The mystery of blue whale song
DEC 03, 2009
DOI: 10.1063/PT.5.023896
Wired.com : Blue whales, the largest animals on Earth, are singing in ever-deeper voices every year. Among the suggested explanations are ocean noise pollution, changing population dynamics, and new mating strategies. But none of them is entirely convincing."We don’t have the answer. We just have a lot of recordings,” said Mark McDonald, president of Whale Acoustics, a company that specializes in the sonic monitoring of cetaceans.McDonald and his collaborators first noticed the change eight years ago, when they kept needing to recalibrate the automated song detectors used to track blue whales off the California coast.After collecting thousands of recordings taken over the last 40 years, he and his colleagues discovered that the songs’ tonal frequency is falling every year by a few fractions of a hertz.
© 2009 American Institute of Physics
