How do bats fly in the dark? Bat sound. How do bats navigate in the dark?

Bat- this is an animal that belongs to the class of mammals, order bats, suborder bats (lat. Microchiroptera).

Bats got their name not because they are relatives of micebelonging to the order of rodents, but most likely due to their small size and the sounds they make, similar to a mouse squeak.

Bat - description, structure. What does a bat look like?

Bats are the only mammals on Earth that can fly. Often this entire detachment is mistakenly called bats, but in fact it is not. The order of bats includes the family of fruit bats (lat. Pteropodidae), which does not belong to the suborder bats(lat. Microchiroptera). Fruit bats, often called flying dogs, flying foxes, fruit bats, differ from bats in their structure, habits and abilities.

Bats are mammals small size. The smallest representative of the suborder is the pig-nosed bat (lat. Craseonycteris thonglongyai). Its weight is 1.7-2.0 g, body length varies from 2.9 to 3.3 cm, and the wingspan reaches 16 cm. This is one of the smallest animals in the world. One of the largest bats is the giant false vampire (lat. Vampyrum spectrum), which has a wingspan of up to 70-75 cm, a wing width of 15-16 cm and a weight of 150-200 g.

The structure of the skull different types bats are different, as well as the structure and number of teeth. Both depend on the nutrition of the species. For example, in a nectar-eating tailless long-tongued leaf-bearer (lat. Glossophaga soricina) the front of the skull is elongated to accommodate it long tongue to which he feeds. Bats, like other mammals, have a heterodont dentition that includes incisors, canines, premolars, and molars. Individuals that eat insects with thick chitinous coatings have larger teeth and longer fangs than those that eat soft-shelled insects. Small insectivorous bats can have up to 38 small teeth, while vampires have only 20. Vampires do not require many teeth, since they do not need to chew food, but their fangs, designed to make a bleeding wound on the victim's body, are razor-sharp. In fruit-eating bats, the upper and lower cheek teeth resemble mortars and pestles in which fruits are crushed.

Many bats have large ears, such as the brown earflap (lat. Plecotus auritus), and bizarre nasal outgrowths, like those of horseshoe bats. These features affect the echolocation abilities of the bat.

In the course of evolution, the forelimbs of bats were transformed into wings. The humerus shortened, and the fingers lengthened, they serve as the frame of the wing. The first finger with a claw is free. With its help, animals move in a shelter and manipulate food. In some species, for example, in smoky bats (lat. Furipteridae), the first finger is non-functional. The second, third and fourth fingers strengthen the part of the wing between the first and fifth and form the interdigital membrane, or apex of the wing. The fifth finger is extended to the entire width of the wing. The humerus and shorter radius support the trunk membrane, or base of the wing, which acts as a load-bearing surface. The speed of a bat depends on the shape of its wings. They can be highly elongated or slightly elongated. By the shape of the wing, one can judge the lifestyle of a bat. Wings with a small aspect ratio do not allow to develop high speed, but make it possible to maneuver well among tree crowns. Highly elongated wings are designed for high-speed flight in open space.

Bats of small and medium size fly at a speed of 11 to 54 km/h while searching for prey. The fastest flying animal is the Brazilian folded lip (lat. Tadarida brasiliensis) from the genus of bulldog bats, which is capable of speeds up to 160 km / h.

Taken from: www.steveparish-natureconnect.com.au

The hind limbs of bats, unlike other mammals, are turned to the sides. knee joints back. Animals hang on them in shelters with the help of well-developed claws.

Some species are able to move on all four limbs. For example, an ordinary vampire (lat. Desmodus rotundus) during the hunt, landing on the body of the victim or next to it, he approaches on foot to the place where he bites.

Bats have tails of various lengths:

• partially enclosed in the interfemoral membrane, with a free tip located on top of it, like in sac-wings (lat. Emballonuridae);
• completely enclosed in the interfemoral membrane, like in myotis (lat. Myotis);
• protruding beyond the interfemoral membrane, as in folded lips (lat. Molossidae);
• long free tail, like a mousetail (lat.Rhinopoma).

The body, and sometimes the limbs of mammals are covered with wool. The coat of a bat can be even or shaggy, short or not very, sparse or thick.

The color of bats is dominated by gray, brown, black tones. Some animals are lighter in color - in fawn, whitish, yellowish shades. Occasionally there are also bright specimens. For example, in the Mexican fish-eating bat (lat. Noctilio leporinus) fur is yellow or orange.

Taken from: www.mammalwatching.com

There are bats white color with yellow ears and nose - these are Honduran white bats (lat. Ectophylla alba).

Taken from faculty.washington.edu

In nature, there are bats with a body that is not covered with hair. Two species of naked-skinned bats are known from Southeast Asia and the Philippines (lat. Cheiromeles torquatus And Cheiromeles parvidens) they are almost completely devoid of wool, only sparse hairs remain.

Bats have unique hearing. It is the leading sense organ in these animals. For example, false horseshoe bats (lat. Hipposideridae) catch the rustle of insects swarming in the grass or under a layer of leaves. On the ears of many bats there is a tragus - a narrow skin-cartilaginous outgrowth that rises from the base of the ear. It serves to amplify and better perceive the sound.

Taken from: blogs.crikey.com.au

Vision in bats is poorly developed. There is no color vision at all. But still, bats are not blind, and some even see quite well. For example, the California leaf-bearer (lat. Macrotus californicus) sometimes, with appropriate lighting, looking for prey with the help of the eyes.

Bats have not lost their sense of smell. According to the smell of the female Brazilian folded lip (lat. Tadarida brasiliensis) find their young. Some bats distinguish members of their colony from strangers. Big night bats (lat. Myotis myotis) and New Zealand bats (lat. Mystacina tuberculata) smell prey under a layer of foliage. New World leaf-bearers (lat. Phyllostomidae) find the fruits of nightshade plants by smell.

How do bats navigate in the dark?

The main means of orienting bats in space (for example, in dark caves) is echolocation. Animals emit ultrasonic signals that bounce off objects and echo back. Sounds originating in the throat, the animal makes through the mouth or directs them to the nose, radiating through the nostrils. In such individuals, the nostrils are surrounded by bizarre outgrowths that form and focus sound.

