Revenge or just a coincidence? Orca ‘supervising’ other killer whales to sink yachts off Gibraltar

Killer whales, or orcas, have attacked and damaged at least three boats off the Iberian coast of Europe in what some scientists say could be vengeful behaviour stoked by a matriarch orca in retaliation for a traumatic encounter she had with humans.

Researchers say the female orca they named White Gladis may have started ramming boats after a “critical moment of agony” from a collision with a boat or being trapped in fishing nets.

She seems to now be tutoring pods of younger killer whales to swarm and attack yachts sailing off the coast of Gibraltar.

Three such encounters were reported in May.

On May 4, three killer whales struck and pierced the rudder of Mr Werner Schaufelberger’s yacht in the Strait of Gibraltar.

“There were two smaller orcas and a larger one. The little ones shook the rudder at the back, while the big one repeatedly backed up and rammed the ship with full force from the side,” Mr Schaufelberger told German publication Yacht.

He said the smaller orcas seemed to be learning the aggressive behaviour from the bigger one.

The Spanish coast guard towed Mr Schaufelberger’s boat towards shore after the attack, but it sank at the port entrance.

On May 2, six orcas slammed into the hull of another yacht also sailing in the Strait of Gibraltar, near Tangier in Morocco.

“It’s an experience I will never forget,” Mr Stephen Bidwell, 58, a photographer who was on board for a sailing course, told Britain’s Daily Telegraph.

“I kept reminding myself we had a 22-tonne boat made of steel,” he said. “But seeing three of them coming at once, quickly and at pace with their fins out of the water was daunting.”

“A clearly larger matriarch was definitely around and was almost supervising,” said Mr Bidwell, suggesting it could be White Gladis herself.

Around the same week, Mr Greg Blackburn from Leeds said he was already dealing with a rolling swell of waves of 1.8m to 3m while on his yacht when orcas hit his rudder with two large blows.

He said he dropped his main sail and tried to make the vessel “as boring as possible”.

The whales eventually lost interest, but not before causing extensive damage, leaving the boat to limp back to port.

‘Revenge’

These incidents are drawing intense scrutiny from researchers over whether the killer whales are learning the aggressive behaviour from one another.

Mr Alfredo Lopez Fernandez, a biologist at the University of Aveiro in Portugal, told the news website Live Science that one “traumatised orca”, possibly White Gladis, could have started ramming boats following a “critical moment of agony”.

Her aggressive behaviour is now being copied by younger killer whales, he said.

“The orcas are doing this on purpose. Of course we don’t know the origin or the motivation, but defensive behaviour based on trauma, as the origin of all this, gains more strength for us every day,” said Mr Lopez Fernandez.

Orcas are social creatures that can easily learn and reproduce behaviours they see others doing.

“We do not interpret that the orcas are teaching the young, although the behaviour has spread to the young vertically, simply by imitation, and later horizontally among them, because they consider it something important in their lives,” said Mr Lopez Fernandez.

May just be a ‘fad’

But others are sceptical, saying the orcas may just be exhibiting territorial, defensive or playful behaviour rather than coordinated aggression.

“I think it gets taken as aggression because it’s causing damage, but I don’t think we can say that the motivation is aggressive necessarily,” Ms Monika Wieland Shields, director of the Orca Behaviour Institute, a non-profit research organisation based in Washington state, told NBC News.

Ms Shields said there have been no clear instances of killer whales exhibiting what could be thought of as revenge behaviour against humans.

“They’ve certainly had reason to engage in that kind of behaviour,” she said.

“There are places where they are shot at by fishermen. They’ve watched family members be taken from their groups into captivity in the 60s and 70s. If something was going to motivate direct aggression, I would think something like that would have done it.

“We’ve given them plenty of opportunities throughout the world to want to take revenge on us for various things, and they just choose not to.”

Accounts of recent “attacks” on boats were more likely be just “fad” behaviour, Ms Shields suggested.

“It’s kind of a new behaviour or game that one whale seems to come up with, and it seems to spread throughout the population – sometimes for a matter of weeks or months, or in some cases years – but then in a lot of cases it just goes away,” she said.

Ms Shields said the behaviour of the orcas off the Iberian coast may also be temporary.

“This feels like the same type of thing, where one whale played with a rudder and said: ‘Hey, this is a fun game. Do you want to try it?’ And it’s the current fad for that population of orcas,” she said.