Zambezi: Wild Water

The Zambezi River tears through the heart of Southern Africa. Its wild waters crash through canyons to form one of the world's most spectacular natural wonders, Victoria Falls. Throughout its epic journey, it touches the lives of millions and weaves a story of power and survival. We journey from source to sea as it stretches for nearly 3,000 kilometers. It profoundly influences life and landscape at every twist in its course, changing personality as it goes. Rising in the highlands of Zambia, the Zambezi flows through Angola and along the borders of Botswana, Namibia and Zimbabwe before emptying into the Indian Ocean in Mozambique. The river quenches the land's thirst, nourishing life and sustaining some of the continent's most magnificent wildernesses. Millions of people rely on the Zambezi for food, water, transport and power. This great river's moves trigger spectacular wildlife events and drive a cycle of life. But its incredible power can also bring death and force people to flee their homes. The Zambezi creates and the Zambezi destroys. It shapes the very land it traverses. Sandbanks build up into fertile floodplains and thundering torrents tear through solid rock. From tranquil broads to terrifying rapids, this immense river matures and changes as it travels its age-old path. It is one of Africa's most epic and influential waterways. But does the mighty Zambezi bring a blessing or a curse? It has decidedly humble beginnings. The Zambezi rises under a small tree in the Kaleni Hills near Munilunga in northwest Zambia. It's hard to believe this insignificant dribble will eventually become the fourth largest river in Africa. But it's not far before the river widens to reveal its true character. And with it come predators keeping a sharp eye out for fish. In sub-Saharan Africa, where there is water, there are fish eagles. Perched high above the river, the eagle uses its sharp eyesight to spot fish near the water's surface. A lazy swoop belies the bird's pinpoint accuracy. It's such an efficient hunter that it only needs to spend about 10 minutes actively fishing each day. Almost as soon as it has begun life in Zambia, the river flows across the border into Angola. But it soon returns to its homeland and snakes through Zambia's remote western corner. Rich layers of silt left by the seasonal rise and fall of the river fertilize a huge floodplain that stretches across 200 kilometers. It is one of the largest wetlands in Africa. To the west, just a few kilometers from the banks of the Zambezi, lies Lua Plain, a vast remote open space and one of the continent's last true wildernesses. Floodwaters from the Zambezi and its tributaries inundate this plain, nourishing a rich grassland that in turn feeds some of Africa's largest herds. Every year, with the arrival of the rainy season, come tens of thousands of wildebeest who gather here to give birth. The entire herd's calves are born within just two or three weeks of each other. The glut of newborns on the plain gives each individual a better chance of survival. But the vulnerable calves are easy targets for predators. And as the scent of new life fills the air, the plain's most abundant killers home in. Spotted hyenas are infamous scavengers, but they are also skillful hunters. A wildebeest calf makes an ideal meal. With predators sniffing at their heels as soon as they enter the world, newborn wildebeest have to grow up fast. They learn to walk and run just a few minutes after birth, earlier than any other antelope. The calves quickly start to practice the sprints and leaps that will help them outrun danger. At two days old, they can already keep up with the herd. Although there is some safety in numbers for the young wildebeest, each calf must depend on its own mother for its survival. One female lies injured, leaving her calf to fend for itself. Unable to suckle, it wanders away from the security of the herd. It doesn't go unnoticed. The calf realizes its mistake in the nick of time and bolts back to safety. Its mother is not so lucky. Unable to get up and run, the injured wildebeest is at the mercy of the hyena's powerful jaws. Soon, the rest of the clan join in, and the wildebeest carcass is devoured in a matter of minutes. Not a scrap goes to waste. The orphaned calf escaped the hyena's clutches this time, but without its own mother to suckle it, it has little hope of survival. Wildebeest cows don't adopt little strangers. The rain continues to soak the land, and the vast Zambezi swells until it bursts its banks. The river created a passing paradise for the animals, but the blessing soon becomes a curse. The endless grassy plains are transformed into a vast swampy lake. As their food supply is flooded, the herds flee to higher ground. This mass migration rivals that of the Serengeti. Wildebeest are not the only species to emigrate. The Lozi people of Zambia have called this floodplain home for 300 years. They