Interesting Facts

18 Interesting facts about dolphins

interesting facts about dolphins
Written by Alizay Khan

From making tools and helping humans to always sleep with one eye open. Here are 18 interesting facts about dolphins 

interesting facts about dolphins

The biggest dolphins are whales

That may not sound right, but it’s accurate. Killer whales are the largest member of the Oceanic Dolphin family and it’s not even close. Also known as ORCAs males can measure 26 feet long. That’s eight meters and weigh more than 13,000 pounds or six metric tons, interesting facts about dolphins.

They’re also one of the fastest marine mammals. With top speeds clocked at 35 miles per hour or 56 kilometres per hour, you might know the dolphins have larger brains than humans but this species has a brain that weighs upwards of 15 pounds or seven kilograms. After the sperm whale, this based has the largest brain’ in the entire animal kingdom. 

Diminutive dolphins

So we go from the largest to the smallest. Hector’s dolphin is the smallest dolphin species that are found globally and about four and a half feet long. One point four meters and weighing 130 pounds or 60 kilograms. It’s one of the smallest cetaceans overall and is endemic to New Zealand as subspecies known as Malee Dolphin has the same basic proportions and a differentiated by the distinctive markings and shorter snouts.

Another distinction is that the Malee dolphin is critically endangered. With less than 65 individuals estimated to exist. Factors including commercial fishing and habitat destruction have contributed to that decline, interesting facts about dolphins. 

Dolphins don’t chew

Maybe they wanted their food. But they can’t. While dolphins have teeth, they’re only used for grasping and holding onto prey. Some researchers say that behaviour is due to the animal’s need to eat fish before they can swim away. It can more easily do that by gulping down its food instead of taking the time to chew it. This precious extra seconds model how their meal to escape. 

Hippos are their relatives

Cetaceans and hippopotamuses share a common semi-aquatic ancestor that dates back around 60 million years. That common ancestor branched off some 40 million years ago and spawned the ancestors of dolphins and hippos. Today, the hippos are the closest living relatives of cetaceans number. 

interesting facts about dolphins

They’re voluntary Breathers

Unlike land-based animals like humans, dolphins have to think about breathing. So far as researchers can tell, it doesn’t appear to be an autonomous function. They sleep at the water’s surface with their blowhole exposed. As a result, the animals are thought to spend most of their lives holding their breaths while underwater. 

Do Dolphins dream

There’s still some debate about this one due to the way they sleep. Dolphins experience little in the way of rapid eye movement REM the phase in which dreams occur. Interesting facts about dolphins is that it’s theorized that dolphin dreams might resemble a type of augmented reality as opposed to human dreams, which are more immersive.

Some researchers think dolphin dreams would be exceptionally lucid since the real world is never completely shut out. What do you think dolphins would dream about? 

interesting facts about dolphins

In old times

The unique relationship between humans and dolphins has been documented since antiquity. The animals were revered by the ancient Greeks, who regarded them as sacred animals. In Greek myths, they were viewed as helpers of humankind, and spotting them in the open seas was considered a good omen.

Killing one was viewed as an act of sacrilege and was punished by death. The ancient Romans also held dolphins in high esteem like the Greeks. They felt that the animals loved music. Unlike the Greeks, the Romans sometimes depicted the cetaceans as scary and dangerous beasts interesting facts about dolphins.

Flippers are interesting facts about dolphins

Some species like spinner dolphins display some real acrobatic ability by leaping some 20 feet or six metres into the air while leaping, it can spin more than five times before landing back in the water.

Bottle nose dolphins are also known to exhibit similar behaviours. Experts theorized that the animals will flip or breach out of the water for several reasons, interesting facts about dolphins. It could be tickling clean parasites off their bodies or to get a better view of things. Or maybe they just do it for the fun of it. 

Their brains are bigger

Did you know that dolphins have bigger brains than humans? Their brain weighs about three and a half pounds, 1.6 kilograms, while ours weighs about two point nine pounds, one point three kilograms. That doesn’t necessarily make them smarter than humans alone. Some might argue that point but some dolphin species do possess more than twice the neurons than we do in the neocortex, interesting facts about dolphins.

That’s the largest and most recently evolved region of the brain. Estimates indicate the dolphins have more than 37 billion neurons. While humans have about 16 billion, their brain power is thought to account for qualities including empathy and building complex social relationships.

interesting facts about dolphins

Naming themselves

Well, there’s still a debate as to whether dolphins have an actual language. They have names for one another, interesting facts about dolphins. Within pods, the animals possess a signature whistle, which functions as a name. The vocalization is unique to a specific individual and serves to identify them.

