An aggressive humpback whale appeared to turn the tables on a pod of orcas off the Canadian coast, stalking then ambushing the group that more usually would have been attacking it.
The rare occurrence took place on the Salish Sea between British Columbia and Washington state and was witnessed and recorded by enthralled tourists on a whale-watching trip.
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“There’s something happening in front of us that hasn’t been seen before,” Olivia Esqueda, an environmentalist, told CHEK News.
“It’s hard not to just kind of be like a kid at Disney World.”
Esqueda described a 20-minute encounter in which a five-year-old humpback of undetermined sex, named Valiant, took on the nine-strong transient pod of Bigg’s orca.
Orca, also known as killer whales, are the largest species of dolphin and usually feed on seals and sea lions individually but will team up to attack other whales.
“The humpback whale was kind of trailing up behind them,” Esqueda said. “We all of a sudden saw the next surface with the humpback right in the middle of all the killer whales.”
Valiant’s aggression might have been because it feared being attacked, experts say. An unnamed observer on the whale-watching boat Prince of Whales told the Vancouver Sun the humpback was “rolling around and trumpeting with each surfacing”, possibly to deter or distract the orcas.
While video footage of such an encounter is rare, humpbacks have been known to go on the offensive. The Sun reported that in 2016 researchers from Oregon State University found 30 cases in which humpbacks attacked orcas when they were pursuing whales and other mammals.
“The humpback whale is, to our knowledge, the only cetacean that deliberately approaches attacking mammal-eating killer whales and can drive them off,” said Dr Robert Pitman, a marine ecologist and report co-author.
Mark Malleson, captain of the Prince of Whales whale-watching boat, said Valiant was known locally for its aggression, perhaps because of earlier encounters with orcas.
“It’s apparent when it was a calf, when it was in its first year, it had had a close call,” he told CHEK News. “[It has] rake marks, the killer whale rake marks. It would have happened when it was with its mom.”