Announcer 600 yards of rope are drawn out in the wounded giants death struggle. Attenborough by the 1960s, there were fewer than 2,000 blue whales surviving, just 1 of their probable original population. The species seemed headed towards extinction until whaling nations finally banned the hunting of blue whales. However, what changed the fortunes of the other great whales were antiwhaling campaigners who turned whole nations against the industry. During the 1970s and early 80s, antiwhaling groups used direct action and mass rallies to put pressure on the whaling nations finally securing a total ban on commercial whaling which came into force in 1986. Since that time, whales have only legally been killed for scientific purposes or by indigenous communities. And i can only hope that, that ban will remain, so that future generations can see what wonderful creatures they are. Today, the worlds blue whale population appears to be recovering slowly. It has doubled in the last 50 years to perhaps as many as 4,500. Of course, its not just the big, charismatic species that we are exterminating. Life on earth is a complex web, and we ignore the millions of tiny creatures in it at our peril. One kind of animal is right now in the grip of the greatest extinction event since the disappearance of the dinosaurs animals like this, amphibians. Globally, the numbers of amphibians are declining at an alarming rate. One third of all species are now critically endangered. In the rainforest of costa rica in the late 70s, we filmed the monteverde toad. Ten years later, inexplicably, it had become extinct. It was only in the last few years that the mystery of what killed the toad was finally solved, and that was not before many other species of amphibians had also died out. In fact, while we were filming life in cold blood in 2007, i actually witnessed the extinction in the wild of the panamanian golden frog, which fell victim to the same insidious killer. Individual males set up their territories beside the river and then wait for females to turn up. And since good positions for the territory are not common, they may have to hold them against intruders. And here one comes. Just in case his call is inaudible, he makes his message clear with a wave. And his rival waves back. He repeats his message so theres no misunderstanding. Sadly, there are no longer any panamanian golden frogs waving in the wild, and the disease that killed them is now sweeping round the world, exterminating hundreds of different species of amphibians. The killer is a fungus. Its highly infectious and believed to have originated in south africa, from where it was transported by the International Trade in captive animals. It was spreading across panama while we were filming, and when we had finished, scientists collected the last few survivors and took them into a specially quarantined building where other endangered amphibians were being kept. Here, they may breed, and then, if a cure for the fungus is found or it runs its course in the wild, the frogs may be returned to their former home. In the last 60 years, ive come face to face with many species that weve put at risk. Sea otters. Chimpanzees. [ attenborough laughing ] manatee. Sadly, this magnificent animal is getting rarer and rarer. How many of these wonderful things will still be around in another 60 years . What an extraordinary creature although the threat to the Natural World from humanity has never been greater than it is today, there are nonetheless causes for hope here and there. In recent decades, when people have become involved with the local population of animals, they have started to take part in the conservation process. And thats certainly the case here in borneo, in the caves at gomantong. The only visitors here when we first came in 1972 were the local people and the people came to the cave for one particular and extraordinary purpose. They collect what is surely one of the strangest commodities to be found in any cuisine. Its so valuable that they risk their lives to get it. They are harvesting the nests that swiftlets construct using their own glutinous spittle. And this is the end product of all this labor and sweat and danger and sheer courage. One cant help wondering who it was who first look at these extraordinary objects and said, thatd be great for making soup out of. But whoever he was, he lived over 1,000 years ago, because there are chinese records in the 9th and 10th centuries which speak of the wonderful delicacy of birds nests that you can get from borneo. I wanted to see what all the fuss was about, so i went into a local restaurant in sandakan to see what birds nest soup actually tastes like. The consistency, perhaps, is a little odd, its a little, sort of, gelatinous, but for the rest of it, well, im afraid there is one great secret about birds nests the fact of the matter is, that pure birds nests taste of nothing whatsoever, provided, that is, its been well cleaned. Even in the 70s, the birds nests were so valuable that there was an obvious risk that the cave would be overexploited. But today, that risk is even greater. A nest like this is worth as much as £100. If you take too many of them, then the birds will have nowhere to raise their young and the colony is doomed. But a total ban would deprive the local people of a very important part of their income. So, a plan was agreed some caves should be regularly harvested, others