The Amazing Social Skills of Sperm Whales | Full Nature Documentary

The story of the giants of the seas began some 55 million years ago, shortly after the disappearance of the dinosaurs. A period of global warming had a major impact on the planet, and sea levels rose. Some land mammals moved towards the water. Among them were the ancestors of the cetaceans, including whales, dolphins, orcas, and toothed whales, which still walked on all fours and hunted on the shoreline. Gradually, they ventured into the shallow waters, before beginning to swim to catch their prey. Ten million years later, their descendants finally quit terra firma for good, taking to the oceans. Swimming proved a wonderfully effective strategy, and with the water supporting their body weight, they evolved into titans. That was how the giants of the seas evolved. To go in search of these ocean-dwelling behemoths, we will follow François Serrano, an oceanographer, a former companion of Jacques Cousteau, and a tireless explorer and defender of the marine environment. François will dive alongside the largest animals on the planet, in an effort to pierce the mystery of their incredible success. When the land-based ancestors of these cetaceans returned to the seas 55 million years ago, they had no chance. They were entering a hostile environment. They had to breathe. They had to hide in an environment where there was nowhere to hide. In the deep blue sea, there are no hiding places. They had to give birth in an environment where the offspring had to be able to breathe right away. Yet, despite all these obstacles, they thrived. In short, these creatures, that to begin with had no chance, ended up conquering the planet. Mauritius, a tiny island at the heart of the Indian Ocean is more than several thousand kilometers from any mainland. The waters around this isle are the hunting grounds for the biggest predator on the planet, the sperm whale. Males can measure up to 20 meters in length and weigh more than 50 tons, sometimes more, like the legendary Moby Dick. François Serrano wants to dive with these giants to observe them up close. With the help of his friend, underwater cameraman René Uzet, who has worked a great deal with whales, he has already had the opportunity to approach them. François wants to dispel the ideas that came from hunters who once pursued them and demonstrate that these giants, who are mammals just like us, are in fact our marine cousins. To reach them, one first has to cross the coral reef which protects the island and then head out to sea where the waters become deep. The high seas and the ocean abysses make up the kingdom of the sperm whale. What am I expecting from this trip to Mauritius? First off, I'm eager to see the sperm whales again that I saw with René in 2013 and then I hope that there will be one of those magical moments when suddenly one of them will come over to me to dance. That's part of it. It's not just the scientific aspect. There's also the discovery side. There's the whole aspect of joie de vivre in terms of your emotions in that untamed universe. But how does one locate the sperm whales in this vast expanse? Navin, who is at the helm of our boat, is an expert in finding them without even seeing them. He can detect better than anyone the sharp, powerful clicking sound that the whales emit when they are hunting in the depths. He uses a hydrophone, an underwater microphone, to pick up the sounds these great creatures make as they search for prey. Attentive to the slightest signal, he plumbs the ocean, pointing his microphone in every direction. The smooth surface of the ocean is a mirror, which masks the presence of the whales. But the body of water gives them away, since sound travels much more quickly in water than in air. Navin will hear the cetaceans long before he sees them. It's not happening, huh? He's struggling. It's always the first click which is hard to pick up against the slapping of the water on the boat. When he says, there it is, you can hear the click and then you hear them. Then you can hear them, but the first sound is the hardest. Navin has finally got a lead and points to where the sound is coming from. Can you hear them clearly? Yes, you can hear them very well. Oh yes, that's a full-on concert. Oh, that's great. Are they far away? I'd say at least 8 kilometers from here. Around 8 kilometers. That means more than 30 minutes by boat. The sperm whales are somewhere over there to the south, but they might be at a depth of several kilometers. They live in a three-dimensional universe, a colossal volume that is so inaccessible we can hardly imagine it. Fortunately, sooner or later, the whales will have to return to our world. Because they are mammals like us, they have to breathe air on the surface. It is there, at the boundary between two elements, air and water, where we have a chance to glimpse them. René Uzay and Aldo Ferrucci, his assistant, are preparing the equipment that will open up the whales' world to us for a brief instant. François scans the horizon on the lookout for the first spout that would indicate the return of these giants to the surface. There's one breathing just beneath the cloud. There's another one over there. There's another one there. Navin. Navin, up ahead. Five degrees to starboard. Did you see them? Just ahead, OK? There's two of them, right? Oh, there's another over there. Look at the back, over there. Look at that back. Two, three. I'm going to dive. This is the long-awaited moment. The crew is tense, not because they are about to come face to face with the giants, but due to the concentration that precedes such a rare encounter. That's good. There are three of them. A third just came up there. Four. A fourth has just surfaced. Like an astronaut in space, François advances towards these creatures from another world. First contact. But for the sperm whales, it is not yet the moment to make contact. They carry on their way, calmly. And with a beat of a