The Behavior of Dolphins


The Brain:

Dolphins have very large and folded brains, which (besides the large body mass) suggest exceptional intellectual capacity. According to brain researcher Pilleri, it can be called into question whether or not the brains of Sapiens(human) are the highest in the rankings. Dolphins are easily trained and they learn exceptionally fast.

However, recent research has shown that the amount of braincells found in dolphins is comparatively small. Scientists are coming to the conclusion that the dolphin is probably less intelligent than once thought. Humans have many more braincells and can therefore learn and think a lot quicker.

Old Stories:

There are lots of old stories about dolphins that took place thousands of years ago. Telemachus, the son of navigator Odysseus, fell into the sea and he nearly drowned. Fortunately, a dolphin saved him and brought him ashore. As a result of this, he thanked the dolphin by engraving a dolphin onto his shield. There is another story, told by the Roman scientist Plinius, about a friendship between a little boy and a dolphin. The dolphin was so attracted to the little boy that the dolphin played with him and brought him to school every day.

These stories are very unrealistic for these times, and are completely discarded by modern scientists.

The Big Question:

Dolphins are highly intelligent mammals. There are a lot of stories claiming that they have talents that are beyond Man’s understanding and which are unresearchable.

There are trips which take incurable patients for a swim with dolphins, and these trips are believed to be able to cure their illnesses because dolphins are thought to bring forth ultrasonic sounds which have a healing function.

The myth about the healing therapy of dolphins can be explained as followed. Humans generally have a very strong willpower and this willpower is very important if one wants to achieve something. Let’s say someone who has got cancer went to swim with a dolphin and he or she is convinced that this dolphin will cure his illness. Fueled by his own belief, his willpower to get well has increased and this will increase the chance that he will actually recover.

Many people also suggested that dolphins have a special liking for humans, meaning also that dolphins can get attached to a particular person. There was a dolphin who at first contact with a man constantly swam to him and implied that it wanted to be stroked. Once the man stroked it, he saw tears in its eyes, like it was crying with pleasure.

Just like humans can save other people from drowning, dolphins can do the same as well. There are also recent stories of people-saving dolphins. Is this because they want to be helpful, or is it instinct? People have also seen that they bring mattresses and other dolphins to shore. This innate behaviour makes it understandable that dolphins occasionally save people.

There has been a lot of research on the behaviour of dolphins. It seems that they have a lot in common with humans. If a dolphin is given a mirror to see itself, it pays attention to its looks. If for example, a black circle is stuck to its side, it will look at it with disgust.

So the big question now is: Why do dolphins do things that humans usually do? Are they really that intelligent?

Dolphins are surely intelligent creatures. But it is doubtful whether their intellectual capabilites exceed that of humans. Some say it is and others deny it. We have not come to a conclusion at this point of time. However, most people agree that the intelligence of a dolphin is comparable to that of a monkey.


Dolphins have a language to communicate with one another. It differs a lot from that of humans.

For an example, we use facial expressions as a way of communicating. When we are angry, this can be read from our facial or body expressions like clenching fists or frowning. When we are happy we smile, and sometimes we will raise our hands to show extreme happiness.

Dolphins cannot do all these. They can’t make facial expressions and they can’t do many actions with its body. The spoken language is another thing which dolphins can’t use. They don’t have vocal chords and the only body part that can create any sound is the blowhole. This makes it very difficult to communicate with one another. Researchers have tried deciphering the sounds of dolphins but nothing really significant has come out of their research.

Another example of a shaky communication is between the dog and the cat. They have the same ways of communicating but not the same language. When for example the dog wags its tail, it means that it is happy. When the cat uses this same signal, it is an indication of hostility. This is the reason that the communication between a dog and a cat falters.

There are two causes for bad communication. Firstly it is the different ways of communicating and secondly the different language. For the communication between people and dolphins, both factors clash. In the first case it is the different communicational methods which cause the clash. Secondly, it is the constant facial expression of dolphins and the incomprehensible sounds that a dolphin produces, of which humans can decipher almost nothing.

The only communication that exists is the movements that we make. This is very helpful in dolphinariums. When an attender turns, the dolphin has to follow. When the attender claps his hands, the dolphin will perform another trick. This is the only effective way of communication so far.

Navigation and Echolocation:


A dolphin moves in a very large area. Navigation is of great importance, because a dolphin would easily lose track of where it is without a good navigational system.

It happens once in a while – not without reason – that a dolphin or a group of dolphins loses its way. Sometimes this is not such a big problem if it is a couple of kilometers away from where he should be. But, if the dolphin is washed ashore in a shallow area, it will be at its end. Washed ashore, it cannot make its own way back to the sea. It is critical for the dolphin to keep its body wet and if it does not, it will die of dehydration. Stranded dolphins can only be saved if humans are able to get there quickly enough to help them back into the water. Hence, these kind of navigational mistakes can thus be fatal.


