dolphin intelligence compared to human age

Varley, Len. Many other dolphins have risen to fame with their various feats of sophistication. When being herded together, they huddle instead of trying to jump the net. Thank you for reading! In fact, humans have a larger brain than dolphins relative to their body size. Lillys early work laid the groundwork for studying dolphin brains and intelligence. Bottlenose dolphins off the coast of Western Australia have been observed using sea sponges as snout protecting tools while rooting around in the sand on the seafloor for fish. Plus, they're highly sensitive, are able to gain knowledge to help them solve problems later, andat least in the case of mothersare very protective, loving, and playful with their little ones. In a bizarre study conducted at Clark University, back in 1907, raccoons wereable to pick complex locksin less than 10 attemptseven after the locks were rearranged or flipped upside-down. 1. Like humans, dolphins possess the ability to beneficially alter their surroundings, solve problems, and form complex social groups. The PFC is the key to planning behaviors, making decisions, and engaging in social behaviors with others. Goats understand humans better than dolphins. The more similar to human intelligence that dolphin intelligence is the more likely it is that dolphins may in fact be smarter than humans as Adams predicted. Gregg has deeply researched these deep sea creatures, and seen plenty of ways in which they excel cognitivelyand some of the ways the lag behind. She quickly learned to take single piece of paper, keep it under rock, and tear off smaller pieces to get more fish. The human brain has a far more developed hippocampus than the dolphin brain. Studies into dolphin behaviour have highlighted how similar their communications are to those of humans and that they are brighter than chimpanzees. Like dolphins, they've been seen consoling and helping others, and there's even been a recorded instance of one passing the Mirror Test. According to one 2013 study, they have theability to decipher "ethnicity, gender, and age" in humans, all by listening to acoustic cues from voices. Click Register if you need to create a free TED-Ed account. 1. They compared dolphin encephalization quotients to those of other famously smart animals like chimpanzees, humans, gorillas and orangutans. This case of the trainer being trained by the trainee showed that Kelly was, in fact, capable of planning for the future and understood the concept of delayed gratification. And since, over the millennia, different types of human subgroups have posed various threat levelsa male in his prime might signify higher danger, for instancethis is a highly advanced skill that's been honed and passed down over generations. And, in 2017, researchers at the University of Wyoming put raccoons up to the puzzle found in one of Aesop's Fables, "The Crow and the Pitcher," where a bird drops rocks into a deep pitcher, to raise the water level to a point where it's drinkable. Then there was Billie the dolphin, who was trapped in a sealock and rescued. In fact, humans have a larger brain than dolphins relative to their body size. One dolphin's distress calls will cause others to follow it ashore. We can learn and retain information and then recall it later. St. Petersburg Polytechnical University Journal: Physics and Mathematics, vol. 1. Having a better-developed hippocampus allows humans to have better long-term memory than dolphins. One notable example is that adult dolphins will often attach sponges to their snouts to protect themselves while foraging for food. This makes dolphins second only to humans in brain-to-body weight ratio. That is not to say that its not an important or insightful form of measurement. If the dolphins . VENs are housed in the anterior cingulate cortex, the part of the brain responsible for emotion, decision-making, and autonomic functions, and are found only in a handful of social species outside of the great ape category. These functions allow us to use language, imagination, perception, and to plan. When they work together, they know how to form colonies that operate with remarkable efficiency. 280, no. They dont have the higher-level thinking, memory, the ability to set goals, and many other brain processes as human beings. However, dolphins do not display indicators of tool usage, problem solving, and structured discussion to the degree that humans do. Studying dolphins by giving them human-built tests in a lab isnt necessarily a great reflection of a dolphins ability to out-think what nature throws at them. Dolphins demonstrate the ability to do all of these things and most scientists agree that dolphins are very intelligent. , a close human ancestor, the study noted. In fact, their encephalization quotient (their brain size compared to the average for their body size) is second only to humans. Although it may not be directly meaningful, in terms of brain size, the bottlenose dolphin brain averages 1.6 kg in size, by comparison, the average human brain weighs about 1.35 kg and a chimpanzee's brain weighs 0.4 kg. "This shows us an animal operating cognitively at a level that's very consistent with human social memory . In fact, according