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. The detectors are triggered by songs that match a particular waveform. Every year, McDonald had to set them lower.
link
No comments:
Post a Comment