"This the Namib Desert in southwest Africa." ""Namib" means vast." "It's 1,600 kilometres long... ..50,000 kilometres square." "The Namib is the oldest desert on earth." "It's the harshest place in the world for elephants to live." "And 25 years ago, out of a herd of 80 desert elephants, poachers killed all but three." "Now large-scale poaching has ended." "The herd is recovering and two young calves have just been born." "Their first six months will be critical, as each calf learns the secrets of survival among the searing sands." "It's May, the cold, dry season in Namibia." "In the Hoarusib valley, several families gather to feed." "One mother is particularly hungry." "Four months ago, Broken Tusk had a new calf, Dusty." "He's always after milk." "Dusty is Broken Tusk's first calf for eight years." "Desert elephants have only half as many calves as their savannah cousins and they may suckle for twice as long." "The family appear to enjoy their new member." "Dusty's relatives will do all they can to prevent him getting into any trouble." "Youngsters are even more welcome than usual because of a recent death in the group." "This is Rosa, the oldest member." "She's just lost her elder daughter, who died within days of giving birth." "In her late 50s, she's unlikely to have any more calves." "Rosa is attempting something elephants don't normally do." "She's trying to raise her dead daughter's son, Himba - she's adopted the orphan." "Luckily, she can give him milk because she's still feeding a seven-year-old daughter." "Rosa's milk is vital because at two weeks, Himba can't cope with solids." "He can't eat grass, so Himba is totally dependent on his grandmother." "The challenge is to guide the new youngsters safely through the next six months." "By then, the two calves will have to be strong enough to endure the long treks that take desert elephants to their next source of food." "For now, the leaders can let the calves play, but in a short time, they will guide the youngsters on journeys that will test them to the limit." "The lead females take the herd on short trips into the surrounding hills to forage." "Exceptionally, the desert is in bloom." "Any young born now are enjoying ideal conditions." "A miraculous transformation has taken place." "Five months ago, deluges in distant mountains unleashed torrents." "For the first time in 30 years, the floods brought dried-up rivers back to life." "The rivers create corridors dotted with waterholes." "While they can," "Rosa and Broken Tusk search for food up and down the river." "The adults can last four or five days without water but the calves must drink every day." "Himba is on a steep learning curve." "He hasn't yet managed to fill his trunk." "He drinks with his mouth instead." "Four-month-old Dusty has learnt by copying the adults." "He can already fill his trunk." "The older elephants can suck ten to fifteen litres into their trunks each time." "They empty the contents straight down their throats." "Water alone won't keep Himba alive." "To grow, he depends on milk, rich in fat and vitamins." "The tiny orphan relies on the milk left over once Rosa's daughter has fed." "At the same time, unusually, Dusty is on double rations." "He's drinking milk from both his mother and his elder sister." "As males, Dusty and Himba should grow faster and larger than their female relatives." "Dusty certainly has an appetite." "If he sees his elder sister suckling her own calf, he'll try to prevent her." "He's able to feed much more than Himba." "Dusty can look forward to drinking milk for years." "At least one of his relatives is still suckling at the age of seven." "Rosa and Broken Tusk will do everything they can to give their offspring the best chance of survival." "The small families need every extra member they can raise." "At the moment, however, the calves keep this part of the herd tied to the water course and its dwindling pools." "Only ten kilometres away, there are other members of the herd." "Leading them is Left Fang, named after her plunging tusk." "She too is raising a family but her calves are older." "The adolescents can traverse more difficult terrain and they can undertake longer journeys." "They travel constantly, from food to isolated food, pausing occasionally to take on water." "Unhindered by young," "Left Fang is free to seek out the individual plants that provide important carbohydrate and much-needed vitamins and minerals." "To fuel their immense bodies, elephants spend some 16 hours out of 24 eating." "They need food more often than water - up to 136 kilos every day." "Left Fang knows when each food is at its best." "She has brought the others to browse on commiphora." "The woody shrub contains a sugary sap, the scented resin known as myrrh." "She handles the tough stems with ease, wielding 40,000 muscles in her massive trunk." "Down below at the riverbed, Rosa and the others are still able to graze." "But the grasses and flowers from the big flood won't last long." "This year, there is so much food and water that, unusually, the desert elephants can spare energy to play and spar." "A visitor arrives, unseen." "Initially, the herd remains oblivious to his presence." "This is the first time the calves have ever seen such a large bull." "Dusty is alarmed." "His relatives rush to reassure him." "Tiny Himba moves closer to Rosa." "The big male leads a separate, solitary life." "He appears only occasionally, when he wants to mate." "He is looking for a receptive female." "The mature bull shows all the signs of being in musth, the time when he is sexually active." "But none of the herd is on heat." "Suddenly he senses another male nearby, also in musth." "He is at his most aggressive, so he