11 Facts About Tiger Sharks

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Weighing 1300 pounds or more and growing up to 15 feet, the tiger shark is the fourth-largest shark on earth. (Only whale sharks, basking sharks, and great whites get bigger.) On top of being big, tiger sharks are also pretty bizarre: They literally eat garbage, give birth to massive litters—and one of them was a player in Australia’s greatest unsolved murder mystery.

1. THEY’RE LIKE SWIMMING GARBAGE DISPOSALS.

Tiger sharks have broad diets: They eat everything from albatrosses, venomous sea snakes, and other sharks to manmade objects like paint cans, leather jackets, rubber tires, and even license plates. (That scene in Jaws where Hooper pulls a Louisiana plate from the stomach of a dead tiger shark is scientifically accurate!)

2. DON’T CONFUSE THEM WITH SAND TIGER SHARKS.

You might assume that the tiger shark (Galeocerdo cuvier) and the sand tiger shark (Carcharias taurus) are cousins, but the latter is more closely related to the great white (Carcharodon carcharias) than it is to the tiger shark.

3. NOT ALL OF THEM HAVE STRIPES.

Hear the word tiger and you think vertical stripes, but those stripes evolve over time. Baby tiger sharks—a.k.a. pups—are covered in roundish gray spots that fuse into stripes as the sharks mature. After a certain age, the stripes start to fade; they’re barely visible in full-grown adults.

4. TIGER SHARKS PREFER WARM WATER.

Tiger sharks are seen in tropical to warm temperate waters all over the world, and a study published in Global Change Biology in March 2018 revealed that the sharks have a "Goldilocks" zone. “Our study suggests that 22 degrees [Celsius, 71.6 degrees Fahrenheit] is not too cold for the animals and it’s not too hot for them,” lead author Nicholas Payne told the BBC. “It’s about right in terms of their optimal preference for temperature.” The scientists reached that conclusion after monitoring tagged sharks near Hawaii and comparing those findings to several decades’ worth of Australian fishing records.

5. THEY HAVE NOTCHED TEETH.

the teeth of the tiger shark with serrated edges

If you could pry open a tiger shark’s jaws, you’d see teeth with dramatic notch tips that point sideways. You'd also notice that the teeth on the left and right halves look like mirror images of each other. A tiger shark’s teeth have a dual function: They help the fish grasp onto struggling victims and can shear right through the thickest of hides, making them well-equipped to go after just about any prey that’s available.

6. THEY MIGHT BE THE ONLY SHARKS TO REGULARLY HUNT SEA TURTLES.

Every year, 12,000 nesting sea turtles visit Raine Island in the Great Barrier Reef, and tiger sharks—which hunt the turtles—aren't far behind.

To get its meal, the shark first has to get a good grip, but the turtle doesn't make it easy: When a shark gets too close for comfort, a turtle may respond by turning itself sideways so the top of the carapace is perpendicular to the shark’s jaws, making themselves too wide to bite into. Turtles in this position will also swim in tight circles around the predator, which protects the reptile’s vulnerable flanks.

According to a 2016 study, the sharks tend to avoid healthy turtles and instead conserve energy by going after sick or dying (or dead) turtles.

7. SEA GRASS SEEMS TO BENEFIT WHEN TIGER SHARKS ARE AROUND.

Though Australia's Shark Bay is home to a diverse array of organisms, it got its moniker for the 28 shark species that have been seen there—including tigers, which are especially common.

Sea grasses are the backbone of Shark Bay's ecosystem; they provide shelter for small animals and food for big herbivores. But the grasses were decimated after a 2011 heat wave. Since then, they've been making a gradual comeback, and scientists have noticed that they grow at a higher rate in places frequented by tiger sharks. This is probably because the sharks frighten off sea turtles and dugongs who like to eat the grass. “Just the fear of sharks can be enough, in many cases, to keep a marine ecosystem healthy and able to respond to stresses,” biologist Michael Heithaus said in a news release.

8. TIGER SHARKS GIVE BIRTH TO HUGE LITTERS.

Female tiger sharks are pregnant for 14 to 16 months and give birth to at least 10 pups, with around 30 being the average. But sometimes, they have many, many more than that: There have been reports of females birthing 80 pups at once. Usually, newborns weigh between six and 13 pounds.

