What sounds do dolphins make

The language of the dolphins: we have to talk

Summary: Dolphins are intelligent animals. Your brain is one of the largest in the animal kingdom. Science is particularly concerned with the variety of sounds that dolphins produce underwater. High-frequency recording devices can capture the entire spectrum of sounds under water, and new evaluation programs enable a more precise analysis of the recordings. Researchers are now trying to use these technologies to interact with the mammals. Their goal: to decipher the code of a possible dolphin language.

Hector and Han are professionals. Again and again they stick their pointed snouts out of the water. They eagerly await commands. You can twist yourself into the air with twists on command. You can water-ski backwards on the tail. You can wave your pectoral fins at the tourists who pass by the Roatán Institute for Marine Sciences (RIMS) several times a week, a holiday and research facility on an island off the coast of Honduras.

But the RIMS scientists are less interested in what these two young adult male dolphins can do. They were interested in how they think. When Hector and Han see the hand signal to "do something new," they know what to do. The dolphin trainer Teri Turner Bolton is doing the test. She brings her palms together over her head. Then she still holds her fists next to each other - the sign that they should do it together. She told the dolphins: "Show us something we haven't seen today - and do it together."

Hector and Han disappear under the surface of the water. Stan Kuczaj, an expert in comparative psychology, dives in and records their behavior with an underwater video camera and microphones: Hector and Han chirp for several seconds; then both of them slowly turn a somersault underwater and hit their tails three times at the same time. They have mastered around a dozen such tricks. And it's unbelievable: They don't show any that they have already performed during this screening. At the top, Bolton forms a circle with his thumb and middle finger. With that she says to the dolphins: “Carry on, together.” They do it. First, the animals let themselves sink deeper, exchange a few high-frequency whistles and at the same time let air bubbles rise. Finally they do a pirouette side by side on the surface, then they dance synchronously on the tail across the water.

There are two possible explanations for this remarkable behavior. Either one dolphin only imitates the other so quickly and precisely that it looks as if they had agreed. Then what we perceive as a coordinated process would be an illusion. Or it really is like this: the two bottlenose dolphins devise a common plan with the whistles they exchange underwater.

If a chimpanzee looks covetously at a piece of fruit or a gorilla male drums himself on the chest to warn an approaching competitor, we easily find ourselves in these behaviors. We can imagine what the animals might be thinking. After all, we are also a kind of great ape, close relatives, so to speak. Dolphins, on the other hand, are very different.

They "see" with ultrasound, and so precisely that they can see from a distance of 30 meters whether an object is made of metal, plastic or wood. You can overhear other dolphins' echolocation signals and know what they are looking at. Dolphins do not breathe automatically like we and all primates do. When dolphins sleep, only half of their brains are at rest. And their eyes work independently of each other. They are an alien form of intelligence that lives with us on the same planet. A kind of E.T. under water.

However, they have one thing in common with us: Dolphins are also very talkative. Not only do they whistle and click, they also make loud noises in a wide range of frequencies to discipline their young or to drive away sharks. Scientists have long tried to find out what such tones mean. These highly social animals with their large brains would certainly not waste so much energy babbling underwater if these utterances did not have some meaningful content. But even after half a century of research, no one can say what the basic units of sound utterance in dolphins are and how they are put together by the animals in order to convey information. To put it bluntly: If dolphins actually have a language, then we neither know its syllables nor the words, let alone the syntax.

"If we were able to combine certain expressions with specific behavior, we would be a big step further," says Kuczaj. The 64-year-old is one of the best experts in the world for everything to do with perception and cognition - in short: cognition - in dolphins. According to Kuczaj, working with the synchronized dolphins at the RIMS could provide the key to their communication. But he also says: "It is precisely because dolphins are so highly developed that they are difficult to research."

So far, no one has found any proof that there is such a thing as a dolphin language. Some scientists claim that the reason for this is obvious: the "dolphin language" is just a fixed idea of ​​a few maritime romantics - in truth it doesn't even exist. But Kuczaj and others point to the multitude of indications: the problem has just not been approached in the right way and with the right tools, he says. Indeed, it has only been possible for about ten years now to use high-frequency recording devices to capture the entire spectrum of dolphin sounds underwater, and it is only in the last few years that new evaluation programs have made it possible to analyze the recordings more precisely. This is how you could track down this ancient intelligence.

