echolocating

Echolocating is the use of biological sonar by certain animals to detect objects in their environment. An echolocating animal emits sound pulses and listens for the returning echoes. By analyzing the time delay between emission and echo, the Doppler shift of the echo, and the echo’s frequency and intensity, the animal estimates distance, size, shape, texture, orientation, and motion of objects such as prey or obstacles.

The most well-known echolocators are bats (order Chiroptera) and toothed whales (suborder Odontoceti). Bats produce ultrasonic calls that can be either frequency-modulated, constant-frequency, or a combination, depending on the species and context. They adjust call rate, duration, and frequency as they approach targets or navigate cluttered environments. Toothed whales, including dolphins and porpoises, emit rapid clicks from nasal structures and focus sound with the melon; echoes are received through the jaw and processed to gauge range, target direction, and speed, even in murky or dark waters.

Some birds, such as certain swiftlets and oilbirds, use echolocation in dark caves to avoid collisions with walls and stalactites. A few small terrestrial mammals, including some shrews, are believed to employ limited echolocation or audial cues to enhance prey detection at close range, though their calls are typically less specialized than those of bats or toothed whales.

Processing of echoes occurs in specialized auditory pathways, allowing the brain to construct a spatial map of the surroundings. Echolocation supports navigation, prey detection, and obstacle avoidance, and has inspired human technologies such as sonar and ultrasonic imaging.