With nearly limitless open ocean at its disposal, a gravelly shoreline seems like a peculiar—and dangerous—place for an orca (Orcinus orca) to find itself. Beaches are usually where disoriented whales and dolphins go to die. Indeed, the vast majority of orcas steer clear of shallow water, foraging for fish, squid, and other marine mammals far offshore, where the chances of stranding are nil. But two small populations of the predatory marine mammals—one found off a remote archipelago in the southern Indian Ocean and another here, off Patagonia’s Peninsula Valdés—routinely venture onto the beach in pursuit of prey, a behavior scientists call “intentional stranding.”

For most of the year, the pods of orcas that frequent the waters off Peninsula Valdés feed primarily on octopus, sand perch, and other fish. But come late summer (shortly after the first of the year in the Southern Hemisphere), they head closer to shore, where they find an unwitting and ready source of protein: sea lion pups. Each spring, some 500 adult South American sea lions (Otaria flavescens) haul out onto the peninsula’s beaches to breed and give birth. By late February and March, their pups are old enough to make their first forays into the sea. While the adult sea lions know to be wary as they dash quickly from the beach to open water, the juveniles often dawdle on the shoreline or in the shallows, unaware of the toothy gauntlet that awaits.

Enticed by the potential for a meaty meal, the orcas engage in a high-risk, high-reward strategy: They wait for high tide, navigate a narrow channel that local guides refer to as “Attack Channel,” and quite often beach themselves in a final predatory lunge. To improve their odds of success, these stranding specialists use echolocation to identify and key-in on the easier-to-catch juveniles. Generally, only one or two seasoned members of the pod actively hunt, while the others patrol the edge of the channel, watching and learning. While this unique hunting tactic takes time to master, it’s a role that will eventually be passed down to the younger members of the family group. In the meantime, the pod’s providers seem more than willing to share the spoils with their pupils.