15 Delightful Facts About Dolphins

iStock
iStock

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 underwater
iStock

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 …

spotted dolphins swimming
iStock

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 Science journal 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.

an orca jumping out of the water
iStock

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.

two smiling dolphins
iStock

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.

mother and baby dolphin
iStock

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.
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.
Brien Aho, U.S. Navy/Getty Images

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.

a pod of dolphins swimming
iStock

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.

Massive Swarms of Migrating Dragonflies Are So Large They’re Popping Up on Weather Radar

emprised/iStock via Getty Images
emprised/iStock via Getty Images

What do Virginia, Pennsylvania, Indiana, and Ohio all have in common? Epic swarms of dragonflies, among other things.

WSLS-TV reports that this week, weather radar registered what might first appear to be late summer rain showers. Instead, the green blotches turned out to be swarms of dragonflies—possibly green darners, a type of dragonfly that migrates south during the fall.

Norman Johnson, a professor of entomology at The Ohio State University, told CNN that although these swarms happen occasionally, they’re definitely not a regular occurrence. He thinks the dragonflies, which usually prefer to travel alone, may form packs based on certain weather conditions. If that sounds vague, it’s because it is: Johnson said that entomologists haven’t worked out all the details when it comes to dragonfly migration. They do know that the airborne insects cover an average of eight miles per day, while some overachievers can fly as far as 86.

Based on the radar footage shared by the National Weather Service’s Cleveland Office, the dragonfly clouds seem almost menacing. But, while swarms of any insect species aren’t exactly delightful, these creatures are both harmless and surprisingly beautiful, at least up close. Anna Barnett, a resident of Jeromesville, Ohio, even told CNN that witnessing the natural phenomenon was “amazing!”

Amazing as it may be to see, it’s hard to hear news about unpredictable animal behavior without wondering if it’s related in some way to Earth’s rising temperatures. After all, climate change has already affected wasps in Alabama, polar bears in Russia, and no doubt countless other animal species around the world.

[h/t WSLW-TV]

6 Fall Festivals Around the World That Celebrate Animals

Prakash Mathema, AFP/Getty Images
Prakash Mathema, AFP/Getty Images

Where would humans be without animals? Chickens and cows give us eggs and milk, providing nourishment (and also cake). Horses, donkeys, and water buffalo are as hardworking as any person, and thanks to our pets, we always have a source of love and entertainment to come home to. It's time we celebrate animals more often, and to get you started, here are six fall festivals around the world that do just that.

1. Kukur Tihar

Dog in Nepal during a fall festival
Tuayai/iStock via Getty Images

A big part of Tihar, a five-day Hindu festival held in late autumn in Nepal, is giving thanks to other species. Crows, believed to be the messengers of death, are worshipped on the first day. Cows are worshipped on the third, and often oxen on the fourth. The second day, though, is all about man's best friend. Dogs are described favorably in Hindu religious texts, and it’s believed that they can warn people of impending danger and even death. In a ceremony called Kukur Tihar, people place flower garlands around the necks of both pet dogs and stray dogs to show their respect. A red dot (tika) is placed on their foreheads in an act of worship, and naturally, the dogs are spoiled with lots and lots of treats.

2. Transhumance Festival

Hundreds of sheep in the street
Pierre Philippe Marcou, AFP/Getty Images

In Spanish, this festival in Madrid is called Fiesta de la Trashumancia. The word transhumance refers to the act of moving herds of livestock to different grazing grounds depending on the season. In practice, it's quite the spectacle. Thousands of sheep have been led through the streets of Madrid each autumn since the festival was formally established in 1994. Men and women in traditional garb lead the way, singing and dancing along the parade route in celebration of centuries-old shepherding traditions.

3. Monkey Buffet Festival

A monkey eating various kinds of fruit
Saeed Khan, AFP/Getty Images

Visitors to Thailand’s temples are advised not to feed the monkeys (they can get awfully handsy), but the locals of Lopburi make an exception on the last Sunday of November. On this day, towers of fruit and banquet tables containing several tons of food and even cans of Coca-Cola are set up in the ruins of a 13th-century temple. Once a sheet is removed to unveil the spread, it doesn’t take long for Lopburi’s thousands of macaques to arrive. Thailand's reverence for monkeys dates back some 2000 years to legends surrounding the monkey king Hanuman and his heroic feats. Nowadays, the creatures are considered a sign of good luck in the country.

4. Woolly Worm Festival

The woolly worm is to Banner Elk, North Carolina, what the groundhog is to Punxsutawney, Pennsylvania. According to local folklore, the color of this fuzzy caterpillar can be analyzed in autumn to predict how severe the forthcoming winter will be. The 13 segments on its body are thought to correspond to the 13 weeks of winter—more black means colder weather and snow, while more brown means the weather will be fair. To make this prognostication process more official, the Woolly Worm Festival was established on the third weekend of October in 1978. This year, it will be held October 20-21. A worm race is the main event, and the caterpillar that climbs the fastest up three feet of string gets the honor of helping to predict the winter (plus a $1000 cash prize for the worm’s coach). “Patsy Climb” and “Dale Wormhardt” were a couple of past competitors.

5. Pushkar Camel Fair

Decorated camels
Roberto Schmidt, AFP/Getty Images

The Indian state of Rajasthan is a vibrant place. It’s home to the Pink City, Blue City, and Yellow City, and it also hosts a colorful cultural event each November called the Pushkar Camel Fair. Celebrated on a full moon day of the Hindu lunar calendar, it’s one of the largest fairs of its kind in the world. The annual gathering is a chance for traders to show off their camels and livestock, while also celebrating local culture and traditions. Both the people and camels sport brilliant attire, participate in a variety of competitions, and dance to lively music. (Yes, there’s video evidence of a dancing camel, but the word dance is used loosely.)

6. Birds of Chile Festival

Held each fall in Viña del Mar along Chile's Pacific coast, the Festival de Aves de Chile celebrates the beauty and diversity of the country's birds. Festival-goers have the chance to see Chile’s national bird—the wide-winged Andean condor, which happens to be one of the largest flying birds in the world—as well as other feathered friends in their natural environment. A series of excursions and talks featuring bird experts are organized each year.

SECTIONS

arrow
LIVE SMARTER