Southern Resident male killer whale K35 in Juan de Fuca strait as J's & K's make their way back into the waters of the Salish Sea.
May 1, 2017

‘Unprecedented’ series of killer whale attacks filmed in California

A group of orcas was caught on video killing a gray whale calf last Friday – the latest fatality in what experts are calling an “unprecedented” series of attacks which were led by a group of nine related killer whales and which claimed a total of four victims over a seven-day span.

The attacks have taken place in Monterey Bay, California, and the most recent occurred on Wednesday and was filmed by Nancy Black, a marine biologist at Monterey Bay Whale Watch, according to reports published by The Guardian and the San Francisco Chronicle.

The video shows the group of nine orcas separating a gray whale calf from its mother and killing it over the span of just 20 minutes. Earlier attacks had involved as many as 33 killer whales, said Black, but the same group of nine orcas, related across four generations and led by a matriarch.

Orca attacks often take hours to complete and are unsuccessful, the biologist explained. But the efficiency of Wednesday’s kill was “like a record,” she told The Guardian. “I’ve been studying them for 30 years... [and] this has really never happened before... It’s pretty unprecedented just because the same group of killer whales has been feeding on them each time.”

Delayed start to hunting season likely to blame

In a typical killer whale attack, Black told the Chronicle, the mother gray whale uses her tail in an attempt to fight off the predators, and will also roll over, belly-up with her calf on top. But in Wednesday’s attack, she said, the mother and calf were skinnier and likely weaker than typical gray whales, making them easier prey for the hunting orcas.

While unfortunately for the gray whales, Black said told The Guardian that it has been “kind of exciting to see this group and how they’ve gotten really good at hunting.” The first attack, which was the one that involved a total of 33 whales, took place on April 20, the Huffington Post noted, and despite the fact that they have already claimed and consumed multiple victims, the biologist said that they do not appear to be slowing down in their hunting efforts.

“You'd think they'd already be full,” she told the Chronicle, “yet [they] continue to eat... I expect they will become... more social in upcoming days as they [usually] do after stuffing themselves.” Black believes that the killing spree may be due to the late arrival of the gray whales, who travel north from Mexico each year, and thus the delayed start of the orcas’ hunting season.

In addition to gray sharks, killer whale calves tend to prey on seals, sea lions, dolphins, tuna, and even great white sharks. Like wolves, the creatures work in packs, attempting to separate the calf from its mother so that they can pick off the smaller, weaker whale while attempting to avoid the massive tail of its much larger mother. They also attempt to hunt humpback whales, Black noted, but those creatures tend to band together in an attempt to fight off their predators.

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