Killer Whales and Dolphins May Team Up to Hunt Salmon

Killer whales and dolphins could team up to hunt salmon

By Meghan Bartels edited by Andrea Thompson

We could all use a friend to help us find dinner from time to time.

New research published on December 11 in Scientific reports postulates that killer whales (Killer whale) off the coast of British Columbia could forge hunting partnerships that bridge the gap between species.

Sarah Fortune, a marine ecologist at Dalhousie University in Nova Scotia, and her colleagues used drones and camera-equipped tags to study killer whales for two weeks in August 2020. While observing them, they noticed something strange: the regular presence of Pacific white-sided dolphins (Lagenorhynchus obliquidens).

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“We kept finding that when the killer whales were feeding, the dolphins were there,” Fortune says. “That gave us a little inkling that maybe something big was going on.”

So the scientists delved into the data, looking for evidence of how these different marine mammals interacted during killer whale feedings, when the animals hunt large adult Chinook salmon (Oncorhynchus tshawytscha). The researchers noticed that the killer whale hunters they studied seemed to show a notable preference for following dolphins. In one particularly striking sighting, a killer whale caught a salmon and dined while nearby dolphins gobbled up pieces of fish.

To Fortune and his colleagues, the interactions suggest that these killer whales – part of what is called the Northern Resident population – and the dolphins are teaming up, with one or more dolphins helping a killer whale catch its prey and then sharing the feast in a striking display of interspecific cooperation. “Killer whales that are salmon specialists, that’s what they rely on,” Fortune says. “The fact that they were following the dolphins and dragging them behind them and kind of letting the dolphins guide them really surprised me.”

But it may be too early to announce a power alliance with marine mammals, says Janet Mann, a behavioral ecologist at Georgetown University who specializes in marine mammals and was not involved in the new research. She would like to see more evidence that dolphins actually benefit from and seek partnership rather than simply being exploited by killer whales eager to use their hunting skills.

“I don’t think it was demonstrated as cooperation because I think the standards for cooperation are a little higher,” Mann says. “It’s not like the dolphins are waiting for the killer whales to arrive and then say, ‘Let’s go’.”

Fortune agrees, saying that his and his colleagues’ observations support the scientific definition of cooperation they used — behavioral coordination — but do not yet fit a definition of mutualism, which requires that both species benefit.

Editor’s Note (11/12/25): This article was updated after publication to include additional commentary from Sarah Fortune.

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