"Out of the darkness emerges a 12 tonne giant." "She is a an Indricothere and she is about to give birth." "She seeks out a secluded spot in a canyon where she hopes the new born will be safe from predators." "It is now just before dawn and at last her two year pregnancy is coming to an end." "The calf is a male and he is already in trouble." "The noise and smell of the mother's labour has attracted the predators" "Hyaenodon." "Despite the name, these are not relatives of hyenas." "These are more dangerous by f ar." "Next to the Indricothere they may look small but these carnivores are as big as rhinos and they are easily capable of killing the calf, if they can get past his mother." "As the predators circle she desperately tries to keep the baby between her" "legs where she can defend him with powerful kicks." "But the Hyaenodon keep coming and coming." "This calf will be lucky to see his first sunrise." "It is a time called the OgIiocene." "The world has just been through years of catastrophic climate change that" "led to the extinction of one species in five." "Earth has since bounced back but in the process it's become a changed world - different weather different plants and different animals." "Here in mongolia some animals have grown enormous." "This programme will follow the f ate of just one of these giants, a baby Indricothere." "During the night this canyon was the scene of his dramatic birth but it seems his mother saw off the Hyaenodon." "He is a very lucky calf." "As a new born he already weighs a quarter of a tonne." "And his legs aren't used to bearing any weight at all so he'II spend the rest of the morning learning how to walk." "Around him, the other residents of the canyon are starting to stir." "Strange beasts like the ChaIicotheres." "almost three metres tall they walk on their knuckles to protect their long claws." "These powerful limbs are very effective defensive weapons." "But more often these herbivores use them to hook down branches to get at the softest leaves" "They walk like gorillas and eat like pandas but their closest modern relatives are actually horses." "The new born calf also has food on his mind." "This is the beginning of the most vulnerable period of his life." "He'II be totally dependent on his mother for at Ieast three years." "He needs her protection and for the first year he also relies on her milk." "This is an astonishingly long commitment for any mother." "But if he can just survive that long his size will mean there will not be a predator on earth that can touch him." "In the OIigocene large parts of the world have become highly seasonal." "Here in mongolia long, dry seasons are broken by short, violent, wet seasons." "The climate has shaped not only the environment but also the animals." "It is survival of the meanest." "And they don't come much meaner than this - a giant EnteIodont, the bully of the plains." "These are distant relatives of the pig, two metres tall, aggressive and built like tanks but with a brain no bigger than an orange." "The bear dog mother and cubs retreat to a safer distance but it isn't going to be their day." "although these relatives of both bears and dogs are vicious" "little predators, at the water hole it's size that matters." "The mother Indricothere has also come here to drink but her calf is nowhere to be seen." "A second male EnteIodont arrives at the water hole." "During the mating season these huge scavengers get very aggressive towards each other as they try to establish who is top hog." "EnteIodonts are their own worst enemy." "It is enough to put off even an Indricothere." "The EnteIodont's fearsome set of teeth have inflicted deep wounds on the loser" "Back in the canyon, the calf lies motionless." "He is playing dead." "until disturbed that is." "This is the young calf's survival strategy." "In his mother's absence he instinctively lies still to avoid the attentions of predators." "only when she eventually returns does he come out of hiding." "He remains within the comparative safety of the canyon walls for another week." "But then his mother decides it is time to leave." "The calf is now strong and sure-footed enough to venture out onto the open plains where he will spend the rest of his life." "Not since the dinosaurs has nature got this big." "Indricotheres are related to rhinos but their size is in a different league." "A fully grown male stands over seven metres tall and weighs in at 15 tonnes." "That's equivalent to eight modern rhinos." "No other land animal even comes close." "Being big not only protects them from predators but in this dry" "Iand allows them to go without food or water for days." "The calf is eager to explore this big new world." "But his first encounter is a shock for him." "An aggressive bear dog has no time for his curiosity." "Her cubs are nearby." "And to her, the gawky calf is a threat." "It doesn't take much to send him running back to his mother." "Right from the beginning, the calf starts copying his mother to Iearn how to deal with the world." "So when she arrives in her usual feeding area and sniffs a pile of dung he does the same." "One day he will understand that since every Indricothere has a unique odour this is how his mother tells which other animals are in the area." "His lessons in survival have begun." "Nearby is a juvenile Indricothere just over three years old." "This is not stranger but his mother's previous calf." "However she has no time for him now and violently repeIs him." "He doesn't know it but our calf is looking at his own future." "The long, dry season is just starting." "But there is still plenty of food around." "In another month or so the situation will be very different." "And so animals are gorging themselves while the going is good." "As the mother browses she has the tops of the trees to herself." "It's another advantage of being big." "only two months old, the calf doesn't need to eat." "He is still living off his mother's milk." "But it doesn't stop him trying to imitate her." "This is how calves learn which plants are safe to eat." "However, this is a bad time for him to wander off on his own." "Just 20 metres away a Hyaenodon is stalking." "Hyaenodon's jaws have a bone-shattering force of over 1000Ibs per square inch." "One bits breaks the ChaIicothere's neck." "They are capable of eating everything on a carcass." "But today he isn't going to get the chance." "The local bullies have arrived and he is outnumbered." "In a futile attempt to hide the smell of the carcass the Hyaenodon defecates on it." "But it will take more than that to put off the EnteIodonts." "The hogs from hell have won the prize." "The dry season has transformed the