Dolphin Senses, Communication and Language | Sea Life, Islands and Oceania

DOLPHIN SENSES

Dolphin head sound production
Dolphins sense using vision, touch, sound, ultrasound, echolocation (emitting sound waves and sensing their reflections to determine the location of objects) and chemicals usually detected by smell-like senses and communicate with touch and sound.[Source: Eric J. Ellis and Allison Poor, Animal Diversity Web (ADW) /=]

Dolphin eyes are relatively small for animals of their size, but most species have fairly good eyesight. Their eyes are on the sides of their head, so their vision consists of two fields, rather than a binocular view as humans have. Olfactory lobes are absent in toothed whales. Unlike baleen whales, they lack the vomeronasal organ, suggesting they have no sense of smell. It is believed that toothed whales don’t have a good sense of taste either, as their taste buds are atrophied or missing altogether. However, some dolphins have preferences for different kinds of fish, indicating some sort of taste or taste-like mechanism.

Even though they rely mainly on sound to communicate, dolphins are able to see fairly well in both water and air. River dolphins are the exception. There is little use for vision in the turbid waters where they reside, so their eyes are greatly reduced and some are nearly blind. Social toothed whales use touch extensively with pod-mates, which may be an important form of communication.

Websites and Resources: Britain-based Whale and Dolphin Conservation Society uk.whales.org ; Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Fishbase fishbase.se; Encyclopedia of Life eol.org; Smithsonian Oceans Portal ocean.si.edu/ocean-life-ecosystems ; Monterey Bay Aquarium montereybayaquarium.org ; MarineBio marinebio.org/oceans/creatures

Dolphin Vision

Eye of a typical dolphin: Co = cornea; L = lens; Ir = iris; O = operculum; S = sclera; Ch = choroids; R = retina; ON = optic nerve; OF = optic disc; black arrows indicate the retina [Source: Mass & Supin (2007)]

Dolphins also use vision to perceive their surroundings. Like those of humans, their eyes contain rods and cones, but they are not used in the same way as humans. Cones, for example, are used to provide good acuity when light levels are high. These and other adaptations allow dolphins to use their vision at different times of the day and at different depths. [Source: Jessica Jenkins, Animal Diversity Web (ADW)]

According to research by Masaki Tomonaga, Yuka Uwano and Toyoshi Saito: Relatively few systematic studies have examined dolphin’s visual perception. We tested dolphins on a visual-matching task using two-dimensional geometric forms including various features. Based on error patterns, we used multidimensional scaling to analyse perceptual similarities among stimuli. In addition to dolphins, we conducted comparable tests with terrestrial species: chimpanzees were tested on a computer-controlled matching task and humans were tested on a rating task. The overall perceptual similarities among stimuli in dolphins were similar to those in the two species of primates. These results clearly indicate that the visual world is perceived similarly by the three species of mammals, even though each has adapted to a different environment and has differing degrees of dependence on vision. [Source: Masaki Tomonaga, Yuka Uwano & Toyoshi Saito, Scientific Reports volume 4, Article number: 3717, January 16, 2014]

A few studies have investigated dolphins' ability to use cross-modal integration through vision–echolocation matching. In these studies, dolphins were very accurate in matching three-dimensional complex objects using information gathered via echolocation. On the other hand, these results indirectly suggest that dolphins may also visually discriminate complex objects. Dolphins (such as, bottlenose dolphins) have poorer in-air and underwater visual acuity (12.6 min of visual angle from a distance of 2.5 meters) than that of primates. Nevertheless, they still visually recognise and discriminate human gestural signs, mirror images of themselves, numbers of objects, three-dimensional objects and two-dimensional forms. Moreover, researchers have used visual stimuli to study the basic features of the vision and various cognitive abilities of dolphins.

In the present study, we tested the visual form perception of dolphins using simpler geometric forms, composed of basic features. Although three-dimensionally complex stimuli might be more naturalistic, thus ecologically valid, we used these simpler patterns to compare basic properties of the visual perception of dolphins with those of other species more systematically. Bottlenose dolphins living in the Port of Nagoya Public Aquarium have been trained on face-to-face matching tasks using various kinds of three-dimensional junk objects, such as PET bottles and flying discs. In this study, we introduced nine, novel two-dimensional forms to this matching task...To our surprise, the visual perception of bottlenose dolphins is very similar to that of primates, as evidenced by our data from two visually acute terrestrial mammalian species.