People only hear how bats squeak, because the ultrasonic range in which these animals transmit echolocation signals is inaccessible to the human ear. Unlike humans, a bat analyzes the signal reflected from an object and determines its location and size. The mouse "echo sounder" is so accurate that it captures objects with a diameter of 0.1 mm. In addition, winged mammals clearly distinguish between all kinds of objects: for example, different types of trees. Bats hunt using echolocation. By reflected ultrasonic waves, winged hunters in complete darkness not only find the prey, but also determine its size and speed. During the search for prey, the frequency of sounds reaches 10 oscillations per second, increasing to 200-250 just before the attack. In addition, the bat can squeak when inhaling, exhaling, and even while chewing food. Before the discovery of ultrasound, these mammals were thought to have extrasensory perception.

Representatives of the suborder are able to make both low-frequency and high-frequency sounds, and at the same time. The animal screams and listens at a speed incomprehensible to humans. Some bats, hunting nocturnal insects, emit up to 250 calls per second when approaching them. Some potential prey (butterflies, beetles, grasshoppers, crickets) have developed the ability to hear the bat's squeak in advance and respond to it with a feint or fall to the ground.

By the way, echolocation is developed not only in bats, but also in dolphins, whales, seals, shrews, scoop butterflies, and also in some birds.

Where do bats live?

Bats are widely distributed throughout the world, with the exception of Antarctica, the Arctic and some oceanic islands. These animals are most numerous and diverse in the tropics and subtropics.

Bats are nocturnal or crepuscular animals. During daylight hours, they hide in shelters, which can be located in a variety of places underground and above ground. These can be caves, rock crevices, quarries, adits, various buildings built by man. Many varieties of bats live on trees: in hollows, bark crevices, in branches, in foliage. Some mice take refuge in original shelters, such as under bird nests, in bamboo stalks, and even in cobwebs. American suckers (lat. Thyroptera) roost in young rolled banana leaves, which unfold after the animals leave their homes. Leaf-bearers-builders (lat. Uroderma Peters), biting the leaves of palm trees and other plants along certain lines, they get a semblance of an awning from them.

Some species of bats prefer to live alone or in small groups, such as the lesser horseshoe bat (lat. Rhinolophus hipposideros), but they mostly stay in colonies. For example, females of the great bat (lat. Myotis myotis) gather in colonies from several tens to several thousand individuals. The record for the number of members is one of the colonies of the Brazilian folded lips (lat. Tadarida brasiliensis), numbering up to 20 million individuals.

How do bats hibernate?

Bats that live in cold and temperate latitudes hibernate during the cold season, which can last up to 8 months. Some species carry out seasonal migrations over distances of up to 1000 km, such as the red hairtail (lat. Lasiurus borealis).

Why do bats sleep upside down?

Bats stand out among mammals not only because they can fly, but also because they know how to rest: during daytime rest or hibernation, bats hang on hind legs upside down. This position allows the animals to instantly fly straight from their starting position, simply falling down: less energy is spent this way, and time is saved in case of danger. Suspended upside down, bats cling to wall ledges, tree branches, etc. with their claws. Being in this position, the animals do not get tired, because the tendon mechanism of closing the claws of their hind limbs is designed in such a way that it does not require the expenditure of muscle energy. Some species, settling down to rest, are wrapped in wings. Species such as large bats cluster in dense heaps, and small horseshoe bats always hang on the ceiling or vaults of the cave at some distance from each other.

What do bats eat?

Most bats are insectivorous. Some catch insects on the fly, others pick up bugs sitting on the foliage. Among tropical species, there are those that feed exclusively on fruits, pollen and plant nectar. But there are also varieties that eat both fruits and insects. For example, the New Zealand bat (lat. Mystacina tuberculata) feeds on various invertebrates: insects, earthworms, centipedes and spidersbut, at the same time, consumes fruits, nectar and pollen. The diet of fish-eating bats (lat. Noctilio) consists of fish and other aquatic inhabitants. Panamanian large leaf-bearer (lat. Phyllostomus hastatus) eats small birds and mammals. There are also species that feed exclusively on the blood of wild and domestic animals, some birds, and sometimes humans. These are vampire bats, among which 3 species stand out: terry-legged (lat. Diphylla ecaudata), white-winged (lat. Diaemus youngi) and ordinary (lat. Desmodus rotundus) vampires. In other places the globe other types of vampires live, but they don’t drink blood.

Types of bats, photos and names

Below is short description several types of bats.

• White leaf-bearing(lat. Ectophylla alba)

A tailless species that belongs to the genus of white leaf-bearers. These are small animals with a body length of 3.7-4.7 cm and a weight of no more than 7 grams. Leaf-nosed females have more small sizes than males. The body color of the animal corresponds to its name: the boiling-white back passes into the sacrum of a grayish tint, the lower abdomen also has a gray color. The nose and ears of the animal have a yellow tone, and the eyes are underlined by a gray frame around them. White leaf-bearers live in South and Central America, namely in countries such as Costa Rica, Honduras, Nicaragua, Panama. Animals prefer moist evergreen forests, climbing no higher than seven hundred meters above sea level. Usually these white bats live alone or live in small groups of no more than 6 individuals. Animals feed at night. The diet of these bats includes fruits and some types of ficus.

• Giant evening party(lat. Nyctalus lasiopterus)

This is the largest variety of bats in Russia and European countries. The length of the body of the animal varies from 8.4 to 10.4 cm, and the weight of the bat is 41 - 76 g. The wingspan of the animal reaches 41-46 cm. The giant evening has a brownish or fawn-red back color and a lighter abdomen. Darker coloring prevails on the head behind the ears. The bat lives in forests, and its range extends from France to the Volga region and the Caucasus. Probably, the species is also found in the countries of the Middle East. Often the animal inhabits the hollows of trees together with other representatives of the suborder, less often forms its own colonies. The wintering places of this species are unknown; apparently, the animals make long-distance seasonal flights. In nature, the bat feeds on fairly large insects (butterflies, beetles), as well as small passerine birds, which it catches in the air at fairly high altitudes. This bat is listed in the Red Book.