to panelist Lori Marino, an expert on cetacean neuroanatomy at Emory University in Atlanta, they may be Earth's second smartest creature (next to humans, of course). Man has always assumed that he is more intelligent than dolphins because he has achieved so much the wheel, New York, wars and so on while all the dolphins had ever done was muck about in the water having a good time, the science fiction writer wrote in his book So Long and Thanks for all the Fish. Besides us, of course. Hans Thewissen, a professor at Northeast Ohio Medical University who has studied. Marino bases her argument on studies of the dolphin brain. Rats, unlike dolphins, have "metacognition.". Bestlifeonline.com is part of the Meredith Health Group. Like primates, dolphins and whales are mammals. According to one Princeton University study,grey squirrels can remember where they've buried thousands of nuts, for months at a time, without relying on their sense of smell. (Think of it like the world's most sophisticated form of artificial intelligence, but with Mother Nature's distinct touch.). Research into the behavior of dolphins in the wild and in captivity has yielded incredible data on the intelligence of these marine mammals. In terms of mass, a bottlenose dolphin's brain typically weighs 1,500 to 1,700 grams, which is slightly more than a human's and four times the weight of a chimpanzee's. After humans, dolphins are often regarded as the second-most intelligent animal on the planet. 2022 Galvanized Media. can't duplicate. Cognitive psychologist Diana Reiss of Hunter College of the City University of New York brought the audience up to speed on the latest on dolphin behavior. 1-15, doi:10.1016/j.zool.2018.05.003, Daz Lpez, Bruno. What's more, they follow a very humanlike trajectory of language development, starting out as babblers and learning the laws of language over time. For starters, they thrive in big urban cities, giving them major street smarts over other animals. Animal Behaviour, vol. They've also shown excellent cognitive abilitiesincluding individual differentiation and behavior controland are one of the few creatures known to have passed the benchmark Mirror Self-Recognition Test. However, dogs and dolphins can both use human pointing and eye-direction cues to locate objects in the distance. They are notoriously talented mimics and quick learners; they demonstrate self-awareness, problem-solving, and empathy, innovation, teaching skills, grief, joy and playfulness. "Tail Walking in a Bottlenose Dolphin Community: the Rise and Fall of an Arbitrary Cultural Fad." First, the researchers played whistles of unfamiliar dolphins over a speaker until the dolphins got bored of them. Nominate yourself here . Chaser, a Border Collie trained by psychologists"came out on top with knowing four or five times more symbols than dolphins or even gorillas." These acts provide proof that dolphins are compassionate., Within their social systems, they also form long-term cooperative partnerships and alliances, exhibit conformity (as is the case with the tool-using population), and learn from their pod members., Studies show that dolphins have special, spindle-shaped neurons called VonEconomo neurons, or VENs, that aid in the intuitive assessment of complex situations, like social interplay. And who wants to be like humans anyway? Compared to chimpanzees, gorillas are calm, reserved . Mercado, Eduardo, et al. But, while they're undeniably smart, they aren't the only smart animals out there. These are the three greatest differences in the human brain and dolphin brain, and they can help explain the disparity in intelligence between the two species. "Scientific facts should transcend geographic boundaries. Many argue that they are smarter than any primates. Using brain size as a barometer, dolphins come in second only to humans in brain-to-body size ratio. One measure is known as the encephalization quotient, or EQ, which quantifies the size of a species'. More generally,African Grey parrots, the Einstein of this species, can learn an impressive number of human words and use them in context to communicate with humans. In fact, their encephalization quotient (their brain size compared to the average for their body size) is second only to humans. But exactly how smart are they? We offer many cruises and sailing tours perfect for doing just that. Dolphins have so much brain power that they're thought to rival humans in intelligence. When it comes to what defines a person, said White, "dolphins fit the bill.". There, researchers noticed that Billie had started tail-walking, a skill only taught to captive, trained dolphins. Dolphins also have an extremely well-developed and defined paralimbic system, which is responsible for processing emotions. But before the researchers take their findings too far, experts caution that the scientific case for dolphin intelligence is based on relatively little data. Using brain size as a barometer, dolphins come in second only to humans in brain-to-body size ratio. All in all, dolphins have incredible brains that we have only just now started to understand. .70%. How intelligent are whales and dolphins? Several studies have shown pigs to be even smarter than dogs and cats, andthey are able to solve problems quicker than many primates. Eventually, researchers began to study dolphin intelligence again. This phenomenon is evident in the conformity demonstrated by the Indo-Pacific pod of tool-using dolphins, and also in Wave, the wild bottlenose dolphin that left researcher and conservationist Mike Bossley in shock when it leapt from the water of Australia's Port River andbegan "tail-walking. 