A pod of killer whales spotted far off the west coast of California and Oregon have been observed hunting sperm whales, with UBC researches calling them a new population unique to what they've seen before. (Dreamstime)
big game hunters

UBC researchers discover possible new pod of orcas seen hunting sperm whales

Mar 16, 2024 | 8:45 AM

NANAIMO — A possible discovery of a new population of killer whales off the west coast of the United States is exciting researchers from the University of British Columbia.

At least 49 of the new whales have been identified off the west coast of California and Oregon hunting sperm whales, although researchers say the number in the pod could be as high as 70.

Lead author of the study Josh McInnes said this group of orcas were observed far out in the open ocean, between 60 and 370 kilometres off-shore.

“We took a look at the dorsal fins in the photographs that were sent in, and we couldn’t recognize any of the individuals, which was pretty exciting in many ways, because a lot of the killer whales we’re used to seeing we recognize them and we know who they are, they can be sighted along the coast, but this was something different.”

He said killer whales are normally very social, so it’s rare and “more unique” to possibly be seeing this pod for the first time.

A big clue was bite marks and scars seen on the killer whales from what researchers suspect were cookie-cutter sharks, which live out in the open ocean, areas where prey can be sparse.

“All coastal animals that we’ve seen have never had these shark bite marks. They’re found in water ranging from about 18 degrees Celsius to about 25, but only in really deep, pelagic areas, and it’s kind of a parasite. What they do is they go up to large vertebrates, not just killer whales but tuna, other species of big fish, sharks, other shark species, whales, and they rasp off chunks of flesh.”

He said the bite marks ranged from fresh and pink to dark grey and black indicating an older scar, which helps researches determine how often the orcas are venturing out into the open ocean.

The area of the North Pacific Ocean has three ecotypes of killer whales, which are orcas categorized based on their behaviour and genetic traits, according to McInnes.

“We have resident killer whales which we all know, they eat salmon. We have transit killer whales that eat marine mammals, and then we have another group called the offshore killer whales which also eat fish. But the killer whales that we’re seeing in the open ocean did not resemble the offshore killer whales…because they were also eating marine mammals and we couldn’t match them with an identification. So this is pretty unique.”

with files from Jon De Roo/97.3 The Eagle

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