.
10:04But the mistletoe is itself a host plant.
10:09The caterpillar of the sapphire butterfly lives only on the leaves of the protea mistletoe,
10:16feeding off it until it is ready to begin the next stage of its metamorphosis.
10:23Over the next two to three weeks, this lowly caterpillar will transform into a sapphire butterfly.
10:34For this butterfly, the protea mistletoe is everything.
10:39Without it, it would not survive.
10:47The sapphire butterfly exists here in the Freer de Forte dome due to a specific set of conditions,
10:53which would not have come about had the meteorite not struck all those years ago.
11:00Over 100 species of butterfly now live in its 115 square miles.
11:09More than double the number found in the whole of the United Kingdom.
11:13And they're not only here for the host plants.
11:19In sexual selection, many butterflies resort to a behaviour known as hill-topping.
11:27Males fly to the highest point of the mountain and occupy a prominent perch until a female appears.
11:35When she does, the males take off in a courting flurry.
11:42Flying to the very tops of hills demonstrates their physical prowess, and therefore their strength
11:49as a mate.
11:54These mountains provide food, shelter and opportunities for a range of animals perfectly adapted to
12:01their unique ecosystem.
12:08Contexting through the Freer de Forte crater is one of South Africa's largest rivers.
12:18A vital water source, the Val winds its way through more than 600 miles of the country on its
12:24westward journey toward the Atlantic Ocean.
12:32Its route courses straight through the crater, providing habitats for a range of life.
12:44Sacred ibises are early risers, making the most of what the river has to offer.
12:53The flock probes the mud, searching for crabs, worms, frogs and anything else they can find.
13:10Later in the day, they'll head to the grasslands to hunt.
13:18The river is a magnet for bird life of all kinds.
13:37From wagtails to yellow-billed ducks.
13:57A Nile monitor enjoys the morning sun.
14:02Three feet in length, it is only half the size it will eventually reach.
14:10Cold-blooded, the reptile needs the sun's heat to warm its blood before it can start to hunt.
14:20Once fully charged, it heads off in search of breakfast.
14:42With predators about, this white-browed sparrow weaver is taking no chances.
14:47He's building his nests high up in the branches of a thorn tree.
14:54In a land covered with grass, supplies should be easy to come by, but this weaver only uses
15:15the best.
15:16He's using it to attract a mate.
15:22Two entrances allow the weaver to make a swift getaway should a predator find the nest.
15:45However, once he has found a mate and she has laid her eggs, he will have to seal the back
15:51door for protection.
15:56A male red bishop is also showing off.
16:02But he doesn't only rely on his DIY skills.
16:10During the breeding season, his feathers turn bright red to attract females.
16:17If he's successful, he'll mate with as many as eight in a season.
16:38He'll be able to get a fisherman.
16:48Throughout the day, many other species are drawn to the water.
16:55But not all are in search of sustenance.
17:08Damselflies use stagnant pools to mate.
17:15The male uses special grasping clips on his tail to hold the female, often for more than
17:22an hour.
17:24Its clips fit into neat depressions behind her head, locking tight.
17:31Each species has a unique lock and key.
17:38Even once the pair has mated, the male's job is not done.
17:45The female begins laying her eggs, and the male retains his vice-like grip.
17:50If he leaves, other males will remove his sperm and mate with her.
17:57So he remains with his partner until she has finished laying.
18:12The male retains the male retains the male retains.
18:19The male retains the male retains the male retains the male retains.
18:24Despite this, they are selective hunters, spending as much as 75% of their time standing completely
18:31still, waiting for just the right-sized prey to cross their path.
18:36Under a hot African sun, the birds can't sweat to cool down.
18:43To solve the problem, they have developed a technique called gula fluttering, similar to the panting
18:52of dogs.
18:53By rapidly moving air through a pouch in their throats, which has a rich blood supply, they
19:00are able to cool their bodies.
19:04The val is a crucial feature in the Freirefort landscape, providing water that is so vital
19:22for supporting life.
19:29From here it flows westward on its long, lonely journey to the sea, striking out across the
19:37high-felt grasslands.
19:50In the summer months, the grasslands on the outskirts of the Freirefort crater come alive.
19:59The rains have come, and new life is everywhere.
20:06The open grassy plains, which have lain dormant all through the dry, cold winter, have rebounded.
20:13And the animals have a new spring in their step.
20:26At first glance, these grasslands may look flat and uniform, but they harbour a unique variety
20:35of life.
20:42A long-tailed widow bird is looking for a mate.
20:54Dragging his enormous tail behind him, he is showing off with a display of strength.
21:02Males are territorial, and they perch on prominent vegetation to advertise their presence, before
21:16taking to the wing to perform.
21:19their tail feathers can be up to 40 inches long, and drag below them as they patrol their territory.
21:26While his tail is cumbersome, his efforts are likely to pay off.
21:44If successful, he will mate with as many as five females during the season.
22:02These grasslands support the weird and the wonderful.
