♪♪ ♪♪ [ Animal calling ] ♪♪ NARRATOR: It is the beginning of the end of our story. ♪♪ The final chapter of a river that has run its course. ♪♪ ♪♪ They walk as if to the end of the world on a journey to nowhere. ♪♪ ♪♪ Some go in search of the water that is always just out of reach. Others follow the searchers, themselves expelled from paradise, banished to the far fringes of the great river like phantoms wandering aimlessly in the inferno. ♪♪ ♪♪ It is a place of nomads, hardy survivors, exiled hunters of illusions. ♪♪ This ancient land is where the water turns to salt, the air burns on the inhale, and everything seems to wait to exhale. ♪♪ What little water is left is as dangerous as it is a salvation -- because it is a distraction. ♪♪ A place where someone's mistake is someone else's lifeline. ♪♪ A mistaken burst of energy can change your destiny. ♪♪ This extraordinary realm is the ancient extension of the Okavango, a river of dreams. MANSON: ♪ ...looking for something ♪ ♪ Some of them want to use you ♪ ♪ Some of them want to get used by you ♪ ♪ Some of them want to abuse you ♪ ♪ Some of them want to be abused ♪ ♪♪ ♪♪ ♪♪ NARRATOR: The next and final chapter of our story of the great Okavango in Botswana is where its fingers clutch onto life, as the water touches the desert, where paradise turns into an inferno. ♪♪ ♪♪ Each droplet is a jewel that holds the fate of a small part of all life here. It is the story of movement. Everyone is on the move. Like fragile porcelain, this part of the delta is vulnerable to the smallest change -- in water, in temperature, and from the swirling influences of tiny animals. ♪♪ Red billed quelea in their millions start to flock. These are the most abundant birds on the whole planet. A single super-flock of quelea can devour twenty tons of feed a day, and that changes everything here. ♪♪ ♪♪ The quelea will change the lives of the nearby leopard family, as the flock strips the grasses down to bare sand. [ Wings fluttering ] The little female's brother has less time for such reflections, he is more interested in how things work in the world. ♪♪ ♪♪ ♪♪ Like the bees, returning laden with pollen. He hasn't learned the dangers of being curious yet. ♪♪ Bee-eaters swoop in to take advantage. ♪♪ Bored with killer bees, he takes to irritating his more serious twin sister. ♪♪ It's the season of the sausage tree flowers. Good for bees... and the ideal place for the twin's mother to hang out. ♪♪ She's not resting, she's waiting for the fallen flowers to attract attention. ♪♪ Usually, leopards catch just once in every 5 attempts, but by using this sausage tree technique, she has a much higher success rate. It's also why we call her "Moporoto" -- the local name for sausage tree. The cubs are developing their own killing skills, but by watching Moporoto, they might understand exactly what these flowers can give them. Rest is impossible, so within minutes, she heads back to the trees. ♪♪ ♪♪ The throat hold makes it a silent death. Stealth after the kill is as important as before for one of the smallest of the big cats. ♪♪ In this complex mosaic of the Okavango, bigger predators and scavengers stride across the landscape as if they own it. They do own it. ♪♪ Here, the water separates into streams and rivulets, winding fingers that cut through the grassland and sausage tree islands. ♪♪ The lions are in search of shade, but the breeze has hints of the smell of meat on it. ♪♪ ♪♪ If the cubs panic, they could slip. It would end their story. The lions want the kill, but just can't get to it. ♪♪ ♪♪ Thankfully, the lions have their own cubs, and the massive sausage pods distract them. [ Cubs grunting ] Their fascination with the woody pods is a mystery to the leopard cubs. But from now on, their lives will be intertwined with all these other predators, because the Okavango has one of the highest densities of carnivores in Africa. And they're periodically thrown together by the flood. There is a chill in the morning air now, but during the day, the temperature starts to rise. This signals the start of the dry season, when the channels begin to shrink. Oxygen levels drop. The fish that recognize that turn and head