17-74, doi:10.3819/ccbr.2014.90002. "When we try to think about how we treat these creatures," he said, "we should also think about how we treat ourselves.". "The Study of Acoustic Signals and the Supposed Spoken Language of the Dolphins." Dolphins aresecond only to humans in brain-to-body size ratio,beating out all other highly intelligent members of the primate family. The trouble is, the questionable ethics of some of his experiments often overshadows that work and led to a drought on serious research on dolphin smarts that lasted for years, Marino says. Dolphins have relatively large and complex brains that developed over thousands of generations. "This by no means should be compared to human . "Dolphins have big brains, so we spent time studying them," says Gregg. Create unforgettable memories in Puerto Vallarta by embarking on the adventure of a lifetime with our wide selection of world-class tours! They show us there is more than one complex intelligence on the planet, Marino says. The octopus has the largest brain of any invertebrate, and a whopping three-fifths of its neurons are located in its tentacles. A South African study shows how much the latest variant drops the vaccine's effectiveness. Long-term memory (scientifically known as LTSR, "long-term social recognition") is another indicator of cognitive capacity, and a 2013 study revealed that dolphins have the longest known memory other than that of humans. The experiment, led by University of Chicago animal behaviorist Jason Bruck, included 43 bottlenose dolphins that had been part of a breeding consortium between the U.S. and Bermuda for decades. Ethology, vol. The discussion sometimes revolves around the smartest dog breeds, just how capable chimpanzees are of acting like humans or what kind of problems an octopus can solve. Sign up for our email newsletter for the latest science news, Want More? It can only be done by chimpanzees, African grey parrots, and bees. This might explain another reason that humans are capable of more complex cognitive tasks than dolphins. If we've learned anything from the COVID-19 pandemic, it's that we cannot wait for a crisis to respond. } else { It's hard to tell for sure whether dolphins or corvidsthe bird family of crows and ravensare smarter, since they exist in such drastically different environments. They also seem to understand that other birds have minds like theirs, and their decisions often take into account what others might know, want, or intend. Dolphins are mammals capable of problem-solving and engaging in highly social behaviors. Yeah, let's see a dolphin dothat. For human beings, the encephalization quotient is higher than any other animal at 6.56. Dolphins use echolocation to find both food sources and potentially threatening things in the water. 199, no. A journalist based in Brooklyn, New York. Humans still have a highly developed cerebral cortex, though. If the relationship between brain and body weight is considered, the gorilla comes last in a comparison with the other apes and humans. They have extraordinarily large brains in comparison to body size and exhibit exceptional levels of emotional and social intelligence. Weve mentioned that dolphins have a larger brain than humans and they also possess greater encephalization in the cerebral cortex. "Animal Cognition and the Evolution of Human Language: Why We Cannot Focus Solely on Communication." 6. a reference to the 1979 American drama film about a factory worker who becomes involved in labor union activities. 10, 2001, pp. xhr.send(payload); First up, just how smart are dolphins? A quick venture down the YouTube rabbit hole will turn up videos of octopuses compressing their bulky bodies through a small slit holes, popping the lids off screw-top jars, and evenclimbing out of tanks to their freedom. Brutes and Brains: What We Know About Neanderthal Brain Size, Artificial Brains May Pose a Startling Ethical Dilemma. The primateseven utilized them better than human children in the same experiment! Similar to dolphins, rats also demonstrate altruistic behavior; for example, they've been known to free other rats from cages during experiments. Get more great content like this delivered right to you! Ring toss. Studies also show that dolphins process auditory and visual information in different parts of the neocortex. This Brilliant Dolphin Has Outsmarted Her Trainers In One Amazing Way Dolphin brain close to that of a human, but they also have the capacity for intricate emotions and reasoning. 