flipper, they leave the diver to his dreams and his questions. Only a large female remains behind. She is having her teeth cleaned by some remora, teeth that she inherited from her land-based carnivorous ancestors. But she too ends up leaving to rejoin the group, already far away and out of sight. Ah, they didn't wait for us. No, they didn't wait this time. They're avoiding us. But they're not running away. They're not diving. That's a good sign. I think we have to wait until they accept us, that's all. We'll see. They're certainly keeping me busy this morning. They're keeping me busy this morning. It remains a hostile, harsh environment in which one moves around very, very slowly, whereas they are at ease. We are practically fixed points, and for them, one flipper movement and suddenly they are 10 meters away. That goes to show that what is rare is precious. We are waiting for that rarity, that precious moment when they grant us an audience, when they finally come welcome us. She had her mouth open. There were two remora that came. She was getting a good clean. It's not often we see them like that. Diving with sperm whales is not only a privilege that has to be earned. It's the only way to understand them. Sperm whales used to be hunted by whaling ships, so for a long time, they would avoid boats and humans. They only allowed the tiniest glimpses into their lives. A spout. A tail rising up. Another striking the water. But nothing to reveal the mysteries of their oceanic life. For years, scientists had to make do with observing whales from ships and would interpret the few clues they picked up to imagine what these marine creatures do beneath the surface. But if we really want to understand them, we have to forget that we are land animals and dive alongside them, immersing ourselves in their world. Above all, this means waiting for the right moment when the sperm whales will accept our presence. Or better still, when their curiosity prompts them to come to us. A young sperm whale comes up calmly beneath our boat. This is incredible, given that a few years ago these whales were afraid of vessels with their steel hulls and deadly harpoons. Francois seizes this unexpected occasion that the sperm whale seems to be offering him. He dives with a portable directional hydrophone designed to record the sounds emitted by each individual separately. Surprisingly, the sperm whale is as curious about Francois as Francois is about the whale. They explore each other in their own way. The whale does not have a hydrophone, but it has an extraordinary sense. Echolocation. It emits powerful sonic pulses, then analyzes the echoes that come back from the target object, in this case Francois, to form a sonic image as precise as an ultrasound. The sperm whale's echolocation pulse is the loudest sound produced by any animal. It's an incredibly effective sense. When the sperm whale scans the boat, it doesn't just detect the shape of the hull. Echolocation also gives it an idea of its thickness, and it can tell that it is not full. It's a little like the way an ultrasound produces the image of the fetus inside its mother's belly. Echolocation also means sperm whales have become exceptional hunters and can detect their prey at great depths, where it is permanently dark. To do this, they carry out a series of amazing physiological exploits. They dive for more than an hour to depths of up to 2,000 meters. At such depths, the pressure is 200 times greater than on the surface. A human diver would literally implode if he or she tried to follow. Adult whales spend a good quarter of an hour taking deep breaths to store as much oxygen as possible in their blood and muscles. Then they dive vertically, heading for the great depths. No one has ever witnessed what goes on in the abyss, and probably no one ever will. No light penetrates here. It is absolute blackness. It is in this total darkness that the sperm whales vanish. Francois has to make do with the distant echoes of the hunt, but thanks to these sounds picked up from a distance, he can imagine what is going on 2,000 meters below. He can hear the echolocation clicks. The sperm whale is scanning the ocean floor. The clicks become more frequent. The sperm whale has detected some prey in its echolocation beam. The clicks speed up yet more. Then suddenly, there's silence. The sperm whale has caught its prey. The clicks start again. It's back on the hunt. The young sperm whales have remained on the surface. They haven't yet learned to dive to the great depths, but they remain in contact with the adults thanks to the sounds they emit which travel for kilometers. They have to await the return of the adult females to either suckle or feed on regurgitated prey. The young can be easily recognized by the remora attached to their bodies, sometimes by the dozen. These fish feed on their waste and parasites. The returning adults are surprisingly free of remora, perhaps because they cannot withstand the rapid change in pressure between the surface and the abyss, which the adult sperm whales would impose on them. Francois makes the most of the presence of the adults to collect some precious clues from the excrement they leave behind. Look at this treasure. What have you found? Look at that. Wait, wait. Look. The sperm whale dropped his load. And we were right in the middle of it. Look at all those squid beaks I picked up. Eaten up one by one. It's amazing. Fantastic. Look at that. That's horn. It's indestructible. It never rots. That's why it stays in the sperm whale's faeces. That shows all the squid it catches in the deep, diving down to catch them at 1,000 or 1,500 metres during the day. At night, it's easier. At night, the squid rise up to a shallower area at 600 metres. I think whales hunt a lot at night because it's easier to find them. That's a great cloud of it. You know how it is. Then the whale just picks it off bit by bit. It's funny because it floats, then it slowly sinks. It's great. Who would