Dolphins Recognize Each Other by Tasting One Another's Urine

Dolphin family According to a study published in May 2022 in the the journal Science Advances, dolphins have a unique sense of taste that allows them to sense friends and family members through pee and other excretions based on the animal’s tendency to show more interest in urine collected from animals they knew rather than strangers. “Dolphins explored urine samples for longer if they came from known animals or when they were presented together with the dolphin’s unique and distinctive signature whistle, an acoustic identifier that works like a name,” professor Vincent Janik, director of the Scottish Oceans Institute and lead author of the study, told the Guardian. [Source: David Moye, Huffington Post, May 24, 2022]

The Huffington Post reported: Researchers employed the services of bottlenose dolphins who swim with tourists at the Dolphin Quest resorts in Hawaii and Bermuda. Fellow researcher Jason Bruck, a marine biologist at Stephen F. Austin State University in Texas, told National Geographic the original goal was to test whether dolphins use their signature whistles in the same way people rely on names. Bruck couldn’t do that unless he found a second way dolphins could identify each other. Luckily, he remembered that a fellow scientist had previously observed wild dolphins swimming through what the website called “plumes of urine” and he figured the creatures might be using it as an ID technique. “It was a shot in the dark,” Bruck said. “And I was not expecting it to work, to be honest.”

But it did. Dolphins don’t have a sense of smell, so the way they would identify each other went like this: When one dolphin peed or pooped, the others would swim through the excretions with their mouths to get a big taste of their friend, according to the Canadian Broadcasting Company. “In other animals, it’s very difficult to separate the sense of smell from the sense of taste. So this is a really exciting opportunity to just study how taste works in this really unique way,” Bruck told the network.

The researchers noticed the participating dolphins spent three times longer analyzing urine they recognized than pee from strangers. Bruck also noticed the dolphins seemed to be as fascinated with the experiment as he was. “The dolphins were very, very keen to participate,” Bruck told National Geographic. “Usually, dolphins get bored with my experiments. We were tapping into something that is part of the dolphins’ world.”

Dolphin Sounds

All toothed whales and dolphins produce sound to communicate, navigate, and locate prey and have a melon, an oval fat-filled organ in their foreheads. A melon focuses outgoing sounds. It evolved from a sac off the main nasal passage for moving air back and forth to create sound vibrations. The lower jaw helps catch returning vibrations.

Dolphin click frequency
Dolphins are capable of making a broad range of sounds using nasal airsacs located just below the blowhole. Exactly how they make the noises is still unclear. The clicking noises are used for echolocation (emitting sound waves and sensing their reflections to determine the location of objects).

Dolphins produce a wide range of sounds, including whistles, oinks, squawks, squeaks, blats, chirps, grunts and clicking noises,
Most sounds are made in the nasal passages not the larynx. Dolphins communicate with whistles. These sounds are most likely produced by opening and closing nasal plugs. They also make whistles, and ultra-sounds with frequencies of 200,000 vibrations a second with their larynx. Dolphins make a variety of hissing noises like air escaping from a balloon by blowing air through nasal sacs inside their skull.

Dolphins also hear a wide range of sounds, While humans can hear sounds ranging from 20Hertz (Hz) to 20,000Hz, bottlenose dolphins can hear up to 160,000Hz – beyond the range of dogs, famously sensitive to high pitches we cannot hear. The highest pitches digs hear is 44,000Hz.

Roughly three categories of sounds can be identified: 1) frequency-modulated whistles, 2) burst-pulsed sounds, and 3) clicks. Dolphins communicate with whistle-like sounds produced by vibrating connective tissue, similar to the way human vocal cords function, and through burst-pulsed sounds. The clicks are directional and are used for echolocation, often occurring in short series called click trains. The click rate increases when approaching an object of interest. Toothed whale biosonar clicks are amongst the loudest sounds made by marine animals.

Dolphin Melon and Hearing

All toothed whales and dolphins have a melon, a lens of fatty tissue used in navigation and finding prey. Many toothed whales use echolocation to locate objects, with the melon sending out high-frequency clicks and focusing outgoing sounds. The skull of creatures with a melon will have a large depression. The melon size varies between species, the bigger it is, the more dependent they are on it. The melon evolved from a sac off the main nasal passage and is used for moving air back and forth to create sound vibrations. The lower jaw helps catch returning vibrations.

