Population structure and mating patterns of killer whales ("Orcinus orca") as revealed by DNA analysis. Vocal learning has also been seen in killer whales ("Orcinus orca"). The "Orcaella" dolphins are also close relatives of the orca ("Orcinus orca"). Predation by killer whales ("Orcinus orca") is poorly documented, though all ages are hunted. The islands are famous for their resident pods of orcas ("Orcinus orca"). Orcas ("Orcinus orca") are regular visitors around the islands. Dolphins are frequently sighted and killer whales ("Orcinus orca") are infrequently sighted near the island. The killer whale ("Orcinus orca") is the largest species of the Dolphin family. Orca ("Orcinus orca") are famous throughout the Sound, and are a large tourist attraction. Killer whales ("Orcinus orca") and sharks are known to prey on the dwarf sperm whale. Potential predators of the silky shark include larger sharks and killer whales ("Orcinus orca").