benefit from its bounty, but every year they're forced to bend to the mighty river's will. Villages are abandoned and belongings packed into barges and canoes. The whole tribe must retreat from the rising waters. As a mark of respect to the river, the mandatory migration is marked by the kumbaka ceremony. The king leads the exodus in his royal barge, paddled by over 100 men. It is a great honor to paddle the king's boat. The barge is crowned by an elephant, the Lozi symbol of power. But it is the river that holds the power now. The Lozi people surrender to the Zambezi's might. They won't return to these fertile plains until the waters relinquish their grip on the land. Every year, the great Zambezi flood transforms the river into a lake that stretches 40 kilometers across. The repercussions for animals and people are dramatic. The river ripples on, flowing steadily over a huge basalt plateau. Tributaries feed the great river as it makes its wide and lazy way south, across the border between Zambia and Zimbabwe. It was on these placid shores that the first European immigrants made their camp at the end of the 19th century. A ferry crossing called the Old Drift began to operate, serving the traders and missionaries that ventured into this wild place. But these outsiders knew little of the perils hidden in the African bush. A mysterious disease soon began to claim lives. More and more victims succumbed to a deadly fever. But no one made the connection with the mosquitoes that swarmed the swampy riverbanks. The devastation of malaria was as yet unknown. The Old Drift Cemetery is the only relic of this doomed encampment. The frightened survivors fled the cursed area and resettled on higher ground. They named their new town of Livingston after the Scottish missionary David Livingston, who was the first European to explore the area. Today, the old camp is home to animals much better adapted to the place than people. The tough, gnarled skin of white rhinos is thick enough to withstand the bites of the ever-present mosquitoes. When adventurer David Livingston paddled this broad and gentle stretch of river by canoe in 1855, he had no idea what lay ahead. Creeping towards the mysterious rising mists that locals called the smoke that thunders, Livingston peered over a ledge and saw the most wonderful sight he had witnessed in Africa. He named it after the then Queen of England, Victoria Falls. Over 150 years later, this spectacular waterfall is one of the world's most famous landmarks. The full breadth of the river plummets into a gigantic fissure 100 meters deep. This massive split in the earth's crust stretches almost two kilometers across the river's path and swallows the entire watercourse. Victoria Falls is the largest sheet of falling water in the world. At the height of the rainy season, columns of spray rising 300 meters into the air can be seen from 50 kilometers away as over 500 billion liters of water plummet over the edge every minute. The spray drenches the surrounding area in a permanent rain-like mist. Rainbows form in the African sun and at full moon, the light is bright enough to see a lunar rainbow called a moonbow. Livingston was so impressed that he later wrote, scenes so lovely must have been gazed upon by angels in their flight. The falls transform the placid Zambezi into a fierce torrent, slicing through a series of dramatic rock gorges. And yet the river maintains its composure right up until the last minute. For over 100 generations, the steel-nerved Lea people have fished here for purple labios and yellowfish, which gather in the pools at the lip of the falls. At least these brave fishermen are safe from hippos and crocodiles, since they never venture this close to the precipice. But just one wrong step could result in instant death. Every year, fishermen underestimate the Zambezi and become food for the very fish they risk so much to catch. Despite the fact they have fished and waded here since childhood and think they understand the river's whims. And even though they were taught by their fathers and grandfathers which channels are safe and which could sweep them to certain death. The Zambezi is gradually eating away at the gorge. The falls are changing, imperceptibly but persistently. Over millennia, the river has carved a zigzag footprint through the rock. The falls have surged down each of these vertical walls at different times over the last 100,000 years. The current waterfall is the eighth, but it won't be the last. The process has already begun again. On the western edge of the falls, in a crevice known as the Devil's Cataract, the flow of the Zambezi steadily works away at a weak spot in the rock. In a few thousand years, Victoria Falls will plunge into a new gorge upriver. Downstream from the falls, the great Zambezi takes on a new personality. The Lethargic River metamorphoses into a boiling, cacophonous torrent. The whitewater rapids in these gorges