14 Awesome Facts About Dolphins

Dolphins are known for being smart, playful creatures that can learn to perform impressive tricks. But you might not know that dolphins are also champion nappers who have helped the U.S. Navy protect nuclear warheads. We're celebrating National Dolphin Day with these 15 facts about the cute, friendly cetaceans.

1. THEY'RE EXCELLENT NAPPERS.

Since dolphins can't breathe underwater, they need to swim up to the ocean's surface to get air. So how do they sleep without drowning? Essentially, dolphins are champion power nappers. Rather than sleep for several hours at a time, they rest one hemisphere of their brain for 15 to 20 minutes at a time, and they take these "naps" several times each day. By resting one hemisphere of their brain at a time, dolphins can continue swimming, breathing, and watching for predators 24/7.

2. THEY COMMUNICATE WITH CLICKS AND WHISTLES …
Dolphins communicate with one another underwater by making a variety of vocalizations. To find prey and navigate the ocean, they make clicking sounds, and they "speak" to other dolphins by whistling. Dolphins also produce loud burst-pulse sounds when they feel excited or aggressive, such as when they need to scare off a nearby shark. Some female dolphins also produce a burst-pulse to reprimand their offspring, called calves, for bad behavior.

3. … BUT THEIR LANGUAGE REMAINS A MYSTERY.

Although marine scientists have studied and recorded dolphin vocalizations for decades, many aspects of the animals’ language and how they communicate are still unknown. Scientists have not yet broken down the individual units of dolphin sounds, and they're still searching for a Rosetta Stone that links the animals' vocalizations to their behavior. By using new technologies—including algorithms and high-frequency recorders that work underwater—scientists hope to finally unlock the mystery of the dolphin language.

4. THEY USE ECHOLOCATION TO NAVIGATE.
To know where they are in relation to other objects and animals, dolphins use echolocation (a.k.a. biological sonar). After emitting a series of high-pitched clicks, they listen for the echoes to bounce off their surroundings. Based on these echoes, dolphins can judge where they are in space and determine the size and shape of nearby objects. Besides helping dolphins evade predators, echolocation allows them to trap, catch, and eat fish and squid. 

5. THEY MAKE FRIENDS WITH OTHER DOLPHINS …

Dolphins are highly social, and scientists are still discovering fascinating details about how the aquatic mammals socialize with one another. In 2015, scientists at Florida Atlantic University's Harbor Branch Oceanographic Institute published research in the Marine Mammal Sciencejournal about the social networks of dolphins. After spending over six years tracking 200 bottlenose dolphins in Florida's Indian River Lagoon, the scientists discovered that dolphins have friends. Instead of spending equal time with the dolphins around them, the animals actually segregate themselves into friend groups. Just like humans, dolphins seem to prefer the company of certain peers more than others.

6. … AND EACH DOLPHIN RESPONDS TO ITS OWN NAME.
Dolphins aren't swimming around with name tags, but every dolphin has its own unique whistle. Scientists believe that dolphins use these signature whistles for life, and female dolphins may even teach their calves their whistles before they're born. Dolphins use their signature whistles to call out to one another and may be able to remember other dolphins' whistles after decades apart.

7. THERE ARE 44 DIFFERENT DOLPHIN SPECIES.

Although bottlenose dolphins are the most well-known and recognizable, there are 43 other dolphin species. Most species live in temperate and tropical oceans, but a few live in colder oceans or rivers. Depending on their species, dolphins can vary considerably in their physical attributes and behavior. For example, the largest dolphin species, the Orca (also called Killer Whale), can be 30 feet long—10 times longer than the smallest dolphins.

8. THEY DON'T USE THEIR TEETH TO CHEW FOOD.
Dolphins have teeth, but they don't use their chompers to chew food. Instead, dolphins use their teeth to catch prey (fish, crustaceans, and squid) and swallow it whole. Since they forgo chewing, digestion occurs in their stomach—or, more precisely, in part of their stomach. Dolphins have multiple stomach chambers, one of which is devoted to digestion, while the other chambers store food before it's digested.

9. THEY TYPICALLY GIVE BIRTH TO JUST ONE CALF.

Depending on their species, most female dolphins (called cows) carry their babies for nine to 17 months before giving birth to a calf. Interestingly, calves are born tail first, rather than head first, so they don't drown during the birthing process. After nursing for one to two years, a calf typically stays with its mother for the next one to seven years, before mating and having its own calves.

10. THEIR SKIN CAN BE REGENERATED EVERY TWO HOURS.
If you've ever swum with dolphins, you know their skin looks and feels super smooth and sleek. There's a reason for that—a dolphin's epidermis (outer layer of skin) can be sloughed off and replaced with new skin cells as often as every two hours. Because their skin regenerates so often, it stays smooth and, as most scientists believe, reduces drag as they swim.

11. THE U.S. NAVY TRAINS DOLPHINS TO PROTECT NUCLEAR WEAPONS.

A bottlenose dolphin named K-Dog from the Commander Task Unit jumps out of the water in 2003. Commander Task Unit is comprised of special mine clearing teams from The United Kingdom, Australia, and the U.S.

