The 52-hertz whale is an individual whale of unidentified species, which calls at the very unusual frequency of 52 Hz. This pitch is a much higher frequency than that of the other whale species with migration patterns most closely resembling this whale's[1] – the blue whale (10–39 Hz)[2] or fin whale (20 Hz).[1] It has been detected regularly in many locations since the late 1980s and appears to be the only individual emitting a whale call at this frequency. It has been described as the "world's loneliest whale".[3]