9. IN THE ATLANTIC, THEY MIGRATE SOUTH FOR THE WINTER.

There's still a lot to learn about the travel habits of tiger sharks. A seven-year study found that Hawaiian females tend to travel more often—and more widely—around the island chain than males do. Another analysis, published in 2015 in Scientific Reports, focused on 24 adult tiger sharks in the Atlantic and found that, in the winter months, they stayed in the area around the Caribbean and West Indies. Then, for summer, they headed north and spent the warmest part of the year in the mid-Atlantic, venturing as far north as Connecticut (and far away from the coast). No one knows why the sharks make the trip, but it may have something to do with the young loggerhead turtles who dwell in those northern waters.

10. ONE TIGER SHARK BARFED UP A MURDER MYSTERY.

In April 1935, Coogee Aquarium in Sydney, Australia was looking for a big fish to occupy its newly-built pool. On a fishing trip off Coogee beach, Bert Hobson snared a 13-foot tiger shark for the aquarium.

The shark was a big hit at the aquarium, but it didn’t last very long. Seven days after its arrival, it got sick and vomited up a bird, a rat, some nasty-looking brown goo—and a human arm, which had a rope tied around its wrist and a forearm tattoo of two boxers.

An amateur boxer named James Smith had recently gone missing, and he had the exact same tattoo on one arm. Forensic analysis determined that the arm hadn’t been bitten off—it had been removed from the rest of Smith's body with a knife.

Detectives learned that Smith was last seen playing cards at the Hotel Cecil in Cronulla with his longtime associate Patrick Brady, a forger, who quickly became the number one suspect. The authorities were later informed by a boat-builder (and suspected criminal) named Reginald Holmes that Brady had murdered Smith in an argument. But before Holmes could testify in court, somebody shot him.

Brady's lawyers argued that a severed arm didn’t constitute proof of a murder. Smith, they argued, might still be alive somewhere—sans one limb, of course. Brady got off scot-free, which was more than could be said for the poor tiger shark—it died in captivity. A necropsy did not reveal any other human remains.

11. IT’S RARE, BUT TIGER SHARKS HAVE BEEN KNOWN TO SHARE FOOD WITH CROCODILES AND GREAT WHITES.

Bloated, rotting whale carcasses lure all kinds of animals out of the woodwork. Carnivores that normally don’t cross paths sometimes end up feasting on the dead mammals side-by-side. In 2015, two great whites and three tiger sharks were filmed tearing into the colossal body of a sperm whale near New South Wales, Australia. Years earlier, off the South African coastline, witnesses saw members of both species eating a Byrd’s whale carcass [PDF]. Australian drone footage from 2017 (above) shows a humpback carcass getting picked apart by both tiger sharks and saltwater crocodiles. Look at the video closely and you’ll see the croc and fish coming within a few yards of each other.

20 Black-and-White Facts About Penguins

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Happy Penguin Awareness Day! To celebrated, here are a few fun facts about these adorable tuxedoed birds.

1. All 17 species of penguins are found exclusively in the Southern Hemisphere.

A group of penguins on an iceberg.
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2. Emperor Penguins are the tallest species, standing nearly 4 feet tall. The smallest is the Little Blue Penguin, which is only about 16 inches.

Three emperor penguins
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3. The fastest species is the Gentoo Penguin, which can reach swimming speeds up to 22 mph.

A gentoo penguin swimming underwater
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4. A penguin's striking coloring is a matter of camouflage; from above, its black back blends into the murky depths of the ocean. From below, its white belly is hidden against the bright surface.

Penguins swimming in the ocean
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5. Fossils place the earliest penguin relative at some 60 million years ago, meaning an ancestor of the birds we see today survived the mass extinction of the dinosaurs.

Emperor penguins with chicks
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6. Penguins ingest a lot of seawater while hunting for fish, but a special gland behind their eyes—the supraorbital gland—filters out the saltwater from their blood stream. Penguins excrete it through their beaks, or by sneezing.

Penguin swimming in the ocean
iStock/Musat

7. Unlike most birds—which lose and replace a few feathers at a time—penguins molt all at once, spending two or three weeks land-bound as they undergo what is called the catastrophic molt.

Gentoo penguin chick molting
iStock/ChristianWilkinson

8. All but two species of penguins breed in large colonies of up to a thousand birds.

A colony of king penguins
iStock/DurkTalsma

9. It varies by species, but many penguins will mate with the same member of the opposite sex season after season.

Two chinstrap penguins
iStock/Legacy-Images

10. Similarly, most species are also loyal to their exact nesting site, often returning to the same rookery in which they were born.