Despite dolphins' general friendliness, some of them are trained for combat. The Navy Marine Mammal Program at San Diego's Space and Naval Warfare Systems Command (SPAWAR) trains dozens of bottlenose dolphins (as well as sea lions) to help the U.S. Navy. In the past, the U.S. military has used dolphins in conflicts in Vietnam and the Persian Gulf. Today, thanks to their intelligence, speed, and echolocation skills, dolphins are trained to find enemy swimmers, locate underwater mines, and guard nuclear arsenals.

12. THEY'RE NOT THE SAME AS PORPOISES.

To the untrained eye, dolphins and porpoises look nearly identical, and many people mistakenly think that porpoises are a type of dolphin. But the two species belong to completely different families and differ in their physical attributes. So how can you tell them apart? Dolphins, which are usually bigger than porpoises, typically have longer beaks and curved dorsal fins. Porpoises, on the other hand, have more triangular dorsal fins as well as spade-shaped (rather than conical) teeth.

13. HUNTING, OVERFISHING, AND RISING OCEAN TEMPERATURES THREATEN THEM.
Some dolphin species are endangered or functionally extinct (like China's baiji dolphin) due to hunting, overfishing, and pollution. Although dolphin meat is high in mercury, the animals are still hunted for their meat and eaten in parts of Japan and the Faroe Islands of Denmark. Overfishing means that dolphins' food sources are shrinking, and some dolphins get caught up in fishing nets and die. Additionally, climate change and rising ocean temperatures are driving some fish and squid away from their natural habitats, putting dolphins' main food source at risk.

14. A SUPERPOD CAN CONSIST OF MORE THAN 1000 DOLPHINS.

Dolphins live in groups, called pods, that typically contain dozens or hundreds of dolphins. By swimming in a pod, dolphins work together to hunt prey, evade predators, and care for sick or injured members. But different pods can also merge, forming a superpod of more than 1000 dolphins. Superpods are typically temporary and occur in parts of the ocean with plentiful food (and less competition for tasty squid).

15. THE OLDEST DOLPHIN IN CAPTIVITY LIVED TO 61 YEARS OLD.

Dolphin lifespan varies greatly by species. Most dolphins in the wild live for a few decades, while those in captivity have a drastically reduced lifespan and may live for only a few years. So it's all the more shocking that the oldest dolphin in captivity lived to be a sexagenarian. Nellie, a bottlenose dolphin who lived in a marine entertainment park in Florida, was born in 1953. She appeared on TV shows and commercials and performed tricks for the park's attendees before passing away in 2014.

Top Facts About Smiley Emoji You Never Know, The Poop Emoji Is Funnier

For many people, speaking in emoji is almost as natural as speaking in, well, words. However, less than two decades ago, the collection of symbols was just a blip on the digital horizon. You may be adept at planning dinner with friends using only smileys and food characters, but how much do you really know about emoji? 

1. SHIGETAKA KURITA IS CONSIDERED THE FATHER OF EMOJI.


Back in 1999, the Japanese designer Shigetaka Kurita created the first collection of cell phone emoji for the debut of "the world’s first major mobile internet system," called NTT Docomo's i-mode. The program they were working with "limited users to up to 250 characters in an email," according to Kurita, "so we thought emoji would be a quick and easy way for them to communicate. Plus using only words in such a short message could lead to misunderstandings … It’s difficult to express yourself properly in so few characters." He used a variety of everyday symbols, Chinese characters, street signs, and manga imagery for inspiration, and eventually came up with 176 12-pixel by 12-pixel characters—a much-simplified version of the images we now text on a regular basis.

"At first we were just designing for the Japanese market," Kurita said last year. "I didn’t assume that emoji would spread and become so popular internationally. I’m surprised at how widespread they have become. Then again, they are universal, so they are useful communication tools that transcend language."

2. THERE WAS A LOT OF DEBATE ABOUT THE ADDITION OF A HOT DOG.
Seriously. Digital Trends reported on the dispute back in 2014, when some users were so incensed over the lack of a hot dog emoji that they even petitioned the White House to make it happen. As it turns out, there is a very good reason that the character wasn’t initially created.

"The problem with the hot dog emoji," Mark Davis, co-founder of the Unicode Consortium, told The Wall Street Journal, "is, what do you then want with the hot dog? Would we do one with ketchup or without?" He makes a valid point—toppings are important. But Kurita wasn’t opposed to adding in the traditional stateside cuisine: "In Japan, we have onigiri [rice ball] emoji, so why not hot dogs? Hot dogs are onigiri for Americans, right?"

(Not to worry—the hot dog won out in 2015, and Apple now has a mustard-covered emoji.)

3. EVEN KURITA IS MYSTIFIED BY THE AMBIGUITY OF THE HEART EMOJI.


"People of all ages understand that a single emoji can say more about their emotions than text," Kurita recently said of his creation. "Emoji have grown because they meet a need among mobile phone users. I accept that it’s difficult to use emoji to express complicated or nuanced feelings, but they are great for getting the general message across." However, even he acknowledges that messages can get mixed when it comes to emoji like the heart, even though he initially designed the heart to mean "love."

