A series of orca attacks on sea vessels off the southern coast of Europe has raised speculation about the reasons behind the killer whales’ recent unusual behavior.
Officials in Portugal and Spain have reported multiple attacks on ships by killer whales off the coasts of these respective nations, according to Live Science. The reports of aggressive orca behavior began in May 2022, and such incidents have occurred frequently since then.
The attacks have caused three ships to sink. However, no humans have been injured or killed in the attacks.
The most recent incident occurred on May 4 in the Strait of Gibraltar, where an encounter with three killer whales caused the boat to sink, according to Live Science.
Skipper Werner Schaufelberger told Yacht magazine that two smaller orcas appeared to be imitating the largest 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,” said Schaufelberger, according to Yacht. “The two little orcas observed the bigger one’s technique and, with a slight run-up, they too slammed into the boat,” he continued.
Just two days earlier, another sailing vessel was attacked by six orcas in the same area, as 9News reported. Witnesses of this event also claimed that the creatures appeared to be teaching their young to attack the boat.
Researchers released a study in 2022 that observed that interaction between sea vessels and orcas had increased over the years, with over 500 occurring since 2020. Most of these interactions had been completely harmless.
Orcas are also incredibly intelligent, with IQs comparable to a 15 to 16-year-old human, according to Orca Torch. Typically, these creatures do not attempt to attack humans.
One theory that has been postulated by some marine animal experts is that the aggressive behavior is revenge for some traumatic event or injury.
Alfredo López Fernandez, the co-author of the 2022 study, told Live Science that these attacks may be traced to one orca that experienced some form of trauma. Fernandez theorizes that this specific creature is an orca named White Gladis.
White Gladis, considered a matriarch among these creatures, may have become aggressive as a result of a collision with a sea vessel or entanglement with fishing equipment, Fernandez said, according to NBC News.
“That traumatized orca is the one that started this behavior of physical contact with the boat,” Fernandez theorized, as Fox News reported.
Fernandez said that while these interactions are done on purpose, the spread of this behavior is likely from imitation rather than the orcas teaching their young.
“We do not interpret that the orcas are teaching the young, although the behavior has spread to the young vertically, simply by imitation, and later horizontally among them, because they consider it something important in their lives,” said Fernandez, according to Fox News.
Some scientists also theorize that this behavior can be attributed to the creatures just being playful.
“They are incredibly curious and playful animals, and so this might be more of a ‘play’ thing as opposed to an ‘aggressive’ thing,” said Deborah Giles, an orca researcher from the University of Washington, according to Live Science.
Whether this new behavior is playful or aggressive, scientists are concerned that this situation will become a safety issue for the whales and sea-faring people.
“If this situation continues or intensifies, it could become a real concern for the mariners’ safety and a conservation issue for this endangered subpopulation of killer whales,” said researchers in the 2022 study, as Live Science reported.