Minke Whales' Ultrasonic Hearing Revealed in New Study

A team of marine biologists from Norway, the United States, and Denmark has conducted a groundbreaking experiment by testing the hearing abilities of live baleen whales for the first time. Their research, which was published in the journal Science, involved monitoring the brain activity of two wild minke whales. The aim of the study was to understand how human-generated ocean noise may affect marine life, as scientists are increasingly concerned about the impact of such sounds on sea creatures.

To carry out this test, the researchers came up with a method to measure the hearing of the whales by recording their brain waves in response to different sounds. The team chose minke whales due to their smaller size compared to other whale species, which made them easier to study. They tracked the whales through a narrow waterway between two islands in Norway, where they used net barriers to guide the animals into a confined area.

After trapping the whales, the researchers raised a net below them to bring them to the surface, where they attached electrodes to their heads to measure their brain waves. The team played various sounds from speakers, observing how the whales responded. One whale was tested for 30 minutes, while the other was tested for 90 minutes. Once the tests were complete, both whales were released back into the wild.

This experiment marked the first time that baleen whales’ brain waves were successfully recorded in response to sound. The results largely matched previous predictions based on studies of whale ear structures from deceased animals. However, the team discovered an unexpected finding: the whales were able to hear ultrasonic frequencies. This suggests that all baleen whales may have the ability to perceive high-frequency sounds.

This new insight may lead scientists to reconsider past research on how whales react to sonar, underwater sound equipment, and other noises produced by ships and vessels. It could also open up new areas of study on how baleen whales might defend themselves against killer whales.