A dolphin does not only use its sonar sounds for navigation, but also to locate certain objects (or other things, like fish). This is of great importance for the dolphin. Since the dolphin cannot look straight ahead because its eyes are on the side of the head, it sends out a sonar sound and the sound waves will be reflected if they hit anything. The way that the sound vibrations come back to the dolphin will tell the dolphin where (in this case) the fish is located.

This way of locating things is called echolocation. The echo (the reflected sound) makes sure the dolphin has an exact location of the object. Because of the nearly constant sonar, the dolphin lives in a complete ‘sound-world’, and this is especially the case in the dark.

How does Echolocation Work?

Dolphins produce separate, short click-sounds, with a maximum length of 0.2 milliseconds (this is 0.0002 seconds) each. One second fits 5000 of these sounds. These sounds have a frequency of 150000 Hertz (vibrations per second).

Research has been done on this subject with the dolphins. Firstly, one of the dolphins was ‘blindfolded’. Whenever it got near a place where there was food, it would make these sounds at a higher rate. These echosounds are sent out with direction and in this way it can distinguish a piece of plastic (with the same size as the feed) from a piece of fish. In dolphinariums they swim in complete darkness – without losing speed – without hitting anything.

There is a difference between dolphins and other animals in how they use echolocation. The other most important animal with this ability is the bat. The bat has two very large earshells, while the dolphin only has two holes.


General Information

Dolphins are generally playful animals. It is a fact that they spend most of their time playing. But how far do dolphins go with their playfulness? To answer this question, I’ll illustrate this with a few examples:

There are stories about dolphins saving drowning people from the sea. These people had nearly drowned, but dolphins brought them to shore just in time. These stories are so beautiful that they resemble fairytales. Extensive research however has shown that these are only pure coincidences. The reason is mainly because of the dolphin’s playful nature. More than once researchers have observed dolphins bringing a lot of things to shore, like rubbish and mattresses. This means that it is possible that a dolphin will bring a human being to shore instead of an object.

Dolphins are often observed swimming along with boats. This is not because they like the people on board the ship especially, but just because they enjoy the current of the boat. This has everything to do with the playfulness of the dolphin.

Dolphins that stay in a dolphinarium usually enjoy their stay. There are dolphins totally crazy about balls, hoolahoops, and the trainers themselves are also treated as a toy. Of all the toys that exist, humans are perhaps the most entertaining to the dolphins.

It is a pity that the attraction of humans on dolphins is nowhere as beautiful and as great as often thought. Humans are not a natural love for dolphins. Dolphins receive fish, attention, and people play all sorts of games with the dolphins. This is a bit of a pity, but dolphins are ‘just’ animals, as in the case of monkeys. The so called smiling is also not what it seems. Even if a dolphin is angry, it will keep on smiling. It is because of the way its face is structured, but we as humans often think that the animal is happy. That is our way of communicating and often, we tend to misunderstand the feelings of dolphins. (Go to the ‘Social Intercourse and Communication’ section of this website for more information)

In the next subchapter you can read more about the different games dolphins play. Multimedia fragments are also available.

Back to OutlineExamples of Games

This section is a renumeration of different games, which dolphins participate in daily, either in dolphinariums or in the wild. Sometimes multimedia fragments are available with the game in question.

  • Toys made by humans: In dolphinariums, the dolphins have toys like balls, hoolahoops etc. These toys are not naturally available of course, but they are appreciated by the dolphins. Some dolphins are so crazy about these toys, take for example a ball, that the trainers won’t get the ball back once it has been given to the dolphin. The interest in toys differs in individual dolphins. Some want a ball to play with, while others prefer a hoolahoop. The interest in playing also differs in individual dolphins.
  • Air rings: Air rings are special toys made by the dolphins. The dolphins dive down deep, and then they blow a beautiful round air ring through the blowhole. It looks like a hoolahoop of air. They would use it to swim through, or try to keep the ring down, or they would just look at it for fun.
  • Humans: As this was said earlier, humans are a popular toy for dolphins. In a dolphinarium, this trait is easily spotted, and also on the beaches in Australia and Greece, you can see that humans are particularly interesting for dolphins. Dolphins like people because they can play with them (for example swimming, think of dolphinariums where this happens), and because they feed the dolphins fish.
  • Swimming: Dolphins like swimming a lot. They can perform the craziest tricks, like jumping high in the sky, and then entering the water like a corkscrew. They like swimming along with sailing boats. A dolphin does not only like swimming, it is also very capable of doing it. In the water, dolphins (the tumbler) can reach a speed of around 40 kilometres an hour. This is comparable to the speed of a motorcycle.
  • Each other: If they choose to do something different, they still have each other. They can chat to each other, swim together, blow air rings together. However they seem to find all the abovementioned activities more enjoyable than the activities they do with their peers.


Social Intercourse With One Another

Dolphins live in groups. Social intercourse with one another is similar to that of humans. They are attached to each other and live together as a family.

Sociability for dolphins is not the main reason to live in a big group. It is also a certain form of security which they do not have as induviduals but do have as a group.

