Animal Echolocation
When you think of the incredible wonders of nature, you may not think of sound. But animals use sound in a truly remarkable way: a feature known as echolocation. Echolocation is a type of process in which animals send out sound waves and then interpret the returning echoes to build up a picture or “map” of their environment. It’s like having built-in sonar (the technology used by ships to detect and locate objects under water). Animals have used echolocation in different ways to survive in environments all over the world, from bats in caves to killer whales in the open ocean. Let’s explore the incredible variety of animal echolocation.
What is Echolocation?
Echolocation is defined as the process in which an animal sends out sound signals and uses the returning echoes to determine the location of objects in its surroundings. This type of natural sonar can help animals gain a greater understanding of their environment and find food, avoid predators, and communicate with other animals.
Types of Animal Echolocation
Animals make use of echolocation in a variety of ways, and one way to classify them is based on their calls and the behaviors that accompany their use of echolocation. Some animals, such as bats, use high-frequency calls to search for food. In contrast, whales and dolphins use low-frequency calls to map the ocean floor or to find mates and keep track of their young. Here is a look at the major categories of animal echolocation:
Active Echolocation
This type of echolocation is used by some species of bats and dolphins. An animal that uses active echolocation emits a call or sound pulse, and then listens for the echo that is reflected back from its environment. This echo is then used to build a “sound map” of the animal’s surroundings.
Passive Echolocation
This type of echolocation is used by some species of whales and dolphins. Passive echolocation does not involve any active emission of sound pulses or calls; rather, the animals use the sound waves that are naturally present in their environment to build a picture of their surroundings.
Whistling
Some animals, such as the capuchin monkey and certain species of bats, produce a sound that resembles whistling. These animals use the sound to communicate with one another, to mark their territory and to find food.
Ultrasound
Ultrasound is a high-frequency sound that lies beyond the range of human hearing. Some animals use ultrasound for communication, and some bats use it for echolocation.
Facial glands
Some species of bats, such as the pallid bat, use their facial glands to produce larynx-derived echolocation calls. These calls are used to detect items such as insect prey and other objects in the bat’s surroundings.
Types of Sound Emission
When studying echolocation, scientists have identified two primary types of sound emission:
Pulse Emission
Pulse emission is the kind of sound emission used by some species of bats, dolphins and whales. This type of sound emission involves the production of a pulse or call, followed by a listening period during which the animal listens for the echoes created by the sound wave.
Continuous Emission
Continuous emission is the kind of sound emission used by some species of whales and dolphins. This type of sound emission involves the production of sustained or prolonged calls, without any pauses in between.
The Role of Echolocation in Animal Navigation
Echolocation is used by animals for navigation in a number of ways. For example, dolphins use echolocation to detect food, by listening for echoes from small prey hidden in the sediment at the ocean floor. Bats use echolocation to search for food in the dark, such as insects flying in the night sky. And whales can use echolocation to locate and follow prey, even in murky ocean waters.
How Echolocation Can Help Us
Echolocation is an important tool for animal navigation, but it can also be useful for humans. For example, echolocation can be used by sailors or fishermen to find their way in foggy or cloudy conditions. It can also be used by biologists studying animal movements.
Echolocation in animals is a remarkable adaptation that has allowed them to navigate and survive in a variety of environments. Animals have used echolocation to find food, avoid predators, and even communicate with one another. And as scientists continue to uncover more about this fascinating adaptation, they are sure to unlock more of the mysteries about the natural world.