Orcas have been putting on quite the predatory show off the coast of California in recent months. 

In Southern Californian waters, orcas of the Eastern Tropical Pacific (ETP) stock – thought to mainly range from Mexico’s Baja Peninsula down to South America – on a northerly swim-about have been dramatically visible while pursuing some of their smaller cousins. This month, for example, the killer whales were filmed hunting common dolphins off San Diego, including an orca ramming a dolphin clear out of the water in what appeared to be a training exercise for a young member of the pod.

“The orcas catch the dolphin, but let it go after it’s subdued because it’s not as fast anymore, and they bring the baby orca over to try and catch it itself,” Domenic Biagini of Gone Whale Watching, who shared the footage of the dolphin-punting, told NBC News.  

It’s not just common dolphins that have been landing on the ETPs’ menu in Southern California lately: Back in October, the orcas were seen hot on the tail of bottlenose dolphins, which attempted high-leaping acrobatics to steer clear of their big, black-and-white relatives.

“There’s no way for us to know what made them decide to take a road trip up the coast,” California Killer Whale Project lead research biologist Alisa Schulman-Janifer explained to NBC San Diego. “But we do know that they linger in areas where dolphins are. They may be revisiting places where they had a lot of success.”

Indeed, ETP whales, while overall a rare sight here, do make cameos off Southern California, including in 2019, when they chased dolphins near San Clemente. These killer whales can be distinguished from other orca subtypes that periodically ply regional waters – including so-called transient (or Bigg’s) orcas, which prey on marine mammals, and fish-eating resident orcas – by their more faded-looking saddle patches and the barnacles that commonly stud their dorsal fins. 

Research on ETP orcas suggests they may have a more generalist menu compared with some other better-studied populations of killer whales, pursuing not only dolphins and other marine mammals (up to the size of blue whales) but also rays, bony fish, and sea turtles. The California Killer Whale Project notes that ETP orcas “are not a defined ecotype; the ETP designation refers to the area in which they are most often encountered (between the Mexican border and the equator).” 

Orcas – the biggest members of the dolphin family, and sitting pretty at the apex of the oceanic food chain – are known to snack on a wide variety of smaller toothed whales. They may engage in “herding” strategies to snag dolphins, and the kind of torpedoing move the ETP whales were seen doing with common dolphins has been documented elsewhere –as have apparent dolphin-dispatching lessons for young orcas. In one 2013 incident off Argentina, relayed in an Aquatic Mammals paper, a female orca known as Maga struck a dusky dolphin to devastating effect while hunting with several other adult killer whales and a calf. “The injured dolphin tried to swim away,” the researchers wrote, “but Maga took it with her mouth and gently brought it to the calf, which, at times, repeated the same ‘tossing the prey up into the air’ behaviour.”

Meanwhile, farther north up the California seaboard, Bigg’s orcas have also recently been wowing onlookers with high-octane hunts of sea lions in Monterey Bay (where, incidentally, a white killer whale nicknamed “Frosty” showed up this past October):

According to the California Killer Whale Project, some of these sea-lion hunts may also have served as hunting tutorials for orca calves. Predation 101’s been in session up and down the Golden State coast, it seems.

Top header image: Miles Ritter, Flickr