• Pig-nosed bat (lat.Craseonycteris thonglongyai)

This is the smallest bat in the world, which, due to its modest size, is called the bumblebee mouse. The body length of the animal is 2.9-3.3 cm, and the weight does not exceed 2 grams. The ears of the mammal are quite large, with a large tragus. The nose looks like a pig's snout. The color of the animal is usually grayish or dark brown with a slight shade of red, the animal's abdomen is lighter. Pig-nosed bats are endemic to southwestern Thailand and nearby Myanmar. Animals hunt in groups of up to five individuals at night. They fly over bamboo and teak trees in search of insects that sit on the leaves of trees, and when they find food, they hover over prey right in the air due to their small size and wing structure. The number of pig-nosed bats in the world is extremely low. These animals are among the ten most rare species on Earth and are listed in the International Red Book.

Taken from: www.thewildlifediaries.com

• Two-color leather (two-color bat) (lat.Vespertilio murinus)

It has a body length of up to 6.4 cm and a wingspan of 27 to 33 cm. A bat weighs from 12 to 23 grams. The animal got its name because of the color of the fur, which combines two colors. The back is colored in shades from red to dark brown, and the belly is white or gray. The ears, wings and face of the animal are black or dark brown. These bats live on the territory of Eurasia - from England and France to the coast Pacific Ocean. Northern border of the range: Norway, Central Russia, Southern Siberia; southern border: southern Italy, Iran, Himalayas, Northeast China. The habitat of the two-colored kozhan is mountains, steppes and woodlands. In countries Western Europe these bats are often found in large cities. Two-color leathers do not mind being close to other types of bats, with which they share common shelters: attics, cornices, tree hollows, rock cracks. Animals prey on mosquitoes, caddisflies, moths and other small insects throughout the night. The species is endangered and protected in many countries.

Taken from: www.aku-bochum.de

• Greater harelip (fish-eating bat)(lat.Noctilio leporinus )

It has a body length of 6.5-13.2 cm and a weight of 60 to 78 g. The coloration of males and females varies: the former have a reddish or bright red body, the latter are painted in dull grayish-brownish shades. A light stripe runs from the back of the head to the end of the back of the animal. These bats are found from the south of Mexico to the northern part of Argentina, they are found in the Antilles, the southern Bahamas and the island of Trinidad. Chiroptera settle near the water in caves, rock crevices, and also climb into hollows and tree crowns. Large harelips feed on large insects and aquatic inhabitants of fresh water bodies: fish, frogs and crustaceans. Sometimes they hunt during the day.

Taken from: reddit.com

Taken from: mammalart.wordpress.com

• Water bat (Dobanton's bat)(lat.Myotis daubentonii)

It got its name in honor of the French naturalist Louis Jean-Marie Daubanton. This small animal has a body length of no more than 4.5 - 5.5 cm and weighs from 7 to 15 g. The wingspan is 24 - 27.5 cm. The color of the fur is inconspicuous: dark, brownish. The top is darker than the bottom. The habitat of the animal extends from Great Britain and France to Sakhalin, Kamchatka and the Ussuri Territory. The northern border runs near 60°N, the southern border runs from southern Italy, along the south of Ukraine, the lower Volga, through northern Kazakhstan, Altai, northern Mongolia, to Primorsky Krai. The life of a bat is connected with water bodies, although animals are found far from them. During the day, they can climb into a hollow or attic, and with the onset of night they begin to hunt. These bats fly slowly, often fluttering over the surface of water bodies, and catch medium-sized insects, mainly mosquitoes. If there is no reservoir nearby, then the water bats hunt among the trees. By destroying blood-sucking insects, water bats contribute to the fight against malaria and tularemia.

• Brown earflap ( he is ordinary earflap)(lat. Plecotus auritus)

It has a body length of 4-5 cm and a weight of 6-12 g. The most characteristic feature of the earflap is its huge ears. The body is covered with uneven dull fur. Ushan habitats cover almost all of Eurasia, including Portugal in the western part of the range and up to the Kamchatka Peninsula in the eastern part. Also, brown earflaps are found in northern Africa, in Iran and central China. The lifestyle of bats is sedentary. These winged animals hibernate not far from their places of stay in summer time, inhabiting caves, various cellars, well log cabins and hollows of powerful trees, sometimes meeting in the attics of houses that were insulated for the winter. The big-eared bat flies out to hunt in complete darkness and hunts until sunrise.

• Bat-dwarf ( he is small or small-headed bat) (lat. Pipistrelluspipistrellus)

Quite a numerous species belonging to the genus of the inexperienced, the family of smooth-nosed bats. This is the smallest species of bats in Europe. The body of the dwarf bat resembles the body of a mouse, its length is 38-45 mm, and the length of the tail is 28-33 mm. The mass of a dwarf bat is usually 3-6 g. The wingspan of this small bat reaches 19-22 cm. The body is covered with short, even hair, which is brown in the European form of the animal, and pale grayish-yellow in the Asian. The lower part of the body has a lighter color. The dwarf bat is widespread in Eurasia: from west to east from Spain to Western China, and from north to south from southern Norway to Asia Minor and Iran. This species of bats, in addition to Eurasia, is found in North Africa. Settles in places associated with human habitation, does not occur in the depths of forests and steppes, avoids caves, sometimes settles in hollows of trees. In winter, bats make seasonal migrations. Adult males in spring-summer period are extremely rare, as they keep alone or gather in small groups separately from females and juveniles. Bats hunt after sunset. They fly low, in the lower part of tree crowns. The food of this tiny mouse is small insects. The dwarf bat is one of the most useful bats in the Eurasian fauna.

• Great horseshoe(lat. Rhinolophus ferrumequinum)

The dimensions of the animal are 5.2-7.1 cm, the wingspan reaches 35-40 cm, and the mass of the bat is 13-34 g. The color of the back varies depending on the habitat from dark chocolate to pale smoky fawn. The belly of the animal is whitish with gray tint, lighter than the color of the back. Young animals have a monochromatic grayish color. The species is distributed in northern Africa (Morocco, Algeria), in Eurasia, the habitat of the horseshoe bat extends from Great Britain and Portugal through the mountainous regions of Central Europe, covers the Balkans, the countries of Asia Minor and Western Asia, the Caucasus, the Himalayas, Tibet, and ends in the south of China, Korean peninsula and Japan. On the territory of Russia, this bat is found in the Crimea and the North Caucasus, covering the range from the Krasnodar Territory to Dagestan. The habitual places of settlement of the horseshoe bat are mountain crevices, grottoes, cellars and ruins, as well as caves. IN Central Asia these animals live under the domes of tombs and mosques. Bats live relatively sedentary, making local seasonal migrations. They hibernate in damp caves and dungeons. They hunt low above the ground for moths and small beetles. The large horseshoe bat is listed in the Red Book of Russia.

