Whale Songs' Changing Pitch may be Response to Population, Climate Change

A new study states that a seasonal variation in the whales' pitch is in due part of breaking sea ice in the southern Indian Ocean. The new research also extends the mysterious long-term falling pitch to related Baleen Whales. This also rules out noise pollution as the cause of the global long-term trend.Blue and Fin Whales are among the loudest and largest animals in the ocean. Only the males sing. They creating a humming sound that can be as loud as a large ship and can travel up to 1,000 miles; allowing for long distance communication across larger oceans. The pitch of Blue Whales though has been dropping incrementally over the past several decades, but the reason why has remained a mystery. The new study also finds the same pattern of falling pitch in Fin and Madagascan Whales. The researches involved with the new study use new data from the Southern Indian Ocean to rule out noise pollution as the cause of the pitch change. Instead, the new study suggests the pitch drop is a consequence of singing less loudly due to growing numbers of whales or changes in the ocean due to climate change. The new research also uncovers a seasonal counterpoint in the calls of Antarctic Blue Whales This could potentially be related to the noise of melting sea ice. The new study finds Blue Whale calls in the southern Indian Ocean increase in pitch during the summer. The pitch could be increasing as Whales sing louder to be heard over breaking sea ice in the Arctic.

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