Killer whales are one of the most widespread animals on earth, but spread out among vast oceans, they can remain quite mysterious.
Previously, scientists thought that killer whales, or orcas, found along south Alaska to Southern California belonged to a single West Coast population.
But According to Hakai magazine, after anaylizing over 100,000 photographs, Canadian researchers have discovered a new kind of killer whale that hunts large mammals, like grey whale calves. And they also prefer the deep water canyons rather than staying along the coasts. Known as “outer coast killer whales,” they’ve largely gone unnoticed.
During the study, which took place from 2006 to 2018, the researchers have identified 150 of such whales, though only 26 have ever been seen in the coastal waters of the northeast Pacific.
The photographic evidence suggests that there is very little mixing between the outer coast killer whales and the far more familiar coastal ones. They also appear to have different dialects, with higher-pitched calls than the coastal kind.
“Killer whales are found all over the world,” says Josh McInnes, a master’s student at the University of British Columbia, who led the study. “They spend most of their time in coastal waters, but we’re now finding that they do inhabit the offshore oceanic waters. And there’s basically nothing known about them out there.”
The outer coast killer whales are thought to be a subset of transient, or Bigg’s, killer whales, marine mammals known for their highly coordinated hunting sorties.
“When you look at the open ocean, you can’t see anything but water,” says McInnes. “But below the surface, deep down, there is a whole interesting bathymetry that supports life.”
As Hakai further noted, “Some killer whales in the study’s catalog turned up in even more remote locations, leading the researchers to suspect that they may be yet another distinct community. These killer whales, which McInnes and his colleagues dubbed the oceanic killer whales, are predominantly found hundreds of kilometers from land. Shark-eating open ocean killer whales, known as offshore killer whales, have been documented in the northeast Pacific before, but the oceanic killer whales were seen hunting marine mammals, which makes them a complete mystery.”
“To us,” McInnes adds, “it shows that we don’t know anything about what is happening out there on the open ocean.”