should be protected from any human interference, and one should be open for the public to visit and wonder. Its an almost ideal situation the local economy benefits, the wildlife benefits, and an ancient tradition, with luck, is kept alive for many years to come. Other creatures in borneo are now also being protected by people who once put them in danger. This is selingaan island, off the northern coast of borneo. And turtles come up here onto beaches like this at night in order to lay their eggs. And back in the 1950s, local people would come to such places in order to dig up those eggs and eat them. And i have to admit, they werent the only people to do that. [young attenborough] if turtles use this beach, it occurred to me that there might be a chance that we could find a turtles nest, with eggs, which would be a very welcome addition to the rice, bananas, and bully beef on which wed been living almost entirely for the past week. And here, buried three feet deep, were the eggs. There were 88 eggs in that nest, enough to provide us with breakfast for many days to come, and they were all produced by one female turtle. Attenborough looking back, it all seems rather shocking, and i hadnt got a clue how to cook them. The result, wasnt, im afraid, particularly delicious. Turtle eggs may not have been to my taste, but the local people loved them, and they were an important source not only of nutriment, but income. The trouble was that the human population was growing so fast that the turtle eggs were being collected in huge numbers and turtles worldwide were in decline. In the decades that followed, the malaysian government stepped in to save their turtles. Harvesting the eggs was banned, and a hatchery established on selingaan island which people visit to see whats going on. During the breeding season, the eggs are collected from the beach and reburied in the hatchery, each clutch being kept together inside its own little fence. But its only after dark that the adult turtles reveal themselves, crawling out of the sea and laying their eggs to the delight of the onlookers. Man there may be another location. Anybody else . No take picture. Attenborough the visitors pay good money for the privilege of watching the turtles at close quarters, and that gives an income to the local people. Man thats about the age. Attenborough once the eggs hatch, the youngsters are collected and taken down to the shore. Off you go. Off you go. Millions of baby turtles have now been released under this conservation program, and as a consequence, the population of adult green turtles here is now increasing. But the survival of green turtles needs more than their protection by local people at their nesting beaches. Turtles migrate. They swim across National Borders into unprotected foreign waters. And that can be a problem. Its now clear that many conservation projects will only succeed in the long term if they Transcend National boundaries and allow wildlife to cross frontiers without hindrance. And thats exactly whats happening here in the rainforest in the island of borneo. Indonesia, malaysia, and brunei signed the heart of borneo agreement in 2007, declaring that the rainforest will be protected, while allowing sustainable use and access by local people. This sort of international crossborder cooperation is vital if we are to safeguard an area of wildlife and ultimately the health of the planet. And thinking about the health of the planet as a whole was not something many people did until one truly extraordinary and historic event. Announcer the engines are armed. Four, three, two, one, zero. We have commit, we have, we have lift off, lift off at 7 51 a. M. Pictures of the launch of apollo 8 arrived in britain back in 1968 by way of the bbcs Central Control room here in the Television Center in london where i had a job as a network controller. What you see at the top is the north pole, in the center, just forward to the center is south america, all the way down to cape horn. Those images were instrumental in changing the way that many of us viewed the planet. We began to think globally. Looking at the earth from outer space made us realize just how small our world is and how finite its resources. It also helped us understand that we have to cherish not just individual species, nor even individual patches of wilderness, but the whole planet as a single, integrated ecosystem. But back in 1968, few people could imagine that the activities of just one species, our own, could interfere with the way that the planet worked. That we could actually change the climate of the earth. It was in the oceans that this threat first became apparent. Ill never forget the first time i put my head beneath the surface of the sea and saw all around me a coral reef, in all its complexity and richness, and almost unbelievable beauty. If the jungle is the place on land where there are the greatest number and the greatest variety of life, then this, the coral reef, is surely the jungle of the sea. Although coral reefs occupy just 1 of the oceans, they support a quarter of all their fish. The fragility of these complex ecosystems suddenly became alarmingly clear in 1998. Almost overnight, in oceans all around the globe, coral turned white. The temperature of the sea had risen, and it had devastated 16 of the worlds coral reefs. Even a rise of a couple of degrees fahrenheit can be enough to kill the organisms that build the coral, leaving their limestone skeletons a naked white. If the rise is brief, then the coral can recover; but if it is sustained, then the coral may die completely. And this coral bleaching hints at an even bigger problem. The average temperature of our planet has increased by 1. 