Advice 1: Why swallows build nests under the ridge of the house

Swallows are very common wherever there are settlements or open space above the water. In cities and towns are the most common whale ("swallow") and funnels (urban swallow), they can deliver to the residents a lot of trouble, building their nests under the eaves or roofs along the eaves of houses.
Why swallows build nests under the ridge of the house

In order to build a nest, swallow the necessary vertical surface. She finds in the puddles, the damp earth, rolls it into balls and brings in the beak to the chosen place by attaching to the nest with their own saliva. For strength swallow can strengthen the structure with straw, hair, stems. The construction takes place purely mechanically, always on the same principle. Being in a new environment, the swallow is lost, and cannot adapt to them (for example, it cannot build a nest if there is no vertical surface).

One of the most suitable places for nesting – building walls along the eaves, under the eaves and skates houses, under supports of bridges. Swallow tries to choose a place comfortable for the flight and at the same time under the roof to the building has not soaked from the rain, and the Chicks were protected. The reason swallows choose nesting sites of the city, is simple – here are a lot of food. They are happy to kill hundreds and thousands of mosquitoes, midges and flies of the day.

According to popular belief, the swallow's nest on the wall of the house – fortunately. However, not all residents of the house agree on this neighborhood and try to drive the swallows from the selected point. In fact, it is quite difficult, which is associated with instinctive relation to the site.

Well-known Russian naturalist, V. A., Wagner conducted experiments in which hung the nests of swallows on a small distance, and in front of their parents. Swallows have long sought its nest in the place where it was built, was ready to feed someone else's Chicks. The scientist concluded that the swallows are very important the place where he built the nest – even more important than the nests and Chicks. So the simple destruction of nests no nothing, just swallows will build a new one. The only opportunity to scare the birds to make the walls slippery so that the lumps of dirt it was impossible to fix.

Advice 2: Why swallows fly low

Swallows – national "barometer": if they fly low it will rain. Luck is correct 100%. The explanation of this fact is quite simple: follow the swallows eat small flying insects.
Why swallows fly low
Swallows actually fly low, and just before the rain, in cloudy weather. Widely known national sign – "swallows fly above the earth – the rain" - always borne out in practice. But in a good, Sunny weather, the swallows flashed high in the sky. They practically live in the air, rarely landing. Prefer to sit on the wire where it is easier to take off. Even drink a swallow on the fly, make the throat of the water, flying over the pond.The fact that swallows are insectivorous birds, they feed exclusively on flying insects. In clear weather, ascending from the earth currents of warm air rise up and all sorts of midges, flies, mosquitoes, horseflies and other winged insects. There they catch swallows, feeding themselves and their vykarmlivaya Chicks.Before the rain the air humidity increases, the wings of insects congenerous microscopic droplets of moisture, whereby the wings are heavy, and insects, it becomes difficult to climb high from the ground. They have to fly very low above the ground or water, and after them (for their food) are reduced and swallows. People small insects like midges and mosquitoes are not visible, and the swallows are well marked; and there was the sign.Insects to feed the swallows need a lot to make up for energy loss and feed the Chicks. Jack swallows down hundreds of times per day, bringing in its beak not one, but several insects. I understand why the swallows are forced to follow the insects: flies high in the air and swallows high, flies low and the swallows above the earth. The nest of swallows is located in places where the birds can easily fly in the air: cliffs, steep slopes of the ravines or under the roofs of houses.Feeding on flying midges, swallows, naturally, can not we have to spend the winter and early in autumn they fly South, Africa and South Asia.

Advice 3: Why before rain, swallows fly low

In the world there is a huge amount to take that can help to predict future events on the behavior of living organisms. No exception, and swallows. People say: "Swallows fly low – rain". Is there any science behind this belief?
Why before rain, swallows fly low

Too romantic nature can assert that swallows – extraordinary birdss, endowed with a special instinct and intuition, they are able to feel the weather change and his behavior to warn about it.

However, everything is much easier. Enough to appeal to the school physics course and remember the law of gravity (F=mg) in order to explain the behavior of swallows before rain.

Swallows are birds of prey that feed themselves and their Chicks suckling the smallest of insects and midges in abundance living in the air and not always noticeable to the naked human eye.

Shortly before it rains, humidity is significantly increased. As a result, on the wings of the insect are deposited tiny droplets of water. This leads not only to an increase in the severity of the wings, but also to increase the body mass of the insect, whose activity is accordingly reduced. Gnats, bugs, etc. are forced to fly lower than usual. Therefore, their pursuers – swallows - down in his flight closer to the surface of the earth.

Man, unable to see the true reason for this flight of birds, ascribes the signs of extraordinary abilities and capabilities.

But not only the approaching rain can "make" the swallows to change the usual altitude. Sudden changes in temperature, for example cooling of the evening, lead to the same effect. And again, the reason lies in the changing at the same time, a lower flying insects. Therefore, virtuosic, exciting "dance of swallows in the evening sky is not always the harbingers of bad weather.

The younger generation of these beautiful birds often "rejects" became a familiar sign. And even during small precipitation can be observed high in the sky frolicking swallows. The fact that the unencumbered production of food "youths" work out new skill – flying.

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