Whale calls at unique frequency for decades, no response from others

A lone whale has been tracked for decades calling at a frequency of 52 hertz, a pitch far higher than the 15 to 25 hertz typical of blue whales or the 20 to 40 hertz of fin whales. No other whale has ever been recorded responding to this call, leaving scientists uncertain whether the animal is a unique hybrid, has a physical deformity, or simply belongs to an unknown species. The whale, first detected by the U.S. Navy in 1989 and later studied by marine biologist Mary Ann Daher, has been heard annually across the North Pacific, from the Aleutian Islands to the coast of California. Its call pattern suggests it is a baleen whale, but its frequency does not match any known species. The whale's solitary signal raises questions about communication and social behavior in the ocean, as it continues to broadcast a call that no other whale answers. Researchers have no explanation for its uniqueness and no plans for further study, leaving the mystery unsolved.