The silent flight of an owl. The undisputed winner of this study is the owl, as it flies absolutely silently.

For many centuries, the attitude towards owls was purely negative. These birds were considered assistants to sorcerers and the living embodiment of evil. The reason for this was their nocturnal lifestyle, as well as the ruthlessness with which owls overtook their prey during the hunt.

This is how the ancient Roman poet Virgil wrote about owls in the 12th book of the Aeneid, his epic work telling about the legendary Trojan hero Aeneas, who moved to Italy:

I leave the fight. Do not multiply, vile birds,

My horror: I recognize the deadly noise and blows

your wings. Your haughty command, O great Jupiter...

In the era of early Christianity, an owl opposed cross. As a creature leading a nocturnal lifestyle, the owl has become a symbol of evil spirits and witchcraft in Christianity, its images in the Christian tradition are a symbol of the blindness of unbelief.

Subsequently, the attitude towards the owl changed. And in the 20th century, these animals even began to be studied. In the XXI century, when science is concerned about applied issues, scientists decided to try to understand how owls manage to remain ideal nocturnal predators.

So, scientists have found out how the feathers of an owl ensure the noiselessness of its flight and how this information can be used in the design of aircraft. An article about this was published in a scientific journal Bioinspired, Biomimetic and Nanobiomaterials .

The researchers were able to establish that these birds have real stealth technology, which allows them to overtake prey undetected.

The fact is that owl feathers absorb aerodynamic noise and suppress vibrations that occur when a bird flaps its wings. During the flight, the mechanical energy released by the feathers is converted into heat, which ensures silent flight. In order to find out, the researchers observed the flight long-eared owl, eagle and dove using high speed cameras and lasers. The choice of these three birds was not accidental - the flapping of the wings of each of the three is very similar, but at the same time it is the owls who do it silently.

“The mechanism of silent flight of owls has always interested engineers. Now we need to apply what we have learned for the benefit of society,” said lead author of the study, Professor Jinkui Chu from Dalian University.

According to him, the ability to suppress aerodynamic noise along with dynamic noise makes the owl the queen of winged predators.

Nevertheless, Chinese scientists are not pioneers in the field of owl flight research - on a par with them. American researchers speak. So, representatives of Cambridge recently said that they managed to understand what happens to the feathers of these birds.

In the acoustic characteristics of the wing, the trailing edge is of paramount importance. In "normal" wings, it is rigid, which is why the wing creates quite loud sounds in flight. Owls have found a solution to this problem: the trailing edge of their wings is soft and "porous", which significantly reduces the noise level. But the owls did not stop there, their wings have at least two more features that contribute to the elimination of secondary noise factors. One of these factors is the roughness of the wing surface, which creates noise when it comes into contact with air currents.

But the owls did it too: the fluff on the upper part of the wing forms a rough, but at the same time soft and elastic surface, which is very effective at reducing noise levels.

The researchers believe that the mechanism by which this structure works is unique and very different from the mechanisms by which known noise absorbers work. To reveal these mechanisms, the researchers developed a model that reflects the changes in noise with different relative positions of down fibers.

Based on their findings, scientists designed a coating for the blades of windmills. It turned out that this allows you to make their work almost silent. At the same time, the aerodynamic properties of the blades turned out to be the same.

Now the researchers set themselves a promising but difficult task - to apply the obtained data in the field of aircraft manufacturing and design a silent aircraft based on the technologies being developed.

The Aztecs and Mayans were of the opinion that a demonic nocturnal creature was embodied in an owl: sending terrible omens to an underground god, acting as a messenger of death, and also a guide of souls after death. What kind of bird is an owl? We will tell you more about this amazing and mysterious creature ..

On the front of the wings, the owl has special irregularities that cause air turbulence. This reduces the noise from the wings, and makes the flight silent. This distinguishes them from diurnal predators - eagles, falcons, vultures, which have a different wing edge structure, and the wing “whistles” a little in flight. Also, like other nocturnal mammals, the owl has a layer of special cells in the eye that improves sensitivity to the most insignificant light sources. A side effect of this is that the owl's eyes glow in reflected light.

In the pre-Aztec culture of Ancient Mexico, Teotihuacan, the goddess of rain, was revered in the form of a sacred owl.

