Why do birds fly?
Many people, admiring the beautiful flight of birds, often think about why birds fly. And the romantics ask themselves: "Why don't people fly like birds?" The answers to these questions are related to the particular structure of the birds. What and why helps the bird to float in the air and not to fall?
- The most important instrument in flight is wings. The bird's wing has a curved shape, and this allows you to create a force that counteracts the force of gravity. When the wing operates, the air flow rate over it increases, while the pressure decreases. It is the pressure difference above and below the wing that can withstand gravity, and the bird can rise into the air.
- Feathers are horny skin formations that give the body of the bird a smooth and streamlined shape. This makes flight easier, since there is not much resistance with oncoming air. Feathers also help create cravings and lift. The bird has feathers that regulate the direction of flight (tail feathers on the tail). In addition, they fit snugly together, which protects the bird's body from adverse environmental conditions (rain, wind, heat, cold, etc.).
- Features of the skeleton and muscles also affect the ability of birds to fly.The bird's skeleton is very durable and lightweight, and it helps to rise into the air and resist the environment. The strength of the skeleton is achieved due to the accretion of its bones. The ease of the skeleton is due to the fact that some bones contain air-cavity. The bird skeleton also has an important feature - there is a keel on the surface of the sternum (small outgrowth). It serves as a fixation point for the pectoral muscles that move the wings. The large muscles that move the limbs are located on the body, and the limbs have tendons. Therefore, the bird's legs are thin and light, which also reduces air resistance when flying.
- Features of the body of the bird. The bird must be strong in order to fly at high speed over long distances. Therefore, the more a bird flies, the larger and sturdier the heart is. The frequency of contractions of the heart - up to 1000 beats / min. This is much more than in mammals. This ensures fast blood circulation and helps the bird to become saturated with oxygen. The more oxygen a bird receives, the easier it is to fly. The body temperature of the birds and the pressure also have high rates compared to mammals (temperature - from 40 to 42 ° C; pressure - 180 mm Hg).High body temperature increases the vital processes, in particular, the rate of muscle contraction. This, in turn, increases the speed of flight. The nervous system of birds also has one significant plus - the developed cerebellum. It helps to control the coordination of movements, and this plays an important role during flight.
Now you know why birds fly. This is due not only to the wings and feathers, but also to all body systems. For many, the question arises: why then do many birds fly, and some do not fly at all? The problem lies in the mass and in the structure of the body of flightless birds. Small birds can fly because they weigh little, have well-developed musculature for flight, and the size of their wings is proportional to the size of their bodies. Some birds, such as the ostrich and the penguin, do not have such well-developed musculature, and their body mass is large enough to take to the air. But the lack of flight they compensate for movement on land or water. Such birds swim well, walk, run, and some even climb trees! Unlike flying birds, they have well developed lower limbs, with the help of which they move.
Why do birds fly south? Many people mistakenly assume that birds leave us in the winter because of the cold. Of course, the birds are warmer in the south, but the main reason lies elsewhere. This is the lack of food. With the onset of cold weather, birds lose their usual food - insects, frogs, toads, fish and their larvae. All this they find in the southern regions. We have quite a few migratory birds: tits, swallows, swifts, cranes, larks, ducks, geese, swans, etc. Most of the birds in Russia are migratory. But there are non-migrants who have adapted to feed on waste. These are rooks, jackdaws, magpies, crows, sparrows, pigeons. So do not forget to feed the birds in the winter!
How to choose the tone of the foundation
Help - why the leaves of hibiscus turned yellow
Insolent neighbors who have expanded the balcony
New motherhood, or How not to dissolve in the child
The main trends of the Fashion Week in Paris - 2016
How profitable to buy luxury perfumes