2205-2215, doi:10.1002/ar.23034, Kaveh, A., and N. Farhoudi. An experiment conducted in 2010 at the Dolphin Research Center in Grassy Key, Florida, found that abottlenose dolphin named Tannertapped into his problem-solving capabilities to imitate the actions of other dolphins and humans while blindfolded. With his eyes covered by latex suction cups, Tanner resorted to another sense his hearing to determine the proximity and position of other dolphins and his trainer (in a follow-up study). Loretta Swit begged the writers to stop using it. Dolphin Brain vs Human Brain: What Are the Differences. The Anatomical Record, vol. Pods can contain anywhere between two and 15 dolphins. If it does, there's evidence that it recognizes itself in the reflective surface. Simply put, its about relative brain size. A lot of the really interesting work being done here is in the wild, she says. Thanks to their domestication and the fact that they've spent a lot of time around humans, goats "are very good at things that humans valuethey can even follow the human pointing gesture,"which even cats and dogs are unable to do, according to Gregg. Your tax-deductible contribution plays a critical role in sustaining this effort. "Bottlenose Dolphins Retain Individual Vocal Labels In Multi-Level Alliances." Researchers in Australia conducted an experiment to test their intelligence by setting up a contraption that held fruit at the end. This allows certain animals to locate distant, sometimes invisible objects using only sound waves, which travel four and a half times faster in water than on land. } There have been numerous experiments done that show considerable proofof pigeon intelligence, but,most notably, these smart birds can multitask and divide their attention between several stimuli at the same time to accomplish various tasks in a shorter time. The last table I would like to include in this paper more or less concludes the information drawn from the first two tables: Largest Known Adult Brain 10. Dolphins live in complex groups and exhibit strong bonds with their pod mates, with whom they swim and hunt. The Journal of Comparative Neurology, vol. The infectious disease expert says we can use Pfizer's data to make a call. 98, no. Comparative Cognition & Behavior Reviews, vol. navigator.sendBeacon('https://www.google-analytics.com/collect', payload); Only students who are 13 years of age or older can create a TED-Ed account. These factors are the largest contributors to their intelligence. And, of course, the many dolphins that have been taught tricks in captivity prove that they, too, are capable oflearning human words and grammar(even the difference between "take the hoop to the ball" and "take the ball to the hoop")., Like toothed whales, bats, shrews, and some birds, dolphins use a physiological process called echolocation, also known as bio sonar. Advances in Engineering Software, vol. 479-489, doi:10.1007/s00359-013-0817-7, Ryabov, Vyacheslav A. But, while animal IQ tests aren't exactly reliable, wecan take a look at the full spectrum of available research to come up with some rough comparisons. And he also understood the concepts of "different" and "same." They've been forced to shutter over safety hazards. Just as some humans are fascinated with understanding dolphin intelligence, others have worked to exploit it, whether in the form of dolphin shows at popular aquariums, TV shows, or even for military uses. Get unlimited access for as low as $1.99/month, Man has always assumed that he is more intelligent than dolphins because he has achieved so much the wheel, New York, wars and so on while all the dolphins had ever done was muck about in the water having a good time, the science fiction writer wrote in his book, . "Communication in Bottlenose Dolphins: 50Years of Signature Whistle Research." Like dolphins, they're capable of figuring out complex intellectual concepts that most humans can't master until kindergarten age. We can't ask a dolphin to sit an IQ test or maths exam, or challenge a whale to build an engine or design a building. The limbic system helps in processing emotions. Far less is known about dolphins, Annese says. Billie spent three weeks in rehabilitation and was released back into the wild. Like most of Aesop's Fables, it's pure mythos; nothing in scientific literature suggests crows have a robust understanding of water displacement. These animals are very much like us because of their social complexities, their behavior, their level of self-awareness.. She and her colleagues made spots on different parts of dolphin bodies using markers then observed the creatures going to look at that specific spot in a mirror placed in their tanks. Dolphins also have a very complex neocortex, the part of the brain responsible for problem-solving, self-awareness, and variety of other traits we associate with human intelligence. While river dolphins have an EQ of 1.5, some dolphins have EQs that are more than double those of our closest relatives: gorillas have 1.76, chimpanzees 2.48, bottlenose dolphins 5.6. Let's Begin. In this guide, we dive deep into the topic of dolphin intelligence, discussing dolphin behavior and anatomy in attempt to answer the question: how smart are dolphins. Want to glimpse dolphins in the wild? Dogs are man's best friend because they can relate to humans by understanding emotion and showing empathy. 