Hooded crow nesting. Where, how do crows sleep and live? When crows start to build their nests

Common raven - the largest bird not only in the corvidae family, but also in the entire order of passerines. Its body length is about 64 cm, and it can weigh up to 1.5 kg. The crow is easily recognizable by its large size, general "raven" appearance and by its uniform black color with a metallic sheen. Attention is drawn to the large and powerful beak of this bird and a peculiar voice - a guttural croak, which has many shades and options.

Crows keep in pairs throughout the year. Hearing a hoarse "kru-kru" over the forest and looking around, you can almost always find the second bird with your eyes. Now crows have become the most common birds, and a rare trip out of town does without not seeing at least a couple of these birds. And there was a time when I specially traveled 75 km from Moscow to look at the ravens nesting in the old spruce forest near the station. Golitsyno.

Crow nest

Crows begin to nest earlier than all our birds, with the exception of crossbills and doves, which can lay eggs in the middle of winter. In the middle lane, they begin their spectacular aerial games over the forest already in January, and in March they start building new or repairing old nests, which they sometimes use for many years. Nests are located in large trees, usually at a high altitude, often at least 20 m on the ground, and therefore difficult to reach for observation. In recent decades, near Moscow, some crows have begun building nests on metal masts for high-voltage transmission lines. In the east, in the steppe regions, I found nests of ravens under the roofs of tall wooden buildings, and in the north - on ledges of rocks. There are cases of nesting of these birds on bell towers and city towers.

The crow's nest is very similar to the common crow's nest, only larger. Outside it is made of dry, rather thick branches, and inside it is lined with wool. In central Russia, female crows lay their first eggs at the very beginning of March, and since then they have not left the nest. The male comes from time to time to feed his incubating girlfriend. Full clutch contains 3-7 eggs. They are greenish or grayish-bluish in color, over which dark superficial and lighter deep spots are scattered. Outwardly, raven eggs are very similar to raven eggs, but noticeably larger. Their average size is 49.7 × 33.4 mm. Incubation lasts about 3 weeks. Young crows leave the nest at the end of May. By the end of the nesting cycle, the ground under the crow's nest is heavily stained with white blots of droppings. Here you can also find pellets of birds, sometimes remnants of food brought by birds to their chicks, and, as a rule, at least 1-2 blue-black feathers lost by them.

Raven food

The raven is a scavenger. These birds sometimes gather in large numbers near slaughterhouses or in fishing and animal hunting. They are very brave predators. If a crow does not dare to attack an adult gray rat, then the crow fearlessly attacks it and kills it with several blows of its beak. You look, and a couple of minutes have not passed since the moment of the attack, and he is already carrying the killed rat to some more secluded place where they will not interfere with his meals. When the crow leaves this place, having been full, it remains only blood-stained snow, trampled by large paws. Usually he eats the whole animal without a trace. The crows also decide to attack larger prey, for example, sick or wounded large birds and even hares.

Raven footprints while walking (left) and jumping

When carrion appears in the forest, the raven often learns about it by the excited chirping of magpies or the croaking of crows. However, he is careful and does not rush to the plentiful food, but descends from the tree only after he is convinced of complete safety. Despite the powerful beak, it is very difficult for him to peck the strong skin of an elk or a cow, so he begins to eat carrion after dogs or foxes gnaw through the skin, or if he himself finds any wounds on the body of the animal. In a fallen sheep or dog, the raven pecks out its eyes, but in a large cow it cannot.

Raven pellets can be found not only under the nesting tree. Sometimes they can be found under trees and rocks where birds spend the night. They resemble raven pellets, which are found quite often, but in a raven they are larger - (6 × 2.2) - (4.3 × 2.7) cm. The weather usually consists of the wool of eaten animals and fragments of bones interspersed into it. Often you notice the seeds of cultivated cereals in them. In the southern regions, raven pellets are found entirely consisting of any fruits, for example, from half-digested ephedra berries.

