11 Facts About Tiger Sharks

iStock
iStock

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.

This Stylish Cardboard Box Is Designed to Be Your Cat’s New Favorite Hideout

Scott Salzman
Scott Salzman

You can buy your cat a fancy bed or perch, but when it comes right down to it, your feline friend is probably going to be more eager to curl up in the cardboard box that it arrived in. So why not just cut out the part where you spend time and money picking out something your cat couldn’t care less about? Just get a really nice box. That’s the premise behind the Purrfect Cat Box, a cardboard box specifically tailored to cats’ needs.

While every cat is finicky in his or her own way, almost all cats love a good cardboard box. (Seriously, it’s science.) Squeezing into a cozy box makes cats feel protected, and, since cats like warmer temperatures, the insulating cardboard also helps keep them at their preferred level of toasty.

Designed by Colorado-based inventor Scott Salzman, the Purrfect Cat Box is made to be just the right size for ultimate kitty comfort. At about the size of a shoebox, it’s big enough for most cats to squeeze into without being cramped—though Salzman doesn’t specify whether it will work for big breeds like Maine Coons—but small enough that they still feel protected inside. It has a small cutout in the front to allow your cat to peek his head outside the box, and, most importantly, to get in a really good chin scratch.

While we humans might find cardboard cars or cardboard Taj Mahal replicas adorable, most cats just want a plain box that makes them feel safe and comfortable. The geometric-patterned Purrfect Cat Box walks the line between utilitarian and chic, making the empty cardboard box in your living room a little bit less of an eyesore.

Plus, it’s cardboard-priced. At $6 a box, it's about what you'd pay to have a regular cardboard box full of anything from Amazon delivered to your door, but it’s still inexpensive enough that if your cat destroys it, it’s easy enough to throw in the recycle bin and get a new one.

Get it on Indiegogo.

Signalman Jack: The Baboon Who Worked for the Railroad—and Never Made a Mistake

Wikimedia Commons // Public Domain
Wikimedia Commons // Public Domain

One day in the 1880s, a peg-legged railway signalman named James Edwin Wide was visiting a buzzing South African market when he witnessed something surreal: A chacma baboon driving an oxcart. Impressed by the primate’s skills, Wide bought him, named him Jack, and made him his pet and personal assistant.

Wide needed the help. Years earlier, he had lost both his legs in a work accident, which made his half-mile commute to the train station extremely difficult for him. So the first thing he trained the primate to do was push him to and from work in a small trolley. Soon, Jack was also helping with household chores, sweeping floors and taking out the trash.

But the signal box is where Jack truly shined. As trains approached the rail switches at the Uitenhage train station, they’d toot their whistle a specific number of times to alert the signalman which tracks to change. By watching his owner, Jack picked up the pattern and started tugging on the levers himself.

Soon, Wide was able to kick back and relax as his furry helper did all of the work switching the rails. According to The Railway Signal, Wide “trained the baboon to such perfection that he was able to sit in his cabin stuffing birds, etc., while the animal, which was chained up outside, pulled all the levers and points.”

As the story goes, one day a posh train passenger staring out the window saw that a baboon, and not a human, was manning the gears and complained to railway authorities. Rather than fire Wide, the railway managers decided to resolve the complaint by testing the baboon’s abilities. They came away astounded.

“Jack knows the signal whistle as well as I do, also every one of the levers,” wrote railway superintendent George B. Howe, who visited the baboon sometime around 1890. “It was very touching to see his fondness for his master. As I drew near they were both sitting on the trolley. The baboon’s arms round his master’s neck, the other stroking Wide’s face.”

Jack was reportedly given an official employment number, and was paid 20 cents a day and half a bottle of beer weekly. Jack passed away in 1890, after developing tuberculosis. He worked the rails for nine years without ever making a mistake—evidence that perfectionism may be more than just a human condition.

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