Dolphins “hear” using their jaws. They don’t have an outer ear. Instead, sound travels to the inner ear through a thin "window" in the lower jawbone. The ears of whale and dolphins are adapted for their marine environment. Humans have a middle ear which aid in the collection of sounds. In whales, instead of sound passing through the outer ear to the middle ear, whales receive sound through the throat, from where it passes through a low-impedance, fat-filled cavity to the inner ear. The ear is acoustically isolated from the skull by air-filled sinus pockets, which allow for greater directional hearing underwater

Dolphins and toothed whales are well adapted to hear sounds at ultrasonic frequencies, as opposed to baleen whale who generally hear sounds within the range of infrasonic frequencies. Dolphin a hearing range that greatly exceeds that of humans; they can perceive ultrasounds up to 120 kHz.

Dolphin Echolocation

Delfinekko
cetacean biosonar
Dolphins — like bats and many whales — employ echolocation (emitting sound waves and sensing their reflections to determine the location of objects). They use clicks for echolocation to navigate and to find food. They have a fatty organ called a melon on the forehead that focuses acoustic signals as they are emitted, and they receive sounds in the middle ear via the mandible. Blindfolded dolphins can detect a object three inches in diameter from a distance of a 120 meters [Source: Eric J. Ellis and Allison Poor, Animal Diversity Web (ADW) /=]

Dolphins “see” with sonar and rely on echolocation more than sight to sense objects and hunt prey. Not only can they deduce the presence of an object with echolocation they can deduce its size and what it is. They can tell from 30 meters away whether an object is made of metal, plastic, or wood. They can also also determine if a container is full or empty and distinguish between a rock and a piece of flesh. Studies have shown that dolphins are almost as good at picking out objects of different shapes and sizes when they blindfolded as when they are not blindfolded. They can even eavesdrop on the echolocating clicks of other dolphins to figure out what they’re looking at.

Zoe Cormier wrote in for BBC Earth: By vibrating the 'phonic lips' on their nasal bulbs at the top of their heads, dolphins and porpoises channel beams of sound through the melon (the globe of oily tissue in their forehead) towards their prey, and by picking up the echoes that bounce back (mostly through the jaw), can figure out not just the location of a fish, but also how big it is. Dolphin echolocation is so sensitive, they can figure out the size of a fish based on the size of the swim bladder (a sac full of air that fish use to move vertically in the water). [Source: Zoe Cormier, BBC Earth]

Professor Wenwu Cao in the Department of Mathematics at Penn State Materials Research Institute published a study in the journal Physical Review Applied describing how porpoises can use the oily material in their heads (described as a 'meta material') to create narrow beams of sound instead of regular sound waves that travel in all directions. “We began our study by trying to figure out why such a small animal with such a small head could locate fish very far away – this ability could not be explained by textbooks,” he says. “They use muscles to physically deform their heads to change the angle of the beam – this was not known at the time. But we still don’t’ understand how exactly they receive the signals. I also want to understand how they form clear images.For us, we have two eyes, which we use to form three dimensional images. But with their acoustic system, we still don’t know how they receive information from objects at different angles. It could be that they use their ears, or it could be that they use their teeth – we still don’t know.”

Researchers have found that sonar may harm dolphins. In the spring of 2000, a dolphin beached itself and died on a beach on a northern Bahamas island, near where United States Navy ships were using powerful sonar (230 decibels, as loud as a rocket taking off) in anti-submarine exercises. A necropsy showed hemorrhaging around the brain and ear bones that may have caused them to beach themselves and may been caused by the impact of the sonar from the ships. See Whales.

Dolphin Clicks

Dolphin click time

Toothed whales echolocate by creating a series of clicks emitted at various frequencies. Sound pulses emitted through their melon-shaped foreheads reflected off objects, and retrieved through the lower jaw. They produce clicks by forcing air through special passages and sinuses in the heads.