The droppings of these birds can be either in the form of a semi-liquid diffuse white blot, or in the form of a thicker short "sausage" of dark color, but covered with a white bloom at one end - it all depends on the food eaten. The size of such a "sausage" is about 4.5 × 0.8 cm.

Crow paw print

It is not difficult to find the footprints of a raven; one has only to leave the city and walk along the field or along the edge of the forest. On the prints of his paws, it is easy to notice all kinds of individual characteristics. You can, for example, pay attention to the fact that the prints left by different crows differ markedly in size. As a rule, larger prints belong to males and smaller ones to females. The male leaves an imprint (11.4 × 4.8) - (12.5 × 5), and the female - about 10.5 × 4 cm.The length of the claws on the middle fingers is up to 1.7, and on the back - 2 cm. ravens either in measured steps 16-20 cm long, or in oblique jumps, placing one paw slightly in front of the other.

The most widespread is the hooded crow. In size, a crow is larger than a jackdaw or a rook, but, in fact, half the size of a crow. The body of the hooded raven is ash gray, and the head, wings, tail, beak, legs, and the front of the throat are blue-black. Raven nests are very similar to rooks. Usually they arrange them in the forks of the trunk of a thick tree, but sometimes a crow's nest can be seen in city parks or gardens. Some crows can even make a nest on the eaves of tall houses.

Very often children are interested in where the crows live in winter. After observing these birds, scientists have found that crows make regular flights in spring and autumn. In autumn, they fly to more southern regions, and in spring they return. So, for example, crows from the Moscow region fly away to Kharkov or Kiev, and the Arkhangelsk crows settle in the Moscow region. Therefore, the crows that we meet in winter are not at all the ones that originally built their nests here and raised their chicks, but those that flew in from places with more severe frosts. However, only young crows fly. The old ones fly away from human habitation in the spring, and in the winter they return again and adjoin flocks of newcomer young crows and jackdaws.

In captivity, a crow is very easy to tame. This bird has a rather light disposition, but loves to be mischievous. She does it cunningly so that the owner does not notice. The crow is easily trainable. She can be taught to speak not only words, but also small phrases. They feed her in captivity with porridge, meat, bread and other common products.

Despite the fact that crows have nests, it is sometimes very difficult to answer the question of where crows sleep in winter. This is due to the fact that these birds very rarely spend the night in their own nest. In winter, they usually sleep on the branches of tall trees. However, places for this are chosen quieter, away from strongly lit areas or busy roads. At other times of the year, crows fly to the forest or planting for the night. Observing the crow, scientists have found that if it is not disturbed, then it will visit the same tree every year to spend the night. Quite often, the sleeping place can be very far from the place where the crow spends his time during the day.

On a note

IN spring time male and female together build a nest in which they hatch chicks. They feed babies with a wide variety of foods. It can be mollusks, insects, lizards, fish, earthworms, frogs, mice, bird eggs and even chicks of other birds. Even when the matured chicks begin to fly (after five weeks), the parents continue to feed and take care of them. After a certain time, when the chicks become completely independent, they adjoin the flocks and return to their nesting sites only for the night. In autumn, crows begin to fly to wintering places. From their native places, they can fly away at a distance of about two - two and a half thousand kilometers. At the same time, the flight speed is reached fifty kilometers per hour, although in ordinary life the crow is quite sedate.

On the one hand, crows are beneficial, since they exterminate harmful insects, pick up a carrion. On the other hand, these birds cause quite significant harm to the fields, as they peck grains from the ears, peck cucumbers and melons, and destroy the eggs of other birds.

Raven's behavior natural environment cannot be called imprudent, as they are very careful and observant. People who make some mistakes are often called crows, but this is not at all consistent with the behavior of birds. Crows are very good at understanding people. Whether a person can benefit or harm them depends on their attitude towards him. Let's say they will flock to the place where they noticed a person carrying a trash can to the container. If they notice a child throwing stones or sticks at them, the whole flock will immediately disappear. If ravens have ever met a hunter, then they will fly away from a person with a gun, while they are not at all afraid of a person with a stick.

