"South America is a continent of extremes." "It has the world's longest mountain range... the Andes." "In Amazonia, it has the mightiest river and the greatest expanse of rainforest on the planet." "And the driest desert on earth the Atacama, lies beside one of the world's richest seas." "South America also contains incredible variety." "Almost no other continent can boast such a wealth of wildlife living in such a range of different landscapes." "Almost everywhere you go there's an extraordinary diversity of life." "But how did all these unique worlds come about?" "To understand the natural history of South America we must go back in time back to the age of the dinosaurs." "South America was then part of Gondwana a massive continent that also included what are now Africa Australia, India and Antarctica." "This was a world dominated by reptiles." "Descendants of those ancient creatures still live in South America today." "And the forests of southern Chile still have plants that the dinosaurs would have recognised tree ferns and the bizarre monkey puzzle tree." "Then, a new group of animals appeared animals like this." "The early mammals were small and many were marsupials like this shrew opossum." "It lives in the cold damp forests of southern Chile where it hunts for insects and earthworms." "The shrew opossum shares these ancient forests with this other small marsupial." "Local people call it the 'monito del monte' or 'monkey of the mountains'." "It's so tiny you could hold it in the palm of your hand." "It too eats insects but also has a taste for fruit." "When we think of mammals with a pouch it's perhaps Australia with its kangaroos that comes to mind." "But South America also has over eighty species of marsupial a legacy of the time when the two continents were joined together." "Around a hundred million years ago the giant continent of Gondwana slowly split apart." "South America became an enormous island cut off from the rest of the world." "The next chapter in South America's history was violent and prolonged." "It changed the face of the continent for ever." "Starting some eighty million years ago the island was convulsed by a series of massive volcanic eruptions that continue today." "Forced up by movements deep in the earth's crust a huge chain of mountains arose spanning the length of the continent The Andes." "Running over five thousand miles this is the longest mountain chain on earth." "At its northern end tropical cloudforest covers the slopes yet its peaks are so high that even on the equator they carry permanent snow and ice." "In the central Andes there's a high dry desert the altiplano." "As you travel further south the mountains are lower but they're that much closer to the Antarctic." "In the far south the Patagonian ice sheets are the largest expanse of ice outside the polar regions." "They cover more than seven thousand square miles and their glaciers flow all the way to the sea." "But even here in the shadow of the ice animals survive." "In the shadow of the Patagonian icecap animals must survive ferocious winds and winters of heavy snow." "Only the hardiest animals can live here like guanacos South American relatives of the camel" "and foxes." "Even for them surviving the winter is a challenge" "Patagonia may be severe but it's not the most extreme part of the Andes." "That's back in the heart of the range an oxygen-starved plateau more than four thousand metres high." "Here, in the Altiplano meltwater from the surrounding peaks evaporates in huge salt lakes." "Frozen by night and baked by day these caustic saltflats must be one of the most inhospitable places on earth." "This is Salar Uyuni in the Bolivian Andes." "Covering four and a half thousand square miles it's the largest expanse of salt on the planet." "Incredibly, islands in this sea of salt actually support life." "Viscachas." "These rabbit-sized rodents have to contend with thin air, bitter cold, and an almost total lack of water." "They get just enough moisture to survive from their food." "Thick fur keeps them warm and extra red blood cells help to absorb sufficient oxygen." "The thin air's a problem for this hummingbird too." "To conserve energy when it's feeding it has to perch, rather than hover." "The high altiplano may seem hostile but some animals actually choose to come here." "Flamingos come here to breed because these caustic waters are full of their favourite food." "They display to each other with a massed courtship dance." "The rise of the Andes created whole new environments within the mountains but it also had more far-reaching effects." "This great barrier changed the climate of South America." "It also re-drew the map of the entire continent radically altering the course of its major rivers." "The Iguazu Falls are one of the wonders of the world." "Four times as wide as Niagara they carry sixty thousand tons of water a second." "Part of Amazonia was once a huge swamp connected to the Pacific and the