Since dolphins are highly social, maybe it’s unsurprising that they’ve evolved a way to communicate and coordinate with each other in such a manner. That opens the question as to whether they do have a language that we are yet to translate. Do you think they speak in a type of Delphine’s?


Working relationships between humans and dolphins have been recorded since the time of ancient Rome. They were known to give rides to the ancient Greeks. And even today, they’re known to help humans catch fish. In Brazil, Dolphins will drive schools of fish to fishermen waiting on the shore. They’ll even give the signal for when they should cast their nets.

In return, the dolphins are paid with whatever fish managed to escape the nets. Dolphins have also been lifesavers for humans. Cases are documented where the cetaceans have protected humans from sharks or even toads stranded swimmers to shore. 

Superior sonar

Dolphins are renowned for their use of echolocation or sonar. But did you know it said to be superior to bats, sonar or sonar that is made for humans? They can issue clicks for sonar while simultaneously producing vocalizations for communication.

It would be like a human holding two separate conversations in two different voices at the same time but while their sonar can detect an object size and shape, it doesn’t seem to be able to detect fishing nets. As a result, millions of dolphins have drowned after becoming entangled.

interesting facts about dolphins


Maybe you’ve noticed that many dolphins have an area of their head that has a pronounced bulge that’s caused by an organ called the melon, which is possessed by old toothed whales and is filled with wax and liquid fat. It functions as a sound lens to focus and modulate the dolphins, clicks into a narrow sound beam while its precise purpose is still unknown. It plays a major role in communication and echoes location. 

Military dolphins

Given their higher cues. Maybe it’s not surprising to learn the Dolphins have been drafted for military duties. Several countries have trained them to locate underwater mines with echolocation or to locate and help rescue stranded swimmers. There have been unsubstantiated rumours that the animals have been trained for more lethal purposes. In addition to seeking mines, they may have allegedly been trained to lay them as well.

Other stories involve dolphins being trained to seek out and destroy enemy submarines in kamikaze-style attacks. The U.S. Navy Marine Mammal Program is known to train dolphins and sea lions for purposes of harbour and ship protection. The Soviet Navy had its marine mammal program, which was thought to have been closed in the early 1990s. In 2000, there were reports that dolphins trained to kill had been sold to other nations. For its part, the U.S. Navy denies that their animals have ever been trained to harm humans or to carry weapons.

Swimming with sharks

Dolphins have fewer marine predators but some smaller species can be threatened by sharks, including the great white tiger and bull sharks. Marine biologists have noted that when the cetaceans are attacked by sharks, they can quickly recover from the injury. Extreme damage is rapidly fixed, and even the deepest wounds don’t cause excessive haemorrhaging as gaping wounds are repaired.

The animal’s body structure is restored and infection is rare. For now, it’s still unknown exactly how this healing mechanism works but other methods of overcoming shark attacks include dolphins using sophisticated combat moves and teaming up to repel sharks. 

Sleepless cetaceans

Since we mentioned earlier, that dolphins cannot breathe involuntarily. That brings up an interesting question. How can they sleep without drowning? As it turns out, they do so with one eye open, literally. They can stay awake for weeks on end through a process identified as Uni-hemispheric sleep. It means that one half of their brain is resting while the other half stays active. When the right side of the brain is awake, the right eye is alert and open and vice versa.

The two hemispheres switch back and forth to ensure the brain is fully rested. It ensures that the dolphin surfaces for air and stays aware of predators overall. The process takes about two hours for each side or four hours total as an added precaution. The dolphins rarely sleep without others nearby. Research has shown that dolphins can stay awake for weeks on end. 

They can make tools

Experts say the dolphin tool use displays behaviour that is remarkably similar to humans. Researchers noted the bottlenose dolphins in Western Australia’s Shark Bay used sponges as a way of protecting their rostrum or beak or nose as they forage for food on the sandy sea bottom. It was a way to protect themselves from sharp objects like shells or rocks.

The practice is employed mostly by females who also teach the technique to the young. That technique is said to alter the Dolphins genetic structure in the wild. The practice is an example of cultural hitchhiking, a phenomenon most often identified with humans. It’s theorized that a single dolphin may have discovered the technique nearly 200 years ago and the hunting tactic was passed down along succeeding generations. 

They evolved from land animals

Did you know that dolphins evolved from land-based animals? What’s more, those distant ancestors resembled wolves. They were herbivorous creatures with strong jaws, long skulls and hoof-like toes on their feet. Experts say that around 50 million years ago, those animals eventually returned to the oceans and developed evolutionary adaptations. That includes their legs evolving into flippers and their nostrils being relocated to the tops of their heads to become blowholes. Traces of those ancestors still exist in dolphins today with the remnants of finger bones in their flippers.

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Alizay Khan

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