In addition to caution, crows are also distinguished by a passion for savings and thrift. They will never leave the rest of the food. Usually they try to hide excess food in a place of their choice in order to return after it. Moreover, they can remember this place for quite a long time. A passion for everything shiny is developed in all types of crows. As soon as she sees some shiny object or candy wrapper, she begins to circle around him. She will observe the thing of interest to her until she can drag her away.

In the conclusion of the article, it should be noted that the attitude towards crows of a person should be in accordance with the role these birds play in the economy of the area in which they live. In the event of great harm, many farmers try to get rid of them.

Remember the once popular song by Zemfira about Muscovite crows? Minsk dwellers also have problems with these birds, but they do not dispose of lyrics at all. The correspondent of the agency "Minsk-Novosti" investigated the situation.

An angry reader called the agency and complained that the crows in the courtyard did not give life. At dawn, they arrange a bird market, all the paths in the yard have been turned into a toilet. Passing by and then scary - then on the head that falls, the birds themselves attack ... But no one cares. The problem, in the Minsk resident's opinion, is not worth a damn: to drive a car with a cradle and throw off the nests, once and for all put an end to bird lawlessness. The correspondent of the agency "Minsk-Novosti" tried to understand the situation. As it turned out, there really is a problem with crows, or rather corvids, in the city.

Missed

According to some reports, their number in Minsk and its environs has doubled over the past quarter century. Crows settle in flocks in the capital's courtyards, occupy trees, playgrounds, parking lots, causing anxiety to residents. They croak, shout, and often arrange noisy showdowns among themselves. Bloom the territory. So is there really nothing you can do to pacify the arrogant birds? Or has the raven become like a sacred cow in India - untouchable?

As it turned out, the number of these birds in Minsk can be regulated. But only by humane methods.

- According to Article 19 of the Law of the Republic of Belarus "On Animal World", the distribution and number of birds that worsen the sanitary and aesthetic condition of settlements, residential, industrial, cultural, domestic and other buildings or cause disturbance to residents are allowed to be regulated, - said the deputy head of the department of state control over the protection and use of lands, forests, animals and flora Minsk City Committee for Natural Resources and Protection environment Tatiana Zhichko. - This is done by destroying their nests. But only strictly certain period - from August 15 to February 15, when the nests are empty.

The fact that the yard was occupied by crows must be reported to your housing organization. There they are obliged to take measures and destroy the nests within the permitted period of time.

- None of the residents have contacted us about the large number of crows in the yards., - noted the head of the department of improvement and sanitary maintenance of the housing stock of housing and communal services-2 of the Frunzensky district Natalya Shcherbachenya. - But we know about the problem, and empty bird nests, as a rule, are removed. We also make sure that waste from container sites is removed in a timely manner..

However, the inhabitants themselves often create a food base for birds in their yards: they throw away the remains of food, feed the birds. And this cannot be done. After all, crows fly to where there is food. When throwing waste into containers, cover them with lids. In places where nests are destroyed and there is nothing to eat, birds will not settle.

Nakarkali

There are times when crows attack people and animals. One spring, opening the window, I heard a loud plaintive squeak from the street. I went out onto the balcony and saw a hooded crow tormenting a pigeon in the yard parking lot. The poor thing tried to escape, and he succeeded. Climbed under the car. Running back and forth, the crow flew away. However, as soon as the bird got out of hiding, the offender was right there. On another occasion I witnessed how in the yard several crows attacked a ginger cat, which climbed a tree. They would peck to death if the tenants did not come out to protect the four-legged. A colleague said that a gray predator once attacked her friend. She dived on her head, and the crow's beak is sharp as a nail. The woman barely fought back.

