Experts explain the calm attitude of killer whales towards people by the fact that these formidable predators simply do not consider humans as food. Killer whale groups have a strict social hierarchy, headed by the female matriarch.
In our Far East, there are two populations of fish-eating and carnivorous killer whales. The former feed on small fish, the latter on marine mammals. Killer whales are the top of the food chain in the ocean, but this does not protect the species from extinction if the resources necessary to feed it are depleted.