  • One of the security reasons is the younger generation. Until they are about two years old they are protected by their mother. If the mother needs to search for food, one of the aunts takes over the nursing. They do this by swimming in between the mother and the offspring. When the mother returns, she takes back her offspring in the same way. Good communication is essential for young dolphins, and it is for their own security.
  • The search for food also takes place in a group. They will surround a large shoal of fish and feed one by one. They do this by swimming ‘straight up’ in a circle around the fish. If the dolphins are selfish or if they do not cooperate, then the feeding will not be successful.
  • Another advantage of working in a group is that the dolphins will be able to defend themselves much better. Because of their excellent swimming and the high speed they go at (40 kilometers per hour), they can even challenge a whale. They have a very hard nose to attack and to batter the enemy. As an extra weapon they have sharp teeth, and a strong tail with which they can hit hard. A shark probably could not win against a couple of dolphins. Another question immediately comes to mind – will the dolphins use these weapons against one another? The answer is yes, because like us they have rows once in a while. One of the causes can be a female dolphin, or simply just irritation. Most dolphins have a somewhat battered skin (well seen in closeup), which is mostly caused by another dolphin.

Living in groups provides warmth and comfort to the dolphins. Dolphins (again like people), enjoy each other’s company. Playing is part of their daily life. They prefer playing together, but they know quite a few individual games. One of these games is swimming. They like jumping high up out of the water and they also do the craziest things under water. They make air rings out of air with their blowholes, which they then try to keep these air rings under water. (More information about this is found in the next section: ‘Playfulness’) You can also view a few videos in this section.

Another interesting fact of the dolphins is concerned with sleeping. Dolphins can never fall asleep completely, as they would drown if they fall into a deep slumber. How do dolphins then get their rest? They only rest half their body at a time. Dolphins have the option of putting one half of the brain to rest, while they swim around and breathe by using the other half. You can tell very easily when they sleep because one eye is clearly closed. If they occasionally put either half of the brain to rest, they rest completely.

One would not guess it, but dolphins like ‘chatting’ to one another. People working with dolphins sometimes see two dolphins having a big discussion.

Back to OutlineCommunication With One Another

Dolphins can communicate with one another by using very high (ultrasonic) sounds. The hearing of dolphins is much more sensitive than that of humans. It can detect sounds up to the frequency of 200000 Hertz (vibrations per second). This is very high in comparison to our hearing. (up to the frequency of 20000 Hertz) Dolphins can thus produce sounds that are way too high for us to hear.

This high frequency also has advantages for orientation. The ultrasonic sounds are echoed and that is how they can locate objects (or prey) in the dark. Dolphins can be disturbed by other (high-frequency) sounds in the sea and sometimes they lose their orientation completely because of this. The consequence is often read in the papers or seen on television, the dolphins can accidentally be washed ashore. (More information in the ‘Navigation and Echolocation’ section)

Back to OutlineSocial Intercourse and Communication – With Humans

Back to OutlineSocial Intercourse With Humans

As it has been said already, dolphins like to play. They search for a good friend to play with. You often see that dolphins try to swim along with boats, or that they go to shore where there are people. People are also sometimes saved by dolphins, when they happen to drown. Why is it then, that dolphins seemingly enjoy being with humans?

For many people including scientists (biologists), the exact reason is not known. Most people say that this is just playfulness. There have been observations of dolphins bringing mattresses and pieces of wood ashore. This makes the argument of “dolphins save drowning people” invalid. Furthermore it has been proved that dolphins like to play, and people are treated as nice toys by dolphins. This is probably also the reason for the fact that dolphins enjoy social intercourse with people. (Read the ‘Intelligence and Language’ section)

Dolphins are eager to learn. Just like dogs, dolphins are easily trained for appearances. This is usually not against their own will. Some dolphins, when given a ball, keep it because they like it so much. Humans are not only nice toys, but they also make a lot of things which increases the pleasure for the dolphins. We as humans also make use of this by putting them in dolphinariums where they do shows, because we, on the other hand, also see dolphins as toys.

The social intercourse between dolphins and human beings is reasonably good and flexible, but we, like humans and dolphins among themselves, have rows once in a while. These are often flaws in the communication, about which I’ll tell you more in the next section.

Back to OutlineCommunication With Humans

Communication between dolphins and people is dificult. We have a competely different language and dolphins do not have vocal chords. Dolphins communicate using extremely high pitch sounds via the blowhole, which we are unable to hear. Humans have developed appliances – which dolphins incidentally aren’t able to do – that produce and pick up these sounds. There are a lot of biologists deciphering the language, but this has only succeeded to a small extent. The dolphins in a dolphinarium know various signs and these signs are the main means of communication. The movements of a dolphin give humans some clue as to what they mean. This is the case with attendants or other people who have a lot to do with dolphins.

There is another problem with communication. Dolphins do not have facial expressions. They always have the same pleasant smiling snout, even when they are angry. Futhermore, they don’t show a lot when they are angry. If you want to swim with dolphins without creating any problem, you should attend a course on safety. There have been cases where swimmers have been attacked by dolphins because of miscommunication.


One response to “The Behavior of Dolphins

  1. Pingback: Dolphin Times: Issue 2 | Stop Cetacean Captivity

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