To understand why birds show aggression, you need to know something about them. The entire family of corvids, to which the hooded crow belongs, is distinguished by its special ingenuity and even a certain level of intelligence. Bird watchers recorded how birds plucked nuts from trees and threw them on the road. It turned out they were waiting for a car to drive through the fruit and crack the shell. After that, they calmly descended and ate the prey. Mutual assistance and help to each other are at the forefront of the crows. The younger generation, before starting a family, helps parents take care of the babies that have appeared. This is how huge flocks of relatives are formed. Birds are very cunning, vindictive and even vengeful. However, hostility is only shown in certain situations.

- Five species of corvids nest in Minsk: hooded crow, raven, rook, jackdaw and jay, - said the expert on environmental issues of the public association "Ahova ptushak Batskaashchyny" Semyon Levyi. - Aggressiveness is typical for hooded crows in May - June, when chicks emerge. Fledglings leaving the nest fly very badly at first, and they need protection from four-legged predators and a potential threat - humans. Therefore, when chicks are on the ground, adults are ready to attack anyone who gets close to their children. This behavior is nothing more than caring for your offspring.

If ravens attack a person or an animal, then somewhere nearby in the grass is a chick. And the attack on the pigeon and the cat is most likely associated with their approach to the crow's nest in the tree. How to behave so as not to cause aggression of birds?

- Peaceful coexistence is possible, - the specialist continued. - The main thing is not to approach the crows sitting on the ground or trees with nests of birds. If you did not notice the chicks, and the adult birds began to worry or fly at you, you should immediately move to another place. To prevent the crows from injuring you at this time, hold an object above your head.

Chicks grow up quickly and leave the nest. And the aggressiveness of adult birds disappears.

Should we declare all-out war on the crows in the city? Probably not. They bring not only harm, but also benefit. During the season, one individual eats tens of thousands of larvae, caterpillars, worms, destroys the bear, locusts and other pests. He does not disdain gray mice either.

In addition, cruel measures against crows and other birds are prohibited by law. In no case should they be shot or poisoned. For this, in accordance with the Code of the Republic of Belarus on administrative offenses have to be held accountable. In particular, for illegal destruction of bird nests, a fine of up to 30 base units is provided for with natural person, up to 100 - s individual entrepreneur and up to 500 basic ones - from a legal entity.

This beautiful and proud bird can really become a true friend. Its intelligence exceeds that of a dog, cat, and is comparable to that of a horse or dolphin. A raven can, for example, use a stick to reach the food placed next to the cage. He will overpower and overdried bread, soaking it in water. This bird is able to guess to throw stones into a narrow vase until water becomes available to it for drinking.

How not to confuse crow and raven chicks?

However, instead of the expected crow, you may end up with a bird from the same family with a consonant name - the crow. How to tell a raven chick from a raven? The raven is larger, it has a wedge-shaped tail (the raven has a flat tail). The plumage on the crow's craw is disheveled, on the crow's - smooth. The color of a crow chick is the same as that of an adult bird. The crow “croaks”, articulating correctly, while the crow makes another sound - clicks.

And they differ from each other purely in character: like a devoted knight and a pitiful thief. It is not by chance that we used the word “knight” in the context of the name of the bird “raven”, because the British have been honoring and keeping six ravens of the Tower Fortress in the service of the sovereign for many centuries, since the time of King Charles II.

How to avoid misunderstanding by unexpectedly growing a crow? The answer is simple: either take a raven chick from the nursery, or buy from a reputable seller.

We are far from thinking that you will be able to personally sneak into the thicket of the forest in May and pick up a three-week-old chick from the nest of a crow at a great height. Moreover, even if you do such a feat, you will inevitably be attacked by his parents. And an adult raven, having dispersed in flight, as you know, can kill a fox with a blow of its beak. Obviously, it is wiser for the future owner of the chick to avoid such injuries.

Therefore, we focus you on buying a bird by ad. The market price of a raven fledgling chick in the Moscow markets is $ 100.

At what age is a crow chick taken to foster care?