Caribbean." "The rise of the Andes broke those links forcing the major rivers to flow east." "One massive river now drains forty percent of South America... the Amazon." "This is the mightiest river on earth." "Running over four thousand miles from the Andes to the ocean it carries a fifth of all the river water on the planet." "A thousand miles before it reaches the sea its main channel is already ten miles wide." "Every year the mighty Amazon bursts its banks flooding an area of forest the size of England." "At the height of the flood the trees can stand in water ten metres deep." "The floodwaters bring with them the animals of the river like boto dolphins." "Their origins are a mystery." "Could they be a relic of Amazonia's ancient links with the oceans?" "These river dolphins are almost blind no handicap in water that's often very muddy because they navigate by echolocation." "Unlike marine dolphins they have a flexible neck so by sweeping their head from side to side they can scan their path ahead." "Their sonar is so precise that they can weave their way through a maze of submerged branches in search of fish." "Whisker-like bristles on their lips help them zero in on their target." "The botos' origins may be mysterious but some of the Amazon's fish certainly have a marine ancestry like stingrays." "Their nearest living relatives are in the Caribbean." "The Amazon has over three thousand kinds of fish." "This is the pirarucu the world's largest fresh water fish." "And these are the most notorious..." "piranhas." "The variety of life in these waters is extraordinary... and with so many fish there are bound to be fish hunters." "In this water world" "Caiman are the top of the food chain... the aquatic equivalent of the jaguar." "Red-bellied piranhas are predators themselves but to a caiman they're just another mouthful." "The Amazon river and its tributaries drain the largest expanse of tropical rainforest on earth." "Stretching almost unbroken from the Andes to the Atlantic the Amazon jungle has a greater variety of life than any other forest on the planet." "In just over two square miles of forest scientists have counted three thousand varieties of plants five hundred and thirty kinds of birds and eleven different species of monkeys." "There are countless reptiles amphibians and insects." "Six hundred and fifty species of beetle and eighty kinds of ant have been found on a single tree." "Scientists disagree about the reasons for this diversity but in almost every group of animals the number of different species is extraordinary." "Because there are so many species most of them have to specialise." "Pygmy marmosets are the world's smallest monkey." "They live on the sap of just a few kinds of tree gouging the bark with special teeth to release its flow." "They're just one of over thirty species of marmoset and tamarin in the Amazon basin a group of monkeys unique to the lowland rainforests of South America." "Like these tassel-eared marmosets most live in family groups." "A breeding female lives with one or more adult males and several youngsters." "Females typically give birth to twins and unusually among monkeys it's the father who's left holding the babies." "Tassel-eared marmosets are opportunists." "As well as gum, they eat insects fruit, birds' eggs small snakes and lizards... almost anything they can get their hands on." "The youngsters must develop fast if they're to survive in the dangerous and competitive world of the rainforest." "Amazonia lies on the eastern side of the Andes and here torrential tropical rains water the prolific jungle." "But the mountains block the moisture-bearing winds so some of the western side receives almost no rain." "Here lies the world's driest desert..." "the Atacama." "The Atacama can go for years with literally no rain at all." "It's hard to imagine how anything could survive here." "And yet it does." "Guanacos." "These South American camels can tolerate extremes of heat and cold." "A desert might seem a better place for a camel than the snows of Patagonia but the Atacama is a challenge even for them." "Daytime temperatures can rise to forty degrees." "Their only relief is a dry dustbath." "But what can they live on?" "With hardly any water here how could plants possibly grow?" "This is the key to survival in the Atacama the Pacific Ocean." "The desert is a narrow strip between the mountains and the sea." "Moist air over the water is chilled by a cold ocean current just offshore so every day a blanket of fog rolls in from the Pacific." "The fog is almost the only source of water in the desert." "Moisture condenses on the cactus spines enough for lichen to grow." "And every morning the lichen is covered with the precious droplets of water." "This water provides a life-giving drink for the few hardy inhabitants of the Atacama like diuca finches." "The guanacos obtain moisture by eating the lichen delicately extracting it from between the cactus spines with their