Marine Mammals - Sounds Wild
Killer Whales and Gray Whales


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Killer whales

A gentle surf is rolling up a beach near Pashayjack Bay on Kodiak Island. It's June 25, 2018, and there's something unusual rocking in the surf, like a grey log. It's a dead grey whale, a calf. The calf's tongue is missing, indicating that it was likely killed and eaten by killer whales. Two months later, on August 2, in the same area of Kodiak Island, the body of another grey whale washed up on the beach, this one missing its head and jaws, likely another victim of killer whale predation.

Some killer whales feed on fish. Others eat marine mammals, and in Alaska, that's usually seals, sea lions, dolphins and porpoises. But killer whales are known to attack and eat other whales, including the giant blue whale. Australian researchers have documented killer whales in the South Pacific attacking migrating humpback whales, targeting the calves.

Killer whales are known to target grey whales as they migrate up the California coastline in the spring, from their calving grounds in Mexico to their summer feeding areas in Alaska waters. In April of 2017, researchers counted 33 killer whales in Monterey Bay on the central California coast, and the predators intercepted the passing grey whales and killed a number of grey whale calves. The killer whales were back in April 2018, repeating their ambush on the migrating grey whales.