The raven is immensely devoted to only one person, whom he considers to be the master, and simply resigns himself to other roommates. He does not like small children and pets, being jealous of the owner.

For taming it is best to take a two to three week old bird. Females are easier to train and less impulsive. We recommend them for beginners. The specialist distinguishes them at this age exclusively by their external signs. Classes are conducted according to the classical method for hunters. If you buy crow chicks from a breeder, the borderline purchase age is 2–3 months.

Six months later, the chick is identical in size adult bird... At this age, he is already difficult to train. And an adult crow, starting from one year of age, is no longer suitable for living at home. By the way, the bird is considered finally formed only at the age of three.

A crow chick (you can see a photo of a three-week fledgling in the illustration) becomes poultry through persistent domestication and training. Unfortunately, most people who decide to raise this bird act recklessly, believing that a stylized semblance of a parrot will turn out from the chick of a proud bird.

What should the owner of a raven chick be prepared for?

A raven is two in one: a predator and a talking, intelligent, owner-loving bird. But only if you want to become its owner, it is not enough for a crow nestling to formally settle in your home. The owner should love him actively, tinker with him (that is, teach, train, communicate) every day for two to three hours a day.

The raven is a friend. If you succeed in teaching him, he will give you a lot of positives, but he will also ask you a lot. For this friendship, you, as the owner, will have to donate ... at least one room in the apartment. Be sure that after a year of keeping the crow in it, it will be prepared by the bird for repair.

A raven and a cage are incompatible things: an impulsive bird breaks its feathers. If it is not possible to allocate a "personal room" to the bird, you can equip an aviary (at least 2 x 2 m). It should provide a container for bathing birds and toys.

When is it undesirable to have a crow?

It is contraindicated to have this bird in families with small children! It is undesirable to have other animals (dogs, cats) in the house. An adult raven is a bird with character. He will be jealous of their owner and even attack "competitors".

It is not enough for the owner of the bird to proceed solely from mercy, thinking about how to hatch a crow chick. It is equally important to ask yourself the second question: "Will I be able to raise a noble tame raven?"

It is not recommended to keep a bird at home without taking time to train it. In this case, the raven does not feel the owner and begins to compete with the domestic ones in its own way, turning into a real punishment, exercising in all sorts of dirty tricks:

• he will consider not only his room, but the entire apartment as his territory (torn documents, stripped wallpaper, cornices, plinths, household utensils, furniture);
• he will not be trained to relieve himself locally;
• he will attack your guests.

To release a bird that has not been trained by adult ravens is a sure way to kill it. A domestic crow dies in the wild.

If, after reading our warning, you stayed your way and continue to solve the puzzle "How to find a raven chick?", Then the following information is for you.

Foundling chicks

However, there are different cases. Sometimes raven chicks are found falling out of the nest in April-May. Despite the height of the fall, some of them remain intact.

A crow chick is born in April. Being one week old, it even resembles a bird a little: its eyes are not open, a naked body, only on the neck and head there is a fluff. Only in the second week will the tiny rods of future flight feathers appear and the eyes open.

He is weak, his body is not covered with feathers. He is unable to maintain the balance of the heat of his body. The feeding period for him during the first week is about an hour and a half during the daytime. A helpless and completely dependent on care, a crow chick (the photo at the beginning of the article caught this moment) squeaks periodically - this is how it extorts food.

However, the bird will begin to see only after three weeks.

Temperature regime of the first week

If such a bird has fallen out of the nest, and you, having weighed all the pros and cons, have made a desperate decision to raise it, then for this you will need to take a month's leave. In the first week, you will have to equip an impromptu home incubator. A crow chick is placed in a shoe box lined with a soft cloth at the bottom and covered with a thin cloth on top. An incandescent lamp turns on above the canvas. The optimal heating should be monitored:

• increase it if the bird is trembling;
• ventilate the box if it gasps for air.