22:13The white rhino is the largest grazer on the planet, and the biggest animal ever to have
22:19existed solely on a diet of grass.
22:26The short, sweet, nutrient-rich blades of the summer are a welcome treat.
22:37Across the plains, animals are making the most of the flush of life.
22:51Secretary birds use their legs as weapons, stamping larger prey species, including venomous snakes,
22:58to death.
23:00And this pair are busier than usual.
23:09With two hungry mouths to feed, they have their work cut out.
23:14A family of ground squirrels keeps a wary eye on the secretary birds.
23:21Their pups could be prime targets for the predators.
23:29Luckily for the chicks, their arrival coincides with the explosion of new life.
23:41For the rhino mother and calf, the grasslands pose little danger.
23:56In the natural world, adults are practically invincible.
24:01They have sharp horns and thick armored skin, too tough for most predators.
24:10But calves are more vulnerable.
24:12So mothers keep them close until they are big enough to fend for themselves.
24:17For smaller species, the open spaces of the grasslands are a problem.
24:38Out here, they are exposed to predators.
24:45Ground squirrels have adapted to the dangers of the grassland by building their warrens underground.
24:53But when there aren't any predators about, they come to the surface.
24:57Extremely sociable animals, they live in large groups of up to 19 individuals.
25:10As a result, socializing is an important daily activity.
25:17Males live separately and will only visit when the females are ready to mate.
25:29For the rest of the time, groups of dominant females live together with up to nine sub-adults and the females' dependent offspring.
25:44When food is abundant and there aren't predators around, family life is relaxed.
25:51Another unique borrower has chosen a life below ground on these grassy plains.
26:01A giant girdled lizard, known locally as a sun-gazer.
26:12Borrowing makes them unusual.
26:14They are the only girdled lizards to do so.
26:17All the other species live in or on rocks.
26:22But here, in the open grasslands, suitable rock homes are not common.
26:28So if a predator attacks, it dives underground.
26:34Nearby, an Amur Falkam is on the hunt.
26:40But part of life on the grassland is knowing what's a threat and what's not.
26:57And this Amur falcon subsists almost entirely on beetles, locusts and other smaller insects.
27:07These thrive in the grasslands, meaning that prey is plentiful, competition for resources is minimal,
27:14and these falcons can exist here in remarkably high densities.
27:20For the pair of secretary birds, life is tougher.
27:25They need bigger prey and far more of it.
27:31The chicks are increasingly hungry.
27:36But it will be another two months before they stride out onto the grasslands for themselves,
27:51and life returns to normal.
27:56For all animals, finding food is an essential part of life.
28:15One group has developed a unique way of getting their daily nourishment.
28:21After rain, butterflies congregate around puddles on the ground.
28:29Once they have drunk their fill, something surprising happens.
28:35They begin to excrete liquid.
28:38This method allows the butterflies to filter the water, absorbing important nutrients without having to store all the fluid.
28:48A variety of insects obtain the moisture and nutrients they need in this way.
28:54Where there are lots of butterflies, there are lots of caterpillars.
29:11And from the very first day, these are under threat.
29:15To compensate, caterpillars have developed many strategies to prevent themselves being eaten.
29:26Some hide away, whilst others fight back.
29:32They grow long, fibrous hairs that deal a nasty sting to anything that disturbs them.
29:41Others rely on their host plants for protection.
29:45The spotted joker feeds on stinging nettles, which deter predators.
29:51Monarch butterflies have taken toxic warfare to a new level.
29:58Their caterpillars retain toxins from their host plant in their body tissue during metamorphosis.
30:06And adult butterflies emerge as unpalatable as the caterpillars.
30:12This has been so successful for the monarchs, other butterflies have mimicked them.
30:19Not poisonous themselves, predators avoid them, thinking they are.
30:25Throughout the natural world, the predator-prey dynamic drives evolution.
30:34A family of meerkats is on the lookout.
30:38Meerkats live in close family groups, comprising a dominant female and her mate, and many generations of offspring.
30:49In times of plenty, groups can number as many as 30 individuals.
30:55The larger the family, the more eyes to spot predators.
31:00At the first sign of danger, they disappear into the safety of their burrow.
31:07But occasionally, they decide to fight back.
31:12Even if the towering ostrich doesn't pose any sort of threat.
31:26Dotted throughout the Freer de Forte crater's grasslands are wetlands and pans.
31:33The availability of permanent water attracts animals from all around.
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32:47Dotted throughout the crater, in its mountains, rivers and wetlands, animals gather in their
32:54greatest numbers on the grasslands.
32:59The plains are home to the grazers.
33:03Black wildebeest live in mixed herds of females and youngsters, moving through the territories
33:10of adult males.
33:13During the mating season, males corral females on their territory into harems and will defend
33:21their right to mate with them all.
33:24But they have a job on their hands, keeping them all in check.
33:30Black wildebeest were brought to the brink of extinction during the 19th century.
33:36Between 1870 and 1871 alone, the skins of nearly half a million black wildebeest, blessbuck
33:44and zebra were exported from the coastal port of Durban.