Before our own species began its meteoric rise perhaps six or seven million years ago, the dolphins were probably the animals with the largest brains on our planet for tens of millions of years - and probably also the most intelligent. In relation to body size, their brains are still one of the largest in the animal kingdom, even larger than that of chimpanzees. The last common ancestor of humans and chimpanzees lived around six million years ago. The ancestors of the marine mammals, which include dolphins and whales, split off from the lineage of the rest of the mammals around 55 million years ago. The last common ancestor of the dolphins and primates - that is, from us - probably lived 95 million years ago. A very long time, even by evolutionary standards. Therefore, not only does our body look very different from that of a dolphin, but also our brain structure.

In primates, for example, the large frontal lobes are responsible for decision-making and planning processes. Dolphins do not have such large frontal lobes, but they too can solve problems and, it seems, plan for the future. We primates process information that our eyes convey to us in the back of the brain, while speech and acoustic information are processed in the temporal lobes on the right and left sides. Dolphins, on the other hand, process visual and acoustic information in completely different parts of their cerebral cortex, and the information there also takes completely different paths than in humans. Dolphins also have a well-developed paralimbic system for processing emotions. It is in this region that the extraordinary social and emotional bonds that are so typical of dolphins could develop.

“A dolphin is not really a dolphin on its own,” says Lori Marino, biopsychologist and director of the American animal rights organization Kimmela Center. “To be a dolphin means to be part of a complex social network. That is even more true of dolphins than it does to humans. "

When dolphins get into trouble, they show a cohesion that is hardly found in any other animal species. A sick animal that goes into shallow water is sometimes followed by the whole group. In the worst case scenario, everyone gets stranded. It is as if they are only concentrating on the sick conspecific. "Often you can only break through this self-damaging behavior by pretending to them that someone else is still in danger," says Marino. In 2013, for example, a mass stranding off Australia was averted by a trick: people caught a young animal from the group and brought it to the open sea; his cries of complaint lured the whole clan back into deeper water.

But why did the dolphins develop such a large brain? Millions of years earlier than human ancestors? A look at the history of the earth and fossil finds can provide clues. Around 34 million years ago, the ancestors of today's dolphins were still large animals with powerful, wolf-like teeth. At that time a period had begun in which, it is assumed today, the water of the oceans became significantly colder. With this change in temperature, new niches were created for the dolphins, with new prey. They changed their hunting habits. Her brain grew bigger, the terrifying set of teeth turned into a jaw full of tiny, pin-shaped teeth.

From changes in the bones of the inner ear, one can conclude that the dolphins also improved echolocation at that time. In any case, some species turned from solitary hunters chasing large fish into groups that hunted schools of smaller animals. This made communication more important. The dolphins became more social - and probably more intelligent too.

The American behavioral scientist Richard Connor studies the social life of dolphins in Shark Bay, Australia. He identified three stages of alliance building. In the first stage, males form pairs or trios, which together aggressively woo females and, if successful, keep them under strict surveillance. Some of these male couple or threesome relationships are remarkably stable, sometimes lasting for decades.

The males of the small groups in turn form larger teams of four to 14 animals. These are the second order covenants. They work together to steal females from other groups, and they defend their own females from outside attack. In at least one case, Connor knows of such a team that has existed for 16 years.

Even larger third-order alliances can temporarily form when teams from second-order alliances make common cause with one another against a comparably large other grouping.

However, such alliances can also be flexible. Two dolphins on a second-order team can be friends one day and opponent the next, depending on which conspecifics are around. With primates, such alliances are usually more rigid: “You are either for or against us.” With dolphins, this can change depending on the situation, which complicates the assessment of the situation. This, in turn, partially explains the dolphins' large brains: They need it to keep up to date with the status of their relationships.

What humans and dolphins have in common is that both are common around the globe - one on land, the other in the oceans. And like humans, dolphins are extremely inventive when they have to settle down in a special habitat and find food there.

In Shark Bay, for example, bottlenose dolphins release sponges from the seabed and sit on their snouts for protection when they look for fish hidden in the sand - it's a primitive form of tool use. In the shallow waters of Florida Bay, dolphins orbit schools of mullets at up to 32 kilometers per hour. In doing so, they throw up clouds of mud. Graylings that try to jump over them land in the open mouths of the dolphins lurking behind. Off the coast of Patagonia, black dolphins crowd anchovies into dense, spherical schools. Then they take turns pushing in and taking their prey.

