'Seeing' with sound
One of the most startling adaptations of toothed whales is echolocation.
Echolocating whales, such as sperm whales, send out a series of clicks, then interpret the echoes these make when they bounce back from objects. This bio-sonar locates prey with great accuracy and provides a way for these whales to ‘view’ their world.
How does sound travel through water?
Sound travels as vibrations through matter. In fact, sound travels four times faster through the denser medium of water than through air!
Experiments with dolphins show that they can use echolocation to detect a small object at some distance. They can distinguish its shape and what it’s made of. They can also look at an object with their eyes, then identify it again using only echolocation.
Echolocation means these whales are not dependent on light. They can hunt even in the darkness of the deep – as with sperm whales seeking out giant squid.
Human sonar devices work in exactly the same way, although the whale’s bio-sonar is far more sensitive and subtle.