A new study reveals that certain baleen whales have evolved to communicate at frequencies too low for orcas to hear, a strategy to avoid being detected by these predators. The research, published in Marine Mammal Science, sheds light on the acoustic adaptations of whales in response to predation pressure.
Key Findings:
Low-Frequency Communication: Whales like blue, fin, and minke whales use sounds below 100 hertz, which are undetectable to orcas.
Fight vs. Flight: Baleen whales that choose to fight orcas communicate at higher frequencies.
Acoustic Crypsis: The study suggests that this low-frequency communication may have evolved as a defense mechanism.
Trevor Branch, professor at the University of Washington, led the study, which analyzed the hearing ranges of orcas and the vocalizations of various baleen whale populations. The research found that the calls of 'flight' species travel less than a kilometer, making them difficult to track even if heard.
This adaptation influences not only survival but also mating patterns, as males of 'flight' species use simple, repetitive songs to attract mates while minimizing the risk of attracting orcas.