Dolphin clicks and ultra-sounds pass through the melon, where the clicks are focused, and strike objects outside the dolphin and return to the dolphin brain like radar, enabling a dolphin to determine the distance and certain things about the objects. Some believe the clicking noises are generated by forcing air from two sacks near the blowholes. Others believe they are formed by forcing nasal plugs against bony edges of the skull.

A single click is an intense form of energy that lasts less than 1/10,000th of a second yet contains a startling range of frequencies, most of them too high for humans to hear. The sounds emerge from the forehead as a beam, with many toothed whales and dolphins being able to focus or widen the beams with their melon. Some clicks are so loud they can temporarily deafen a person.

Clicks can be rattled off at a rate of up to 700 per second or generated as a drawn-out individual sound. The frequency of these clicks varies between 20 cycles per second and 170,000 cycles per second. The human ear can only detect sounds as high as 16,000 cycles per second. [Source: Kenneth Norris, National Geographic, September 1992; Robert Leslie Conley, National Geographic, September 1966]

Different Voices of Dolphins

Toothed whales and dolphin speak in different voices, including deep, gravelly one called. "vocal fry" to help find their prey, according to a paper published in the journal Science in March 2023. The study also found that dolphin, like people, have three vocal registers: a normal voice, a falsetto along with creaky fry. "The similarities we find are really striking," said Coen Elemans, a voice scientist at the University of Southern Denmark who led the study. "This is the first evidence of broad register use in any animal, besides humans." [Source: Dino Grandoni, Washington Post, March 3, 2023]

The Washington Post reported: Elemans and his colleagues found that toothed whales use the normal and falsetto registers to communicate with each other. They reserve the vocal fry register for navigation...especially in very deep water where they hunt in nearly complete darkness. The animals use sound to find their way underwater, sending out powerful pulses and listening to the echo to spot their meal. Toothed whales rely on vocal fry to make their echolocation clicks, according to the study. Under the sea, air is precious — and whales likely evolved to use the lower register for echolocation since it uses air the most efficiently.

Vocal fry, according to Elemans, "has definitely brought toothed whales very far." His team's series of experiments showed that toothed whales produce their wide repertoire of sounds with the same organ — the phonic lips in their nose, which vibrate much like a larynx does in humans. To reach that conclusion, his team filmed tissue motion on trained bottlenose dolphins and harbor porpoises with a high-speed camera, and also taped wild whales with a small sound-recording tags. "They show, to some extent, that the physical mechanism is the same as the one we use," said Andrea Ravignani, a comparative bioacoustician at Aarhus University in Denmark and the Max Planck Institute for Psycholinguistics in the Netherlands. He wrote an opinion article on whale vocalization in the same issue of Science. He added, "The finding is quite unexpected and mind-blowing."

Dolphins Communication

Bottlenose dolphin mother and juvenile
Dolphins are among the most vocal animals. They communicate by using body language and at least 30 different sounds and vocalizations. Members of a group can communicate with one another of large expanse of open ocean. They can hear each over of at least half a mile. There are still a lot basic things about dolphin communication that scientists don’t understand: for example how they synchronize themselves when the leap in formation.

Dolphins use unique whistles to identify themselves and make sounds to express excitement and moods and exchange messages that help keep groups together and warn others of danger. Individual identity is practiced by humans and dolphins but few other members of the animal kingdom.

Dolphins appear to use body language and non-verbal communication. They touch, nudge and stroke one another in a way that seems to convey meaning. On biologist discovered that young Atlantic spotted dolphins let their mothers know everything is okay by pressing against their backs.

Studies in the Bahamas with wild dolphins indicates that dolphins change the meanings of sound by accompanying them with different postures. At a dolphin park in the Florida Keys a calf born to a deaf dolphin — who spoke in a monotone similar to that of deaf humans who can not speak — was given a “chat line” — consisting of underwater speakers and microphones connected to facilities with other young dolphins’so it could learn to speak normally.

