Owls fly silently. Which of these three birds do you think flies absolutely silently? The peregrine falcon already has a large wingspan, but he needs them not for noiselessness, but for the development of high speed

A unique adaptation characteristic of the overwhelming majority of owls is directly related to the structure of the feather - 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 precisely the noiselessness of the flight. Even large feathers - flight and tail feathers - are comparatively soft in owls.

In addition, along the edge of the outer webs, the end barbs are partially not linked and form a fringe. For example, in medium-sized owls, the fans are spread out over three to four millimeters. This minimizes the whistle of the air being cut by the wing. The special bend of the fan hides the rustle arising from the friction of the feathers against each other.

In this connection, it is interesting to note that certain types, for example, the needle-footed owl, for which the pursuit of the prey is more characteristic, rather than the watching, have plumage that is relatively tight to the body and tough, like in diurnal birds of prey. nights or polar day. To some extent, what has been said also applies to owls and owls.

Particularly noteworthy is the feather structure of owls hunting for fish. Their flight feathers practically do not have racked-up 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 need to fly silently. After all, the hearing organs of fish are not adapted to picking up sounds in the air.

Most owls have a relatively long wing, rounded at the top. There are eleven primary flight feathers, and the first is underdeveloped and hidden by cover 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 horned owl ( Micrathene whitneyi), which has only ten tail feathers. Here, we note that, in general, the structure of the bearing surfaces in owls - the arrangement of coverts, the number of tail feathers and flight feathers - is generally similar to that of birds of prey.

Speaking about the flying 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 that slopes toward the ground. In this case, flapping flight is usually alternated with gliding. True, owls living in the mountains and gorges, according to K.A. Yudin, using ascending currents, sometimes soar for a long time in circles in height. But for most owls, and even for an eagle owl, soaring flight is not typical. Yes, they do not need him: to get food for themselves, looking for prey from above, is the business of daytime birds of prey, and by no means owls.

Literature: Pukinsky Yu. B. Life of Sov. Series: The Life of Our Birds and Animals. Issue 1. L., Publishing House of Leningrad. University, 1977.240 p.

Which can be found on all continents except Antarctica, for centuries have occupied a reliable place in the culture and mythology of man. They are perceived in different ways - from symbols of wisdom and good luck to devilish harbingers of death. Where did such an outstanding role in history and symbolism come from? In part, it is associated with the weirdness of anatomy, because the peculiarities in the structure of the body distinguish owls from all other birds.
Many species are nocturnal, fly almost silently and can wiggle their heads astonishingly. Due to their exceptional camouflage plumage, they are easier to hear than to see, and the faces of these birds are unusually expressive. All this makes the owls very special. Here are five things that make them both creepy and awesome at the same time.

Unusual eyes
Owls do not. Their organs of vision should rather be called the 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 roll their eyes, and this is why the mobility of their necks is so increased, but we will learn more about this.
Because owls' eyes are forward-facing, they have binocular vision similar to humans, which means 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 view and 140 degrees of binocular vision, owls have these figures, respectively, 110 and 70 degrees. But they more than make up for the lack of binocular vision with excellent night vision and farsightedness.
However, due to such farsightedness, they cannot see objects up close. At the time of catching prey, owls use threadlike feathers on their beak and paws, allowing them to feel their prey.
And finally, owls have not one or even two, but three whole centuries: one for blinking, one for sleeping and one for keeping eyes clean.

Let's be clear right away - owls cannot turn their heads 360 degrees. It might seem like it isn't, but in reality the angle is only 135 degrees in any direction from a level position. Thus, collectively, owls have an astonishing 270 degree neck mobility.
It is difficult to turn your head even so as to look over your shoulder, which is why owls are amazing. Firstly, instead of seven vertebrae in the neck, as is the case on average in birds, owls have twice as many of them. But 14 vertebrae in the neck are not all improvements. They have a number of physiological characteristics that allow them to survive with such a quick and sharp head turn. Thus, additional blood vessels supply blood to the head when circulation through the normal system stops due to the angle of rotation of the head. In addition, the vessels lie in special air layers that preserve their 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 located asymmetrically. Two ears with different shapes and positions receive sound at slightly different times, giving the birds an exceptional ability to pinpoint the source of the sound. When the noise is equally loud in both ears, the bird knows that it has established the source and distance.
At the same time, the flat face directs the sound into the ears, amplifying it so much that the owl can recognize even the slightest rustle from the 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 hover and minimize the number of flaps, which, in general, create noise from a flying bird. In addition, many species of owls have special feathers that allow them to swing almost silently.
On the outside of the main flight feathers, there is a rigid, comb-like border that reduces turbulence. On the trailing edge of the same feathers, there is a soft edge, similar to the frayed edge of a rag, which also helps to reduce the remaining turbulence. The down, covering the entire wing plane, provides sound insulation.
Due to this special structure of feathers, we do not hear such a sound of wing blows, as, for example, in