are some of the most violent on earth. They're classified as grade 5, just short of the most vicious rapids in the world. Now, over 1,200 kilometers from its source, the deadly Zambezi thunders onwards with a renewed sense of purpose. But its course is soon interrupted by another dramatic formation. The surging river widens once more as it flows into Lake Kariba, bordering Zambia and Zimbabwe. This huge lake is the result of man's unstoppable urge to tame nature. The all-powerful Zambezi slams into a gigantic concrete wall. Lake Kariba is one of the largest man-made lakes in the world. It was created half a century ago when the great river was dammed to harness its power. It generates as much electricity as a nuclear power plant. Thousands of the local Tonga people were forced to move out of their fertile valley home to make way for the lake. But the Zambezi didn't surrender without a fight. As the valley was cleared and work on the huge dam wall began, the river unleashed some of the most violent flash floods ever recorded. Time and again, hurricane-force winds battered through the valley and torrents of water overwhelmed the half-built wall. The Tonga people believe the construction angered the great Zambezi river god, Nyaminyam, and the floods were his terrible revenge. 86 construction workers were killed and several bodies are still entombed in the millions of tons of cement that make up the dam wall. But the Zambezi was beaten in the end. The river spread into a vast lake, drowning a beautiful, fertile valley. The ghostly branches of dead trees are a testament to the destructive power of these waters. But the lake is also a blessing in disguise. Before the lake was flooded, the valley was burned. The ash left a thick layer of fertile soil that became the lake bed. This now supports a rich community of plants and animals. Even the displaced Tonga people have found a place for Lake Kariba in their lives. At night, Tonga fishing rigs spread out across the lake. They lower bright lights into the gloomy depths and wait. Small sardine-like fish called kapenta shoal in their millions in the lake and flock to the lights. When the fishermen draw in their lamps, the tiny fish follow and are scooped up in fine mesh nets. The kapenta industry has become so important that the fish are known as silver gold. Racks of kapenta dry in the sun along the lake shore and piles of them fill market stalls for miles around. The sun-dried fish taste as strong as they smell and are a local delicacy. The Tonga people, whose livelihoods once depended on the valley submerged beneath these waters, now make a living from Lake Kariba. But many people believe that the river god is only sleeping. One day, Nyaminyami will rise up, destroy the dam, and give the people back their river. Below the giant Kariba dam, the tamed Zambezi meanders sedately through a wide rift valley, which was formed as the earth's crust contorted, split, and cracked millions of years ago. The Zambezi's slow journey across these ancient lowlands gradually erodes the volcanic rocks into mineral-rich soils. It's a far cry from the terrifying destructive force that tears through the gorge upstream. Here, the river has created a living Eden. But for some creatures, the grass always seems greener on the other side. Elephants are excellent swimmers, just as at home in the water as they are on land. Their trunks act as built-in snorkels, allowing them to breathe as they navigate the deep channels. The river marks the border between Zambia and Zimbabwe, but elephants have been fording the Zambezi for generations, long before the land was defined into countries. The prize on the other side is a meal of juicy tamarind fruit, well worth the swim. The elephant's versatile trunks are just as crucial now, picking the pods as nimbly as fingers. The Zambezi River is a very different body of water now compared to the tumultuous cascade of Victoria Falls. The Kariba Dam has dramatically reduced the river's velocity, but the wily Zambezi still has a few surprises up its sleeve. Its river basin is the largest in southern Africa, and the rivers of eight countries drain into it, feeding the river's wild power. One of the largest and most significant of these tributaries is the Luangwa River. Itself one of the biggest rivers on the continent, the pristine Luangwa cuts an easy path through the soft, fertile soils north of the Zambezi. It floods and recedes with the seasons, and when the rains stop, the river wanes to a shadow of its former self. Water holes dry up across the land, and this last remaining water course becomes key to the survival of animals for miles around. It's a chain reaction. If buffalo don't find their way to water, other creatures that depend on them will suffer too. Oxpeckers and egrets always follow in the wake of a buffalo herd. The egrets feed on insects stirred up by the lumbering hooves, but the oxpeckers have a more direct