landscape." "It's as if the whole life blood has drained out of the plains." "This is what it means to be a seasonal world - it hasn't rained for months, there is no greenery left to eat and there is precious little to drink." "Here in mongolia, mammals have evolved to cope with even these kindsof conditions." "But at this time of year they are put under their greatest stress." "The mother Indricothere has not found water for several days." "And in her dehydrated state she is not producing milk." "The calf is now nine months old and it is his first taste of true hardship." "Despite his repeated attempts to suckle, the mother rejects him." "Because of their size, adults can survive without water for days." "But the calf, being smaller has fewer reserves to draw on and is getting dangerously weak." "The nights are cooler and a f ar better time for them to move around." "So every evening they set off in search of water." "Other Indricotheres are on the same journey." "And tonight, the pair is joined by an older female." "Indricotheres can easily live nto their 80s and this longevity gives them a unique knowledge of their environment." "If there is any water nearby, it's a good bet the old female knows where it is." "At last they find the muddy remnant of a lake and just in time because the calf is close to collapse" "He will have to wait a while for his milk but at Ieast" "It is the first night for some time that these giants can lie down and get a proper sleep." "The next morning the mother receives an early call." "The calf is still starving." "But this time she responds and he is rewarded with milk." "When the rains eventually come, they come down hard." "From parched plains to a slippery quagmire, everything changes in aninstant." "But the sudden downpours bring disaster for some." "This bear dog's den has been undermined by the flood waters and collapsed." "An anxious mother is forced to dig to find her cubs." "She finds only one, and it's already dead." "There is a river now where none existed before." "In their search for food the pair must cross it." "This is a whole new ordeal for the calf and at first he is very reluctant to follow his mum into the water." "In the end though, it is obvious that he is more frightened of being" "left behind than he is of crossing the river." "This is the first swim of his life." "unfortunately, it turns out to be the easy bit." "When the calf gets to the other side he still has to get to the top of the opposite bank." "It is steep and slippery and, unlike his mum, he isn't going to make it in one small step." "There is nothing his mother can do to help him." "He is on his own and he doesn't like it." "Not an easy task for such a heavy baby." "The drought might have been a tough time but in many ways the coming of the rains marks the end of the good life for the calf." "It is time for him to feed himself." "Indricothere calves are weaned off milk at about a year old." "But having known little else but milk for his whole life, he needs quite a Iot of persuading to give it up." "Try as he might to get some of his f avourite tippIe, mum is having none of it." "He will have to eat his greens or go without." "After the Iong, dry season, colour slowly returns to the plains as the cycle of Iife starts over again." "And for the Indricotheres it is time for mating." "A young male has caught the scent of a receptive female." "It is the calf's mother who is fertile again now she has stopped suckling her calf." "The calf plainly has no idea what to make of this approaching coIossus." "And at this point his mother show no interest either." "Then a second, older male appears on the scene." "He emphasises his status by spraying the ground liberally with urine." "The younger male isn't so easily intimidated and the two rivals size each other up before starting a brutal contest." "When 30 tonnes worth of Indricothere fight, the forces involved are bone-shattering." "The skulls of males are specially built to withstand these contests." "It takes half an hour of abuse before the older male backs down." "But with the fight over, the calf is now at serious risk." "The biggest threat to a young Indricothere is an adult male." "During mating, calves can get trampled to death." "It is the first time that another individual has come between him and his mother." "In his distress he tries desperately to get in the way, to stop the mating." "Over the next 36 hours the male will mate with the calf's mother several more times, preventing any other males from doing so." "Our calf is in for a tough time." "It's the very beginning of the wet season and the ChaIicotheres have started to search out new growth." "The mother Indricothere is expecting." "She is in f act only days from giving birth." "Standing by her is the calf, now three years old and weighing over a tonne." "He's obviously learnt many of the tricks of Indricothere life from his mother" " Iike using trees to scratch the parasites off his back." "However, nothing he has learnt so f ar will prepare him for what is about to happen." "In the morning the calf will suffer the biggest upset of his life." "The mother is behaving very oddly indeed towards her calf." "But she is only doing what she has to do." "She is chasing him away." "To give her unborn calf the best chance in life, she must sever the three year old bond she has had with the male calf." "It is time for him to make his own way in the world." "This is the hardest lesson of all." "For some time the calf disappears only to turn up a couple of weeks" "later alone on a river bank." "The cause of his limp is unclear but the most likely explanation is that he has had a run in with a young adult Indricothere, one of the few creaturesthat can threaten him." "And now he is heading back to the only safety he knows." "His mother has a new calf in tow and her maternal instincts have been transferred to the new born." "To her, he is now just a threat." "He is never again going to have the protection of his mother." "The rest of his life he will spend alone." "One month, two months, three months go by and there is no sign of the calf." "Then suddenly, one day he reappears, back in his old territory." "His injury has healed and he seems in good health." "But he is dangerously close to an EnteIodont." "Any fears about his safety suddenly seem to be misplaced because this indricothere is now big enough to look after himself." "Next episode prepare to come f ace to f ace with mankind's beginnings ." "when we go back to Africa three million years ago to meet a species of ape that walked upright." "Our ancestors lived in a dangerous world." "unlike us, they weren't predators, they were prey."