26 fahrenheit over the last century, and it seems likely to rise still further. And that could lead to changes in sea level. Even a very small rise in sea temperature could have a devastating effect. Small islands like the one behind me could be totally submerged. Major cities could be at risk. And the reason for that lies far away from here, where the change is already beginning to be seen at the poles. [ wind howling ] i am at the very center of the great white continent, antarctica. The south pole is about half a mile away. For a thousand miles in all directions there is nothing but ice. Im now at the other end of the earth in the north, the arctic. I have been lucky enough to travel in the polar regions several times in the last 30 years, making films about their rich wildlife. His sole object in life at the moment is to make quite sure that he and he alone mates with every single one of them. And for that he must fight. Its heavier even [laughs] than heavier than the adult. These parent birds reunite once they come back here onto their own patch of patch of shingle. And although the antarctic is virtually lifeless over vast areas, there are one or two small oases that teem with life. Slowly i began to realize that things were changing in ways that will affect the wildlife, and eventually ourselves, no matter how far away from the poles we might be. This is the ice that covered the arctic ocean in september 1980. Since then there has been a 30 reduction in the area covered by ice. And not only that, what ice remains is only half as thick as it was. If the sea ice continues to melt at this rate, there will be open ocean in the summer at the north pole within decades. The very whiteness of the snow and ice contributes to the pace of change. Light bouncing off it takes 90 of the suns energy back into space, and this has helped to keep the planet cool. But when the sea ice melts, it exposes the dark sea water that doesnt reflect the suns heat, it absorbs it, so the temperature of the sea rises. Here in the arctic, the climate is warming twice as fast as the rest of the earth, and that could have global consequences including rises in sea level around the world. Climate change is already affecting the lives of not only wild animals, but ourselves, all over the globe. I have spent my life filming the Natural World, and ive traveled to some pretty remote and exciting places in order to do so. Ive enjoyed every minute of it. But every journey seems to have got quicker and shorter its as though the world has shrunk. But then, sadly, so have the wild places. The increasing size of the human population is having a devastating effect on the Natural World. But fortunately, people are becoming aware of that and doing something about it, and id like to think that Natural History films have helped in that process. And there are some signs of hope animals that i thought might become extinct in my lifetime are still with us and growing in numbers. We now have a better understanding of the Natural World than ever. We know how best to protect it for future generations. I can only hope that we will. And wolves in the world do battle. Man weve still got the wolves out there. Here, one wolf pack will struggle to maintain the Family Business bringing down buffalo. Man weve got a buffalo wolf situation here for sure. Its an ancient spectacle of offense and defense, but its future is uncertain as the modern world closes in. [ wolves howling ] now you can watch nature online. Go to pbs. Org to screen complete episodes from this season and seasons past. Visit nature online for production updates from the field. Well, here we are on the alaska coast. Go behind the scenes with our filmmakers. We also used a borescope lens, and that allowed us to put the lens right into a flower. And get connected with natures online community. All at pbs. Org. Nature is made possibleth naturein part by. Mmunity. Leave it untouched by your presence, capture its image and preserve it forever. Canon living and working together to appreciate today and care for tomorrow. The corporation for public broadcasting. And by contributions to your pbs station from viewers like you. On dvd and bluray, call 18003361917. To learn more about what youve seen on this nature program, visit pbs. Org. To learn more about what youve seen on this nature program, ha ha bonneville its quite something to see how much of an impact this show has had on people, a real proper emotional investment. And it is so rewarding to find that people in the street that you meet they sort of go into a slightly other world. Ha ha ha they often sort of you can see them replaying scenes in their head when theyre chatting to you and say, oh, that bit when mary and matthew. Or that bit when sybil and branson, whatever it might be. And its delightful. Its utterly captivating for us that the people have responded to it in such a strong way, and that just seems to have grown, really, between season 1 and season 2. We were in new york at a pbs event last winter to feel for the first time the wave of affection for the show. It was quite overwhelming, but a nice problem to have