Unknown things about Dolphin

To paraphrase Lenny Leonard, a (fictional yellow) man who tragically lost his life to a dolphin, dolphins might be the clowns of the sea but it's dangerous to ever underestimate their intelligence. But are these aquatic mammals really as intelligent as everyone thinks, or are we simply projecting greater intelligence on them because they remind of us of ourselves? Get loosened up for some mental backflips — here come a bunch of dolphin facts you probably weren't ready for.

1. Wear sponges as masks

Dolphins are one of only a handful of animals we've observed using tools in their own environment. Specifically, according to research from Georgetown University, some bottlenose dolphins wear sea sponges on their noses while foraging for food on the ocean floor, protecting their delicate beaks from the pinches of angry crabs and the edges of sharp rocks. The behaviour is more common in females and seems to be passed down by mother dolphins.

2. They can set traps and plan ahead

Dolphins can famously be trained to respond to a baffling array of commands. According to The Guardian, one particularly interesting example of this occurred at the Institute for Marine Mammal Studies in Mississippi where resident dolphins were trained to collect any trash that fell into their tanks and give it to trainers in return for fish. Soon, a dolphin named Kelly learned that she could collect and hide pieces of paper and then tear the paper into smaller pieces to get multiple fish. This showed dolphin are capable of forward planning and can understand the concept of delayed gratification, basically holding off on a small reward now for a possibly much larger reward later.

3. They're exceptionally talented mimics

Dolphins are regarded as one the finest mimics in the animal kingdom, one of the only known species that's consistently good at vocal and behavioral mimicry. Most mimic-capable species can only mimic physical actions or vocal patterns, but dolphins can do both. (That means they have double the opportunity for mockery.) Think of monkeys, for example, which can emulate us physically but cannot mimic our vocalizations, or parrots which can do the opposite.           

4. Regenerative ability

Although you probably don't think about it all that much, dolphins are surprisingly hardy creatures and possess remarkable regenerative abilities bordering on the superhuman (super-dolphin?). To see proof, let's look at how bottlenose dolphins react to being bitten by sharks, or really how they don't react.

Dolphins, to put it bluntly, don't care much about being bitten by sharks and can happily swim around with huge chunks of flesh torn from their bodies "larger than a basketball," according to a researcher from the Georgetown University Medical Centre. We could stop there, but we won't. These wounds heal in mere weeks, rarely get infected, and heal perfectly, leaving behind only light scarring but no indentations or other evidence there was a big ol' shark injury there not too long ago. Dolphins don't even seem to feel pain from these wounds, being observed carrying on as normal with huge holes in their bodies and showing no signs of discomfort even though they have an open wound literally filled with saltwater.

5. They never technically need to sleep

As mammals that need to periodically surface for air every few minutes, dolphins can't sleep without risking drowning. Dolphins and other cetaceans, like whales, have instead evolved a remarkable adaptation. Each creature can turn off half its brain, remaining conscious while essentially being half asleep, according to Live Science. Technically called "unihemispheric slow-wave sleep," when dolphin brains power down to 50 per cent, they close the opposite eye (leaving one open to scan for danger) and enter what amounts to dolphin autopilot to rest while still remaining conscious of their surroundings. Unlike virtually every animal in the world, sleeping dolphins can still control their movements, swimming slowly, surfacing for air, and scanning the environment for threats.

6. They can work with humans for mutual gain

Although they're fantastic hunters and are capable of easily catching a wide array of prey, dolphins much prefer to hustle for their lunch. For example, in the Brazilian municipality of Laguna, dolphins have learned to work with human fishermen. The dolphins will drive large schools of fish toward shallower water before signalling to gathered fisherman to throw out their nets. After they haul in their catch, the fishermen will then reward the dolphins with some fish. Although we know for sure that this symbiotic relationship has existed since at least the 19th century, according to Slate, it isn't clear if the original dolphins were taught by early fishermen, if the dolphins trained the humans, or if the relationship evolved naturally over time.

7. Males lift to impress lady dolphins

Dolphins are often said to be just like us. That statement is hard to argue when you consider that boto dolphins in the Amazon sometimes lift heavy objects just to show off. Yes, just like seasoned gym bros, some dolphins like to lift heavy objects for no other reason than to try to appear more attractive to the opposite sex and to intimidate other males. Fittingly, this is a behaviour mostly witnessed in overly aggressive males. Dolphins who lifted were 40 times more likely to attack or act aggressively toward other males. Male boto ("bro-to"?) dolphins that lifted and carried the sticks and weeds seemed to use the objects as a declaration of their power, thrashing about at the surface of the water while holding them to show off how cool and strong they are. Whether or not this actually has the desired and presumed effect of enticing females and warding off other males isn't clear, although some evidence suggests that lifters might end up fathering more calves. We'll know more when we find the dolphin gyms.

8. Are dolphins really that smart?

Despite their intelligence being one of their most famous attributes, experts and researchers are still divided on whether or not dolphins are as smart as most people think they are. For example, it's commonly claimed that dolphins possess a larger brain than a chimpanzee, so they must be smarter, right? Although dolphins do have very large brains (even larger than ours), the size of a brain doesn't necessarily say anything about the intelligence of the creature it belongs to. Chickens have passed many of the same cognition tests as dolphins, like recognizing members of their own group and displaying empathy for their own kind. Chicken brains are about the size of a walnut, to be generous.

This isn't to say that dolphins aren't intelligent. It's just that many of the feats attributed to them are commonly observed in other animals not often considered to be intelligent. It has been argued by some, like researcher Paul Manger, that dolphin intelligence has been vastly overstated and that the animal's popularity means we just ignore evidence that other animals show similar or greater intellectual ability in tests. Dolphins are still remarkably intelligent creatures capable of cognitive feats not commonly observed in most animals. They can recognize themselves in a mirror! But so can magpies and ants, so, ya know … take it with a grain of salt and maybe tone down the dolphin love.