Killers whales have caused mayhem for boaters since 2020, ramming into the rudders of more than 600 ships and causing many to sink.
Marine biologists have now revealed that their seemingly aggressive behavior may actually just be the actions of boredom among the highly intelligent animals.
In a report released on Friday, biologists, government officials and other marine representatives said the boat rudders are a prime toy for orcas in open waters.
Researchers believe the sudden fad of attacking boatsstarted in around 2019 after a rapid increase in orca's main food source, bluefin tuna, thanks to conservation efforts and fishing bans.
This meant the whales spentless time hunting, leaving them with ample leisure time.
In a report released on Friday, biologists, government officials and other marine representatives said the boat rudders are a prime toy for orcas in open waters.
Although the reason why the attacks started haven't officially been confirmed, marine biologists believe it kicked off when one teenage whale played with the rudder in front of its peers, creating a trend.
'Maybe that individual touched a rudder and felt that it was something fun to play with,' Alex Zerbini, who chairs the scientific committee at the International Whaling Commission toldThe Washington Post.
'And, after playing, it began propagating the behavior among the group until it became as widespread as it is now.'
Orcas have started similar trends in the past like wearing dead salmon as hats and playing games of chicken.
The boat attacks were instigated by a group of 15 mostly juvenile and teen whales - between the ages of five and 18 - who approach the vessels slowly to supposedly nudge their noses gently against the rudders.
Marine biologists reported that although adult females have been observed in the area at the time of the attack, 'they seem to be just sort of keeping an eye on their kids, who are doing the actual playing,' Naomi Rose, a senior scientist at the Animal Welfare Institute told The Post.
Researchers believe the trend started when one teenage whale bumped a rudder with its nose in front of its peers. Pictured: A killer whale attacking Dieter Peschkes's yacht off the Iberian Peninsula in 2021
Orcas have started similar trends in the past like wearing dead salmon as hats and playing games of chicken. Pictured: a killer whale attacking Alan Bruce's yacht off the Iberian Peninsula in 2021
The report said that killer whales are known to play with other objects or animals in the sea but can go overboard, in some cases killing the object of their amusem*nt. Pictured: Two killer whales attacking Dieter Peschkes's yacht off the Iberian Peninsula in 2021
Researchers believe their boredom stems from the abundance of food in the Iberian Peninsula - where the attacks have primarily occurred off the coast of Portugal, Spain and Morocco.
In 2019, orcas faced food shortages as the population of their primary food source, bluefin tuna, diminished causing them to spend the majority of their time hunting and eating any food they could find.
But after the bluefin tuna's population bounced back the following year, whales no longer needed to spend all their time hunting down food, leaving them with nothing to do.
'The sea is a very boring place for an animal,' Renaud de Stephanis, president of CIRCE (Conservation, Information and Research on Cetaceans), an organization dedicated to preserving marine life told USA Today.
'Imagine if you're a dog or some other mammal, you can interact with objects around you. But in the sea, there's not much for the orcas to interact with, so they play with the rudders,' she said.
The report said that killer whales are known to play with other objects or animals in the sea but can go overboard, in some cases killing the object of their amusem*nt.
'... In the southern resident killer whale population of Washington, USA, which feed on salmon, individuals will 'play' with harbor porpoises to the point of killing them, which may be a similar escalation of an initially less harmful interaction,' the report said, adding: 'So this behavior seems on that spectrum.'
The researchers warned mariners against taking it upon themselves to launch flares and other devices to scare the whales, saying it could just make the game more fun for them.
Instead, they suggest making the rudders less fun for the orcas to play with, or if possible, removing them altogether.
The group is working on alternative methods to replace the rudders' smooth surfaces with bumpy or abrasive materials and devices that will make loud noises, like banging sounds, to deter the whales from approaching.
In the report, marine biologists also advised boaters to travel around killer whale hotspots to mitigate an attack before it occurs with the caveat that whales are constantly migrating so predicting where they'll be isn't 100 percent successful.
'We don't want to see more boats being sunk and we don't want to see people in distress,' Zerbini told The Post.
'But we also don't want to see the animals being hurt. And we have to remember that this is their habitat and we're in the way.'
Since the advice for vessels to flee from any possible whale interaction in May of last year, the number of attacks has declined by 70 percent.
Why do orcas attack boats?
A study in Marine Mammal Science last yearconcluded that the attacks on small boats follow the same pattern: orcas join in approaching from the stern, disabling the boat by hitting the rudder, and then lose interest.
Expertsbelieveorcas may be teaching others how to pursue and attack boats, having observed a string of 'coordinated' strikes in Europe.
Some even think that one orca learned how to stop the boats, and then went on to teach others how to do it.
The sociable, intelligent animals have been responsible for more than 500 interactions with vessels since 2020, with at least three sinking.
It does not appear to be a very useful behaviour, and is not clearly helping their survival chances.
In fact, Alfredo Lopez, an orca researcher at the Atlantic Orca Working Group, saysthe critically endangered whales 'run a great risk of getting hurt' in attacks.
Dr Luke Rendell, who researches learning and behaviour among marine mammals at the University of St Andrews, agreed the behaviour does not seem to be an evolved adaptation.
Instead, he pointed to 'short-lived fads', like carrying dead salmon on their heads - a sign of sociability, but not a desperate bid to survive.
The answer to the boat attacks might lie with White Gladis, an orca with a personal vendetta against boats or people.
Lopez said 'that traumatised orca is the one that started this behaviour of physical contact'.
'The orcas are doing this on purpose,' he told livescience.com. 'Of course, we don't know the origin or the motivation, but defensive behavior based on trauma, as the origin of all this, gains more strength for us every day.'
Like humans, the orcas have 'sophisticated learning abilities' that allow them to digest the behaviour of others and replicate it themselves, a study in peer-reviewed journal Biological Conservation indicates.