Owls are the only birds in which the outer ear consists of folds of skin. The ears are slightly asymmetrical, which allows you to accurately determine the direction of the sound source. The accuracy of sound definition in an owl is phenomenal - less than one degree vertically and horizontally. Owls can hear sounds with a frequency of 2 Hz (humans - at best 16). A special kind of owls are barn owls, which rely solely on hearing when hunting. Other owls also use their eyesight for this. By the way, the eyes of owls do not know how to move - they look in different directions, turning their heads in both directions up to 180 degrees

In India Owl revered as the patron of the night, the messenger of the underworld and also - the escort of souls to the kingdom of the dead. Among Hindus, the owl is the "icon" of Yama, the god - the ruler of this kingdom, and is recognized as the mount of Durga, the wife of the god - the destroyer Shiva in one of her formidable incarnations.

For the Celts, the owl is a chthonic symbol, the "night witch".
In the mythology of the Welsh, there is an omniscient Cavlvid owl.
The Etruscans considered it an attribute of the god of darkness and night.
But in ancient Greece - a sacred and even magical bird that belonged to Calypso, the same one that kept Odysseus on his island for 7 years. Well, of course, this is the companion of Athena (Minerva), whom Homer even called the “owl-eyed” goddess. It is in her company that the owl becomes a symbol of wisdom. Although, if we talk about the Greco-Roman tradition, it is worth mentioning that in Rome it was originally an attribute of the allegorical figures of Night and Sleep, and Moira Atropos, interrupting the thread of life, was also associated with this feathered creature. But the Greek warriors believed that an owl that appeared over the battlefield would bring them victory. Owls were guarded, and they were even allowed to live in the Greek Acropolis

Not all owls are nocturnal. Some types of owls hunt during the day, for example, the little owl (Athene noctua), snowy owl(Bubo scandiacus) and great gray owl (Strix nebulosa).

In China, this bird personified evil, crime, cruelty, death, horror, and even ungrateful children. She was considered the antipode of the Phoenix. According to one legend, young owls learn to fly only after they mercilessly gouge out the eyes of their parents. In some places, however, the owl was recognized as the emblem of the "yellow ancestor" and was associated with lightning, thunder and the summer solstice. As a magical animal, it was sometimes dedicated to blacksmiths.

Owls that hunt fish do not have special formations on the edge of the wing, so they fly not so silently. but they have a special structure of claws, which are covered with special notches that help to firmly grab slippery fish.

Among the Egyptians, this is the bird of death, belonging to the kingdom of the night sun, which crosses the lake or sea of ​​\u200b\u200bdarkness. In Africa, owls are still associated with dark forces, in many local dialects it is called the "witch bird" and therefore ruthlessly exterminated, despite the protests of environmentalists.

The Slavs also considered her to be “unclean”, attributed her connection with witches and goblin, called her a harbinger of death or widowhood, an accuser of debauchery, a guardian of treasures. Legends have survived that she is afraid of the revenge of birds for not returning the feathers borrowed from them (Belarusian, Croatian) and is afraid of ridicule for boasting about the beauty of her children (Polish).

Among the North American Indians, it was customary to believe that owls are associated with the souls of the dead, and therefore help shamans to contact them. The legend of the abduction of children by the Owl, who were then rescued by Coyote, was widespread. Sometimes they say that the owl confessed here wise bird, but this is only partly true: it was about shamanic knowledge received from the other world.

The special elastic and porous tips of the feathers on the trailing edge of the owl's wings are able to absorb and suppress most of the sound vibrations that occur during flight, which makes these nocturnal predators silent while hunting, scientists said at a conference of the American Physical Society in Pittsburgh.

If we can replicate this sound absorbing mechanism found in owl wings, then we will be well on our way to creating new types of variable stiffness fiber coverings that can be used as a base for aircraft wing and fuselage skins, as well as the sides of ships,” said Justin. Jaworski from Lehigh University in Bethlehem (USA).

Jaworski and his colleagues analyzed the wing structure, aerodynamics and acoustic properties of owl wings in terms of physics and mathematics in an attempt to unlock the secret of their quietness. During this analysis, the scientists identified three main features of these wings that can affect their acoustic properties - a crest of stiff feathers on the leading edge, soft down on the upper part, and elastic and porous feathers on the trailing edge of the wing.

