Some animals use additional senses to see the world differently than humans. One such sense is called biological sonar. Biological sonar is when an animal releases a series of sounds that may not be audible to humans and waits for the echoes to return. Toothed whales, which includes porpoises, are one of two types of animals that use biological sonar to sense and navigate through their environment (the other being bats).
These clicks are one of the most high-pitched signals produced by any animal. The time between the released clicks and the returning echo tells the porpoise the distance and location of the nearby object.
The porpoise’s way of sensing its surroundings is disrupted by noises emitted by pile driving, seismic explosions, and ships, just to name a few. Understanding how they detect their underwater world can help protect them.
To learn more about the research behind this fascinating ability, read the article titled, “The Acoustic World of Harbor Porpoises” in the January–February 2015 issue of American Scientist (restricted to American Scientist subscribers and Sigma Xi members):
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