These behaviors are undoubtedly signs of intelligence. For Stan Kuczaj, as a behavioral psychologist, the question arises, “whether dolphins are smart. But how they are smart. ”For the American neurophysiologist John Lilly, who researched the language of dolphins 60 years ago, they were simply“ the people of the seas ”. Lilly has worked with them since the 1950s at the National Institute of Mental Health and wrote, among other things, the bestseller "A Dolphin Learns English". Because Lilly's experiments became more and more obscure over time - at some point he even injected the dolphins with LSD - he received less research funding, the credibility of the research area dwindled, and at some point "the" language "of the dolphins was a frowned upon topic among scientists. That didn't change until 1970, when Louis Herman, a psychologist from the University of Hawaii, founded the Kewalo Basin Marine Mammal Laboratory in Honolulu.

“We wanted to get the dolphins to reveal their spiritual potential to us. In addition, we raised them from an early age in the same way as others raise their children, ”explains Adam Pack, who worked at the institute for 21 years. Two of these dolphins in the Kewalo Basin were bottlenose dolphins Phoenix and Akaekamai. They received instruction in an artificial language and learned to associate sounds or hand signals with objects, activities and properties. Each in a different way.

Phoenix learned an acoustic language. The words she heard were arranged in chronological order, their order corresponding to the order of the tasks that Phoenix had to perform. Akeakamai, on the other hand, was taught in a sign language in which the order of the words did not match the order of the tasks. Accordingly, Phoenix could respond word for word, but Akeakamai did not know what to do until she had seen the entire sequence of gestures. But when the two dolphins swam in a pool filled with objects, they both followed the instructions correctly more than 80 percent of the time.

Akeakamai died in 2003, Phoenix a year later, both ashes were taken to the open sea with surfboards and scattered. There were no successors for the two dolphins and the learning project was not continued either. This is one of the reasons why it is still not clear why it was so easy for Phoenix and Akeakamai to learn the respective language. Perhaps there is an innate ability to communicate in dolphins that humans might at some point understand?

At least one form of the sounds that dolphins make suggests that there are certain sounds for certain things or actions: They use characteristic "signature whistles" to recognize and address one another. Today it is assumed that every dolphin invented a unique name for itself as a young animal, which it will keep for its entire life. Dolphins greet each other in the sea by exchanging signature whistles; they remember the signature whistles of other dolphins for decades. Animals of other species also use vocalizations to alert each other to natural enemies, but apart from humans, as far as we know, no species-specific markings for individuals are used.

Signature whistles are just one of several tones that dolphins produce with their voices. Should they really be the only sounds in the animals' repertoire that have any meaning? How likely is it that dolphins have names for their fellow species but not for other things?

Denise Herzing has been investigating this question for three decades. She is a kind of Jane Goodall of the Seas and watches more than 300 rein dolphins from three generations, many of whom she has known from an early age. Her area of ​​work is 450 square kilometers of sea off the Bahamas, where she runs the world's oldest underwater research program for wild dolphins. Recently with a device that is supposed to help her, one day with the dolphins, whose acquaintance she has been trying to get into conversation for a long time. At the same time, she wants to clarify how the animals communicate with one another.

The device is in a shoebox-sized cube made of aluminum and clear plastic. The researchers call it CHAT. This is the abbreviation for cetacean hearing and telemetry. "Eavesdropping" and "remote measurement" - that is what this is about on the one hand. But also about a chat, a conversation.Scientists have a weakness for ambiguous abbreviations.

Underwater, Herzing fastened the nine-kilo device with straps in front of her chest. The box has a small speaker and keyboard on the front, plus two underwater microphones. At the push of a button, the computer in the waterproof interior plays the signature and other whistles of dolphins and records all sounds that come back from the dolphins. If a dolphin repeats one of the whistles, the computer can convert the sound into human words and play them through Herzing's headphones.

Dolphins learn quickly and happily. Herzing wants to get some young females to assign three different whistling noises from the CHAT box to three objects: a cloth, a rope and a piece of brown seaweed, which young dolphins use as toys. These three “words”, so she hopes, could form the basis for a vocabulary of whistles that she and her dolphins have in common. It would be the beginning of a newly created language in which she and the animals might one day be able to converse.

"Once you get it, it could happen very quickly," says Herzing. "Dolphins are social animals, and we may benefit from others watching and imitating them."

At 58 years of age, the lively, optimistic Herzing is the kind of person whom the term “visionary” fits. When she was twelve, she took part in a student competition for which she only had to answer one question: “What would you do for the world if you could do one thing?” Her answer: “I would be a human-animal translation machine develop so that we can understand the thoughts of other living beings on earth. "

She is often with the dolphins for hours on her underwater research, for thousands of hours she has recorded all kinds of behavior and compiled a huge database of the sounds of her chatty partners. On board her research vessel “Stenella” - that's the biological name for the dolphins - is Thad Starner, 45, professor of computer science at the Georgia Institute of Technology. He is a pioneer in the development of portable computers, the wearables, and senior engineer at Google. There he works on the Google Glass, the computer glasses with a mini-screen that conjure up all kinds of information from the Internet in front of the wearer's eyes in a matter of seconds.

