If you’ve ever tried to open your eyes when you’re swimming in a lake or a pool, you know that even on a sunny day, you can’t see very far underwater. So how do whales find their way around the oceans without bumping into things? They rely on hearing rather than sight. Most cetaceans use a technique called echolocation to “see” the things around them. The whale produces a series of sounds; the sound waves travel through the water, bounce off objects in their path, and return to the whale. Cetaceans use echoes to form a picture of their world; tests have shown that dolphins, even when blindfolded, can tell the difference between wood, plastic and metal. Whales can also use sounds to communicate over long distances. Scientists believe that some whales can hear each other when they are as far as 2,000 miles apart. If we could do that, a person in New York City could talk to a friend in Mexico City without using a telephone!
Although they rely on hearing, whales have other senses, too. It was once thought that whales could barely see, and had no sense of smell or taste at all. Scientists now believe that whales can see both in and out of the water, and that they may use taste and smell to identify friends and predators in the ocean. Whales also have a sense of touch, and are thought to have a magnetic sense, too -- this allows them to use the earth’s magnetic field to help them keep track of where they are going when they travel long distances. It sure beats carrying a map ....
