What drove killer whales’ dramatic behavior this year?

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It’s easy to be misunderstood with the word “killer” in your name.

Still, this year seemed to be a wild one for killer whales. From “attacking” and sinking several boats off southwestern Europe to hunting great white sharks around South Africa and Australia, the black-and-white behemoths appeared to live up to their moniker in 2023.

Their surprising behavior has repeatedly thrust one of the ocean’s top predators into the spotlight since the spring, giving rise to internet memes and fueling debate about whether the whales were just playing around or plotting their revenge.

Yet for scientists, the recent orca antics have been more fascinating than fearsome, and some say the highly intelligent marine animals have shown us how much there still is to learn about them.

Perhaps the biggest orca news of the year was the string of puzzling incidents off the Iberian Peninsula, in which killer whales appeared to be ramming boats. In May, three orcas struck the rudder and a side of a sailing yacht in the region, causing it to sink.

The “attack” came amid an observed increase in encounters between orcas and boats since 2020. Monika Wieland Shields, the director of the Orca Behavior Institute, a nonprofit research organization in Washington, said several hundred incidents have been reported in that time.

At least four vessels sank as a result of the damage in the past two years, she said.

No human injuries or deaths were reported — and in most cases, the whales didn’t sink the boats. But the incidents gained such notoriety that they inspired memes heralding an “orca uprising” or the start of the “orca wars.” Many social media users sided with “team orca,” saying the whales were finally fighting back against humans.

But Shields said that along with the lighthearted fun, the sinkings stoked some real fears.

“We’ve had so many people come out here to where I am in Washington state this year, and they’re asking: ‘Is it safe to view whales here? How big is the boat we’re going on? Is there a chance the whales are going to attack this boat?’” she said. “I do worry that people aren’t going to leave with a respect and fascination for the whales but rather a fear of the whales that’s maybe not warranted.”

Among experts, the incidents off the Iberian Peninsula were baffling, and they sparked debates about the whales’ intentions.

Many scientists think the orcas weren’t attacking at all.

“They’re not afraid of boats, and there’s nothing for them to eat there,” said Robert Pitman, a marine ecologist at Oregon State University’s Marine Mammal Institute. “They’re intelligent, social animals, and they live in what I think is probably an under-stimulating environment for their mental capacity.”

As such, he said, the whales sometimes stumble on something that they think is interesting and repeat that behavior for a while.

Shields said that in video from some of the incidents, the orcas didn’t seem to deliberately target the boats’ rudders or hulls. Rather, she thought the animals were most likely acting out of curiosity and playfulness.

Josh McInnes, a behavioral ecologist at the University of British Columbia, agreed and noted that orcas are known to engage in social learning by spreading or picking up behaviors among their pods. That could explain the string of boat encounters, he said.

McInnes likened the behavior to roughhousing.

“Killer whales are very physical,” he said, “and because they’re 25 feet long and weigh up to 80,000 pounds, when they are physical with an object, it can be a little bit more forceful.”

Given their size, the whales would more likely inflict far more damage to vessels and yachts if they were carrying out coordinated assaults, Shields said.

What’s more, the idea that the whales are rising up and fighting back isn’t consistent with what scientists know about orcas.

“Killer whales just want to have fun,” Pitman said. “Revenge is not a useful thing in nature. It’s not adaptive at all — unless you’re a human, I guess.”

But it wasn’t just orcas’ encounters with boats that made headlines this year. The whales also got attention for their ruthless hunting techniques.

In October, the carcass of a great white shark with its liver ripped out washed ashore near Portland, Australia. Researchers determined that killer whales were to blame.

Orcas don’t typically prey on sharks, McInnes said, but they are capable of it, and they have been observed doing it before in waters off Australia, Africa and even the Pacific Northwest.

And why were the sharks missing specific organs? It was purely practical, experts said.

“Sharks in general are not very nutritious for killer whales, because they’re made of cartilage,” McInnes said. “But the liver is full of fat and lipids, so it’s a very nutritious part of the body to eat.”

Orcas have been known to target the liver when preying on sharks in the past. Since 2017, scientists have followed a hunting spree by two killer whales named Port and Starboard, which have killed at least eight great white sharks off South Africa and left their liver-less bodies to wash up on beaches.

In a video captured by a whale watching expedition off San Diego, a killer whale teaches its baby how to hunt by headbutting a dolphin.
In a video captured by a whale watching expedition off San Diego, a killer whale teaches its baby how to hunt by headbutting a dolphin. Erica Sackrison / Gone Whale Watching

But orca behaviors documented in disparate spots around the world aren’t generally connected. McInnes said different populations of killer whales are genetically distinct and typically don’t socialize or interact.

Studying all observed incidents can, however, provide scientists with broader insights into what orcas are capable of and how they live.

Shields said she has “mixed feelings” about the attention orcas attracted in 2023. If anything, she said, she hopes the headlines inspire people to engage more in conservation efforts.

“I really hope that what people take away from these stories is a kind of fascination and appreciation for orcas,” Shields said. “They’re found in every ocean, and they’re all over the planet. There’s probably a population of orcas in the nearest salt water from where you live. So there’s a lot to be learned.”



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