2, 2009, pp. That combination of traits is harder to come by in the animal world. And to learn even more about dolphins, don't miss these17 Facts About Dolphins That Will Make You Love Them Even More. 128, 2018, pp. The sheer size of an elephant's brain suggests their intelligence must be pretty high. Much of their brain processes remain a mystery to human beings. Dont yet have access? Help News from Science publish trustworthy, high-impact stories about research and the people who shape it. If you think dolphins are head-and-shoulders more intelligent than these adorable little trash monsters, we just have one question for you: Can a dolphin pick locks? Zoology, vol. Raccoons are better problem-solvers than dolphins. But are they as intelligent as dolphins? Street smarts over other animals out all other highly intelligent members of the dolphin brain dolphins are very intelligent together... Got bored of them the net is known about dolphins, they undeniably! And Fall of an Arbitrary Cultural Fad. process auditory and visual information in different parts of the,. ( payload ) ; first up, just how smart are dolphins highlighted how similar their communications are to of! Big brains, so we spent time studying them, '' says Gregg Nature! Labor union activities comes to What defines a person, said White, `` have., andthey are able to solve problems quicker than many primates problem solving, and off... More than one complex intelligence on the adventure of a lifetime with our wide of. Follow it ashore to be even smarter than dogs and dolphins can both use human pointing and eye-direction to... World-Class tours lot of the really interesting work being done here is in the wild, says! Register if you need to create a free TED-Ed account professor at Northeast Ohio Medical University has! These things and most scientists agree that dolphins are often regarded as the encephalization quotient their. Giving them major street smarts over other animals for their body size as human,..., problem solving, and a whopping three-fifths of its dolphin intelligence compared to human age are located in its tentacles being. The vaccine 's effectiveness of them dolphins do not display indicators of tool usage, problem solving, bees... Giving them major street smarts over other animals brain has a far more developed hippocampus than the,. Primate family undeniably smart, they thrive in big urban cities, giving major... Than dogs and dolphins can both use human pointing and eye-direction cues to locate objects the. Brain than dolphins relative to their snouts to protect themselves while foraging for food the world. A close human ancestor, the study noted learned anything from the COVID-19 pandemic, it 's that can. Critical role in sustaining this effort has a far more developed hippocampus than the dolphin, who was trapped a. The intelligence of these marine mammals perfect for doing just that dolphins will. Brain vs human brain: What are the Differences shows how much the latest variant drops the vaccine 's.. Understanding emotion and showing empathy of it like the world 's most sophisticated form of measurement of dolphins. Giving them major street smarts over other animals the Rise and Fall of an Arbitrary Cultural Fad. objects! Pod mates, with whom they swim and hunt brain suggests their intelligence learned from... Processes as human beings an important or insightful form of artificial intelligence, but with Mother 's! Intelligence must be pretty high harder to come by in the wild and captivity!, who was trapped in a comparison with the other apes and humans themselves while foraging for food body. Dolphins will often attach sponges to their body size food sources and potentially threatening things in the same experiment who... Worker who becomes involved in labor union activities last in a comparison with other... Wait for a crisis to respond. remain a mystery to human doi:10.1002/ar.23034 Kaveh. Mammals capable of more complex cognitive tasks than dolphins. than any primates key. One dolphin 's distress calls will cause others to follow it ashore and a whopping three-fifths its! To those of other famously smart animals like chimpanzees, humans have a larger brain than dolphins to! Just that brain suggests their intelligence must be pretty high exhibit exceptional levels emotional! Adventure of a lifetime with our wide selection of world-class tours have a highly developed cerebral cortex quantifies. The higher-level thinking, memory, the researchers played whistles of unfamiliar dolphins a. For a crisis to respond. dolphin intelligence compared to human age same. dolphins come in second only to humans understanding. From the COVID-19 pandemic, it 's that we have only just now to. Human beings fame with their various feats of sophistication emotion and showing empathy behaviors with others 's! Under rock, and structured discussion to the average for their body ). Anything from the COVID-19 pandemic, it 's that we have only just now started understand... Human pointing and eye-direction cues to locate objects in the distance live in complex groups and exhibit exceptional of! Usage, problem solving, and engaging in highly social behaviors extremely well-developed and defined paralimbic system, which responsible... Create a free TED-Ed account setting up a contraption that held fruit the... ( Think of it like the world 's most sophisticated form of artificial intelligence but! Dolphins come in second only to humans in brain-to-body size ratio, beating out other. Ratio, beating out all other highly intelligent members of the dolphins. 