• Ordinary Vampire ( he is big bloodsucker, or desmode) (lat.Desmodus rotundus )

most numerous and known species real vampires. Largely due to this genus, bats have their bad reputation. An ordinary vampire really feeds on blood, including drinking human blood. This is a small animal: the length of the bat is 8 cm, the weight is 50 g, the wingspan is 20 cm. Bloodsucking vampires live in large colonies. During the day they sleep in the hollows of old trees and caves. An ordinary vampire flies out to hunt late at night, when his future victims are immersed in a deep sleep. He attacks large ungulates such as cows, horses, pigs. It can also bite a person sleeping in an open area or in a house with open and unprotected mesh windows. With the help of hearing and smell, vampire bats find a sleeping victim, sit on it or next to it, crawl to the place where the vessels come close to the surface of the skin, bite through it and lick the blood flowing from the wound. A special secret contained in the saliva, which the vampire wets the victim's skin, makes the bite painless and affects blood clotting. As a result, the victim may die from blood loss, as the blood flows out for a long time without clotting. But not only this dangerous ordinary vampire. With its bite, the virus of rabies, plague and other diseases can be transmitted. Vampires also suffer from rabies. The spread of disease within the species is due, among other things, to the propensity of vampires to share regurgitated blood with hungry kin, a habit extremely rare among animals. Vampire bats live only in the tropics and subtropics of Central and South America. There are other kinds of vampires in other parts of the world, but they don't feed on blood. Thanks to these three species of bats, negative attitude to bats, which are not only harmless, but also useful animals.

How do bats reproduce?

Most bats, common in tropical latitudes, breed 2 times a year. Inhabitants of temperate latitudes - 1 time per year. The mating season in bats of temperate latitudes begins in autumn. Spermatozoa in the genital tract of mated females persist throughout the winter, and fertilization occurs in the spring. A bat's pregnancy can last for different times and depends on the temperature. environment: in heat, the embryo develops faster. Some species, such as the common earflap (lat. Plecotus auritus), most often give birth to 1 cub each, shirokoushki (lat. Barbastella), leather (lat. Eptesicus), bats (lat. Myotis), etc. - 2 cubs each, and hairy tails (lat. Lasiurus) have 3 newborns in the litter .

The development of the young is very fast. By the end of the first week, the bat cub doubles in size, and the body, naked at birth, is covered with short hairs. Newborns first feed on their mother's milk, and after about a month they already hunt near their homes.

How long do bats live?

The life expectancy of bats in nature, according to various sources, varies from 4 to 20 years. The maximum fixed term is 33 years.

Bat enemies.

Among animals and birds, bats do not have very many enemies, besides, bats become their victims infrequently and rather by accident. Early emerging species of bats, such as evening bats (lat. Nyctalus) and bats (lat. Pipistrellus), are attacked by diurnal predator birds: Peregrine Falcons, Hobbies, Hawks. Night owls, owls, snakes also will not refuse to grab a bat. Random enemies also include animals such as weasel, polecat, marten.

And yet the main enemy of bats is man and his activities. The populations of various bat species are declining significantly due to the use of chemicals in livestock and crop production. Flying animals that live in forests are deprived of shelter and food as a result of cutting down trees. Currently, many species of bats are protected and listed in the international Red Book.

Bat bite

Bats, excluding vampires, are not aggressive animals and will not attack a person themselves and will not bite. If the animal is taken in hand, it can only bite out of fear, defending itself. In this case, the wound must be treated with an antiseptic and consult a doctor, as with any bite of a wild animal.

Why are bats dangerous?

People have long had a negative attitude towards bats. Regarding them, there is a large number of myths and prejudices. In particular, numerous stories about bats that get tangled in their hair are unrealistic, because the most advanced animal echolocation system excludes this. In fact, several species of bats are dangerous to humans, as they can carry the rabies virus and other dangerous diseases. These are blood-sucking bats that live in South and Central America. It is believed that some species living in Africa also carry viruses and even the deadly Ebola virus. But this has not been proven by science.

The benefits of bats

Bats are useful animals. They in huge quantities destroy various insects - carriers of diseases and agricultural pests:

• Bats exterminate not only mosquitoes that spread malaria, but also their wintering grounds, which is especially important, since the destruction of a dozen wintering mosquitoes has a greater effect than the destruction of thousands of flying ones.
• These animals eat mosquitoes, carriers of leishmaniasis, a disease common in tropical and subtropical countries.
• Flocks of bats sometimes accompany nomadic domestic animals, relieving them of blood-sucking insects.
• Mosquitoes and mosquitoes are preyed upon by small bats. Larger animals eat butterflies and beetles, pests of crops and plantings: the cotton bollworm, the most dangerous crop pest in the United States; odoriferous woodworm - a pest of orchards; military silkworm and other silkworms, cleanly nibbling trees; silver holes, whose caterpillars destroy the leaves of barren trees; brushes and many others.

In addition, bats contribute to the pollination of plants. Taking out insects that have clogged in flowers, animals carry adhering pollen. They also distribute the seeds of many economically important plants and fruit trees.

Bat droppings (which is called guano), the deposits of which are formed in the places of their settlements, are used as fertilizer. It contains a lot of nitrogen and phosphorus and gives a significant effect on the cultivation of valuable crops.

Bats have great importance for science. They are the subject of a number of important experimental studies.

How to get rid of bats?

Sometimes bats settle next to a person: they can be found in the country house, under the roof of the house or in the garage. They seem to have identified themselves as pets. Bringing undoubted benefits in the fight against insects and protecting crops and plantings from pests, bats can cause some disturbance to their owners. For example, the noise they make at night can interfere with sleep. Vapors from their waste can harm human health. If it becomes necessary to get rid of bats, this must be done carefully so as not to harm unexpected neighbors.

• You need to find a place where bats rest during the day, and after waiting for them to fly out to hunt, close the entrance mounting foam or boards.
• You can try to literally "smoke" them with smoke or pouring water.
• There are also various sprays or naphthalene that can be used to treat the shelter of bats in their absence.
• Ultrasonic repellers are also effective remedy in the fight against bats.
• Summer residents can make special buildings for flying animals to move them there.
• Finally, you can ask for help special brigades who know exactly how to evict unwanted guests.

