How whales sing without drowning, an anatomical mystery solved
Feb 23, 2024
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An exploration of how baleen whales produce their iconic deep tones, revealing the evolution of their vocal structures. Discover how baleen whales use a modified larynx to create vocalizations, but are limited by their anatomy in escaping anthropogenic noise pollution. Insights into the challenges faced by whales due to human-generated noise and the need for regulations to protect them.
Baleen whales use a modified version of the larynx to produce sounds, limiting frequency and depth.
Toothed whales have evolved a specialized organ in their nose for sound production during deep dives.
Deep dives
Evolution of Sound Production in Baleen Whales
Baleen whales, among the largest animals on Earth, use sound to navigate, communicate, and find food in the vast ocean. They produce low-frequency sounds, ranging from 10 to 300 Hz, to locate each other. Unlike toothed whales, baleen whales maintain the ability to make sounds through adaptations in their larynx, using unique structures that involve vocal folds to create sounds that are ancestral to all baleen whales.
Limitations in Sound Production Depth and Frequency Range
Toothed whales have evolved an organ in their nose to produce sounds independently of their larynx, enabling deep dives while vocalizing. In contrast, baleen whales are limited by air supply, hindering sound production beyond 100 meters deep. Their communication is further constrained by the narrow frequency range of 10 to 300 Hz, aligning with the frequency range of human-generated marine noise, impacting their ability to avoid and escape anthropogenic noise pollution.
Implications for Conservation and Noise Reduction
The physiological evidence of baleen whales' inability to communicate effectively due to human-induced noise underscores the necessity for noise reduction measures in marine environments. Current international laws focusing on noise reduction in oceans need revision to consider the specific frequency and amplitude ranges that affect whales. Understanding these limitations can guide conservation efforts and policy changes to protect whales from the detrimental effects of human-generated noise pollution.
The deep haunting tones of the world's largest animals, baleen whales, are iconic - but how the songs are produced has long been a mystery. Whales evolved from land dwelling mammals which vocalize by passing air through a structure called the larynx - a structure which also helps keep food from entering the respiratory system. However toothed whales like dolphins do not use their larynx to make sound, instead they have evolved a specialized organ in their nose. Now a team of researchers have discovered the structure used by baleen whales - a modified version of the larynx. Whales like Humpbacks and Blue whales are able to create powerful vocalizations but their anatomy also limits the frequency of the sounds they can make and depth at which they can sing. This leaves them unable to escape anthropogenic noise pollution which occur in the same range.