Marine mammals use both vocal and non-vocal sounds to help them find and capture food. Echolocation is the type of vocal sound used by marine mammals. Using sound to see is important to marine mammals because it allows them to feed in the dark at night and in deep or murky water where it is not easy to see. Echolocation is used mostly by whales to capture single prey items such as fish or squid. Bats are the only other mammals known to use echolocation for feeding.
Echolocation used in feeding is different from sounds used in communication. Vocal signals used for communication provide animals with information about other animals in the area. The signals produced by animals during echolocation provide the animal with information about what is in the area. Animals that use echolocation send high frequency click sounds into the environment. The sounds bounce off the objects, and the echoes are received by the animal that produced them. The animal that made the original clicks can determine how far away an object is based on the time an echo takes to return. The farther away the object is, the longer it takes for the echo to return.
