The sonar system of nature, echolocation occurs when an animal emits a sound wave that jumps from an object, returning an echo that provides information about the distance and size of the object.
More than a thousand species are echoing, including most bats, all toothed whales and small mammals. Many are nocturnal, burrowing animals that live in the ocean, which rely on echolocation to find food in a low or no light environment. Animals have several methods of echolocation, from neck vibration to flapping their wings.
Nocturnal oil birds and some stingrays, some of which hunt in dark caves, “produce short clicks with their syringe, the vocal organ of birds,” says Kate Allen, a postdoctoral fellow in the Department of Psychological Studies and the Brain at Johns Hopkins University. -mail.
Some people may also echo by clicking on the tongue, a behavior shared only by a few other animals, including tench, a Madagascar-like animal and the Vietnamese pygmy bedroom, which is actually blind.
Bat signals
Bats are the ultimate animal for echolocation, using their built-in sonar to track prey that fly fast at night.
Most bats, such as little Daubenton’s bat, contract their larynx muscles to make sounds above the human’s hearing range – the batty equivalent of a shout, says Allen. (Regarding: When it comes to echolocation, some bats just wing it.)
The calls of bats vary wildly between species, allowing them to distinguish their voices from other bats in the neighborhood. Their calls are also specific to a particular environment and type of prey: the European bat “whispers” in the presence of moths to avoid detection.
Some moths, however, have developed their own means of defense against green bats. The tiger moth flexes the eardrum organ on both sides of the chest to produce clicks, which blocks sonar and keeps predators at bay.
As expert echolocators, some bats can reach 0.007-inch objects about the width of a human hair. Because insects are always on the move, bats have to click continuously, sometimes making 190 calls per second. Even with such a difficult career, predators can eat half of their insect weight every night.
Leaf-nosed bats make calls for echolocation through their large, folded noses, which help concentrate returning sounds. Some species can quickly change their ear shape to accurately pick up the received signals.
A few fruit bats, such as the little bat in South Asia, even make clicks, flapping their wings, a recent discovery.
Watch a bat use echolocation in total darkness
A slow motion video shows a Macroglossus zero lilac fruit on a perch during an experiment.
Ocean sound waves
Echolocation is a logical strategy in the ocean, where sound moves five times faster than in the air.
Dolphins and other toothed whales, such as the beluga, echo through a specialized organ called the dorsal bursae, which is located at the top of the head, close to the muzzle. (Read how whales have a “sonar beam” to target prey.)
A fat deposit in this area, called a melon, lowers the impedance or resistance to sound waves between the dolphin’s body and water, making the sound clearer, says Wu-Jung Lee, a senior oceanographer at the University of Washington’s Applied Physics Laboratory.
Another fat deposit, which extends from the lower jaw of a whale to the ear, clarifies the echo that returns from prey, such as fish or squid.
Port marks, a favorite prey of orcs, make extremely fast, high-frequency echolocation clicks that their predators cannot hear, allowing them to remain incognito.
Most marine mammal echolocation sounds are too loud for humans to hear, except for cachalos, orcs, and some dolphin species, Lee adds.
Navigate by sound
In addition to hunting or self-defense, some animals echo to navigate their habitats.
For example, large brown bats, which are widespread in America, use their sonar to make their way through noisy environments, such as forests surrounded by other animal calls.
Amazon River dolphins can also echo to move around tree branches and other obstacles created by seasonal floods, Lee says.
Most people who relocate are blind or visually impaired and use their ability to carry out their daily activities. Some click, either with their tongue or with an object, like a stick, and then navigate through the resulting echo. Brain scans of ecologized people show the part of the brain that processes vision is used during this process. (Read how blind people use sonar.)
“Brains don’t like undeveloped buildings,” says Allen, so “it’s too expensive metabolically to maintain” echolocation in people who don’t need them.
Even so, humans are remarkably adaptable, and research shows that we can patiently learn to balance.