Chum, Bruce and Anchor from Finding Nemo/Walt Disney Pictures

Some sharks really are ballsier than others, scientists find

Sharks have personalities, too.

JOSH HRALA
30 MAY 2016
 

When it comes to creatures that threaten our existence, sharks get a pretty bad rap (thanks, Jaws).

In 2015, we experienced the highest amount of unprovoked shark attacks ever, with 99 reported cases around the globe, and in 2014, that number was 72. Though this means sharks do attack and kill people on occasion, the numbers don’t even compare to the estimated 25,000 deaths that dogs cause every year (mostly because of rabies).

 

Many people view sharks as monsters because they’re scary-looking predators that live underwater - an environment where humans already feel extremely vulnerable - but instead of thinking of them as hidden death machineswe should see them for what they really are: complex creatures that have different personalities, just like us.

For the first time, researchers from Macquarie University in Sydney, Australia have found that Port Jackson sharks have individual personalities that they express habitually, suggesting that they're ingrained just like our own personalities are.

In the study, the team designed a set of experiments to test how bold several of their sharks were.

In the first experiment, they introduced sharks to a new tank that had a shelter inside. They monitored how long it took for the shark to be brave enough to venture out of the shelter and explore its new surroundings. A second experiment had a handler pick up the sharks and release them back into the tank.

Both of these activities - handling the shark and introducing it to a strange environment - served to stress the sharks out a bit so the team could see how long it took them to calm down.

The team found that each shark handled these situations in their own way, and continued to react in a similar manner each time, with some of the sharks appearing more bold than others. Though simplistic, the findings suggest that some sharks are, in essence, more outgoing and adventurous than others, signalling that they have different personality traits.

 

"We are excited about these results because they demonstrate that sharks are not just mindless machines. Just like humans, each shark is an individual with its unique preferences and behaviours," said one of the team, Culum Brown.

Besides showing sharks in a new light, the team says that knowing the breadth of responses displayed by these creatures to certain situations will help us better interpret - and maybe even predict - how certain types of predators behave around humans. 

"Understanding how personality influences variation in shark behaviour - such as prey choice, habitat use and activity levels - is critical to better managing these top predators that play important ecological roles in marine ecosystems," says Brown.

The study has been published in the Journal of Fish Biology, and adds to a growing body of research that shows we have a whole lot more to learn about the animals we share the planet with, and it's in our best interest to get to know them better.

"Over the past few decades, personality research has shown that nearly 200 species of animals demonstrate individual personality," says lead researcher, Evan Byrnes. "Personality is no longer considered a strictly human characteristic - rather, it is a characteristic deeply engrained in our evolutionary past."

More From ScienceAlert

Earth's days are getting 2 milliseconds longer every 100 years

But there still aren't enough hours in the day.

18 hours ago
Google says it will be running solely on renewable energy by 2017

Your web search is about to get carbon-neutral.

16 hours ago