Scientists can call dolphins with a pinger. Dolphins can not imitate human sounds very well but they seem to respond to the number of syllables a dolphin makes. If a scientist counts from one to six the dolphin responds with six noises. [Source: Robert Leslie Conley, National Geographic, September 1966]

Dolphin Signature Whistles

Dolphins use distinct “signature whistles” to identify and call to one another. According to National Geographic,: Each dolphin is thought to invent a unique name for itself as a calf and to keep it for life. Dolphins greet one another at sea by exchanging signature whistles and seem to remember the signature whistles of other dolphins for decades. Though other species, like vervet monkeys and prairie dogs, make sounds that refer to predators, no other animal, besides humans, is believed to have specific labels for individuals. [Source: Joshua Foer, National Geographic, May 2015]

"Each dolphin has a distinctive signature whistle," says oceanographer Peter Tyack, "Infants tend to develop a whistle unlike those of their parents, and other dolphins learn to associate each whistle with the appropriate individual. By listening to whistles a dolphin can keep track of the other dolphins even when it cannot see them." The sounds of the whistles vary and serves a purpose similar to a human name. Each dolphin usually develops whistle made up of a pattern of rising and falling tones in its first year. [Source: Kenneth Norris, National Geographic, September 1992 **]

“A signature whistle is often said to be similar to a name because it is individually distinct and serves to identify the animal,” Brittany Jones, a postdoctoral research fellow at the National Marine Mammal Foundation, told NBC News. She said that the owner of the signature whistle uses it more often than other dolphins, whereas with us humans other people use our names more than we do. She also compares signature whistles to our distinctive voice, which can convey information about identity, proximity and emotional states. A 2018 study found male bottlenose dolphins retain their “names” into adulthood just like females. It was previously thought males abandoned their signature whistle to adopt the same whistle as their alliance groups.

In a process called "whistle matching,” it seems that a dolphin can also call a particular individual by imitating its whistle. This is regarded as an important step in developing language. Tyack believes dolphins pass on other kinds information in similar ways. In addition to demonstrating their ability to communicate, he says, the whistles, and they way they are aquired and used, show dolphins are organized into an "educated society, one based on learning.” **

Understanding Dolphin Signature Whistles

In a 2006 study, researchers concluding that bottlenose dolphins "extract identity information from signature whistles, even after all voice features have been removed from the signal." These whistles are a big part of the species' "fission-fusion societies," in which they form a variety of different social relationships, especially since it can be hard to recognize individuals by sight or smell underwater. [Source: Russell McLendon, Mother Nature Network, February 21, 2013]

A study published in February 2013 in the Proceedings of the Royal Society B, researchers discovered that dolphins imitate another’s signature whistle to re-establish contact, at times adding parts of their signature whistle to the call. The study found that dolphins not only name themselves with "signature whistles," but they also recognize the signature whistles of other dolphins they know — an indication of a linguistic behavior known as "referential communication with learned signals," which has traditionally seen as uniquely human. "This use of vocal copying is similar to its use in human language, where the maintenance of social bonds appears to be more important than the immediate defence of resources," the study's authors wrote.

A study published in May 2022 in the journal Scientific Reports said that two important influences on dolphin signature whistles in the Mediterranean Sea were the local ocean environment and the demographics of different dolphin populations. According to NBC News: Scientists found dolphins who live in regions with more seagrass have signature whistles that are higher in pitch and shorter in length when compared to those who live in areas where the seafloor is muddier. Meanwhile, dolphins in smaller groups had whistles that changed pitch more often than dolphins in larger groups. [Source: Sarah Sloat, NBC News, May 27, 2022]

To study the dolphins scientists analyzed 188 hours of recorded acoustic data collected by different research groups from 2006 to 2020. These sounds were recorded at six sites across the Mediterranean Sea, which is divided into west and east basins. Because there is genetic variation between eastern and western dolphin populations, The team extracted 168 individual whistles from the recordings and analyzed their acoustic features in relation to a few factors: precise location where the whistle was recorded, whether or not this was in the eastern or western basin, the local ocean environment and population demographics.

Ultimately, the scientists found that location only partially affected whistle variability, and the genetic differences between the dolphins had “no strong influence on the acoustic structure of their signature whistle.” Meanwhile, the environmental conditions and demographic characteristics did appear to strongly influence signature whistles — findings that align with the “acoustic adaptation hypothesis,” the idea that animals acoustically adapt their vocalizations to their local conditions to optimize the purpose of their sounds. The study claims these are the foundational influences on signature whistle variability — and from here, dolphins influence one another and innovate their own specific sounds.