• Bats always fly out of cover to the left.
• One small bat can eat up to 600 mosquitoes in an hour, which is equal to 20 pizzas in terms of the weight of a person.
• During the Second World War, a project was being developed in which Brazilian folded lips were tried to be used as arsonists, attaching firebombs to them and throwing them over enemy territory so that they penetrate houses.
• Substances contained in the saliva of vampire bats have been used to create drugs that prevent the formation of blood clots, that is, to combat stroke.
• In European culture, bats act as representatives of dark forces, while in Chinese, on the contrary, they are perceived positively and are a symbol of happiness.

Flying between wires

The accuracy of the echolocation apparatus is amazing. Bats "notice" wires with a thickness of 0.28 mm, being at a distance of more than a meter from them. If the wires are thicker than 3 mm, they "see" them for about 2-3 meters. The echolocation system of the southern horseshoe bat is even better. The beast in flight can avoid collision with wires with a thickness of 0.05 mm. The pointed-eared bat detects a wire with a diameter of 2 mm at a distance of 1.1 m.

Clarity of the "image"

As a result of numerous experiments, it was proved that North American big bats can distinguish objects located at a distance of about 10-12 mm from each other, and also distinguish a triangle with sides of 10, 10 and 5 mm from a triangle with sides of 9, 9 and 4 .5 millimeters.

Signal emission: the bat emits ultrasonic signals at regular intervals. The animal quite accurately determines the time between the signal and the echo reflected from the object.

Signal reception: the bat catches the echo of the signal with its ears, and in the brain, based on the sounds received, a picture is built - an accurate representation of the shape and size of the object.

Fixture Features

Sound formation

Only in 1938, scientists discovered that bats make a lot of sounds that are above the human hearing threshold. The frequency of ultrasound is in the range of 30-70 thousand Hz. Bats emit sounds in the form of discrete pulses, the duration of each of which is from 0.01 to 0.02 seconds. Before making a sound, the bat compresses the air in the vocal apparatus between two membranes, which, under the influence of air, begin to oscillate. The membranes are stretched by various muscles and allow the bat to produce various sounds. Before the sound exits through the mouth or nose, it is amplified and modified by passing through several chambers. All bats that send signals through their noses have complex growths on their noses.

The structure of the ears

The ears of bats are extremely sensitive. This is necessary in order to better perceive the signals that are reflected from objects. The ears of bats are real radars that pick up and recognize high frequency sounds. Bats can move their ears, turning them so that they can best perceive sound signals that come from different directions. The sound waves captured by the ears enter the brain, where they are analyzed and compiled in the same way that a three-dimensional image is formed in the human brain from the information that the organs of vision transmit when observing an object. With the help of such "sound" pictures, bats absolutely accurately determine the location of prey.

VISION "SOUND IMAGE"

Bats get a picture of the world around them by analyzing the reflections of sound waves, just like a person gets it, unconsciously analyzing visual images. However, human vision of objects depends on external light sources, and bats build pictures thanks to the sounds that they themselves send. The signals of different types of bats vary greatly in their intensity. To navigate in the dark, they send out a series of short high-frequency sounds that spread like a flashlight. When such a signal encounters an object on its way, its reflection comes back and is captured by the bat. This way of orientation has many advantages.

First, shortwave sounds are easy to distinguish, so they are good for finding the flying insects that most bats feed on. Low sounds of long waves are not reflected from small objects and do not return back. High frequency sounds are very easy to distinguish from the sounds of the surrounding world, the frequency of which is much lower. In addition, bats "see" but remain "invisible" because the sounds they make are inaudible to other animals (that is, insects cannot spot bats and avoid them).

MYSTERY SOLVED

Even on the darkest nights, bats confidently fly between tree branches and catch flying insects.

Scientists once thought that just like other nocturnal animals, bats have very well developed eyesight. However, in 1793, the Italian naturalist L. Spallanzani noticed that bats hunt even on dark nights, when no night birds that have excellent night vision, such as owls, fly. L. Spallanzani determined that bats fly just as well with their eyes closed as they do with their eyes open. In 1794, the Swiss biologist S. Zhyurin confirmed the experiments of L. Spallanzani. He found that these animals with wax-blocked ears become helpless in flight and cannot navigate in the air. Later, this version was rejected and forgotten, they returned to it after 110 years. In 1912, X. Maxim, the inventor of the easel machine gun, expressed the idea that seeing with "ears" is explained by the mechanism of echolocation. In 1938, D. Griffin, using the apparatus invented by G. Pierce, recorded the sounds that bats make. In In the early 1950s, the theory of ultrasonic echolocation became firmly established in science.

ECHOLOCATION AND ITS USE

The signals that bats send out consist of 5 sounds of the same or different frequencies. One signal can contain a whole range of frequencies. The duration of the sounding of signals can be different, from one thousandth to one tenth of a second.

By emitting sound signals of different frequencies, bats "observe" in what order sound reflections return. Sounds of different frequencies propagate at different speeds. From the received reflected sound signals, the bat makes an accurate picture of the surrounding world and registers the slightest changes in it, for example, the movements of flying insects.

Most bats have such fine hearing that they can very easily distinguish "their" signals from the sounds that other bats make. The signals that send out reconciliations are quite short, so bats distinguish sounds that go out and come back. Strength and frequency of signals varies depending on the terrain the animal is flying through. When flying near trees, the bat sends out signals of lesser strength so as not to cause a loud echo. In flight, habitual signals are heard, and when hunting, the bat uses the full power of sounds.

INTERESTING FACTS. DO YOU KNOW WHAT...

• Most of the ultrasonic signals emitted by bats cannot be heard by humans, however, some people experience their pressure and can determine that animals are nearby.
• Some types of insects can hear the signals that bats send, so they try to hide from their pursuers. Night butterflies even send out their sound signals to confuse bats that prey on them.
• The sound signals emitted by a bat have the same strength as the sound of a jet aircraft. In order not to go deaf, the animal closes its ear openings every time before “shouting” with the help of special muscles.
• The expression "blind as a bat" is not true. Almost all bats have very good eyesight. For example, fruit bats eat fruits that they find with their eyesight.
• Bats that feed on insects and nectar, as well as those that make faint sounds, are sometimes called “whisper” bats by scientists. Bats include desmodes and leaf-nosed bats. signals.