"I wouldn’t know if she liked me or not," Kurita told the Verge, when asked what he thinks receiving a heart emoji means, "but I’d think it was a good thing. I wouldn’t think it was a negative."

4. THE ENTIRETY OF MOBY-DICK WAS TRANSLATED INTO EMOJI.
In 2009, Fred Benenson—Kickstarter’s second full-time employee—used his company's platform to fund an emoji-translation project, which he titled Emoji Dick. Benenson was an avid fan of emoji and wanted to find a way to push the characters' creativity. He raised more than $3500 to pay a team to help him translate Herman Melville’s saga of man and whale into emoji. While it doesn’t quite translate in each case, Benenson told Smithsonian magazine, "As a conceptual piece, it’s successful."

But why Moby-Dick, besides the translation’s fantastic title? "I needed a public domain book that I could get the plain-text version of easily," Benenson told The New Yorker. "The Bible seemed too obvious."

These days, Emoji Dick has a place in the Library of Congress, who acquired the work in 2014 and notes that it captures the culture in this particular moment in time. "It’s up to the readers of Emoji Dick to decide whether to take it seriously as content," Michael Neubert, a digital projects specialist at the Library of Congress, said.

If you’re looking for some light reading, you can purchase a copy of the 736-page translation here. 

5. EARLY ON, BUSINESSES USED EMOJI TO CONNECT WITH CUSTOMERS.

Mike Mozart via Flickr // CC BY 2.0

Keeping in mind that emoji launched in 1999, long before cell phones developed into the tech-savvy devices we have today, emoji originally had much different purposes. For example, The New York Times explains that Docomo, the company that developed emoji, used them to deliver weather reports to pager users.

While this explains many of the weather-related emoji, such as the lightning bolt, sun, umbrella, and snowman, Docomo also used the characters to guide users to local businesses. A hamburger represented fast food, while the martini glass stood for a bar.

"Everything was shown by text. Even the weather forecast was displayed as 'fine,'" Kurita told Storify. "When I saw it, I found it difficult to understand. Japanese TV weather forecasts have always included pictures or symbols to describe the weather—for example, a picture of sun meant 'sunny' … I'd rather see a picture of the sun, instead of a text saying 'fine.'" 

6. THE MOST POPULAR EMOJI ISN'T THE SLICE OF PIZZA—OR THE THUMBS UP.
The most popular emoji vary from country to country. In July 2016, Metroreported that Twitter ran some analytics and says the "despairing crying face" is the most-used in the United States, Canada, and the U.K. Another popular choice is the musical notes, which is a top pick in Colombia, Brazil, and Argentina.

Additionally, Twitter users tend to favor the beer emoji over the steaming cup of coffee, and that the full heart is tweeted more frequently than the broken heart. When it comes to food, the birthday cake is most-used, followed by the classic slice of pizza, and the strawberry rounds out the top three.

The popularity of emoji is constantly in flux, so Twitter even did a month-by-month breakdown. Unsurprisingly, the skull was most-used in October, while the Christmas tree owned December. Another classic, the "100" symbol, was the most popular in November.

7. THERE'S A REASON THE IOS POOP EMOJI LOOKS SO SIMILAR TO THE ICE CREAM CONE.


Back in 2012, New York magazine interviewed Willem Van Lancker, who helped create 400 of the original 500 Apple characters. (The conversation took place over text, naturally.) When asked about the similarity between the poop and ice cream emoji, Van Lancker replied, "Some design elements may have been reused between them …"

8. THE FATHER OF EMOTICONS ISN'T A FAN OF EMOJI.
Long before emoji, people communicated with emoticons—representations of facial expressions created with punctuation marks. While emoji are undoubtedly the more detailed, colorful set of characters, Carnegie Mellon computer science professor Scott Fahlman tends to prefer his original form, which he traces to a 1982 message board conversation.

"I propose the following character sequence for joke markers: :-) Read it sideways," Fahlman had told the group, and before long, the expression spread and was soon used at other universities before making its way into casual digital conversations worldwide.

But when it comes to emoji, Fahlman told the Independent, "I think they are ugly, and they ruin the challenge of trying to come up with a clever way to express emotions using standard keyboard characters. But perhaps that's just because I invented the other kind."

9. THE MUSEUM OF MODERN ART OWNS THE ORIGINAL EMOJI COLLECTION.

Getty

Yep, the set of emoji Kurita created back in 1999 is now part of MoMA’s permanent display, starting in December 2016. And they aren't the only digital objects on display: The museum previously acquired the "@" symbol in 2012.

The collection resides in the museum’s lobby and represents a balance between modernity and hieroglyphics, one of the oldest forms of written communication. However, as ancient as the roots of emoji may be, the original collection's influence in modern culture remains strong. "It is hard to overstate it. I mean if you think about it, we cannot live without emojis today," Paola Antonelli, the senior curator in the department of architecture and design, told NPR. "We've become used into condensing our thoughts and our kind of emotions in them."