After analyzing their contribution to the quietness of the owl's wing individually, the scientists concluded that the key element in the owls' built-in noise suppressor was the feathers on the back of their wings. The wings of ordinary birds, the edge of which is composed of relatively hard and not elastic feathers, produce a large amount of noise.

In the case of owls, as the authors of the article explain, this does not happen, as their feathers become more elastic and porous as they approach the tip, which helps to dampen acoustic vibrations. In turn, down and stiff feathers in other parts of the wing help to dampen noise in other ways, which the scientists plan to study in detail in their next work.

Owls are truly one of the most amazing and unusual bird species. They attract the interest and attention of a large number of researchers. And many people simply admire their beauty and mental abilities.

Owls are endowed with sharp hearing and good eyesight, which allows them to lead a nocturnal lifestyle. Almost all types of owls adhere to it. In addition, their eyes have the ability to see well in poor lighting. During the day, owls prefer to rest somewhere - on tree branches, in crevices, under the roofs of abandoned houses. There are some types of owls that make holes and nests for themselves.

The vast majority of owls are sedentary birds, that is, they live in one permanent favorite place. But still there are some species that are migratory. Sedentary owls tend to vehemently and carefully protect their own territory from various dangers, as well as from other predators. But if someone still intends to invade their territory, then the owls become very aggressive and will not calm down until they drive away the intruders.

Owls feed on live prey, which they get for themselves during the hunt. The diet of these birds, of course, depends on the area of ​​​​their residence, but usually consists of various rodents (rats, mice, shrews), rabbits, various insects, mountain hares, fish, snakes.

Owls live in pairs, which can last for years, or even last a lifetime. Owls are loyal and devoted birds. Their reproduction depends on the level of food availability, as well as on weather conditions. If the owl has enough food and does not feel the need for it, she lays a very large number of eggs. If there is a shortage in food, then in laying eggs it is limited to one or two. Then for a long time the owl incubates the eggs, and the male brings her food. When the chicks are born, the mother owl does not leave the nest for a long time. But on the third week of their age, the male, along with the female, begin to teach the chicks to fly. Soon, the chicks master the technique of flight and are already able to feed themselves.

Very beautiful and unique is the plumage of owls, the color of which helps them to camouflage themselves among nature. Also, thick and soft plumage serves as good protection for owls in cold weather.

To date, many varieties of owls are known - about 150 species. These birds of prey live almost in all possible natural areas.

Which can be found on all continents except Antarctica, for centuries occupy a secure place in the culture and mythology of man. They are perceived in different ways - from symbols of wisdom and good luck to diabolical harbingers of death. Where did such an outstanding role in history and symbolism come from? In part, it is connected with the oddities of anatomy, because the features in the structure of the body distinguish owls from all other birds.
Many species are nocturnal, they fly almost silently and can turn their heads amazingly. Their exceptional camouflage plumage makes them easier to hear than to see, and their faces are extraordinarily expressive. All this makes owls very special. Here are five things that make them seem creepy and amazing at the same time.

unusual eyes
Owls don't. Their organs of vision should rather be called eye tubes. They have an elongated shape, and in place they are held by sclerotic rings - bony structures in the skull. Because of this, owls cannot move or rotate their eyes, and that is why the mobility of their neck is so increased, but we will learn more about this.
Since the eyes of owls are directed forward, they have binocular vision similar to humans, which means that they can see objects with both eyes at the same time. This gives the birds an excellent ability to judge height, weight and distance. However, while humans have a 180-degree field of vision and 140 degrees of binocular vision, owls have 110 and 70 degrees, respectively. But what they lack in binocular vision, they more than make up for with excellent night vision and farsightedness.
However, due to such farsightedness, they cannot see objects up close. When catching prey, owls use thread-like feathers on their beak and paws, allowing them to sense prey.
And finally, owls have not one or even two, but three whole eyelids: one for blinking, one for sleeping, and one for keeping their eyes clean.