soft, sensitive lips." "They also eat the flowers of a parasitic plant that grows on the cactus." "Called quintral it's sweet and full of nectar." "Guanacos and everything else in this desert are living on the edge." "Without the moisture from the early morning fog life in the Atacama would be almost impossible." "As you travel South the prevailing weather comes from the opposite direction so the eastern side of the continent is dry." "But here lack of water is not the most extreme problem it's the wind." "This is the land of the Roaring Forties ferocious winds that batter the dry grassy steppes of Patagonia." "Anything that lives here has to contend with almost incessant gales." "These are maras large rodents unique to South America." "Adult maras live and give birth to their young in the open but they rear them in an underground burrow sheltered from the cold winds and predators like foxes." "Mara territories overlap so often several pairs share a burrow." "These warrens act as a community creche." "The parents can leave their young to go and feed but there's always someone to keep an eye on them." "The nursery can have twenty or thirty young." "Sometimes hungry infants try to suckle from the 'baby-sitter'." "She tries to drive them off but they can steal a tenth of their milk this way." "In windswept Patagonia a hole in the ground counts as prime real estate and it's a magnet for squatters." "Here even the birds nest underground." "As soon as the maras backs are turned burrowing owls try to take over their home." "Could this be the moment to move in?" "But they're soon spotted." "This time, the squatters are evicted." "The maras keep their burrow." "In Patagonia burrowing owls aren't the only birds that nest underground." "With no trees to nest in burrowing parrots excavate holes in a sandstone cliff." "There can be over fifty thousand birds in these colonies." "This is one of the few places on earth where parrots nest by the seaside." "The diversity of South American wildlife doesn't end at the coastline." "The seas that surround the continent are some of the richest in the world." "Upwellings of cold, nutrient-rich water feed huge shoals of fish... food in turn for seabirds and marine mammals." "The sheer numbers of fish here are astounding." "A single shoal of anchovies can be hundreds of thousands strong." "These huge concentrations inevitably attract predators... dusky dolphins." "The dolphins' migrations are synchronised with the anchovies' movements." "For the defenceless anchovies there seems to be safety in numbers." "When they come under attack they bunch more tightly together... to form a dizzying ball of swirling fins and scales." "The dolphins find it harder to target any single fish in this dense mass so they try to break up the shoal... by swimming through it." "Once the shoal has been split the dolphins confuse the fish and scatter them even more by blowing bubbles... and by emitting high frequency sounds that stun them." "This drives them to the surface where they become easy prey for seabirds too." "Attracted by the disturbance yet more hunters join the attack..." "southern sealions." "Under assault from all sides the fish are now totally disoriented." "Trapped at the centre of this feeding frenzy they don't stand a chance." "Magellanic penguins mop up the last survivors." "At the end, all that's left are tiny fish scales... drifting down into the deep." "For almost a hundred million years South America was an island." "Its animals evolved in isolation cut off from the rest of the world by the surrounding sea." "But around three million years ago the same kind of movements of the earth's crust that built the Andes raised a land bridge joining North and South America." "Animals could now pass easily between the continents." "The impact on South America was profound." "Among the first mammals to arrive were these... coatis." "Relatives of the North American racoons they're active, agile intelligent and adaptable." "They quickly colonised this land of new opportunities." "Today they're found as far south as Argentina." "These early invaders soon made South America's forests their own." "For the continent's original inhabitants like the sloth life would never be the same again." "These brash newcomers were just so fast." "Sloths are lethargic by nature as well as by name." "They have a low body temperature and very slow metabolism." "Sloths have hung on by doing one thing supremely well eating and digesting leaves." "Coatis succeed because they're opportunists quick to seek out any new snack." "They leave sloths behind at the starting line." "They're social animals living in bands of up to twenty females and their youngsters." "And they're omnivorous eating fruit insects, spiders, slugs, fish, snakes birds and mammals... almost anything they can find." "A flexible nose and a good sense of smell help them sniff out the slightest chance of a meal." "These early colonists were soon followed by