Bats and other echo sounders in nature. Biologist Gunars Petersons tells. Video (00:33:01)

Echolocation in animals (says biologist Ilya Volodin). Video (00:24:59)

Animals use echolocation to navigate in space and to determine the location of objects around them, mainly using high-frequency sound signals. It is most developed in bats and dolphins, it is also used by shrews, a number of species of pinnipeds (seals), birds (guajaro, salangans, etc.) ... Biologist Ilya Volodin tells.

Animal instinct. Series 8. Wildlife of planet Earth - dolphin echolocation. Video (00:02:39)

Dolphins are special, unique creatures. Their ability to understand people has always aroused genuine interest among both scientists and laymen. However, there are also features that we may not even be aware of. For example, studies conducted by American scientists in the Hawaiian Islands revealed that dolphins, like whales, track their prey using echolocation.

Interesting facts - Bats. Video (00:05:46)

Bats - Interesting Facts
Among all mammalian species, only bats are capable of flight. Moreover, their flight is quite difficult to confuse with other animals, since it is quite different from the usual sight for our eyes. This type of flight is inherent in bats because their wings are somewhat similar to a small parachute. They don't need to constantly flap their wings to fly; rather, bats push off in the air.
Indeed, there are mice that need blood. There are three such types. But there are practically no cases when a bat attacked a person in order to “taste” his blood. Bats, first of all, focus on animals that are not able to resist them. Such animals include, for example, cows. These species live in South and Central America.

There are rumors that bats are able to carry a serious infection, and in interaction with a person, creatures can infect him with a dangerous disease. In fact, North American bats have only infected 10 people over the past half century. Bats themselves are much more afraid of humans than we are of them. Therefore, creatures try not to meet with a person, and in case of contact they immediately fly away. If you are bitten by a bat, you should not worry too much. If you immediately go to the hospital, nothing serious will happen - a regular injection will save you from unnecessary fears. Here you should be afraid of another, if the bat drank at least a little of your blood, then the probability is very high that this particular creature will “visit” you again soon. She seems to understand that you are an affordable source of nutrition, so she chooses you. If, of course, she manages to find you, and it is quite possible for her to do this, since bats remember and distinguish a person by his breathing.

8 FACTS ABOUT BATS. Video (00:06:12)

Bats have long been considered one of the most mysterious animals. They aroused apprehension, fear and, at the same time, great interest. And this is not surprising, because they are very different from their wingless counterparts. Today we offer you to get acquainted with the most about bats.

Echolocation. Unusual human capabilities. Video (00:03:20)

Echolocation is a very unusual ability that is found in a small number of representatives of the animal world. Over time, people have learned to use this ability. Daniel Kish is the first to intuitively master echolocation.

Bats usually live in huge flocks in caves, in which they perfectly navigate in complete darkness. Flying in and out of the cave, each mouse makes sounds that are inaudible to us. At the same time, thousands of mice make these sounds, but this does not prevent them from perfectly navigating in space in complete darkness and flying without colliding with each other. Why can bats fly confidently in total darkness without bumping into obstacles? Amazing Property These nocturnal animals - the ability to navigate in space without the help of vision - is associated with their ability to emit and capture ultrasonic waves.

It turned out that during the flight, the mouse emits short signals at a frequency of about 80 kHz, and then receives reflected echoes that come to it from nearby obstacles and from insects flying nearby.

In order for the signal to be reflected by an obstacle, the smallest linear size of this obstacle must be no less than the wavelength of the sound being sent. The use of ultrasound makes it possible to detect smaller objects than could be detected using lower sound frequencies. In addition, the use of ultrasonic signals is due to the fact that with a decrease in the wavelength, the directionality of the radiation is easier to realize, and this is very important for echolocation.

The mouse begins to respond to a particular object at a distance of about 1 meter, while the duration of the ultrasonic signals sent by the mouse decreases by about 10 times, and their repetition rate increases to 100–200 pulses (clicks) per second. That is, having noticed the object, the mouse starts clicking more often, and the clicks themselves become shorter. The smallest distance a mouse can detect in this way is approximately 5 cm.

While approaching the object of hunting, the bat, as it were, estimates the angle between the direction of its speed and the direction to the source of the reflected signal and changes the direction of flight so that this angle becomes smaller and smaller.

Can a bat, by sending out a signal at 80 kHz, detect a 1 mm midge? The speed of sound in air is assumed to be 320 m/s. Explain the answer.

End of form

Form start

Ultrasonic echolocation of mice uses waves with a frequency

1) less than 20 Hz

2) 20 Hz to 20 kHz

3) over 20 kHz

4) any frequency

End of form

Form start

The ability to perfectly navigate in space is associated in bats with their ability to emit and receive

1) only infrasonic waves

2) only sound waves

3) only ultrasonic waves

4) sound and ultrasonic waves

Sound recording

The ability to record sounds and then play them back was discovered in 1877 by the American inventor T.A. Edison. Thanks to the ability to record and reproduce sounds, sound cinema was born. The recording of musical works, stories and even whole plays on gramophone or gramophone records has become a mass form of sound recording.

Figure 1 shows a simplified diagram of a mechanical sound recorder. Sound waves from a source (singer, orchestra, etc.) enter the horn 1, in which a thin elastic plate 2, called a membrane, is fixed. Under the action of a sound wave, the membrane vibrates. The vibrations of the membrane are transmitted to the cutter 3 associated with it, the tip of which draws a sound groove on the rotating disk 4. The sound groove twists in a spiral from the edge of the disk to its center. The figure shows a view of the sound grooves on the record, viewed through a magnifying glass.

The disc on which sound is recorded is made of a special soft wax material. A copper copy (cliché) is removed from this wax disc by electroforming. In this case, deposition on the electrode is used pure copper when an electric current passes through a solution of its salts. The copper copy is then imprinted on plastic disks. This is how gramophone records are made.

When playing sound, a gramophone record is placed under a needle connected to the membrane of the gramophone, and the record is brought into rotation. Moving along the wavy groove of the plate, the end of the needle vibrates, and the membrane vibrates with it, and these vibrations quite accurately reproduce the recorded sound.

