* Fish: This is their main food source, and they eat a variety of fish species, including salmon, herring, cod, and halibut. They use echolocation to find their prey in the water.
* Squid: They also eat squid, which is a good source of protein and energy.
* Other marine mammals: While they are primarily fish eaters, resident killer whales occasionally eat other marine mammals like seals and sea lions, especially when fish are scarce.
Important Note: It's worth mentioning that there are other types of killer whales, like "transient" killer whales, who specialize in eating marine mammals like seals, sea lions, and even other whales. Resident and transient killer whales have different social structures and hunting strategies.