Dolphins at Sea Greet Each Other with Signature Whistles

Bottlenose dolphins exchange signature whistles with each other when they meet in the open sea, which some scientists have described as a greeting or form of conversation. Jennifer Viegas wrote: Earlier research found that signature whistles are unique for each dolphin, with the marine mammals essentially naming themselves and communicating other basic information. A signature dolphin whistle in human speak, might be comparable to, "Hi, I'm George, a large, three-year-old dolphin in good health who means you no harm." [Source: Jennifer Viegas, Discovery Channel, NBC News, Feb. 29, 2012]

The latest study, published in the Proceedings of the Royal Society B, is the first to show how free-ranging dolphins in the wild use these whistles at sea. The findings add to the growing body of evidence that dolphins possess one of the most sophisticated communication systems in the animal kingdom, perhaps even surpassing that of humans. "In my mind, the term 'language' describes the human communication system; it is specific to us," co-author Vincent Janik of the University of St. Andrews Sea Mammal Research Unit, told Discovery News. "It is more fruitful to ask whether there are communication systems with similar complexity. I think the dolphin system is probably as complex as it gets among animals."

Janik and colleague Nicola Quick studied how bottlenose dolphins in St. Andrews Bay, off the coast of northeast Scotland, communicate with each other. While in a small, quiet boat, the researchers followed the wild dolphins and recorded their vocalizations. Analysis of the observations and recordings found that the dolphins usually swam together in a group moving slowly and relatively quietly.

Most animals have some sort of communication system that allows them to make similar introductions and meetings, but dolphins are unique in that they can invent and copy new sounds. This is "unlike non-human primates, who are stuck with their species-specific repertoire," he said. Dolphins at a distance may rely more upon sounds and echolocation for their communications than visual, scent and other signals. This is likely due to their marine environment and social structure. A dolphin can hear the whistle of another dolphin over a distance of about six miles and with lots of noise in the background.

The researchers also noticed that usually just one dolphin from each group would emit a signature whistle before the other group members would join the second group. This might mean that dolphins elect a "spokesman" to represent the entire group during meetings. Such an individual may be an older dolphin, Janik said, but he thinks the other dolphins are not fully silent, and may be using echolocation instead of whistles. "We don't know whether echolocation works in this way, but it seems like a viable hypothesis," he said. "In that case, the whistle exchange is more of a greeting ceremony that communicates a friendly intention and is perhaps not needed to identify the group after the first introduction."

Heidi Harley, a bottlenose dolphin expert who is a professor of psychology at the New College of Florida, told Discovery News that she believes the findings are key to understanding how dolphins use signature whistles. "Now we know that dolphins in groups use signature whistles before they join each other," Harley said. "This is an important piece in the puzzle that we've been constructing about signature whistles." She added, "I was surprised to learn that the exchanges appeared to be between only a single individual in each group."

Dolphins and Language

The study of dolphin “language” was given a big boost in 1970, when a University of Hawaii psychologist Louis Herman founded the Kewalo Basin Marine Mammal Laboratory in Honolulu. “We wanted to educate them to reveal their cognitive potential,” Adam Pack of the University of Hawaii at Hilo, who worked at the lab for 21 years, told National Geographic. “We reared the dolphins as you would a child.” [Source: Joshua Foer, National Geographic, May 2015]

Herman developed sign, hand and arm language, complete with grammar, to communicate with dolphins, including one named Akeakamai. Virginia Morrel wrote in National Geographic, “For instance, a pumping motion of closed fists meant “hoop” and both arms extended overhead (as in jumping jacks) meant “ball.” A “come here” gesture and a single arm told them to “fetch.” Responding to the request “hoop, ball, fetch,” Akeakamai would push the ball to the hoop. But if the word order was changed to “ball, hoop, fetch,” she would have to carry the hoop to the ball.”

Over time Akeakamai could interpret more grammatically complex requests, such as “right basket, left Frisbee” in which she would put a Frisbee on her left in the basket on her right. Morrel wrote: “Reversing “left” and “right” in the instructions would reverse Akeakamai’s actions, Akeakamai could complete such requests the first time they were made, showing a deep understanding of the grammar of the language.” Dolphin “readily imitated motor behaviors of their instructors too. If a trainer bent forward and lifted a leg, the dolphin would turn on its back and lift its tail in the air.” Imitation used be regarded as a simple activity but cognitive scientists now regard it as a complex behavior that requires recognition of the self.