Let's get it straight - owls can't turn their heads 360 degrees. This may not seem like it, but in fact the angle is only 135 degrees in any direction from level. Thus, in the aggregate, owls have an amazing mobility of the neck - 270 degrees.
It is difficult to turn your head even so as to look over your shoulder, and therefore owls demonstrate amazing. First, instead of seven vertebrae in the neck, as is the case with birds on average, owls have twice as many. But 14 vertebrae in the neck are not all improvements. They have a number of physiological features that allow them to survive such a quick and sharp turn of the head. Thus, additional blood vessels supply blood to the head when, due to the angle of rotation of the head, blood circulation through the normal system is stopped. In addition, the vessels lie in special air layers that preserve integrity at the moment of a sharp turn of the head.

sensitive ears
Yes, owls have amazing eyesight. But often the real work during the hunt is done by the ears of the birds. In many species, they are of different sizes, and even asymmetrically located. Two ears with different shapes and positions receive sound at slightly different moments, giving birds an exceptional ability to pinpoint the source of a sound. When the noise is equally loud in both ears, the bird knows that it has managed to establish the source and distance.
At the same time, the flat face directs the sound to the ears, amplifying it so much that the owl can recognize even the slightest rustle from tiny prey.
Silent
Owls are known for their ability to fly silently, as they must approach fast-moving prey very quietly. To do this, owls have wide wings that allow them to soar and minimize the number of strokes, which, in general, create noise from a flying bird. In addition, many species of owls have special feathers that allow them to flap almost silently.
On the outer side of the main flight feathers there is a rigid border, similar to the teeth of a comb, which reduces turbulence. On the trailing edge of the same feathers, there is a soft hem, similar to the frayed edge of a rag, which also helps to reduce the remaining turbulence. Down covering the entire plane of the wing provides sound insulation.
Due to this special structure of feathers, we do not hear such a sound of wing beats, as, for example,

Directly related to the structure of the feather is a unique device characteristic of the vast majority of owls - the noiselessness of flight. It gives them the opportunity to quietly approach the victim. The softness of the contour plumage of owls is caused by the requirement of noiseless flight. Even large feathers - flight and steering - are relatively soft in owls.

In addition, along the edge of the outer webs, the terminal barbules are partially unlinked and form a fringe. For example, in medium-sized owls, the fans are spread out over three to four millimeters. Due to this, the whistle of the air dissected by the wing is minimized. The special bend of the fans hides the rustling caused by the friction of the feathers against each other.

In this connection, it is interesting to note that certain species, for example, the needle-nosed owl, for which the pursuit of the prey is more characteristic than stalking, have plumage that is relatively close to the body and rigid, like in diurnal birds. birds of prey The same is observed in northern species, snowy and hawk owls, forced to hunt in the conditions of white nights or polar day. What has been said to some extent also applies to owls and owls.

The structure of the feather of owls hunting for fish deserves special attention. Their flight feathers practically do not have rasscheny areas. As a result, the flight of, for example, a fish owl in calm weather can be heard fifty or more meters away. Obviously, this bird does not have to fly silently at all. After all, the hearing organs of fish are not adapted to picking up sounds in the air.

In most owls, the wing is relatively long, rounded at the top. There are eleven primary flight feathers, the first being underdeveloped and hidden by covering feathers. Secondary flywheels - from fourteen to eighteen. The tail is relatively short, slightly rounded, usually consisting of twelve tail feathers. The only exceptions are a few of the smallest species of owls, for example, the elf owl living in the deserts of the southern United States and Mexico ( micrathene whitneyi), which has only ten tail feathers. Here we note that, in general, the structure of the bearing surfaces of owls - the location of covert feathers, the number of tail and fly feathers - is generally similar to that of birds of prey.

Speaking about the flight abilities of owls, it should be noted that they are quite perfect. The flight of owls, as a rule, is very fast and maneuverable, although not always long. In most cases, owls fly low above the ground, often in a line inclined to the ground. In this case, flapping flight is usually alternated with gliding. True, the owls living in the mountains and gorges, according to K. A. Yudin, using ascending currents, sometimes hover in circles for a long time in height. But for most owls, and even for the eagle owl, soaring flight is not typical. Yes, they don’t need it: to get their own food, looking out for a victim from above, is the business of diurnal birds of prey, and by no means owls.

Literature: Pukinsky Yu. B. Life of owls. Series: The life of our birds and animals. Issue. 1. L., Leningrad Publishing House. un-ta, 1977. 240 p.