33:49Before the scourge of hunting, these three species dominated South Africa's high grasslands along
33:56with springbok, moving in herds of thousands.
34:03Today they only exist in fragmented pockets, isolated among miles and miles of farmland.
34:15Despite the apparent abundance of food, much of this tall grass is fibrous and of little value.
34:27The animals that live on these plants have developed a number of ways to cope with this low-quality
34:32fodder.
34:38Springbok are pure grazers.
34:43They eat selectively, consuming only grasses that provide them with the nutrients they need.
34:52Springbok complement their grass diet with a range of succulents, herbs and shrubs in order
34:58to survive.
35:04And another resourceful herbivore is the buffalo.
35:09They are predominantly grazers, eating a large variety of grasses.
35:16Buffalo will chew, swallow, regurgitate and continue to chew in order to break down the high cellulose
35:22content of their food, ensuring they get the most out of their meal.
35:34Zebra and wildebeest often occur together because there is little competition between them.
35:41Zebra have evolved a digestive system adept at removing nutrients and protein from fibrous
35:46grasses.
35:49They often clear the way to shorter, sweeter grasses for the wildebeest.
35:59On these grasslands, animals have found a niche for themselves, allowing them all to happily
36:05coexist side by side.
36:10But it's not always peaceful.
36:22Two male giraffes are battling for the right to rule.
36:34Their hard, bony heads can inflict serious damage.
37:02Birds can go on for hours before a winner finally emerges.
37:16A drawback faced by all animals on the open grasslands is that there is nowhere to hide.
37:24Everything side by side benefits some through safety in numbers.
37:29But they are all built for speed.
37:36In large open spaces such as this, their first instinct when startled is to break and run.
37:43And it is only an evolutionary impulse that drives them to flee.
38:10So we can see.
38:37This strategy is in stark contrast to that employed by the bulkier buffalo.
38:47These are built for power.
38:49If threatened, the herd rarely breaks and runs.
38:56Both bulls and cows have formidable horns.
39:02While cows use their horns predominantly for protection, bulls use theirs in fights to
39:10establish dominance with the herd, which are strictly hierarchical, with dominant individuals
39:22winning the right to occupy the center of the gathering.
39:29Others hang on the fringes where they are more exposed to threats.
39:36For both of these old timers, a life of solitude is full of danger.
39:52The grasslands support many giants, including the largest antelope in the world, Irland.
40:12Contests for dominance here are usually settled without coming to blows.
40:17The status is determined by a range of clear visual signals, including the size of the
40:24dewlap, the fleshy skin below the throat.
40:28Mature males will also rub the furry patch on their foreheads in dirt and urine, turning
40:34it into a smelly caked mass.
40:39This strong odor is associated with strength and dominance.
40:48Like many of the animals out on the plains, Irland have not lost their instinct to flee.
40:57They will dash for safety, but unlike the smaller antelope, they haven't evolved for speed and quickly tire.
41:06Instead, they turn to stand their ground against the perceived threat, grouping around in defense
41:14of their young.
41:21Protecting your family is a daily struggle for many of the grassland residents.
41:33Male red hartebeist establish territories to protect their females and offspring.
41:43Excellent eyesight helps them spot both intruders and potential predators.
41:58Herds are strictly organized.
42:03Females establish a dominance hierarchy, and youngsters remain with their mothers for up
42:08to two and a half years.
42:19The vast numbers of grazers draw in even larger numbers of insects, which swarm during the
42:27rainy season.
42:30Even the toughest suffer.
42:34Zebra use their long tails as much as anything else, but they have another ingenious advantage.
42:54Their famous stripes.
42:57Bloodsucking flies locate their hosts by sight and are attracted to large areas of a
43:04single tone.
43:09The zebra's stripes make it harder to home in on, and they suffer less from bites as a result.
43:19Flies are not the only bloodsuckers around.
43:23Ticks thrive.
43:27Without the benefit of wings, they sit on the ends of grasses, waiting for a host to pass by,
43:34climbing on when they get the chance.
43:40In a delicate arms race, animals living on these grasslands are relatively immune to diseases
43:47carried by these parasites.
43:52One such host is baboons.
43:55These primates have two advantages when it comes to parasite control.
44:01Cooperation and opposable thumbs, which are both essential for grooming.
44:07An important way of maintaining social cohesion.
44:11It also helps rid yourself of ticks.
44:17Millions of years ago, another slightly more sophisticated primate came down from the trees
44:24and strode out onto the grasslands of southern Africa.
44:29drawn perhaps by the wide open spaces to hunt and new territory to claim.
44:48The lands covering the Freer du Fort crater contain a fascinating array of animals both big and small.
44:57It is not a uniform world.
45:10But one of intricate details and unique exceptions.
45:16From tiny caterpillars to mighty rivers.
45:24Life occurs in abundance.
45:31A reminder that every species survives in a fabric of time and space, stretching back to the very beginning.
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