back upstream. Those that leave it just too late get cut off, isolated. The birds harvest tons of fish each year. Their collective and organized feeding frenzy will clean out a pool in just a few days. But all the way down the delta, right to the end fingers, these fish traps provide for one of the greatest diversities of water birds in Africa. ♪♪ Being able to move is critical to survival at the fringes, where water supply is fickle during this part of the year. ♪♪ When the feed above ground is depleted, elephants go in search of a new protein source. ♪♪ They start mining the rhizomes and grass roots buried in the sand. ♪♪ In the dry season, the entire value of the grasses is stored below the surface. [ Rumbling ] Local residents have to protest to stay safe. [ Squawking ] [ Elephant roars ] A pack of painted dogs have a small problem today... Actually, 16 problems... Having this many puppies causes a problem because only one female in the pack is allowed to breed. So, the Alpha female has stolen her sisters puppies... but she's struggling to feed them all. It's a free-for-all, but she refuses to share this burden of motherhood or abandon any pups. ♪♪ The headache for the alpha male is that they're going to be called on to hunt twice a day now, and they're already exhausted. ♪♪ So is the river. After its nearly thousand-mile journey, the full thrust of the flood has ended. The water flow settles and starts to seep in. ♪♪ Even sleeping giants can be woken by a small niggling voice. It's a nudge that starts a ripple effect of movement. It's the largest migration of elephants in the world. Now, the air is so dry that it turns the grasses brittle under their feet. They cover hundreds of miles in search of water. It's a 50-gallon-a-day challenge, so these Okavango elephants are seldom far away from water -- water that others live in, fight in, and churn up into mud faster than is necessary. But this pressure on resources sets the elephants off again in search of clean water, and behind them, the land is left to rest. At these fringes, those that can move have an advantage. ♪♪ ♪♪ Warthogs are after the same buried grass roots, rhizomes. It's the season when warthogs cluster around rhizome patches. ♪♪ It's an awkward position to be in. ♪♪ Lionesses have to hunt whatever prey is in their territory. ♪♪ ♪♪ ♪♪ ♪♪ ♪♪ A good pig hunting day will see two or three taken in one hunt. They can hide -- but they shouldn't run... ♪♪ [ Warthog squeals ] Here, it's all about territory. Warthogs will feed the lionesses until the rains, but it's risky being territorial at the far end of the water. A low flood one year, and they will be high and dry. Lions cubs play with anything... ...even old elephant dung. ♪♪ What is just a play thing for lions, is highly valued nesting material for squirrels. ♪♪ They're playing the long game and preparing early. ♪♪ Raiding starlings spot an opportunity for themselves. They are energetically lazy about nesting. The squirrels' nesting material is just easier to steal. ♪♪ When one thing goes wrong, everything falls apart. It's a bad day for squirrels. ♪♪ The lilac-breasted rollers aren't after the nesting material. They're after the whole nest... It's pure harassment, no matter how brightly colored it is. ♪♪ Eventually, it is just easier and quieter to move on, the early squirrel just wasted her time. The rains are some way off anyway. ♪♪ Moporoto has been hunting. The sausage tree technique is still working for her. Her island has been the perfect refuge for her and her cubs. ♪♪ Because the little male always gets to feed first, the female cub tries to hone her tree climbing skills. ♪♪ She doesn't quite have the hang of it yet. ♪♪ ♪♪ Moporoto has to start thinking about moving soon: the smell of meat and cubs has started to attract attention. ♪♪ [ Snarling, grunting ] It's a stolen meal -- next time it might be a cub. ♪♪ ♪♪ ♪♪ ♪♪ ♪♪ She has to move them now. It's their first venture away from their birth place, into a world filled with strangeness for them. ♪♪ ♪♪ ♪♪ It may seem like a harmless duel, but giraffes can do serious damage to each other... with razor sharp hooves and battering ram-like heads. ♪♪ She's followed the line of sausage trees while they have flowers, but now she has to venture out. The open grassland is very risky for a leopard with cubs. Lions are the biggest threat to them. But today, it's stifling hot, and the large, black-maned lion is even hotter than his females. And his shade from the termite mound is steadily disappearing. Even investigating vultures is beyond him today. The cubs feel the same. But for Moporoto, there is just something about the way the vultures are circling... Something definitely worth looking into. It's a giraffe, killed in a fight. [ Insects buzzing ] Out here, there are no free meals the hyenas aren't already aware of. [ Hyenas squeal, Moporoto grunts ] Her cubs panic. One up the tree... the other to the bush. He is safe. Now she has a problem, and it's largely one of communication. She somehow tells him to stay in the tree, but tries to encourage the little female back from the bushes. ♪♪ ♪♪ ♪♪ She tests the night. ♪♪ ♪♪ [ Animals calling, cub grunts ] [ Moporoto grunts ] Her tree climbing lessons paid off. The lost little female is found. ♪♪ ♪♪ It doesn't take the vultures long to claim the kill under the little male's sausage tree hideout. But now, when the hyena senses danger, it isn't from Moporoto. ♪♪ The single event -- a giraffe fight gone wrong -- has attracted a full range of opportunists. It's almost unheard of for painted dogs to scavenge, but the pack needs this now. If they're going to bring up 16 pups, any meat at this fragile water's end will do. This will go a long way. But vultures will just attract other scavengers now, and the real danger to dogs is lions, so it's tense around the carcass... especially for the stranded leopard cub. ♪♪ ♪♪ ♪♪ The alpha male's obsession with vultures is a distraction. ♪♪ It's Moporoto all a-hiss with fury, way out-numbered, but with the confidence of a lion. [ Dog grunts ] [ Insects buzzing ] [ Grunts ] Their adventure, their first in the world beyond their den, is over. [ Calling ] ♪♪ It takes a little coaxing, but he finally understands that she feels it's safe to come down. Backwards is fine, too... ♪♪ ♪♪ A last feed before it starts all over again with hyenas, and possibly lions. But each interaction makes the cubs stronger now, better equipped to grow in this extraordinary swampland and its fingers of water that stretch out into the desert. ♪♪ A full month before the rains, something stirs in the air, something that has local residents paying attention. Zebras have started to migrate south. As they do, they meet strangers. Meerkats can't afford to spend much time gawking. They're on a high-energy diet. Out here, beyond the water's end, they find that in juicy, fat grubs. The family posts a permanent lookout, because the threat to them will come from the ground, as well as from the air. In the soft sand, there is always a ready hole on standby for escape. The farther away from permanent water the herds go, the more closely followed they are by nomadic lions. Desperate hunters without the restriction of territories. But the real mystery is why the herds leave the tip of the Okavango flood at all. The answer is in the quality of the water they leave behind. Water holes are tired, drying to liquid that is rapidly being turned into mud. ♪♪ ♪♪ As these last pools of water get isolated and cut off, the water is virtually undrinkable. ♪♪ ♪♪ Elephants dominate, and it is here that the nomadic lions find the best opportunities. They understand that someone's desperation is their hope. ♪♪ ♪♪ ♪♪ ♪♪ They're often young, displaced siblings, both males and females. Now these nomads must form even stronger bonds, as they move into the unknown thirst land. ♪♪ The heat is hard on anyone who is slightly slower. She was asleep at her den when the nomads found her. Bat-eared foxes mate for life. He has no choice but to watch the lions play with his mate. He will have to raise the family alone now and be the lookout for all of them. Secretary birds are no threat, as long as you stay still. The fox family is ready to bolt if she gets any closer. ♪♪ The scrub hare at the bird's feet knows to freeze. ♪♪ But secretary birds hunt on movement - even the slightest movement... ♪♪ ♪♪ It takes nerves of steel to wait it out. ♪♪ He just didn't have them... ♪♪ ♪♪ If you can't move, you have to change tactics. There are very few that can survive for long beyond the water. Tragedy follows any misstep out here... Procrastination when it comes to a decision to leave a territory, a pool of mud, is simply foolhardy. But some just get caught out. As a last desperate effort, barbel, one of the few fish in the world with accessory breathing capabilities that allow them to breath actual air, start to "walk." Some burrow into the mud and slow their metabolisms right down to barely a heartbeat... waiting for the rains. If they get it wrong, they're on the top layer and simply bake. She doesn't have the bulky body of Moporoto, because she doesn't get the same food. She's a desert leopard. But the wily leopard living on the edge has a talent for finding the impossible... A buried barbel. It's small, but in a few days, the hippo will probably be stuck too. She can wait... ♪♪ ♪♪ ♪♪ It starts with the most gentle of breezes, dusting the scorched sands. ♪♪ ♪♪ The zebras are the first to recognize it. It comes from out there. ♪♪ ♪♪ Where the herds go, the nomads follow. ♪♪ ♪♪ ♪♪ Movement. The hot air rises and cools. As it drops down, the air triggers a cycle of the most extraordinary contrasts. It is the eternal journey of life from death, water from dry, and motion from the static stifling heat. They run on the promise of rain. ♪♪ [ Thunder cracking ] Within days, over 3,000 miles of flat thirst land is transformed by just a few inches of sheet rain water. ♪♪ ♪♪ ♪♪ ♪♪ ♪♪ It takes the pressure off everyone. It unlocks them from purgatory. ♪♪ It releases the nomads to spend energy playing again. It attracts thousands of pink visitors from across the subcontinent. ♪♪ ♪♪ The arrival of the flamingos is all about sodium chloride -- basic salt. ♪♪ ♪♪ The rain has stimulated a hatching of shrimp that they feed on. The sheet water gives them safety, an early warning against being ambushed. ♪♪ ♪♪ ♪♪ Their pantomime is only interrupted by a snooping jackal. ♪♪ ♪♪ ♪♪ ♪♪ He's heading somewhere else anyway. The smell of blood on the wind. ♪♪ ♪♪ ♪♪ ♪♪ A wandering lion, like so many other cats here, prefers the rough and spiky grass islands to the sticky salt water. It's hard for everyone. ♪♪ But it is that salt that the zebras have been coming towards, for months. They desperately need the minerals to fight off the toxins from the grasses they have been eating 300 miles away in the Okavango delta. Without salt, they simply cannot survive. If you are a zebra in Botswana and want to find a mate, fight for your right to a herd, or even give birth in the safety of thousands, this is the place to be. ♪♪ Full moon in the salt pans is a kaleidoscope of night light, dancing off the white salty sands below the water. [ Zebra barking ] [ Lion growling ] ♪♪ To really understand the Okavango is to know that this precious water takes half a year to reach the full extent of its range. It nourishes over 10,000 square miles and everything that lives in it. Every single life here plays its own unique role in creating this pristine landscape. And together, they all change the water's flow. They are a reflection of the river itself. ♪♪ Regal male lions fight and force nomads to wander off. Fires burn underground and gently smoke for years flushing out the old, stimulating the new. It's an enigma. A place where a beautiful stillness hangs in the air. ♪♪ ♪♪ It is one of the last places on Earth where giants can still roam unmolested. ♪♪ Where babies can trust in tomorrow, and where hope is alive. ♪♪ It's where a single lioness can overcome impossible odds, to live another day. It is a jewel, one of the most pristine landscapes left on the planet, and its future is entirely in our hands. We have a choice: we can protect it, or we can just stand back and bear witness to the very last life here, and watch as it all ghosts away... like a dream. MANSON: ♪ Some of them want to get used by you ♪ ♪ Some of them want to abuse you ♪ ♪♪ ♪♪ ♪♪ ♪♪ To learn more about what you've seen on this "Nature" program, visit pbs.org. ♪♪ ♪♪