At Kewalo Basin Akeakamai and another captive bottlenose dolphin Phoenix were raised in an environment of constant education and schooled artificial languages. Joshua Foer wrote in National Geographic: Both were taught to associate either sounds or hand signs with objects, actions, and modifiers. But Phoenix was taught an acoustic language in which words were placed in the order of the tasks to be performed. Akeakamai was taught a gestural language in which the order of the words was not the same as the order of the tasks. Though Phoenix could in theory respond word by word, Akeakamai could interpret her instructions only after she’d seen the entire sequence of gestures. Swimming in a pool filled with objects, the dolphins would carry out their instructions correctly more than 80 percent of the time. [Source: Joshua Foer, National Geographic, May 2015]

After Akeakamai died in 2003 and Phoenix in 2004 and the , their ashes were taken out to sea on surfboards and scattered, and the only research facility in the world dedicated solely to understanding how dolphins think went out of business. A big question remained: Why had Phoenix and Akeakamai found it so easy to learn the languages? Herman dismisses any notion that the researchers were piggybacking on some innate linguistic capacity. In his view, the imposed languages had allowed Phoenix and Akeakamai to express exceptional cognitive abilities common to all bottlenose dolphins — and perhaps other dolphin species — in a way that might never be exhibited in the wild. But is there some native form of dolphin communication that humans could eavesdrop on and eventually understand?

Do Dolphins Really Possess Language?

Dolphins perform certain behaviors in correspondence to certain sounds. Some dolphins respond to "sentences" such the command "surfboard-right-Frisbee-fetch" in which the dolphin chose a Frisbee on the right and places it on a floating surfboard. Some say this constitutes a kind of language but others say it doesn’t. The naysayers insist there is no proof that dolphins use grammar, syntax or are able to construct even two-word sentences.

Herman told National Geographic, Dolphins “are a very vocal species, Our studies showed that they could imitate arbitrary sounds that we broadcast into their tank, an ability that may be tied to their own need to communicate, “I’m not saying they have a dolphin language... But they are capable of understanding the novel instructions that we converse to them in a nurtured language; their brains have that ability...There are many things they could do that people have always doubted about animals. For example, they correctly interpreted, on the very first occasion gesture instructions given by a person displayed on a TV screen behind an underwater window. They recognized that television images were representations of the real world that could be acted on in the way as the real world.”

Joshua Foer wrote in National Geographic: “Dolphins are extraordinarily garrulous. Not only do they whistle and click, but they also emit loud broadband packets of sound called burst pulses to discipline their young and chase away sharks. Scientists listening to all these sounds have long wondered what, if anything, they might mean. Surely such a large-brained, highly social creature wouldn’t waste all that energy babbling beneath the waves unless the vocalizations contained some sort of meaningful content. And yet despite a half century of study, nobody can say what the fundamental units of dolphin vocalization are or how those units get assembled. [Source:Joshua Foer, National Geographic, May 2015]

““If we can find a pattern connecting vocalization to behavior, it’ll be a huge deal,” comparative psychologist Stan Kuczaj who has published more scientific articles on dolphin cognition than almost anyone else in the field, told National Geographic: He believes that his work with the synchronized dolphins may prove to be a Rosetta stone that unlocks dolphin communication, though he adds, “The sophistication of dolphins that makes them so interesting also makes them really difficult to study.”

Thus far there is little or no evidence to supports the existence of a language resembling one of the sophistication that humans have But “Kuczaj and other prominent researchers see a preponderance of circumstantial evidence that leads them to believe that the problem simply hasn’t yet been looked at in the right way, with the right set of tools. It’s only within the past decade or so that high-frequency underwater audio recorders, like the one Kuczaj uses, have been able to capture the full spectrum of dolphin sounds, and only during the past couple of years that new data-mining algorithms have made possible a meaningful analysis of those recordings. Ultimately dolphin vocalization is either one of the greatest unsolved mysteries of science or one of its greatest blind alleys.

Image Source: Wikimedia Commons, NOAA

Text Sources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Wikipedia, National Geographic, Live Science, BBC, Smithsonian, New York Times, Washington Post, Los Angeles Times, The New Yorker, Reuters, Associated Press, Lonely Planet Guides and various books and other publications.

Last Updated June 2023