When it comes to animals in pop culture, sharks are seen as evil and dolphins are seen as friendly. Visually, this is understandable. Dolphins look like they’re smiling and playing. Meanwhile, sharks hunt with rows of jagged teeth and a nose for blood. However, appearances can be deceiving, especially in nature. So as marine experts try to repair sharks’ bad reputation, they also take dolphins down a peg. They are not the cute, splashy buddies people assume. In fact, dolphins have a surprising dark side that can rival pop culture’s version of sharks.
Dolphins Use Pufferfish To Get High
Some dolphins use recreational narcotics. Researchers couldn’t believe it either until they noticed certain dolphin species carefully handling pufferfish that secrete a toxin fatal in large doses. But in small doses, it can act like a narcotic, which may be the reason why dolphins have been filmed gently nibbling and passing it around. Afterward, the mammals slowly float near the surface, likely enjoying the high.
Aggressive Mating
It’s not surprising dolphins are intelligent and social, but a lesser-known fact is that they live in a political society. So the males create alliances in order to mate. Sometimes, pairs or groups of males herd females for this purpose, which looks alarming from a human perspective. However, Denise Herzing, behavioral biologist at Florida Atlantic University and founder of the Wild Dolphin Project, calls this herding “social-sexual behavior.” However, “it’s not always a forced situation,” Herzing says. “The female may pick and choose between the males,” and slap away unwanted mates with her tail. Male groups also protect females with calves from predators.
Infanticide is Common
“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,” explains Andrew Read, director of the Duke University Marine Lab in North Carolina, to National Geographic. Eliminating the calf makes the female more likely to mate again soon, which gives the male the chance to continue his genes. “…It makes sense from an evolutionary perspective,” Read says.
Surprisingly Cases of Dolphin Necrocoitus
Here’s a lesser-known fact: Scientists have documented four surprising cases of necrocoitus, which are intimate interactions between male bottlenose dolphins and dead females in Sarasota Bay, Florida. Keep in mind, this is a very rare observation. The researchers noted the males had no connection to each other or the dead females. They ruled out plausible reasons such as pheromones in the water and the males mistaking the females for live one, so the incidents remain a mystery.
They Can Stay Awake for Weeks
Research into dolphin echolocation found they don’t need much sleep. In fact, the subjects stayed awake for 15 days in a row, only using unihemispheric sleep, which rests one half of the brain at a time. Although this sounds unbelievable, it’s crucial for survival since dolphins need to constantly stay awake to surface for air and avoid drowning, says Treehugger. Newborn dolphins don’t sleep for weeks to keep up their body temperatures, accumulate blubber, and escape predators — which may be other dolphins.
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Dangerous Predators
Dolphins are carnivorous apex predators that eat 2% to 10% of their body weight every day, according to Live Science. Their diverse diet includes fish, octopuses, jellyfish, crabs, turtles, and squid, depending on the type of dolphin and where they live. Their intelligence makes them keen hunters. For example, bottlenose dolphins use the mud-ring feed strategy where they trap schools of fish in a mud tornado and eat them as they escape.
Dolphins Use Tools
Another example of their intelligence is their use of tools. Dolphins press their noses against a sea sponge while plowing across the seafloor. Researchers believe the sponge protects their snouts while scaring small fish out of hiding. Some dolphins hunt with the “shelling” strategy; it involves chasing fish into an empty conch shell before carrying it to the surface and shaking it until the fish falls into their mouths.
They Aren’t Smiling
Despite what it appears, dolphins aren’t smiling. That’s just the shape of their jaws. So while they may look happy to us, they may be trying to exhibit completely different emotions. Signs of aggression include holding their mouths open underwater, blowing bubbles, loud vocalization, and feigned charging like a bear would. “If it was a bison or a grizzly bear,” Read says, “nobody would be surprised” by a show of aggression. But remember, dolphins are “just like big aquatic bison or big aquatic grizzly bears. It’s a large, wild, powerful animal that you can’t predict.”
Dolphins are not People
Keep in mind, dolphins are not monsters, and neither are sharks or any other animal, really. Sitting at the top of the food chain, we pose a much higher threat to other species than they have to us. Consider how many subspecies of dolphins and sharks have become endangered because of human activity such as overfishing and pollution. The most surprising fact about dolphins is that five species and six subspecies are endangered, including the Amazon pink river dolphin. The last documented sighting of the Baiji dolphin was in 2002, according to World Animal Protection.
Dolphins Deserve Our Support
Although we may balk at their behaviors, remember dolphins don’t have the same sense of morals we do. Scientific literature suggests these strange actions are normal for animals, especially those whose main focus is survival. So continue to love them and support conservation; dolphins are incredible creatures with so many more secrets to uncover.
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