Magellanic penguin nesting in the ground
iStock/JeremyRichards

11. Some species create nests for their eggs out of pebbles and loose feathers. Emperor Penguins are an exception: They incubate a single egg each breeding season on the top of their feet. Under a loose fold of skin is a featherless area with a concentration of blood vessels that keeps the egg warm.

Penguin eggs
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12. In some species, it is the male penguin which incubates the eggs while females leave to hunt for weeks at a time. Because of this, pudgy males—with enough fat storage to survive weeks without eating—are most desirable.

A group of emperor penguins and chick
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13. Penguin parents—both male and female—care for their young for several months until the chicks are strong enough to hunt for food on their own.

Penguin chick and parent on a nest
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14. If a female Emperor Penguin's baby dies, she will often "kidnap" an unrelated chick.

Three emperor penguin chicks
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15. Despite their lack of visible ears, penguins have excellent hearing and rely on distinct calls to identify their mates when returning to the crowded breeding grounds.

Gentoo penguins
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16. The first published account of penguins comes from Antonio Pigafetta, who was aboard Ferdinand Magellan's first circumnavigation of the globe in 1520. They spotted the animals near what was probably Punta Tombo in Argentina. (He called them "strange geese.")

A group of magellanic penguins on the seacoast
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17. An earlier, anonymous diary entry from Vasco da Gama's 1497 voyage around the Cape of Good Hope makes mention of flightless birds as large as ducks.

A cape penguin in South Africa
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18. Because they aren't used to danger from animals on solid ground, wild penguins exhibit no particular fear of human tourists.

Man videotaping a penguin in Antarctica
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19. Unlike most sea mammals—which rely on blubber to stay warm—penguins survive because their feathers trap a layer of warm air next to the skin that serves as insulation, especially when they start generating muscular heat by swimming around.

Penguin swimming in the ocean
iStock/Musat

20. In the 16th century, the word penguin actually referred to great auks (scientific name: Pinguinus impennis), a now-extinct species that inhabited the seas around eastern Canada. When explorers traveled to the Southern Hemisphere, they saw black and white birds that resembled auks, and called them penguins. 

13 Fascinating Facts About Pallas’s Cats

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Far across the world, an elusive—and adorable—wildcat called the Pallas’s cat (also known as the manul) roams the grasslands and steppes of Central Asia and Eurasia. Get to know the flat-faced, furry kitty, which has been featured in memes and viral videos and recently received its own wildlife preserve in Asia’s Altai Mountains.

1. It's named after naturalist Peter Pallas.

German naturalist Peter Pallas first described the furry wildcat in 1776. He named the kitty Felis manul, and theorized that it was an ancestor of the Persian cat, due to its round face, luxurious coat, and stocky body. (He was wrong.)

2. Its scientific name means "ugly-eared."

Later on, the cat's scientific name was changed from Felis manul to Otocolobus manul—not exactly the most flattering moniker, since Otocolobus is Greek for “ugly-eared.”

3. Its unusual ears come in handy.

Some may consider the Pallas’s cat’s ears to be ugly, while others might think they’re adorable. Arguments aside, the cat’s round ears—which sit flat on the sides of its head—are one of the feline's most distinguishing features. As Crystal DiMiceli, a former wild animal keeper at Brooklyn's Prospect Park Zoo, explains in the above video, having low-positioned ears helps the cat conceal itself—they don’t poke up to reveal the animal's position while it's hiding or hunting.

4. It has a dense, plush coat.

The coat of the Pallas's cat is its true crowning glory. It’s longer and denser than any other coat belonging to a member of the Felid species (growing in even heavier in the winter), and the undercoat on its belly is twice as long as the fur covering the rest of its body. The shade ranges from silvery grey during the winter to a darker, red-toned hue during warmer months. (Some cats are also red, particularly in Central Asia.) Its broad head is streaked and speckled with dark markings, and its bushy tail is banded with stripes and a dark tip. These markings tend to appear darker during the summer.