have imagined that the land-born ancestors of the sperm whales, which roamed on all fours on the shores of lagoons, would one day develop into conquerors of the abyss? These cetaceans have not only succeeded in overcoming the challenges of the depths. Warm-blooded animals in the kingdom of the cold-blooded fish. These powerful, hardy and fast-swimming creatures can undertake journeys of thousands of kilometres. They are continually pushing back the boundaries of their territory. They even swim up rivers to the heart of the Amazon and venture beneath the frozen ice caps. The huge bowhead whale, measuring up to 20 metres and weighing around 100 tonnes, spends all its time in the Arctic or sub-Arctic waters. It can stay underwater for incredibly long periods. And with one blow of its head, it can break through a metre of ice to take another breath at the surface. This means it can profit from the rich pickings in the Arctic Circle. It is thought to live for more than 100 years. Despite its huge size, the bowhead whale is out-trumped by the blue whale, the largest animal that ever existed. At some 33 metres in length and weighing 170 tonnes, its tail alone measures 7 metres across. Its power and speed makes it safe from all predators. But it nonetheless nearly became extinct. Factory ships with their harpoon guns gave no chance to the 300,000 blue whales that swam the ocean a century ago. Barely 10,000 remain today. Certain species, like the Atlantic grey whale, have been hunted into total extinction. But thankfully, most survive the era of large-scale whaling, and since the moratorium imposed in 1980, they are gradually repopulating the oceans. The cetaceans have succeeded in conquering an environment to which, to begin with, they were ill-adapted, in part because of their attributes as mammals. Their intelligence is obviously a factor, but more important than that is their cooperation and solidarity. And above all, the bond formed with their young. Cetaceans will give birth to only a few calves in the course of their lives, which makes them very precious. They must be cosseted and protected in this vast universe where there is nowhere to hide. These mammals brought something to the oceans that did not exist before their arrival. Tenderness. For the benefit of its calf, the humpbacked whale has swum thousands of kilometers from the polar waters where it feeds to the warm tropical waters. Now it will fast for months, taking care of its offspring with infinite attention. The mother gently assists the clumsy newborn on its first hesitant swim. She gently guides it to the surface to help it breathe. The mother has not eaten for months and must now suckle her baby like all mammals, whether on land or at sea. She will nourish and nurture it so that in due course it is ready to tackle the huge journey back to the feeding grounds. She will teach it to stay underwater, keeping it under its belly until it can control its own buoyancy to live in this three-dimensional world. This is in total contrast to the behavior of fish, which lay their eggs by the thousand and leave them to the mercy of the currents. As soon as they hatch, the fish larvae have to take care of their own survival. Whereas for mammals, all this attention gives the young time to open up to the world and to explore their environment. To catch a glimpse of the magnificent spectacle offered by those creatures living beneath the surface of the ocean, we have to immerse ourselves into their world as often as possible. Back in Mauritius, François and René dive again and again. Okay, stand by. Get ready. It will be on your right. Okay, go. To see a sleeping sperm whale, you have to be underwater. Who would have imagined that a sperm whale sleeps vertically like that if you'd never been down to see it? When you see one or two sperm whales on the surface, who would imagine that there are 20 sleeping in the sperm whale dormitory? That's what's extraordinary. We're only just starting to know these things because we've only just begun to study them in situ. And we can do that because they allow us to. These giants of the seas sleep very lightly. For them, breathing is a voluntary act, unlike humans, for whom it is an automatic reflex. The whale has to face the dilemma of staying awake to breathe or dying if it falls asleep. And once again, they've found a solution. Half of their brain sleeps while the other half remains awake. So they are only ever half asleep. The calves gather and play around the sleeping adults. This is a strangely familiar picture, specific to all mammals, exactly the same as for young monkeys in the rainforest or lion cubs in the savannah. There's no doubt about it. The cetaceans are part of the same class as us, yet they exist in the vastness of the oceans. When we enter their world, we discover their incredible fluidity. They are like elves underwater. Then all of a sudden, these monsters come together. They gather together, rubbing alongside one another. Then suddenly, they literally intertwine, rolling against each other in an unbelievable embrace. They are the only ones to do this. You really wonder what they are expressing that can only be expressed through these incredible caresses. We do not know the meaning of these long moments of intimacy and socialization, nor what triggers them. But when they are over, the sperm whales leave behind strips of skin that come away during these gigantic rubbing sessions. Soon, all that remains is a veil of delicate skin, a fragile reminder of these moments of grace shared with them. It's incredible being in communion with wildlife that is so often denigrated. When you see that, when you experience that, everyone should do it. When you've experienced that once in your lifetime, you're in harmony with the world. You only want one thing, and that is to make room for your roommates, that we allow a space for the wildlife that is straightforward, direct, wonderful. Back on dry land, François teams up