feeding strategy. Oxpeckers survive on blood, sweat, and tears. They feed on blood-sucking ticks that infest Africa's big mammals, and also peck at everything from earwax to saliva. So an open wound is an open invitation to an easy meal. It looks painful, but the little birds are doing the buffalo a favor by keeping wounds clean and free from infection. Parasites pester all the animals here, and some have found ingenious ways to get rid of them. A mud bath is a luxury that elephants learn to enjoy early in life. As the mud dries, ticks and biting insects get stuck and can be rubbed off the elephant's skin. Carmine bee eaters have a very different approach to pest control. These birds nest in vast colonies along the banks of the Luangwa River. With so many birds in one place, parasites are plentiful. A spot of sunbathing turns up the heat and is usually enough to dislodge stubborn ticks. The dwindling river means hardship for most animals here, but for the bee eaters, it opens up opportunities. As the river drops, it exposes soft sandy banks, ideal for excavating nesting burrows. But each year when the rains return, the blessing of the river will become a curse for the bee eaters. Their whole establishment will be washed away. It's a perennial struggle. The river does not tolerate squatters. As the dry season tightens its grip and the river shrinks further still, the animals are forced to crowd together in larger and larger numbers. These muddy river bends in South Luangwa boast the largest concentration of hippos in Africa. Most members of this pod are happy to wallow in peace, but as territories bump boundaries, tensions can run high. A dung shower is a sure sign that a hippo is getting hot under the collar. Usually, sizing up one another's tusks is enough to settle a dispute, but deep scars are a testament to the violence of some fights. Losers are edged out of valuable deep water territory. Others are unluckier still. But even death can bring life. White-backed vultures spend their days circling and searching for carrion. They can soar for hours on natural thermals without ever having to flap their wings. And they can spot death from hundreds of meters up in the air. Eating is a messy business for vultures, so their heads and necks have no feathers that would only get clogged with blood. Marabou storks, Africa's undertaker birds, are always quick to find a carcass too. They wait for the vultures to break through the tough hide, then use their meat cleaver beaks to hack off large hunks of flesh. The shrinking river played its part in the hippo's death, but it offers a gift for scavengers. A carcass this size will feed many mouths. Fertilized by mountains of hippo dung, the twists and turns of the river become rich resources for wildlife. Fishing parties of pelicans and yellow-billed storks flock to the river, hoping to make a catch in the dwindling channels. But bigger predators have their eye on a larger prize. The hippos share their river with some prickly neighbors. The crocodiles glide dangerously close, but an adult hippo is too big a target for even the largest reptile to attack. But the stresses of the dry season have taken their toll on one hippo, yet deliver a feast for the crocodiles. This hippo could have died from dehydration, war wounds, or disease. But feeding on such a big cadaver presents challenges. Crocodiles have a powerful bite, but can't chew. It takes cooperation for the group to get a meal. While some brace against the hippo's body, others use a forceful spin to wrench off chunks of food. It's a strategy that has been keeping crocodile bellies full for millions of years. It seems like a free-for-all, but there is a strict feeding hierarchy, and the most dominant animals feed first. The other hippos have no choice but to witness this gruesome scene. In these dry months, there's nowhere else for them to go. As the Luangwa River moves south towards the Zambezi, its banks are lined with ebony groves. Their twisted torsos show the river's influence, as it has flooded these woods year after year. Water and sun have weathered their bark. The cathedral-like arbors provide many creatures with shade from the midday heat. In the dry season, the trees drop their leaves to conserve water. Puku and kudu nibble the dry leaves, and baboons forage for morsels that could resemble a meal. Baboons will eat almost anything, and can survive on a meager diet of grass and leaves in lean times. When the rains return, the river will flood this woodland floor once more. The trees will sprout new leaves and produce fruit. The cycle will continue as it has for thousands of years. The Luangwa River sustains life in one of Africa's most precious wildlife havens, joining forces with the thirsty Zambezi. Just as the mighty river is replenished, it leaves its homeland of Zambia for good, and flows on into Mozambique. For most of its journey onwards to the ocean, the Zambezi is a broad and