What is Echolocation?
Imagine you’re a crewmember on board a submarine. You believe an enemy sub is in the area, and you want to locate it. A pulse of sound waves is sent out from your submarine. These sound waves bounce off of objects in the water and echo back to you. Computers can calculate how far away your target is by using the speed of sound in water and the time it takes for the sound to return to the submarine.
Did you know this technology was actually developed from the study of bats? Bats also use sound waves to determine the location of objects. We call this echolocation, or sonar. The difference is that bats don’t need a computer to work out the equations. They’re able to process the information as easily as we’re able to understand what we see or hear.
Bats aren’t the only animals to make use of echolocation. It ‘s also used by whales, dolphins, shrews, and some birds. As we continue our lesson, we’ll discuss echolocation as it is used to locate prey, as navigation, and as a means of communication.
One way animals use echolocation is to find food. Bats use echolocation to help them find insects in the dark. Dolphins use echolocation to zero in on the fish they’re trying to catch. Sperm whales and killer whales can even produce sound waves strong enough to stun their prey, making for an easy meal.
The process of echolocation is similar for all animals that use it, but let’s use bats to discuss locating prey in more detail. Bats cannot see their prey well in the dark, so they send out sound waves that echo back to them. You might wonder why you don’t hear bats using echolocation as they fly around your house at night catching insects. This is because the sounds they use for echolocation have such a high pitch that they’re out of the range of human hearing.
We can’t hear the noise, but the bats can find and catch insects as small as a mosquito using this technique. Bats listen to the echoes to determine an object’s size and location. Bigger objects return a powerful echo. Smaller objects return a weaker version of the sound. They also know the object is located in the direction the sound returns from.
Bats can determine which way an object is moving as well. By comparing the pitch of the original sound to the pitch of the echo, they can determine if the object is moving closer or further away. An object moving away from the bat returns an echo with a lower pitch, and an object moving toward the bat returns an echo with a higher pitch. This is known as the doppler effect. You can imagine an insect squealing as it heads toward its fate, or producing a deep laugh as it gets away from a bat.
Echolocation is also used by animals for navigation. In other words, it helps them find their way around. A good example of this is cave swiftlets and oilbirds, which are the only birds to use echolocation. When these birds fly into a cave to roost, it becomes too dark for them to see. Instead, they make a buzzing sound that allows them to use echolocation to find their way without flying into the walls of the cave.
Bats also use echolocation to prevent running into objects. Dolphins and whales use echolocation to find their way around the oceans. It’s even possible for humans to use echolocation. It isn’t a normal human ability, but some blind people have learned to use echolocation to navigate their surroundings.
Some types of whales, like humpbacks, have another use for echolocation. They use it as a form of communication. If you think about it, it makes sense. We use sound waves to produce speech; why wouldn’t a whale use sound waves to communicate? They communicate with the same sound waves used for echolocation because of the distance this type of sound wave can travel underwater.
Echolocation, or sonar, is the use of sound waves to determine the location of objects. Many animals have this ability, including bats, whales, dolphins, shrews, and some birds. These animals send out sound waves that echo back to them to locate prey and for navigation. Because of the distance that sound waves used for echolocation can travel underwater, some whales even use it as a form of communication.
The direction of the echo tells the animal where an object is located. The larger the object the sound bounces off of, the more powerful the echo will be. This allows the animal to determine the size of the object. The animal can also tell whether the object is moving toward them or away from them by comparing the pitch of the original sound to the pitch of the echo. The doppler effect makes objects moving toward the animal return a higher pitch and objects moving away from the animal return a lower pitch.