Social media loves to villainize dolphins. Here's why it's wrong.

These marine mammals have a bad reputation online, but the truth behind their behavior might surprise you.

Dolphins swimming in blue water.
Male bottlenose dolphins (pictured, animals in French Polynesia's Rangiroa Channel) aggressively guard females.
Photograph By Greg Lecoeur, Nat Geo Image Collection
ByLiz Langley
August 27, 2024

To many people, bottlenose dolphins represent playfulness, particularly due to their friendly depictions on screen and in aquariums.           

So, when did they become “evil?” Take a look on TikTok and YouTube and you’d think all dolphins were depraved, with a little-known "dark side." Recent reports of an Indo-Pacific bottlenose dolphin biting people at beaches in Japan may only worsen these stereotypes.

Yet demonizing animals can have consequences. The movie Jaws, for example, caused people to fear great white sharks, leading to a boom in the trophy hunting of the apex species.         

So we asked scientists who study the slandered cetaceans to help us separate truth from hyperbole. (See 10 intimate photos of dolphins.)

The problem arises when people observe bottlenose dolphins in real life, and think, “’Oh, dolphins aren't as nice as I remember from watching Flipper,’” says Andrew Read, director of the Duke University Marine Lab in North Carolina. In truth, dolphins often display aggression, particularly males when interacting with females.

For social media creators, it’s likely appealing “to turn the Flipper era on its head and overdo the ‘bad‘ behavior of dolphins, which is really just evolutionary behavior,” adds Amber Lea Kincaid, an animal behaviorist and founder of the Florida-based nonprofit Wildlife Research Alliance.

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“They do what makes the most sense in propagating a species.”

Males behaving badly? Not so fast

Bottlenose dolphins are intelligent, social creatures that live in a political society, forming alliances to get the things they need. For males, that’s access to females.

In some populations, pairs or groups of males control females in a way that seems violent, leading some people to refer to these actions in human terms, such as kidnapping.

Scientists call this “social-sexual behavior,” says Denise Herzing, behavioral biologist at Florida Atlantic University and founder of the Wild Dolphin Project, an ongoing 40-year study of a Atlantic spotted dolphin pod in the Bahamas.

In the Bahamas population, the males “monopolize” females in estrus, hovering nearby and fending off other males.

But “it’s not always a forced situation,” Herzing says. The female may pick and choose between the males,” and over the years bear the offspring of many different males. Females also sometimes slap unwanted males with their tails to keep them at bay.

“We call their societies fission-fusion,” she says. “They're getting together, they're breaking up. They're pretty flexible.” (See how dolphins use tools, teamwork, and trickery to get their dinner.)

Male groups also protect moms with calves from sharks and other dangers.

A well-studied population of Indo-Pacific dolphins of Shark Bay, Australia, is thought to have one of the most complex social orders beyond humans, with multi-tiered groups allying to form federations to secure females.

The “herding“ of females in this group can last can last for weeks. A 2022 study of males in Shark Bay found that socially bonded males sired more calves than those without social bonds.

Shocking to us, but normal to them

In some bottlenose dolphin populations, males regularly commit infanticide.

“If a male dolphin knows that a female dolphin is accompanied by a calf that he didn't sire, that male may try and kill that calf,” making the female more receptive to mating more quickly and giving him the opportunity to continue his genes, Read says.

When a male African lion takes over a pride, “the first thing they do is kill all the cubs because they're not their cubs. It makes sense from an evolutionary perspective,” he says.

"Within the human construct of social behavior and morality, we’d think that’s a horrible thing,” but it’s common in the animal kingdom, he says.

"Bottlenose, as a species, do have a kind of a bullying temperament,” says Herzing. Lone bottlenose dolphins have been known to kill harbor porpoises for reasons not yet fully understood, she says.

Moral codes are a human construct

Far more perplexing is necrocoitus, or sexual interaction with a dead member of the same species. Scientists have documented four such incidents among male bottlenose dolphins around Sarasota Bay, Florida.

“This is such an extremely rare observation,” says Kincaid, who reported the incidents in a 2022 study while working with Mote Marine Laboratory and Aquarium. The study authors worked with Brookfield Zoo in Chicago's Sarasota Dolphin Research Program, the longest-running dolphin study in the world.

Researchers observing the necrocoitus knew the four bonded male pairs had no connection to each other or the dead females with whom they copulated. (Read: "Wild dolphins have bold and shy personalities—just like us.")

The team ruled out the main explanations for necrocoitus, including pheromones in the water or the males thinking the females were still alive—leaving the phenomenon a mystery.

“They don’t have a human moral code,” Kincaid says, and even if they did, it’s hard to know their intentions.

Aquatic grizzlies

Repeated exposure to people, either from swimmers or boat activity, can easily stress a dolphin, Read says. Some experts suspect that may be behind the Japanese animal's aggression, according to Kyodo News.

And though most dolphins don’t injure people, it’s important to know the warning signs of dolphin aggression, such as holding their mouths open underwater; blowing bubbles; vocalizing loudly; and bluff charging, like bears and gorillas do.   

“If it was a bison or a grizzly bear,” Read says, “nobody would be surprised” by their aggression. But bottlenose dolphins are “just like big aquatic bison or big aquatic grizzly bears.” 

“It’s a large, wild, powerful animal that you can’t predict.”

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