mature river. It has lived through many geysers, from tiny brook to raging torrent. It has fed giant waterfalls and colossal dams. The Zambezi is no longer in a hurry, and flows gently on to the sea. But before the great river reaches its final destination, it absorbs one last tributary. The Shire River drains out of Lake Malawi, one of the largest lakes in the world. When storms hit this giant lake, the surface can rise as much as three meters. Trillions of liters of extra water spill out into the Shire River, the lake's only outlet, and the longest and largest river in Malawi. The floodwaters rush south to unite with the Zambezi, as it makes its last big push for the sea. When these two huge rivers meet, the Zambezi still has over 100 kilometers to travel before it reaches the Indian Ocean, the end of its epic journey. Once again, the mighty river takes on a new character. It spreads out into several branches, and finally reaches the Mozambique coast, forming a vast flat delta that stretches 200 kilometers along the shore. Over thousands of years, the Zambezi has deposited silt here, carried from its birthplace high in the hills, and collected on its journey east. The silt creates fertile soils, making the Zambezi Delta a rich and bountiful haven where wildlife thrives. But as always with this powerful river, where there is a blessing, there is also a curse. Below the water's surface lurks a deadly predator with a trunk part. The Zambezi sharks, also known as bull sharks, have a unique adaptation that makes them one of the most remarkable sharks in the world. They are the only marine sharks able to tolerate fresh water. Their blood is much less salty than that of other sharks, whose kidneys would fail if they left the sea. But bull sharks can hunt both in the ocean and far upriver. And the Zambezi Delta is an ideal hunting ground. Females are much larger than males, growing up to three and a half meters. Despite their large size, Zambezi sharks are stealthy hunters, sneaking up on their prey in murky waters. The poor visibility is no drawback. Sharks detect prey by picking up vibrations in the water caused by movement. And the faint electrical pulses emitted by all living things. Just because you can't see a shark, it doesn't mean it can't see you. The Zambezi Delta plays a crucial role for another charismatic animal. A brood of loggerhead turtle hatchlings scrambles free of the sandy nest hole where they've been incubating for the last two months. Their mother's only act of parental care was to lay her eggs in a safe place, deep in the soft sand, hidden from danger. Now, the tiny turtles are on their own. Their first instinct is to head straight to water. The nest is high up the beach, so their first journey to the sea is an intrepid one. Not all of them will survive. At just five centimeters long, the baby turtles are vulnerable to predators. This one's short life comes to an abrupt end in a ghost crab's lair. Those that make it to the sea take their first swim and just keep on going. Their tiny flippers take them far out into the open ocean. And it could be several days before they reach the relative safety of a raft of algae. Here, they will stay drifting at the mercy of the ocean currents, feeding on whatever floats within reach of their little jaws. Eventually, they will grow to be over a meter long. From hatchling to adult, a loggerhead's weight will increase more than 6,000 times. Adults can hold their breath for up to 10 hours at a time, longer than any other marine vertebrate. But they must eventually break the surface for a lungful of air. Loggerhead turtles get their name from their reinforced jaws, which they use to crush the shells of mollusks and crustaceans, their favorite foods. These far-ranging feeding machines provide a useful service to remoras, which often save energy by hitching a ride with a turtle. A modified fin works like a suction cup, allowing them to cling on. Remoras feed on parasites and hoover up any scraps of food that the turtle overlooks. Adult loggerheads are one of the ocean's great travelers. They swim tens of thousands of kilometers in their lifetimes. But despite this wanderlust, every female returns to the very beach where she was born to lay eggs of her own. With a bit of luck, many female hatchlings will find their way back to the Zambezi Delta in the years to come. Like the tiny turtles, the Zambezi is itself swallowed up by the vast Indian Ocean after a long and wonderful journey. This great river that started out as a tiny trickle under a shady tree has forged a unique path through Africa and has breathed life into this land for millennia. It has a far-reaching power that stretches across thousands of kilometers. Humans and animals depend on its waters for life and yet are at the mercy of its moors. Livingston recognized this tremendous river's extraordinary influence and dubbed it God's Highway. It is truly the mighty Zambezi.