For many centuries, the attitude towards owls has been purely negative. These birds were considered helpers of sorcerers and the living embodiment of evil. The reason for this was their nocturnal lifestyle, as well as the mercilessness with which owls overtook their prey while hunting.

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 give up the fight. Do not multiply, vile birds,

My horror: I recognize the ruinous noise and blows

Of your wings. Your haughty order, O great Jupiter ...

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

Subsequently, the attitude towards the owl changed. And in the XX century, these animals even began to be studied. In the 21st century, when science is concerned with questions of an applied nature, 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 describing this was published in a scientific journal Bioinspired, Biomimetic and Nanobiomaterials .

Researchers have established that these birds possess true stealth technology, which allows them to overtake their prey unnoticed.

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, due to which a silent flight is ensured. To find out, the researchers observed the flight of a long-eared owl, an eagle and a pigeon using high-speed cameras and lasers. The choice of these three birds was not accidental - the flap 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 Professor Jinkui Chu of Dalian University.

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

However, Chinese scientists are not pioneers in the study of owl flights - just like them American researchers speak... So, representatives of Cambridge recently said that they managed to understand what is happening with the feathers of these birds.

In the acoustic performance of the wing, the trailing edge is of paramount importance. In "normal" wings, it is stiff, which is why the wing makes rather loud sounds in flight. Owls have found a solution to this problem: the rear 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 help to eliminate minor noise factors. One of these factors is the roughness of the wing surface, which creates noise when in contact with air currents.

But the owls have coped with this: the down of the upper part of the wing forms a rough, but at the same time soft and elastic surface, which is very effective in reducing the noise level.

Researchers are confident that the mechanism by which this structure works is unique and very different from the mechanisms by which known noise absorbers work. To uncover these mechanisms, the researchers developed a model that reflects the changes in noise with different relative positions of the fibers of the fluff.

Based on their findings, the scientists designed a coating for the blades of wind turbines. It turned out that this allows them to make their work almost silent. In this case, the aerodynamic properties of the blades were the same.

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

Birds are a separate class of animals with incredible diversity. Among birds, there are both herbivorous vegetarians and formidable carnivorous killers. Each of the birds has its own color, wing length and body weight, and all this is not without reason. Nature has made birds different so that each bird species can survive in their environment according to their needs. In this regard, each bird not only fly differently and emit sounds of different volume. Inquiring minds from the BBC Earth TV channel decided to conduct an experiment to find out which of these three birds: a dove, a peregrine falcon or an owl, flies quieter than others. What do you think?

An experiment that showed the amazing ability of one of these three birds to fly absolutely silently

As you understood from the video above, the owl flies not only quieter than other birds, but does it absolutely silently, but why?

The pigeon flies loudest of all, since it has the largest body mass of the birds presented and the smallest wings, which it has to flap more often than others.

The pigeon does not hunt for anyone, but is engaged in gathering, therefore, to move the body, it does not need large and powerful wings

The peregrine falcon already has a large wingspan, but he needs them not for noiselessness, but for the development of high speed

With rare exceptions, these birds always catch their prey on the fly, and their diet is based on birds of medium and small size.

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

If pigeons hunt for seeds and crumbs almost around the clock, and peregrine falcons mainly in the morning and evening, then owls look for their victims exclusively at night. In such conditions, noiselessness is extremely important factor... It is also worth noting that owls have the largest wingspan, on which they have learned not only to fly silently, but also to glide expertly.