5. Its fur blends with its habitat, which conceals it from predators.

Pallas's cats live in areas ranging from Pakistan and northern India to central China, Mongolia, and southern Russia. According to Wild Cats of the World, by Luke Hunter, its body isn’t adapted for snow, so it sticks to cold, arid habitats—particularly grassy or rocky areas, which help conceal it from predators—at elevations of around 1500 to nearly 17,000 feet. The stocky cat isn’t a fast runner, so when it senses danger, it freezes and crouches flat and motionless on the ground, and its fur helps it blend in with its surroundings.

6. Pallas's cats aren't fat—they're just furry.

Pallas's cats typically weigh less than 12 pounds, and they’re usually only 2 feet or less in body length—meaning they’re not that much larger than an ordinary house cat. Yet their dense coat of fur makes them appear much larger.

7. Their pupils are round instead of vertical.

Pallas's cats do share one feature in common with larger wildcats, like lions and tigers: their eyes. Their pupils are round, whereas a house cat's pupils are vertical and slit-shaped. Wondering why some cats have round pupils while others have vertical ones? A 2015 study conducted by researchers at the University of California, Berkeley found that animals’ pupil shapes might indicate their role in the predator/prey food chain. They analyzed 214 species of land animals (including cats), and noted that species with vertical pupils tended to be ambush predators that were active during both day and night. In contrast, species with vertical pupils were often “active foragers,” meaning they chase their prey. Also, predators that are closer to the ground, like house cats, were prone to vertical pupils, whereas larger wildcats had round ones. Pallas’s cats are small, and they are primarily ambush hunters, so the jury’s still out on whether the study's findings hold true for all creatures.

8. They subsist mostly on pika.

A Pallas's cat sticks its tongue out
iStock.com/Nikolai Vakhrushev

Pallas's cats are ambush hunters and spend much of their time hunting pika, a small mammal, and other critters like gerbils, voles, hares, ground squirrels, birds, and young marmots. Pika typically make up more than 50 percent of the cat's diet. 

9. They may be distantly related to the leopard cat.

Peter Pallas thought the animal was related to the Persian cat. (We think it looks like a Maine Coon and a Scottish Fold had a baby and weaned it on steroid milk.) However, experts have uncovered evidence that the wildcat’s nearest—yet still pretty distant—relative might be the leopard cat.

10. They's not social animals.

The Pallas's cat is notoriously elusive and spends much of its time hiding in caves, crevices, or abandoned burrows.

11. They don't seem to like each other much.

A pair of Pallas's cats size each other up
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Pallas's cats may be adorably fluffy, but they aren’t the world’s sweetest, most cuddly creatures. In fact, they’re very aggressive. Case in point: In The Wild Cat Book, authors Fiona and Mel Sunquist recount an anecdote provided by Bill Swanson, the Cincinnati Zoo’s director of animal research. Zookeepers thought that a litter of newborn Pallas's cats were having difficulty breathing, but “when they listened closely, they realized that the noise they were hearing was the kittens growling and hissing at each other—before they had even opened their eyes!"

12. Their mating period is brief.

Pallas’s cats mate between December and March; the females typically give birth between the end of March and May, after a gestation period of 66 to 75 days. Pallas’s cats usually give birth to three or four kittens, but litters can sometimes have as many as eight kittens. Kittens become independent by four to five months, and when they reach nine to 10 months, they’re mature enough to reproduce. 

13. They're classified as "near-threatened."

It's estimated that Pallas's cats can live up to six years in the wild, but because of predators and other dangers, their lifespan is likely to be half this length. In captivity, they’ve been known to survive for nearly 12 years.

In 2002, the International Union for Conservation of Nature classified the Pallas’s cat as “near-threatened,” and that status remains today. Many factors contribute to their low numbers, including farming, agricultural activities, mining, and poisoning campaigns aimed at reducing pika and marmot populations. They're also often killed in traps meant for wolves and foxes, or by domestic dogs. And despite international trading bans and legal protections in some countries, they're often hunted for their fur. (The cat's fat and organs are also used to make traditional medicines.) 

Scientists don't have enough data to estimate the Pallas’s cat's population size, but due to their scarcity and the many threats they face, experts believe that their numbers have dropped by 10 to 15 percent over the past decade or so. To better understand—and protect—the animal, an international team of conservationists recently secured a 12-mile swath of land in Sailyugemsky Nature Park, which lies in the Altai Mountains between Kazakhstan and Mongolia, as a sanctuary for the rare cat. There, they hope to monitor its population, study its habitat, and build a database of information detailing encounters with it. 

Additional Source:
Wild Cats of the World by Luke Hunter

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