Shark or Orca: Which Should You Fear More?
Is a human more likely to survive an encounter with an orca or great white shark in the wild?
— Kameryn F., Yardley, Pa.
According to the figures, white sharks are much more dangerous to humans than killer whales. Despite the name “orca”, there is only one well-documented case of a wild killer whale attacking someone – Hans Kretschmer, who was bitten in the leg while surfing in California in 1972. White shark attacks, while still rare, are slightly more common; there are several hundred officially.
So why are orca attacks so rare? Emma Luck, a marine mammal researcher at the University of Alaska, told me that for the most part, killer whales don’t encounter humans very often. “Orcas are found in all oceans, but they are usually found in higher densities around cold regions at high latitudes,” she wrote in a post. “These are areas where the water isn’t exactly inviting for the average beachgoer!”
She said the 1972 killer whale attack was likely a case of misidentification, as is the case with many shark attacks. “In an open water context, where all parties can see each other clearly, I bet both the shark and the killer whale will leave you alone,” she said.
In fact, you don’t have to search long for police blotters to confirm that killer whale attacks are not only rarer than shark attacks, they’re also rarer than documented cases of swimmers being attacked and bitten by other people. Granted, that’s because there are far more humans than orcas around, but that doesn’t change the conclusion: In the ocean, you’re more likely to be attacked and bitten by a person than by a killer whale.
Since sharks and killer whales both spend most of their time hidden underwater, we often think of them in terms of their brief interactions with us – will they attack us or not? If the only two options are “Don’t attack the human” and “Attack the human”, then it’s hard not to focus on the second one. After all, it’s the second most likely option!
But sharks and killer whales don’t just hang out there to decide if they want to attack us. Just like the people you meet on the street, they are mainly busy doing their own thing.
And in the case of killer whales, one of the things they do is worry about humpback whales.
For reasons unclear to scientists, humpback whales almost seem to have a vendetta against orcas, as a 2016 paper in the journal Marine Mammal Science noted. Around the world, killer whales trying to chase food are routinely interrupted by attacks from humpback whales. Humpback whales will unite and travel great distances to intervene in the hunt for killer whales, regardless of the prey species.
The paper even documents cases of humpback whales seemingly lifting seals out of the water and keeping them out of the orcas’ reach. The humpback whales stayed and protected the prey for hours, until the orcas had to leave hungry.
Why do humpback whales do this? Is this altruism? Game theory? Cross-mammal solidarity? A side effect of their instinct to protect calves? Or do they just hate orcas, for reasons only they know?
“It’s hard to understand why it’s happening,” Ms Luck said. “Especially because it’s not limited to just one population of humpback whales. It’s happening all over the world.”
So don’t worry if you come across a killer whale in the ocean, it’s unlikely to attack you. And if you’re still concerned… maybe consider befriending a humpback whale.