Weighing up to 380,000 pounds and stretching some 100 feet long, the blue whale -- the largest creature to have ever lived on Earth -- might at first seem difficult for human eyes and ears to miss. But a previously unknown population of the leviathans has long been lurking in the Indian Ocean, leaving scientists none the wiser, new research suggests. From a report: The covert cadre of whales, described in a paper published last week in the journal Endangered Species Research, has its own signature anthem: a slow, bellowing ballad that's distinct from any other whale song ever described. It joins only a dozen or so other blue whale songs that have been documented, each the calling card of a unique population. "It's like hearing different songs within a genre -- Stevie Ray Vaughan versus B. B. King," said Salvatore Cerchio, a marine mammal biologist at the African Aquatic Conservation Fund in Massachusetts and the study's lead author. "It's all blues, but you know the different styles."
The find is "a great reminder that our oceans are still this very unexplored place," said Asha de Vos, a marine biologist who has studied blue whales in the Indian Ocean but was not involved in the new study. Dr. Cerchio and his colleagues first tuned into the whales' newfound song while in scientific pursuit of a pod of Omura's whales off the coast of Madagascar several years ago. After hearing the rumblings of blue whales via a recorder planted on the coastal shelf, the researchers decided to drop their instruments into deeper water in the hopes of eavesdropping further. A number of blue whale populations, each with its own characteristic croon, have long been known to visit this pocket of the Indian Ocean, Dr. Cerchio said. But one of the songs that crackled through the team's Madagascar recordings was unlike any the researchers had heard.
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