Stunning video taken from a drone has emerged of an extremely rare sight caught on camera: two adult female killer whales and their two calves eating a shark alive in California’s Monterey Bay. This type of killer whale, the offshore killer whale, is tough to catch on film, and even tougher to see eating, but drone pilot Slater Moore managed to capture the incredible footage, which you can view below.

Reports indicate that the shark was probably a sevengill shark, which can be up to 10 feet long, although this was about half that length. Still, it was bigger than the calves themselves.

Offshore killer whales are tough to catch feeding because they usually eat fish, sharks and squid, and thus are usually underwater when they’re doing so. Spotted killer whales are the most common type of killer whales found in Monterey Bay, and they typically eat other mammals.

Katlyn Taylor, a marine biologist with the tour company Monterey Bay Whale Watch, was quoted in news reports as saying that the whale suddenly emerged and brought up the whole shark, “and it was still alive, it was squirming around.”

“They’re kinda tricky animals to study,” she said according to a The Verge report. “They hold their breath a long time, they swim really fast, they travel way offshore. That’s part of the fun though, you never know what’s going to happen.”

“Offshore Killer Whales are similar to resident whales, but can be distinguished generally8 by features such as their: rounded fins with multiple nicks on the edge, smaller overall size, tendency for males and females to be more similar in size (less “sexual dimorphism”),” NOAA says on its website. “Offshores have the largest geographic range of any killer whale community in the northeastern Pacific and often occur 9 miles (15 km) or more offshore. But, they also visit coastal waters and occasionally enter protected inshore waters. Animals typically congregate in groups of 20-75 animals with occasional sightings of larger groups up to 200 whales. They are presumed to feed primarily on fish, though they have been documented feeding on sharks. Genetic analyses indicate that offshore killer whales are reproductively isolated from other forms of killer whales. Offshore killer whales are among the least observed and understood of all killer whale populations.”