The captain of a California charter boat who observed a “spectacular,” rare and co-ordinated killer whale pod attack on two adult gray whales last month is sharing his experience with Global News.
Danny Frank, an operator for Discovery Whale Watch in Monterey Bay, was on board when the seasonal hunting activity was recorded on March 30 and recorded it with a drone.
Two Bigg’s killer whale pods with over a dozen members joined forces for more than five hours to take down two adult gray whales. The badly wounded gray whales escaped by heading into shallow waters
“Basically, two females were swimming at high speed, about 20 miles an hour … on the approach, they dive down and come up for basically a sucker punch to initiate the attack,” Frank explained.
“They want to ram them on the underside, the soft portion where the internal organs are.”
Videos of the extraordinary encounter are posted to the tour group’s Facebook page, attracting a mix of ‘like,’ and ‘wow’ reactions. Frank said the attack on the gray whales is a “polarizer,” with some people on “Team Gray Whale” and others on “Team Orca.”
“In the end, it’s just nature,” he said. “We are there to observe. We never interfere, we just watch it happen.”
What makes the encounter so rare, Frank added, is that killer whales normally prey on gray whale calves protected by a single mother. In that instance, he said a mother would normally try to hoist the calf up on her belly, out of the water, to keep it out of striking distance.
This was a unique opportunity to watch unencumbered adult grays defend themselves.
“You see that these animals actually come together several times and turn their backs to the killer whales,” he said.
“What that does is that offers them some protection because they have the ribs, of course, on the rib cage on their back … and the ribs are going to protect their internal organs.”
In the video, the orcas can be seen taking turns ramming the adult gray whales and biting their pectoral fins — “trading off shots,” according to Frank. One of them appeared to be “Louise,” he added, a notorious and “well-documented whale hunter.”
Western North Pacific gray whales are endangered baleen whales that regularly travel in waters between Alaska and Mexico.
According to the U.S. National Oceanic and Atmospheric Administration, they typically weigh up to 90,000 pounds and reach lengths up to 49 feet. Killer whales, by contrast, normally weigh around 24,000 pounds with lengths up to 32 feet.
Josh McInnis, a marine mammal scientist at the University of British Columbia, said the interaction recorded by Frank is “surprising” and not often heard of.
“We do hear of killer whales harassing adult gray whales, but these killer whales were intent on actually killing one of these gray whales or both,” he said Thursday.
“It really shows us that the population of killer whales that we’re currently studying off the coast of California in Monterey are big game hunters … we don’t see that with transients so often up here in British Columbia.”
McInnis, a behavioural ecologist whose focus is on transient killer whales, said reports of orca attacks on gray whales have existed since the 1950s. Such occurrences are normal in the deep waters of Monterey, he added, where killer whales can chase and tire gray whale calves, and attempt to separate them from their mothers.
He had a few theories, however, as to the pods’ unusual decision to target two adults on March 30.
“Maybe the killer whales had mistaken the two adult gray whales as potentially a mother and a calf, and by that moment, they were already involved and giving it a try to see,” he suggested.
“They may have been testing the gray whales for weaknesses, seeing if either were sick. There could be multiple factors that made this predation interesting.”