gives chase." "The newcomer doesn't want to fight, but the big bull will pursue him, to make sure." "The group moves on, in search of richer vegetation." "The tamarisk trees along the banks are too bitter and salty." "The youngsters' constant thirst confines the hungry group to the narrow riverbed." "In the hills above, where more food grows, the 50 degree heat is too much for the calves." "Left Fang and the others protect themselves with dust." "Elephants can't sweat." "They seek out even the smallest hint of shade." "What they do now was thought to be a myth." "Every 20 minutes or so Left Fang's group spray themselves down." "vessels that cover their ears." "But up here, there are no springs or streams to provide water." "Remarkably, Left Fang's group are filling their trunks from hidden pouches in their throat." "This has rarely been seen, and never filmed before." "But the heat is drying them out." "They are losing several litres of water an hour." "The family won't be able to spend a second day up here." "At last, night brings the animals respite." "Dawn at the riverbed." "Rosa's surviving daughter is waking a sleepy Himba." "He's basking in her attention, and the warmth of a new day." "The seven-year-old aunt gently readies her nephew." "She gives him a dusting of sunscreen." "She can't feed him, but young females often mother small calves." "As Himba is an orphan, his aunt's efforts are even more valuable." "Dusty is already up and raring to go." "Along the riverbed, the elephants are finding it harder to locate palatable vegetation." "Rosa and Broken Tusk take the entire group off towards the nearby slopes, to look for the woody species they prefer." "Left Fang and her relatives are well fed and restored after a night high in the mountains." "They are making straight for the river again." "Her family learn the routes from her." "The older they grow, the more complex are their mental maps." "Theirs is the more typical life of a nomad." "Once at the river," "Left Fang's family makes up for the day in the desiccating sun." "But with little suitable forage to be had, they won't stay." "After a bout of friendly sparring," "Left Fang's family will set off again." "On their way to distant food, they come across the corpse of another elephant." "The bare skull lies separate from the skin-covered body." "From the smell, Left Fang can probably recognise the remains." "It is what is left of Himba's mother." "The find fascinates them." "Himba was just a few days old when she died." "His grandmother is the only mother he's ever known." "Elephants often linger, smelling and touching the bones." "It's one of the things that make them seem so human." "20 kilometres away," "Rosa's group is still hampered by the two young calves." "Himba is hot, thirsty and above all, hungry." "He won't be able to eat even grass till he's at least three months." "At six weeks, he remains entirely dependent on his adoptive mother." "His real mother would keep her son within trunk reach, in the shade of her body, and she would feed him every half hour." "Rosa must eat, as she is struggling to breastfeed two calves at the same time." "The little calf is doing his best to stay near." "Himba needs 15 litres of milk each day." "He manages to snatch only a few mouthfuls." "Rosa seems reluctant to suckle him." "He's desperate for more." "Himba is completely confused." "Without milk, he won't last long." "The calf's instinctive efforts to suckle lead only to rejection." "Now the undersized orphan looks frightened of Rosa." "For some reason, the aged female can't make enough milk." "She may not be finding enough food, or her teeth may be worn out." "Himba can only trail beside her, hoping the supply will return." "It's now August, two months on." "At one of the few remaining wallows," "Dusty's family are playing excitedly." "Dusty has more than enough energy." "Himba has no strength to play." "The others make the most of the plentiful water." "Normally, it would have vanished months ago." "A few weeks later, there is a sudden change." "Searing blasts scorch the land." "The usual wind from the south is giving way to winds from the east, across the blazing Kalahari." "In a short time, the greenery in the inland oases will shrivel." "Rosa, Broken Tusk and Left Fang face life or death decisions that will affect their whole families." "When should they leave?" "Where should they go?" "Which is the best course, with the lives of youngsters at stake?" "Each leader will make a different choice." "High on a plateau, Left Fang is the first to sense the threat." "Her response will be swift." "She will hurry her family towards cool and shelter down at the coast." "There are no small calves to slow them down." "They leave at once." "This is no light undertaking." "Even though her family are all fit and well, the arduous journey will take at least five days." "Left Fang must gamble on her experience to guide her family across arid, strength-sapping terrain." "Down at the dry riverbed," "Himba is now so hungry he's chewing on thorn pods." "For Rosa, the choice of when to leave and where to go is not so simple." "Try as he may, Himba can barely obtain any nourishment." "His grandmother's milk is slowly drying up." "He really needs his dead mother." "But Rosa is still trying to suckle her daughter as well." "In frustration," "Himba pushes the competition away." "But he manages only a few extra drops." "And his victory is short-lived." "Until the calf is stronger, the family are unable to move on." "But the more Rosa feeds Himba, the less there is for her own daughter." "Rosa is caught in a dilemma." "Dusty's aunts are all over him with help." "If he's too small to mount an obstacle, they give