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Animal Navigators

Did you know...


Dolphins and whales are called CETACEANS (pronounced si-tay-shuns). Cetaceans are marine mammals with a torpedo-shaped, virtually hairless, body. They have special ways of navigating through water.

Dolphins have a well-developed biosonar system.

Knowing this is important if you want to understand how bottlenose dolphins find their way around in the water. What is biosonar? Bio is a rootword that means life. Sonar means sound.

Sonar allows dolphins to navigate well under water - even in the dark! The sounds they make are called"clicks" which have a high-pitched frequency. This sound comes from their nasal sac system - their nose. The sound they make travels as waves. These sound waves travel through water, bounce off objects or 'targets' in front of the dolphins, and bounce back to the dolphins as an echo. This technique of using sonar is called echolocation (pronounced eh-co-lo-cay-shun). Dolphins get a sense of what their surroundings look like based on how quickly the echo returns to them and from which direction the echo returns. Their sonar system helps them detect other fish, how deep the water is, or whether there's a coral reef in front of them.

When they are feeding, the dolphins' clicking sounds bounce off prey, too. Because of the echo, the dolphins know exactly how far away the fish are, where they are, and in what direction they are heading. The fish, however, don't know that they are going to be prey for the dolphins. They don't know the dolphins are sending sonar to locate them.

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This document was last modified on Tuesday, September 30, 2008 at 11:51:12.