others larger and more deadly like the jaguar." "South America had large carnivores before cat and dog-like marsupials." "But many had already died out before the newcomers got here." "Coatis may have had it easy when they first arrived but once large hunters followed life became tougher." "On the whole, the invaders were very successful." "Some may have out-competed the original inhabitants others may have eaten them but many of the new animals simply moved into spaces that were already empty." "Today, almost half of South America's mammal families are North American in origin." "Eventually the immigrants in this new found land spread to all corners of the continent." "As the invaders adapted to their new surroundings some evolved into new forms." "A simple, dog-like ancestor gave rise to this the maned wolf." "Like a fox on stilts this long-legged predator hunts the grassy plains of southern Brazil." "It eats small animals and must travel far to find enough to eat." "The great plains are one of South America's most ancient landscapes." "Throughout the continent's history they've remained relatively unchanged." "Today they have a strange mixture of animals the old and the new." "Deer are relatively recent arrivals from North America." "On the plains they rub shoulders with animals that have been here for tens of millions of years..." "Like the rhea" "South America's equivalent of the ostrich." "If the maned wolf is one of the most recent animals on the plains this is one of the oldest" "The giant anteater." "It's one of the most specialised insect-eaters on earth and that bizarre snout is one of its secret weapons." "The snout houses a long sticky tongue ideal for delving into termite mounds." "But first you've got to break in." "Termite mounds can be almost as hard as concrete so you also need a set of very powerful claws." "The giant anteater is one of the few surviving members of a group of animals that has lived in South America for over fifty million years." "This is another one, the armadillo." "Armadillos and anteaters survived the invasion because they specialise in food the invaders can't tackle." "They eat mostly ants and termites." "The maned wolf doesn't compete with them because it prefers mice." "But catching them isn't easy." "All that effort for just one tiny mouthful." "The animals of today's South America are a pale shadow of what was once here two ton armadillos flesh-eating birds three metres tall a giant ground-living sloth the size of an elephant." "The ground sloth disappeared less than ten thousand years ago." "What drove these giants to extinction?" "Long after the land bridge linked North and South America there was one last great invasion the most far-reaching of all." "No one knows exactly when the first people arrived or even how they came by boat along the coast or overland from North America." "We do know they've been here for at least twelve thousand years and they soon penetrated every part of the continent from the sea coast to the high peaks of the Andes." "The first hunter-gatherers may have hastened the extinction of creatures like the giant sloth but they made little direct impact on the landscape." "But the development of settled agriculture eventually changed the face of South America." "Elaborate civilisations flourished in the most remote corners of the mountains." "Their last monuments can still be seen high in the Andes in the ruins of the legendary Inca city of Machu Picchu." "People even changed the animals." "Around seven thousand years ago they domesticated wild relatives of the guanaco to produce llamas and alpacas." "As sources of meat and wool and beasts of burden these were the key to survival in the high Andes." "These domestic animals are still important to the people of the altiplano today and are an integral part of their culture." "By selectively breeding from their wild ancestors the mountain people have developed different aspects of the animals to suit different needs." "Llamas are better pack animals and have good meat whereas alpacas are more valued for their dense wool." "Llama fairs, and even races are a high point on the local calendar." "And they're more than just an excuse for a party." "The animals carry weights so the race is a test of stamina especially at this high altitude." "Traditional cultures have survived in places like this because they are so isolated from the outside world." "Wildlife too survives because much of the continent remains isolated and remote." "People may have irretrievably changed parts of South America but it's a vast continent and much of it is too extreme for people to settle." "So it still retains huge areas of stunning wild landscapes." "For sheer variety it's without rival anywhere on earth." "South America's natural landscapes and their wildlife owe their existence to the continent's unique history." "They're the latest spectacular chapter in a story that has been unfolding for over a hundred million years."