him a hand." "Broken Tusk will risk a long dash to safety but she won't leave until she's certain Dusty is up to the challenge." "Left Fang's family are already 40 kilometres away now, two days into their journey." "Down river, the sand beneath the sun-baked surface is much cooler." "This will help them endure the burning valleys, bare of shade." "The elephants browse on occasional bushes." "The thin vegetation gives Left Fang's family temporary relief from their hunger." "Nearer the coast, there's water below and above ground." "The smell draws other animals - prey and predators." "Baboons are opportunists." "They'll eat small mammals or insects, eggs or even grass." "They soon spot a chance." "Newly-hatched chicks behind a pair of Egyptian geese." "For all the birds' bravery, there's no contest." "Their attackers are ten times as heavy and much stronger." "Both parents try to head off the baby-snatchers, but they can't protect every gosling." "Finally, a thief seizes one." "The parents try to locate any survivors." "At least one got away." "It's the youngest that are the most at risk in any species." "By September, in the rapidly-drying interior," "Rosa's family are reduced to the last spiny bushes." "Himba is still too young to gain strength from the meagre fibres." "Rosa herself is increasingly short of energy." "The undernourished youngster gains little from his grandmother." "The small amount of milk that remains has precious little fat and nutrients." "The bones in his forehead are showing." "Himba is growing weaker and weaker." "None of the others have the commitment a real mother would." "The orphan's efforts to feed are increasingly in vain." "Rosa's attempt to save her grandson may be putting the rest of the family's lives at risk." "He is so small, none of them can travel to better grazing." "Rosa knows where she wants to head to but the journey could kill Himba." "Their five-day march completed," "Left Fang's family can enjoy the cooler surroundings of the coastal dunes." "They're locating the foods they crave at this time of year." "This makes their extraordinary journey worthwhile." "Here, lush tree foliage is within easy reach." "Left Fang's family can relax." "With some plants, they love the roots." "With dwarf palms, only found here, they particularly relish the tender bark." "Left Fang has made sure her family's needs are met" "They are safe, watered and at full strength again." "The family can regroup before their next great journey." "In the interior, Rosa is under pressure." "She can smell rain upriver, over 100 kilometres away." "Fresh pasture might give her enough milk to restore Himba, but they need to reach it within days." "Dusty's family is on the move, too." "Broken Tusk seizes the moment." "She knows an area where extremely rich food is about to become available." "The coming 48 hours will face Dusty with the hardest test of his life so far." "To reach the new food involves a marathon trek, 70 kilometres long, south, beyond a mountain ridge into the next major river valley." "Further inland, Himba has barely moved from the river." "The surrounding vegetation is no longer edible." "They have to leave as soon as possible." "Rosa and her daughter know that if the infant doesn't get up quickly, he may become too weak to rise again." "They want to keep him moving." "They lead him towards a mud hole." "The others wallow." "They coat themselves in mud as a protection from the sun." "Himba has run out of strength." "Rosa and her daughter won't leave the calf but without food they can't stay at the waterhole any longer." "Once more his family rally round to get him going again." "It's all too much for Himba." "70 kilometres south, Dusty is within sight of success." "After a whole day and two nights on the move, the longest Dusty has ever walked, his efforts are about to be rewarded." "For a short time, a delicacy lies on the ground here." "The ana trees are dropping their seeds." "The pods are packed with goodness." "For Dusty, milk from his mother and his older sister enabled him to reach fresh food." "His family's unique double suckling strategy is paying off." "Dusty's new-found stamina takes the pressure off the whole family." "Back at the dry riverbed, as November comes," "Rosa can still smell rain to the east." "She's desperate to head there in search of fresh food." "She has decided they must set out, despite Himba's weakened state." "Himba has collapsed, exhausted." "Lying next to him, his aunt tries to rouse him." "Without her help, his chances of getting up again are slim." "Himba's aunt becomes increasingly concerned - frantic, even - as he fails to respond." "The lack of milk is taking a cruel toll." "Yet if they can lead Himba to a new grazing area, he might get more." "Finally, the pair help him struggle to his feet." "How long and how far the small calf can keep going, they do not know." "Rosa and his aunt have ignored their own need to eat for too long." "Himba's weakness and their persistence" "Himba has not been seen since." "At the coast," "Left Fang's family are attracting attention from a male in musth." "Fresh and cool, full of their favourite palms and bushes," "Left Fang and her family are in prime breeding condition." "And one of the females may even be carrying the herd's next calf." "For the survivors of the poaching holocaust, each calf that lives helps rebuild this herd." "Dusty is now strong enough to master the routes and routines that will continue down the generations." "It's this knowledge and experience gathered over many lifetimes, combined with exceptional endurance, that is giving these elephant nomads their second chance." "Subtitles by Red Bee Media Ltd" "Email subtitling@bbc.co.uk"