with Mathieu, who has gotten hold of the day's footage, to watch and interpret it. It's a very important stage, because in the emotion of the moment, one cannot study all that is going on. It's also the only way to clearly identify each of the sperm whales. That's interesting. It's incredible when they are socializing. They pack right in, up against each other. It's extraordinary seeing this again. When you're in the middle of it, you think, oh, hello, Arthur, wait, stop, look, look. You see here? That's typical. Arthur's tail fin has been eaten. It's lost its tip. It was maybe eaten by an orca or a pilot whale. There are a lot of them here. You could say that each whale has its own identity card, which can be read through the scars left on its tail or pectoral fins, either by large predators or by small sharks, known as cookie-cutter sharks, which leave their marks. That way you can recognize all of them. There, take a look. Go forward a bit. There, that's typical. You see the little round one? That little notch, which is very distinctive. If you don't know which details on the fin you need to recognize them, there are a lot of sperm whales. There are sperm whales around Mauritius. Whereas here, it's no longer sperm whales from Mauritius. It's a particular family. It's as though you were visiting a city. You see people everywhere, nothing but people. Then suddenly, you meet a family. Then it's no longer just people. They are individuals with personalities. Some of them have amazing personalities. You can tell that Germine is the matriarch. She doesn't let anyone push her around. She runs the group. She's also curious. She comes over to see you. That's sensational. For François, these elegant movements are no longer simply a behavior to be decoded, and these sperm whales are no longer just anonymous cetaceans. François recognizes Arthur, a two-year-old male with a severed fin. Alongside him is Maurice, who's a year older. They play under the discreet surveillance of the half-asleep Lucy, one of the adult females in the clan. François has already identified around 50 of them. There's the young Elliot, and also Germine, Agathe, Eugenie, Whitespot, and Irene. Although he gives them names, this is not a question of anthropomorphism. On the contrary, it's a way of granting each of them the status of an individual in its own right. How could the whale hunters from the decks of their ships have imagined all that and realized that humankind has so much in common with sperm whales? In the 19th and start of the 20th century, Mauritius was a major center for hunting sperm whale. Since the 1980s, when the Indian Ocean Sanctuary was created, the population has finally found peace and respite and is now growing again. When I was on the Calypso 30 years ago, we'd never have imagined being in the midst of a pod of sperm whales. We'd never have imagined a relationship like that, like the one you have with Irene. When I started filming, I would see one sperm whale or ten sperm whales, but I never knew which one was which. I really got to recognize Irene last year when I stayed alone with her for 20 minutes. She was in the vertical position. She didn't move. She opened an eye and then closed it. I began to think there's an interaction between animal and human. One thing's for sure, she knows who you are. There are people who have relationships with dogs or cats. Well, I have this relationship with a sperm whale. Watch out, a sperm whale takes up a lot of space. Well, I'll leave her where she is. It's me that will come and see her. I'll come into her territory, you see. That's the difference with a wild animal. I'll go to her. And if she wants to see me, she'll accept me. And if she doesn't want to, well, she'll simply swim off. When you think of those guys who came to shoot at these animals that are so gentle, a sperm whale is just 50 tons of tenderness. It's amazing. Just take a look at them. They rub up against each other and cuddle. It's incredible. Then all of a sudden, they look at you with an empathy that you can practically see. It's very, very powerful. François wants to dive one last time with the beasts he says allowed him to discover the true face of wildlife. This time he goes without breathing apparatus, like the whales, holding his breath. As François approaches, Elliot, the young male, does not swim away. He controls his great strength, coming very close without ever touching. The whale seems to be inviting François to play and embarks on an astonishing dance with him. Each of them, in turn, initiates the movements. Elliot dances to satisfy his own curiosity, without expecting either food or protection in exchange. He is untrained, wild and free. Free to go and disappear into the deep blue, whenever he decides. That dance with this young male was overwhelming because we are from the same family, us and sperm whales. We are both warm-blooded mammals. And like us, sperm whales, these giant cetaceans, have developed senses which are specific to mammals. Attention towards others, tenderness, empathy. You can see that when they look at you. They are really looking at you. It's an inquisitive look. An invitation. I like to think that there was communication between us, because I felt something. And when I spun around and saw him respond to my movements, with that acrobatic swimming, I like to think that he felt something too. And that, for an instant, we distant cousins were more like brothers. To understand whales, it is necessary to get up close to them, listen to them, accept their offering, accept that they come to us. Today, that seems possible, since the end of whale hunting and the relative peace they have found. We are no doubt still in the early stages of forming a new relationship with our ocean-going cousins, one that will allow us to finally understand their environment, how they communicate, and their social structures. And this means that we tiny human beings can now venture into this world of titans.