Temperature regulation in the second week

After the appearance of feathers (in the second week), the temperature regime is simplified. Just keep an eye on the temperature in the room where the crow chick is located during the day, to be kept at about 20 degrees Celsius. The home incubator should still be heated at night.

As the fluff covers the entire body of the bird, it will be possible to remove the top sheet. Next, we will briefly consider the organization of the feeding of the crow chick, noting the importance of the presence of clean, non-chlorinated water in the aviary and the addition of calcium (rubbed shell) to its food for the formation of full plumage.

Feeding the chick

The question of what to feed a raven chick at home has two different answers: for the yellow-mouth and fledgling.

The little moth is fed with tweezers. Food is served from top to bottom. In this case, his reflex is triggered: he lifts his head and opens his beak. The food itself is a mash. If we are talking about nursing a sick chick, then it is fed from a syringe, on which a rubber nozzle is put on.

• meat offal (or pate, or minced meat) - 40%;
• steamed finely cut flakes (crushed - wheat, barley, millet, oat, corn, rye) - 30%;
• fat-free cottage cheese - 10%;
• sprouted grain in finely chopped form - 10%;
• grated apple, beets, carrots - 10%.

Feeding fledglings

Let's imagine one of the recipes showing how to feed a fledgling raven chick. It is also a mash, only a slightly different consistency, also suitable for adult birds:

• cereal flakes, boiled buckwheat or boiled brown rice - 30%;
• finely chopped meat by-products - 30%;
• fat-free cottage cheese - 20%;
• grated squeezed apple, carrot, beet - 10%;
• finely chopped sprouted grain - 10%.

Flying

Let us highlight this complex issue in a thesis.

1. Raven chicks are taught to fly according to the classics of training birds of prey, observing the necessary requisites (additive, glove, etc.). This technique is fully functional in our case.
2. When training a raven to fly, the probability of no return should be minimized. Therefore, it is better to choose suburban fields for the realization of the natural need of the bird. In a city with its traffic and noise, it is highly likely that an inexperienced raven will get lost.

Teaching a raven chick to speak

If the parrot perceives the female timbre of the voice better, then the raven practically does not react to it. But hoarse, squeaky masculine overtones are his element. He repeats not only the creak, barking of a dog, hoarse male laughter, but also shows good ability to speak. Similar abilities of another black bird - the rook - were described by Mikhail Mikhailovich Prishvin in the story of the same name.

Where to begin? Firstly, we recommend that you call the crow so, he could easily call himself, for example, Karl. Secondly, when entering and leaving, say the standard phrases ("Hello", "Bye"). Start by teaching the raven to pronounce these words, then you can start phrases.

He remembers whole sentences no worse than a parrot, but he pronounces them (this is confirmed by experts) more consciously. For this, the owner should talk to him.

Instead of a conclusion

Agree, there is something special, noble in a raven - one of the most difficult birds to keep at home.

A raven chick is not a spineless toy, it is a friend for an adult, making adjustments to the rhythm of his life. But if you really manage to grow a friend out of him, he will adequately respond to you with love and devotion for many years.

Why are crows nests multi-storey? Do they build a new nest every spring? and got the best answer

Answer from Valera world yao [guru]
The colonial type of nesting has certain advantages over the solitary one, mainly in terms of protection from predators. In this case, there is usually no intense competition for space for nesting. Nesting colonies have existed for many decades. So, rooks use the same nest many times in a slightly modified form. However, observations show that the old nest is used only as a base for the new one, and the side walls are rebuilt and the tray is always re-lined. A significant part of the old nests is taken away by birds and used as building material for new buildings. Although there is no exact data on the duration of the use by birds of the same nest in such a nesting colony, it can still be assumed that, undergoing annual repairs, it has been used by rooks for many years. , after creating a family, they settle next to others, forming friendly communities. Together they get food, defend themselves from enemies, setting up sentries who warn the whole bird community in time about danger, and provide mutual assistance. And sometimes birds from such communities also build nests together, and each of them works no less diligently on building someone else's nest than on their own. Raven community life. Common ravens, such as village ravens, have long been known for their well-organized social behavior. Waking up, dawn will dawn a little, one of the main crows flies out into the open, sits on a high tree and begins to croak. Gradually, from all sides of this area, crows flock to her voice and, with a response croaking, they sit in a flock in the trees. At dawn, their groups go to the field or meadow to search for worms, insects, field mice, etc. Around noon, crows usually rest in the dense branches of a tree. All day, constantly replacing each other, the sentries sit high in the trees and carefully examine the surroundings. In case of danger, they raise the alarm with a loud croak, and then the whole group rises into the air. And if it is a predator approaching in the air, the sentries take off with a cry to meet it. The foremost sentry is especially brave - he leads the pack. Having driven off the enemy, the guards go to their post, and the crows - to rest.