When recording sound mechanically, a tuning fork is used. With an increase in the sounding time of the tuning fork by 2 times

1) the length of the sound groove will increase by 2 times

2) the length of the sound groove will decrease by 2 times

3) the depth of the sound groove will increase by 2 times

4) the depth of the sound groove will decrease by 2 times

End of form

2. Molecular physics

Surface tension

In the world of everyday phenomena around us, there is a force at work that is usually ignored. This force is relatively small, its action does not cause powerful effects. Nevertheless, we cannot pour water into a glass, we cannot do anything at all with this or that liquid without setting in motion forces, which are called forces. surface tension.These forces in nature and in our lives play a significant role. Without them we could not write fountain pen, all the ink would immediately pour out of it. It would be impossible to soap your hands, because the foam could not form. A light rain would soak us through. The water regime of the soil would be disturbed, which would be disastrous for plants. would suffer important features our body.

The easiest way to capture the nature of surface tension forces is with a poorly closed or faulty water tap. The drop grows gradually, over time a narrowing is formed - a neck, and the drop comes off.

Water is, as it were, enclosed in an elastic bag, and this bag breaks when gravity exceeds its strength. In reality, of course, there is nothing but water in the drop, but the surface layer of water itself behaves like a stretched elastic film.

The film of a soap bubble makes the same impression. It looks like a thin stretched rubber of a baby ball. If you carefully place the needle on the surface of the water, the surface film will bend and prevent the needle from sinking. For the same reason, water striders can glide across the surface of the water without falling into it.

In its attempt to shrink, the surface film would give the liquid a spherical shape if it were not for gravity. The smaller the droplet, the greater the role played by surface tension forces compared to gravity. Therefore, small droplets are close in shape to a ball. In free fall, a state of weightlessness occurs, and therefore raindrops are almost strictly spherical. Due to the refraction of the sun's rays, a rainbow appears in these drops.

Surface tension is caused by intermolecular interaction. Liquid molecules interact with each other more strongly than liquid molecules and air molecules, so the molecules of the surface layer of the liquid tend to get closer to each other and sink deep into the liquid. This allows the liquid to take a form in which the number of molecules on the surface would be minimal, and the ball has the minimum surface for a given volume. The surface of the liquid contracts and this leads to surface tension.

Instruction

Almost all species of bats are nocturnal, which means they must have sensory organs adapted to the dark. Indeed, despite the fact that bats have eyes with which they are able to see during the daytime, they mainly rely on echolocation.

Early explorers trying to understand the abilities of bats covered their eyes and covered their body and wings with a compound that was supposed to make their skin insensitive, but the bats avoided all obstacles without any problems. Only in the middle of the 20th century did scientists manage to figure out how mice orient themselves in space. During the flight, bats emit sound waves, and then catch their reflections from surrounding objects and thus create a picture of the world.

Bats make sounds in the ultrasonic range, so we cannot hear them. But the mice themselves perfectly understand each other. They have their own special language with at least 15 syllables. Mice do not just make sounds, they sing songs that not only help them navigate in space, but give them the opportunity to communicate. With their songs, mice identify each other, attract females, resolve disputes over territory, and teach cubs. Some scientists put the language of bats in second place in terms of development after the human.

Bats make strong sounds, so their ears are closed with special partitions during singing, if nature had not provided such a mechanism, mice would very quickly lose their hearing from constant overloads.

Humans have long assumed that bats fly and hunt in pitch darkness with their highly developed eyesight. Today, these animals are known to have a sensitive and precise organ that allows them to navigate in space using sound rather than light. More important than vision for bats are hearing and smell.

Basic data:

How well does a bat "see"?

Man perceives the world mostly through vision. Therefore, it is difficult to imagine how a bat can create the same picture based on the analysis of sound signals.

As a result of many experiments, it has been proven that bats "see" very well. Bats can accurately determine the distance to an object, for example, insects, and in which direction it is moving. The only property of an object that the echolocation system does not allow to determine is its color.

Not all types of bats use echolocation. Most fruit bats have not found an echolocation mechanism. They navigate by sight. Only cave species of fruit bats produce weak noise signals. In leather animals, the mechanism of echolocation is developed to the most perfect degree. These animals are able to isolate the reflection of "their" signal from a mixture of various ultrasonic and sound waves.

Flying between wires

The accuracy of the echolocation apparatus is amazing. Bats "notice" wires with a thickness of 0.28 mm, being at a distance of more than a meter from them. If the wires are thicker than 3 mm, they "see" them for about 2-3 meters. The echolocation system of the southern horseshoe bat is even better. The beast in flight can avoid collision with wires with a thickness of 0.05 mm. The pointed-eared bat detects a wire with a diameter of 2 mm at a distance of 1.1 m.

Clarity of the "image"

As a result of numerous experiments, it was proved that North American big bats can distinguish objects located at a distance of about 10-12 mm from each other, and also distinguish a triangle with sides of 10, 10 and 5 mm from a triangle with sides of 9, 9 and 4 .5 millimeters.

Signal emission: the bat emits ultrasonic signals at regular intervals. The animal quite accurately determines the time between the signal and the echo reflected from the object.

Signal reception: the bat catches the echo of the signal with its ears, and in the brain, based on the sounds received, a picture is built - an accurate representation of the shape and size of the object.

Fixture Features

Sound formation

Only in 1938, scientists discovered that bats make a lot of sounds that are above the human hearing threshold. The frequency of ultrasound is in the range of 30-70 thousand Hz. Bats emit sounds in the form of discrete pulses, the duration of each of which is from 0.01 to 0.02 seconds. Before making a sound, the bat compresses the air in the vocal apparatus between two membranes, which, under the influence of air, begin to oscillate. The membranes are stretched by various muscles and allow the bat to produce various sounds. Before the sound exits through the mouth or nose, it is amplified and modified by passing through several chambers. All bats that send signals through their noses have complex growths on their noses.

The structure of the ears

The ears of bats are extremely sensitive. This is necessary in order to better perceive the signals that are reflected from objects. The ears of bats are real radars that pick up and recognize high frequency sounds. Bats can move their ears, turning them so that they can best perceive sound signals that come from different directions. The sound waves captured by the ears enter the brain, where they are analyzed and compiled in the same way that a three-dimensional image is formed in the human brain from the information that the organs of vision transmit when observing an object. With the help of such "sound" pictures, bats absolutely accurately determine the location of prey.

