Orcas, the largest dolphins in the sea, subsist on a diet of fish, seals, sea lions, squid and dolphins, and they also eat porpoises and whales. Also called killer whales, orcas are highly social animals that travel in family groups called pods.
Killer whales are apex predators that feed on prey of all sizes, including the blue whale, the largest animal on Earth. Scientists have observed killer whale pods coordinating attacks on their prey. As highly social animals, killer whales travel in pods that are each led by a matriarch. There are three types of pods to which killer whales can belong: resident, transient and offshore, and each pod type has different prey choices.
Resident pods tend to remain in one area, feeding on local fish populations. Transient pods tend to travel over a larger area than resident pods and prey on a wider selection of animals, including other marine mammals. Offshore pods travel beyond the coastal waters frequented by resident and transient killer whale pods and also prey on a wide selection of marine animals. Offshore killer whales also have a preference for eating sharks, and researchers have discovered that biting into shark skin can contribute to excessive tooth wear.