Starner wears the glass almost all the time and takes notes on a lemon-shaped keyboard that fits in the palm of his left hand. Starner's team built the CHAT box, and he's on board for ten days to test the technology and collect data.

If one day the secrets of dolphin communication will be revealed, it will also be because of the data analysis programs that Starner is using out here for the first time. You search systematically for patterns in the huge databases. For example, from video recordings of people talking in sign language, the computer automatically filters out the signs that mean something from the confusion of all hand movements. The program finds recurring motifs where people don't even know what to look for.

In the first test run, Starner receives from Herzing the recording of a series of sounds that she has recorded underwater. But she does not tell him that he heard the signature whistles between mothers and boys.

The evaluation program soon recognized five basic units, an indication that the signature whistles consisted of fixed components. These were repeated constantly between mothers and boys and may also be recombined into different terms.

"At some point we want to have all the basic units of the dolphin sounds stored in a CHAT box," said Starner. “Then the box will translate everything the system hears into a series of symbols. Conversely, Denise should also be able to send rows of symbolic sounds to the dolphins. Ideally, we can do this on the spot, in some kind of conversation between humans and dolphins. The only question is: what are the basic units of this language? That is the holy grail we are looking for. "

After the preliminary tests, the CHAT-Box is finally tried out in the sea. Two rein dolphins approach the "Stenella" - not just any, but two good acquaintances of Herzing: Meridian and Nereid. The recordings of her signature whistles are even programmed into the CHATBox because the biologist had hoped to greet the two of them and talk to them.

Herzing has known most of the dolphins in the area since they were born, and she also knows who their mothers, aunts, and grandmothers are, but Meridian and Nereid are top candidates for her research. Female rein dolphins become sexually mature at nine years of age and are more than 50 years old. However, these two have not yet had their own offspring, and like high-spirited children they enjoy the freedom to play and explore new things full of curiosity.

Herzing dives and plays Meridian's signature whistle underwater. The dolphin then turns to her and comes closer - with no visible sign of the surprise one might expect when an animal hears another species calling its own name.

While swimming, Herzing stretches her right arm forward and points to a red cloth that she has pulled from her diving suit. Again and again she presses the button for "cloth" on the CHAT box: a rolling chirp that first gets deeper and then increases at the end. It takes about a second. One of the dolphins swims by, grabs the piece of cloth and pushes it back and forth between its snout and pectoral fin. When he dives into the depths temporarily, the cloth hangs like a flag on the dolphin's tail.

One of Herzing's students recorded the encounter with an underwater camera. Will one of the two dolphins run away with the cloth? No, obviously they want to get in touch, albeit hesitantly. The animals pass the cloth back and forth between them, circle the researchers, disappear for a moment and finally hold it up to Herzing again. She takes it, puts it in her wetsuit and pulls out some seaweed in its place. Immediately Nereid shoots down, grabs him in the teeth and swims away. Herzing follows her and repeatedly blows the seaweed whistle on the CHAT box as if she wanted the piece back. But they ignore Meridian and Nereid.

Later on board, Herzing ponders what the observation might mean. “If the dolphins understand that we are using symbols, it is conceivable that they want to show us something. And imagine what it would be like if the dolphins suddenly start using the word we have coined for seaweed. "

So far, however, there is no evidence of this. During the hour-long encounter, the CHAT box did not record anything that could be interpreted in the sense of learning or imitation. “It doesn't matter,” says Herzing, “we just have to repeat the experiment often enough. And repeat again. I know you are curious. You can almost watch how they gradually establish the connection between a thing and a sound. It will happen, you can see it in their eyes as they think about it. I can hardly wait for a female voice from the CHATBox to say 'cloth' in my headphones one day. "

Maybe the feedback already exists in some form, people just don't understand it. Nereid had temporarily wrapped the cloth around her tail, finally shaken it off and playfully let rise a large bubble. A sign?

After a few hours with the researchers, the dolphins lost interest. Nereid swam away and let out another long, enigmatic whistle. Before she disappeared into the blue darkness, she turned once more to face the people.

(NG, issue 05/2015, page (s) 60 to 83)