Famous for their ability to learn and even rescue humans, the real story behind the immense intelligence of dolphins lies in their astounding wild behaviour
Whales and dolphins have fascinated human beings for millennia, with dolphins featuring in cave paintings dating back almost 3,000 years. The first descriptions of dolphins came from sailors, who spoke of enormous creatures with large eyes, long beaks and sharp teeth. Artistic depictions of them at the time looked more like sea monsters than the animals we know today. Over the years, humans soon discovered that dolphins were intelligent mammals of the sea and began to study them. As technology developed that could record their underwater calls, scientists began to realise how complex their behaviour and communication truly was. Exactly what dolphins are speaking about is still unclear, but as research progresses we are learning more and more about the most intelligent animals in the ocean.
Living under water means that dolphin communication works extremely differently from animals that live on land. Sound is the basis of almost all dolphin interactions and the exact information different noises contain is still a mystery to marine biologists. Staying in contact is crucial for dolphin survival and their social intelligence has developed over thousands of years of evolution. Each dolphin makes a unique whistle sound that acts as a name tag. Dolphins introduce themselves to others around them and recognise one another by these signature sounds. Closely bonded dolphins even mimic one another’s whistles, which is like calling out for a friend by name. The dominant form of communication in primates is through sound, but the primary sense of apes and monkeys is visual. Scientists now think that dolphin communication is more efficient than our own, because they can replicate any sound that they hear. These animals build up mental pictures of the environment using biological sonar and they might be able to project these pictures to others, like a hologram. This surpasses the amount of information humans can convey with speech and dolphin conversations could be up to 20-times more detailed than that of apes and other primates. Not all dolphin communication is based on sound, though, after arriving and before leaving a group they touch each other. Even altering their posture while swimming is a form of communication and a dolphin can invite others to play by wriggling its body.
Dolphin groups have a very fluid social structure, with smaller groups constantly combining and splitting up again. This means that they can meet hundreds of others on a daily basis. This has been likened to social networking, with dolphins maintaining lots of weak bonds with others they have met briefly in the past. The networks that build up help transfer information over long distances and work just like Facebook. News is transferred through friends of friends and means that dolphins can stay in touch.
Feelings of happiness, love and heartbreak are human concepts but these animals share our ability to feel emotion. These animals form extremely close bonds with their families and experience emotions that humans might call love. Newborn dolphins rely on their mothers and older siblings for survival and calves stay with their family for around six years. When a relative dies, dolphins experience grief and mother dolphins carry their lost calves around with them for extended periods of time. Young that have lost their mother are known to visit their mother’s favourite locations after her death. When a dolphin group spies a dolphin carcass they approach it and even take it in turns to surface for a breath of air so the corpse isn’t left unattended. Dolphins are famous for their tendency to help animals of other species. There are reports of dolphins helping exhausted seals back to shore and even leading beached whales back to the safety of deep water. In 2008, a bottlenose dolphin arrived at the scene of a stranded mother-calf pair of pygmy sperm whales on a beach in New Zealand. The dolphin, known by locals as Moko, led the pair of whales from the shallows directly into deeper water. The only explanation of this behaviour is that dolphins are capable of experiencing empathy.
How dolphins think
The emotional centre of a dolphin’s brain is more complex than in a human brain. It has a larger surface area and more folds, which indicates that their brains have evolved to process emotion. Whale and dolphin brains also contain specialised nerve cells called spindle neurons. These cells are associated with the ability to reason, experience emotions and make quick decisions. These were once thought to be possessed only by humans and were even nicknamed ‘the cells that make us human’. What’s more, dolphins have three-times as many of these cells as humans do, even when accounting for their larger brain size. Not only do dolphins and their relatives have these spindle cells, but they have also had them for twice as long as humans. Along with this amazing brainpower, dolphins have one of the longest memories of the entire animal kingdom. Even if dolphins are separated for 20 years, they are still able to remember a familiar face. This was noted in aquaria in the United States, when dolphins that had been briefly housed together at the age of only six months old were played audio of one another’s signature whistles. Upon hearing the familiar call they instantly responded, whereas an unfamiliar call is often ignored. Dolphins also have good short term memory and can remember lists of items. Some dolphins are even able to understand sentences of human speech. Dolphins in a 1993 study could remember strings of up to five words and responded to what the human was asking for.
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