All around the world, blue whales aren’t singing like they used to, and scientists have no idea why. 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.
Scientists 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. The detectors are triggered by songs that match a particular waveform. Their analysis shows that the songs’ tonal frequency is falling every year by a few fractions of a hertz. There seem to distinct populations of whales in different oceans, yet they’re all showing this common shift.Because only male blue whales sing, the answer may involve mate choice and sexual selection. The researchers hypothesize that as larger, ostensibly more virile whales tend to produce deeper songs, other males may be trying to emulate them, just as human guys might lower their voices when trying to impress a woman.
Scientists note that whale songs are a cultural affair. Humpback whales are known to learn from each other, and whales have extraordinarily large and complex brains. They appear to share many social and cognitive traits with people.
Read more at the original article here.
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