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.

10 Terrifyingly Huge Birds You Should Know

AndreaWillmore/iStock via Getty Images
AndreaWillmore/iStock via Getty Images

They’re gigantic, they’re often defensive, and you wouldn’t want to run into them in a zoo after hours. Meet a few of the world’s biggest birds with attitude, from flightless giants to modern-day pterodactyls.

1. Ostrich

Everyone knows that the ostrich is the world’s biggest bird, weighing an average of 230 pounds and standing 7 feet tall (and some individuals can grow up to 9 feet). They can also chase you down: Ostriches are the fastest species on two legs, with a top speed of about 43 mph. They can maintain a swift 30 mph pace for 10 miles, making them the marathon champs of the avian world.

2. Southern Cassowary

Often called the most dangerous bird on Earth, in addition to being one of the planet’s biggest birds, the southern cassowary is roughly 150 pounds of mean. On each foot is a 5-inch claw that cassowaries use to defend themselves. At least two people have been kicked to death by cassowaries, the most recent being a Florida man who unwisely kept one of the birds as a pet.

3. Emu

Emu with eggs
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Like a smaller, shaggier ostrich, the 5- to 6-foot emu is the second-largest bird on Earth (as well as a goofy spokesbird for insurance). During the breeding season, female emus fight enthusiastically over unattached males. But the results of this mating ritual are impressive: clutches of forest-green, oval eggs that resemble giant avocados.

4. Greater Rhea

This flightless bird is named for the Titan goddess Rhea, who gave birth to all of the Olympian gods and goddesses in Greek mythology. At up to 5 feet tall and 66 pounds, the greater rhea may not seem like as much of a terror as the ostrich. But it gathers in massive flocks of up to 100 birds during the non-breeding season, so watch out if you happen to be in its South American habitat.

5. Dalmatian Pelican

Dalmatian pelicans
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How scary can a pelican be, you ask? When it stands almost 6 feet tall, weighs 33 pounds, and has a wingspan of 9 feet—all traits of the Dalmatian pelican—it's pretty petrifying. These scruffy-feathered monsters, native to Europe and Asia, breed in colonies of up to 250 pairs and can gulp impressive mouthfuls of fish in one go.

6. Mute Swan

One of the heaviest flying birds, mute swans look harmless as they glide over ponds, lakes, and rivers. But mute swans are far from silent when defending their families and territory. Male swans warn interlopers that they’re getting too close with a hiss, then can launch a straight-up assault, bashing the intruder with their wings. They’ll even attack kayakers, canoeists, and people just minding their own business.

7. Andean Condor

Andean condor
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This freakishly big vulture isn’t satisfied with just any carrion—it prefers large carcasses like cattle and deer for dinner. Maintaining its average weight of 25 pounds requires a lot of calories, after all. Its wingspan is slightly less than its northern cousin, the California condor, but it still reaches a dramatic 9 to 10 feet.

8. Cinereous Vulture

Another big bird with a 10-foot wingspan, this Old World vulture has excellent vision to spot carrion while it flies, and a featherless head that resists the accumulation of gore when it feeds. Though it’s intimidating to look at, the cinereous vulture plays an important role in its ecosystem by cleaning up roadkill and other dead animals.

9. Marabou Stork

Marabou stork
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As if its red-tinged wattle, black back, and dagger-esque bill weren’t alarming enough, the marabou stork is sometimes called the “undertaker bird” thanks to its Dracula-like appearance. It also eats other birds. The largest verified wingspan on a marabou stork measured 10.5 feet, though unverified reports cited a specimen with 13.3-foot span.

10. Shoebill

Shoebill storks may not be the tallest, heaviest, or widest-winged birds, but just look at that death stare. On top of having a nutcracker for a face, the 5-foot-tall shoebill leads a fearsome lifestyle. It stands absolutely still for hours to hunt prey, watching for lungfish or baby crocodiles, then spreads its wings and collapses over it while trapping the target in its bill.

Scientists Capture Video of Deepstaria, a Rarely Seen, Shapeshifting Jellyfish

OET/NautilusLive
OET/NautilusLive

Millions of years of evolution taking place beneath the sea's surface have produced some bizarre animals. Jellyfish are among the oldest—and strangest—of the bunch. Some have "transient" anuses that only form when necessary, and others can renew their life cycles indefinitely. Little is known about Deepstaria, a jellyfish recently spotted by the crew of the Nautilus research vessel in the central Pacific Ocean, but as the video below shows, it's no less unusual than other species of jellyfish.

As Live Science reports, scientists aboard the Nautilus were scanning the seafloor about halfway between the U.S. and Australia when they spotted a spooky-looking creature hovering in front of them. It soon became clear that cosplaying a ghost wasn't all it could do. The jelly unfurled its sheet-like bell to reveal a geometric mesh membrane used to distribute nutrients throughout its body—a telltale sign of Deepstaria. It spends the rest of the video putting on a show for its guests, transforming from something resembling a crumpled plastic bag to a billowing blanket shape.

Deepstaria enigmatica was discovered by the Jacques Cousteau-designed Deepstar 4000 submersible—the vessel the species is named after—in the 1960s. It's only been spotted about a dozen times in the years since, and many details of how it lives remain a mystery to researchers.

Deepstaria's most distinctive feature is its massive, flowing bell. It lacks the tentacles most jellyfish use to wrangle prey, and scientists suspect it instead uses its bell as a net when hunting. The specimen captured in this video appears to be harboring a stowaway: a bright-red, living isopod suspended inside the bell. It isn't clear if the creature hitched a ride on purpose to evade more ferocious predators, if it's some type of parasite, or if it's the jellyfish's lunch.

With so many undiscovered and understudied species living in the sea, the Nautilus research vessel is frequently stumbling upon extraordinary examples of ocean life. In 2016 alone, it recorded footage of a googly-eyed stubby squid and a mysterious purple orb.

[h/t Live Science]

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