Scientists are perplexed after seeing orcas, sometimes known as killer whales, collaborating with white-sided dolphins to hunt salmon off the coast of British Columbia. According to the research, published in the journal Scientific Reports, the two predators may have evolved a cooperative partnership.
Unlikely Ocean Alliance
“One such perplexing association exists between Pacific white-sided dolphins and northern resident killer whales near the coast of British Columbia, Canada, where these two cetacean species are often sighted within meters of each other,” the report said.
Scientists from the University of British Columbia, the Leibniz Institute, and the Hakai Institute gathered drone footage and acoustic recordings and concluded that this is the first time orcas and dolphins have worked together to enhance their food demands.
“These whales are great salmon hunters. They are extremely specialized and adept predators. “To watch children following dolphins as if they were leaders was both paradoxical and exhilarating,” Sarah Fortune, the study’s principal author, told The Guardian.
Marine Predators Cooperating
Though scientists are dubious why the newly created friendship between the two predators, one possible explanation is kleptoparasitism, in which dolphins steal food from killer whales.
“Another is that the dolphins are looking for safety from mammal-eating transient killer whales and, to a lesser extent, huge sharks.”
According to Fortune, if the dolphins were serving as parasites, the killer whales, which are normally fiercely protective of newly caught food, would not have stayed as docile as they have. This left researchers with the last and most persuasive explanation: the two predators were coordinating.
“The killer whales were positioning themselves to follow the dolphins, and the dolphins looked to be in a leadership role,” Fortune said. “This piqued our curiosity in looking further into our data and seeing if we could figure out what was actually going on.”
The partnership is even more intriguing considering that northern resident orcas hunt salmon, whilst white-sided dolphins prefer tiny fish like herring and anchovies.
