Echolocation

echolocation

Physiological process for locating distant or invisible objects (such as prey) by emitting sound waves that are reflected back to the emitter by the objects. Echolocation is used by an animal to orient itself, avoid obstacles, find food, and interact socially. Most bats employ echolocation, as do most, if not all, toothed whales (but apparently no baleen whales), a few shrews, and two kinds of birds (oilbirds and certain cave swiftlets). Echolocation pulses consist of short bursts of sound at frequencies ranging from about 1,000 Hz in birds to at least 200,000 Hz in whales. Bats use frequencies from about 30,000 to about 120,000 Hz.

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echolocation

determination of the position of an object by measuring the time taken for an echo to return from it and its direction

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echolocation [′ek·ō·lō‚kā·shən]

(biophysics)

An animal's use of sound reflections to localize objects and to orient in the environment.

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Echolocation 

the perception of reflected sound waves, usually high-frequency, by certain animals, which emit them to detect objects in space, such as prey or obstacles, and determine their properties and dimensions. Echolocation is one of the means by which animals orient themselves in space. It is developed in bats and dolphins and has been discovered in shrews, a number of species of seals, and birds, including oilbirds and salanganes.

In dolphins and bats, echolocation is based on the emission of ultrasonic impulses with frequencies of as high as 130–200 kilo-hertz (kHz) and duration of signals usually from 0.2 to 4–5 milliseconds, sometimes more. In birds that live in dark caves, such as oilbirds and salanganes, it is used for orientation in the dark; they emit low-frequency signals of 7–4 kHz. Dolphins and bats use echolocation not only to determine their general orientation, but also to determine the spatial position of an object and its dimensions. In a number of cases echolocation even enables them to recognize the appearance of an object and therefore often serves as an important means of searching out and capturing food.

REFERENCE

Airapet’iants, E. Sh., and A. I. Konstantinov. Ekholokatsiia v prirode, 2nd ed. Leningrad, 1974.

G. N. SIMKIN