Natures wonders: seal hunting orca packs (Introduction)

by David Turell , Wednesday, October 11, 2023, 21:06 (198 days ago) @ David Turell

In the Antarctic as ice breaks up seals will be resting on icefloes:

https://www.nationalgeographic.com/animals/article/animals-up-close-wave-washing-killer...

The first time the Weddell seal notices the orcas, it’s already surrounded. Until moments before, it had been resting on an ice floe deep in an Antarctic channel. Then three killer whales’ heads appear, bobbing up and down. The orcas are hunting.

On this sheet of sea ice, the nearly thousand-pound seal would be unreachable for most marine predators. But these orcas—a matriarch with her daughter and granddaughter—are three of about a hundred known to have mastered a hunting technique called wave washing. The secret: working together to turn water into a weapon.

The orcas, having identified their target, form a battle line and start charging toward the floe. Just before reaching it, they rotate to their sides in a single, synchronized motion and plunge underwater. The momentum creates a wave so powerful that it floods the ice sheet, cracking the surface and whipping the flailing seal around. Slowly and methodically, they repeat the charge. The ice fractures more. On the third charge, the wave sends the seal flying into the sea. It scrambles to climb onto a piece of ice, then disappears from view, grabbed from below by a killer whale.

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Only about a hundred of this special type of wave-washing killer whale are believed to exist. The population is known as B1. Using mind-blowing problem-solving and communication skills, they are able to locate seals resting on ice floes, and then using teamwork, they create waves to wash the seals into the water.

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“It’s completely sinister to watch,” says wildlife filmmaker Bertie Gregory, who’s spent a decade tracking the orcas, known as B1, a population of pack ice killer whales. The level of intelligence that goes into making each wave “is staggering,” he says. “This isn’t subtle. They are problem solving using very complex teamwork. They’re using water as a tool.” Sometimes it’ll take one wave, about five minutes, before a seal is flung into the sea. Other times a pod can wave wash up to 30 times, about two to three hours, before getting the prey. Scientists rarely see failed hunts. “This behavior is not innate; it’s learned and mastered over decades,” says Gregory. “Every time they make waves, it almost feels like more of a teaching experience than hunting.”

Comment: I have a subscription which allows me to watch the video, so I can't offer the video here. The animal intelligence involved is staggering. In Alaska I've seen humpbacks in a circle produce bubble-net feeding, trapping millions of krill in a bubble circle and ingesting them by coming up to the surface upen-mouthed in the middle of the bubble. Also a learned technique.