VISION "SOUND IMAGE"

Bats get a picture of the world around them by analyzing the reflections of sound waves, just like a person gets it, unconsciously analyzing visual images. However, human vision of objects depends on external light sources, and bats build pictures thanks to the sounds that they themselves send. The signals of different types of bats vary greatly in their intensity. To navigate in the dark, they send out a series of short high-frequency sounds that spread like a flashlight. When such a signal encounters an object on its way, its reflection comes back and is captured by the bat. This way of orientation has many advantages.

First, shortwave sounds are easy to distinguish, so they are good for finding the flying insects that most bats feed on. Low sounds of long waves are not reflected from small objects and do not return back. High frequency sounds are very easy to distinguish from the sounds of the surrounding world, the frequency of which is much lower. In addition, bats "see" but remain "invisible" because the sounds they make are inaudible to other animals (that is, insects cannot spot bats and avoid them).

MYSTERY SOLVED

Even on the darkest nights, bats confidently fly between tree branches and catch flying insects.

Scientists once thought that just like other nocturnal animals, bats have very well developed eyesight. However, in 1793, the Italian naturalist L. Spallanzani noticed that bats hunt even on dark nights, when no night birds that have excellent night vision, such as owls, fly. L. Spallanzani determined that bats fly just as well with their eyes closed as they do with their eyes open. In 1794, the Swiss biologist S. Zhyurin confirmed the experiments of L. Spallanzani. He found that these animals with wax-blocked ears become helpless in flight and cannot navigate in the air. Later, this version was rejected and forgotten, they returned to it after 110 years. In 1912, X. Maxim, the inventor of the easel machine gun, expressed the idea that seeing with "ears" is explained by the mechanism of echolocation. In 1938, D. Griffin, using the apparatus invented by G. Pierce, recorded the sounds that bats make. In In the early 1950s, the theory of ultrasonic echolocation became firmly established in science.

ECHOLOCATION AND ITS USE

The signals that bats send out consist of 5 sounds of the same or different frequencies. One signal can contain a whole range of frequencies. The duration of the sounding of signals can be different, from one thousandth to one tenth of a second.

By emitting sound signals of different frequencies, bats "observe" in what order sound reflections return. Sounds of different frequencies propagate at different speeds. From the received reflected sound signals, the bat makes an accurate picture of the surrounding world and registers the slightest changes in it, for example, the movements of flying insects.

Most bats have such fine hearing that they can very easily distinguish "their" signals from the sounds that other bats make. The signals that send out reconciliations are quite short, so bats distinguish sounds that go out and come back. Strength and frequency of signals varies depending on the terrain the animal is flying through. When flying near trees, the bat sends out signals of lesser strength so as not to cause a loud echo. In flight, habitual signals are heard, and when hunting, the bat uses the full power of sounds.

INTERESTING FACTS. DO YOU KNOW WHAT...

• Most of the ultrasonic signals emitted by bats cannot be heard by humans, however, some people experience their pressure and can determine that animals are nearby.
• Some types of insects can hear the signals that bats send, so they try to hide from their pursuers. Night butterflies even send out their sound signals to confuse bats that prey on them.
• The sound signals emitted by a bat have the same strength as the sound of a jet aircraft. In order not to go deaf, the animal closes its ear openings every time before “shouting” with the help of special muscles.
• The expression "blind as a bat" is not true. Almost all bats have very good eyesight. For example, fruit bats eat fruits that they find with their eyesight.
• Bats that feed on insects and nectar, as well as those that make faint sounds, are sometimes called “whisper” bats by scientists. Bats include desmodes and leaf-nosed bats. signals.

Bats and other echo sounders in nature. Biologist Gunars Petersons tells. Video (00:33:01)

Echolocation in animals (says biologist Ilya Volodin). Video (00:24:59)

Animals use echolocation to navigate in space and to determine the location of objects around them, mainly using high-frequency sound signals. It is most developed in bats and dolphins, it is also used by shrews, a number of species of pinnipeds (seals), birds (guajaro, salangans, etc.) ... Biologist Ilya Volodin tells.

Animal instinct. Series 8. Wildlife of planet Earth - dolphin echolocation. Video (00:02:39)

Dolphins are special, unique creatures. Their ability to understand people has always aroused genuine interest among both scientists and laymen. However, there are also features that we may not even be aware of. For example, studies conducted by American scientists in the Hawaiian Islands revealed that dolphins, like whales, track their prey using echolocation.

Interesting facts - Bats. Video (00:05:46)

Bats - Interesting Facts
Among all mammalian species, only bats are capable of flight. Moreover, their flight is quite difficult to confuse with other animals, since it is quite different from the usual sight for our eyes. This type of flight is inherent in bats because their wings are somewhat similar to a small parachute. They don't need to constantly flap their wings to fly; rather, bats push off in the air.
Indeed, there are mice that need blood. There are three such types. But there are practically no cases when a bat attacked a person in order to “taste” his blood. Bats, first of all, focus on animals that are not able to resist them. Such animals include, for example, cows. These species live in South and Central America.

There are rumors that bats are able to carry a serious infection, and in interaction with a person, creatures can infect him with a dangerous disease. In fact, North American bats have only infected 10 people over the past half century. Bats themselves are much more afraid of humans than we are of them. Therefore, creatures try not to meet with a person, and in case of contact they immediately fly away. If you are bitten by a bat, you should not worry too much. If you immediately go to the hospital, nothing serious will happen - a regular injection will save you from unnecessary fears. Here you should be afraid of another, if the bat drank at least a little of your blood, then the probability is very high that this particular creature will “visit” you again soon. She seems to understand that you are an affordable source of nutrition, so she chooses you. If, of course, she manages to find you, and it is quite possible for her to do this, since bats remember and distinguish a person by his breathing.

8 FACTS ABOUT BATS. Video (00:06:12)

Bats have long been considered one of the most mysterious animals. They aroused apprehension, fear and, at the same time, great interest. And this is not surprising, because they are very different from their wingless counterparts. Today we invite you to get acquainted with the most interesting facts about bats.

Echolocation. Unusual human capabilities. Video (00:03:20)

Echolocation is a very unusual ability that is found in a small number of representatives of the animal world. Over time, people have learned to use this ability. Daniel Kish is the first to intuitively master echolocation.