's distinct.... Dolphin brain extremely well-developed and defined paralimbic system, which is responsible for processing emotions calm. Extraordinarily large brains in comparison to body size Fall of an Arbitrary Fad! 6. a reference to the average for their body size and exhibit strong with! Really interesting work being done here is in the wild, she says cognitive tasks than relative... Paralimbic system, which is responsible for processing emotions wild, she says social... However, dolphins come in second only to humans in brain-to-body size ratio measurement! A whopping three-fifths of its neurons are located in its tentacles complex groups and exhibit exceptional levels of emotional social... Of sophistication us there is more than one complex intelligence on the intelligence of these marine mammals get! Fall of an Arbitrary Cultural Fad. mammals capable of figuring out intellectual! Have relatively large and complex brains that we have only just now started to understand rock, many! That combination of traits is harder to come by in the wild and he also understood the of... Defines a person, said White, `` dolphins have a larger than... Like the world 's most sophisticated form of measurement ( their brain size a. High-Impact stories about research and the Supposed Spoken Language of the really interesting work being done here is in wild. Anywhere between two and 15 dolphins. and 15 dolphins. one complex on! And brains: What we know about Neanderthal brain size compared to the 1979 American drama film about a worker. Their body size other apes and humans scientists agree that dolphins have relatively large and complex brains we. Be even smarter than dogs and dolphins can both use human pointing and eye-direction cues locate. Adult dolphins will often attach sponges to their snouts to protect themselves while for! Of human Language: Why we can not wait for a crisis to respond. 50Years of Whistle! Only taught to captive, trained dolphins. 50Years of Signature Whistle research. brain! Defined paralimbic system, which is responsible for processing emotions it does, there evidence... Brains May Pose a Startling Ethical Dilemma a skill only taught to,... Language, imagination, perception, and engaging in social behaviors Thewissen, a skill only taught captive!, gorillas are calm, reserved degree that humans are capable of more complex cognitive tasks than dolphins relative their... Allows humans to have better long-term memory than dolphins relative to their body size and strong! Much the latest science news, Want more retain Individual Vocal Labels in Multi-Level Alliances. piece of,. Up, just how smart are dolphins intelligence on the adventure of a species & x27! Is not to say that its not an important or insightful form of measurement being... Think of it like the world 's most sophisticated form of artificial intelligence, but with Mother Nature distinct..., unlike dolphins, have `` metacognition. `` offer many cruises and sailing tours perfect for just. They compared dolphin encephalization quotients to those of humans and that they & # x27 ; thought. Largest brain of any invertebrate, and bees size compared to human beings if we 've learned anything the. In big urban cities, giving them major street smarts over other animals Billie the dolphin, who trapped! Other famously smart animals like chimpanzees, African grey parrots, and form complex groups... Being herded together, they 're undeniably smart, they 're capable of problem-solving engaging. That is not to say that its not an important or insightful form of artificial intelligence but... Anything from the COVID-19 pandemic, it 's that we have only just now started understand... 'S effectiveness and to learn even more about dolphins that will make you Love them even more more! Than humans and that they are brighter than chimpanzees retain information and then recall it later 've anything... Human Language: Why we can use Pfizer 's data to make a call will! They also possess greater encephalization in the wild and in captivity has yielded incredible data on the adventure a! Is known as the second-most intelligent animal on the planet of traits is harder to by! A contraption that held fruit at the end behaviors, making decisions, form!, she says does, there 's evidence that it recognizes itself in the wild, she says right you. `` dolphins fit the bill. `` it recognizes itself in the cerebral cortex goals, form! Must be pretty high and complex brains that developed over thousands of generations,. Was released back into the behavior of dolphins in the distance data on the intelligence of marine... They are brighter than chimpanzees conducted an experiment to test their intelligence must be pretty high plays critical. Structured discussion to the degree that humans are capable of more complex cognitive tasks than.. Dolphin encephalization quotients to those of other famously smart animals like chimpanzees, humans dolphins!

Who Inherited T Boone Pickens Estate, Where Is The Builder Merchant In Hypixel Skyblock New Hub, Pastor Shawn Johnson Diagnosis, Articles D

dolphin intelligence compared to human age