Answer from Victoria[guru]
The shape and size of the nest. The compact heap nest has a thick base, low edges and a fairly flat tray. The base of the nest consists of relatively thick branches, 15-20 mm in diameter, the upper part is made of thinner branches. The nest is small, considering the size of the bird, when it sits on the nest, it is clearly visible. The birds occupy the nest for a number of years, but, each time renewing it, they gradually increase in size. Nest diameter 320-660 mm, nest height 200-430 mm, tray diameter 170-240 mm, tray depth 85-140 mm.
Features of masonry. Clutch of 4-5 pale green, bluish-green or pure green eggs with brownish specks and dots is more often. Egg sizes: (38-42) x (28-32) mm.
Breeding dates. Hooded crow in the middle lane starts nesting at the end of March. Full clutches are found in mid-April. Incubation lasts 21 days, and chicks appear in the first half of May. At the age of about five weeks, young birds become flying birds. Chicks leave the nest in mid-June.
In January-February they make mating flights, in February they appear at old nests, which crows usually use several times. The nests are repaired in March. In March-April, the female lays eggs. With the onset of egg laying, ravens begin to moult fully annually. The female hatches eggs. Chicks appear in April, and fledglings are observed in May. Chicks are with their parents until August and wander around the nesting sites, by autumn they migrate to the south. Hoodie
When we walk in a park or forest, wander along the river, relax on the lawn, we do not even suspect that we are ... being watched. A person, and even more so a group of people everywhere, attracts the attention of hooded crows. These birds are not watching us out of idle curiosity. They have long noticed that where people stay for quite a long time, you can often find something edible, for example, the remains of a meal in the bosom of nature.
Now let's imagine that while walking among the white-trunked birches of the May forest, we suddenly stumbled upon a skillfully hidden chaffinch nest. Of course, you want to take a good look at it, touch it - and now the disguise is broken. Soon we will leave, but we will be replaced by a thunderstorm of birds' nests - a hooded crow. It was not in vain that she kept her distance and for a full hour was observing nature lovers. As a reward for his patience and attentiveness, the crow will receive a nice dinner, and the couple of finches will have to accept the loss and start building a new nest.
But no matter how ruthless the robber is in relation to other people's eggs and chicks, she tries to protect her offspring from predators and builds a nest-bowl in tall, branchy trees. For greater strength, in addition to coarse branches, aluminum wire is often woven into the walls. And the tray for warmth and softness is lined with animal hair, sometimes with an admixture of rags, scraps of newspaper and even polyethylene.
Exactly 21 days, like a chicken, a hooded crow incubates ravens. And then out of five or six green speckled eggs, voracious chicks are born, and our cheats have more trouble!

Answer from Victor Alexandrov[guru]
Very often, if an old nest is arranged in a very good place and has slightly suffered from the past winter, the crows simply finish building it, having squatted a certain amount of branches or other building material. If this is done several times, the nest becomes much larger than the initial size and, if desired, you can even count how many repairs the birds have made, that is, how many years they hatch chicks in one place and even assume the size of the clutches in different years (on the remnants of the shell of previous years.