Flight for birds is a fundamental quality that allows you to ensure the search for food and nesting, to choose a way of protection. And the vast majority of representatives of this class dominate in the ground-air space. Adaptation of this class to flight was the cause of many features of their external structure and internal structure.
General signs of device
The main features that birds give the possibility of flight and dominance in the atmosphere can be considered:
Bone system and skeleton
To be able to fly, the birds have acquired a light body frame, which is formed from the bones that are equipped inside the air cavities. And many bones of the skeleton are connected together to ensure the general strength of the structure.
The skeleton of the bird
The frame of the skeleton of almost all birds consists of the following parts:
The main distinguishing feature of birds and their skeletal structure is the presence of a special bone, keel, which ensures muscle fastening, due to which the movement of wings occurs.
Cover (feathers)
Characterizing the device for flight in many birds is the features of the skin. Birds are the only group of animals in which the feathers are formed.
Featers of birds are divided into several species:
This type of coating, depending on the position and functionality, is customary to attribute the lid, fly feathers, as well as any tail plumage: thanks to this type of plumage, the contours of the limbs (wings) and tail are formed.
Any type of feathers consists of several parts:
All feathers in their composition have keratin, or protein that forms the skin of a person, and they are formed in a special skin area, called the follicle. With the development of the pen, it is initially equipped with blood vessels (arteries and veins) located in the rod and feed the pen.
At this stage of development, this formation is called blood: due to the presence of blood, the color of such a pen is dark, and later the feather receives the white color of the rod. The blood feather has a more significant pond (unlike an adult), and it grows from a keratin cover of wax that protects the pen during growth. Wax protection is removed by a bird as the pen forms.
Warmbloodedness
It is such an adaptation that is one of the most important characteristics of birds. And it is the presence of warm blood that helps to provide a constant temperature indicator of the body of birds, which does not depend on the surrounding space (it is clear that the higher the height of the bird, the lower the ambient temperature will be). If the birds remained coldblooded, like their ancestors, amphibians or fish, then they could simply die.
Such heatbloodedness is ensured due to the progressive structure of the circulatory system (two circles of blood circulation) characterized by the presence of a fourchamber heart. Several circles of blood circulation allows you not to mix the venous and arterial flow of blood, since the metabolism of birds in birds is quite intense.
All organs and systems of poultry are supplied with arterial blood, and due to the intensity of vital activity in the body of the bird, a significant amount of heat is produced, which allows it to provide constant temperature indicators.
External structure
The external structure of the body of birds is divided into several departments:
It is the modification of the upper extremities that were transformed into wings in birds that are the main external sign of the adaptation of this group of animals to flight. The lower limbs of almost all birds are also covered with horn scales, which was transmitted to birds from their ancestors from the class of reptiles. And the ability to stay on the surface of the birds provide claws on the fingers of the legs.
The external structure of the bird
Internal structure
Features of the structure of many internal organs of birds are also imprisoned for the need to stay in flight:
Features of the structure of this system are connected, first of all, with the need to split significant volume of food in a short time, as well as with a decrease in the total mass of the tract. Such a task is achieved by lack of teeth in birds, the use of beak and tongue as a tool for obtaining food, and the formation of a whole department (goiter), where it is softened, as well as the grounding of food in the muscle section of the stomach, as if on the millstones.
Thanks to the good development of the cerebellum in birds, high coordination of movements, and they are able to quickly respond to danger or prey.
Compactness is the main characteristic for flying birds, and this is mandatory even applies to the reproductive system: males have small testicles that can open directly into the cloaca, and the females have one ovary in general (the other is simply reduced to facilitate weight). In general, such a compact design of all internal systems significantly helps to relieve bird weight relief.
Adaptation of birds flight table
| External structure | Most of small birds. The body of the birds is streamlined. The plumage reduces air resistance. The tail during the flight plays the role of the steering wheel, and when landing helps to slow down. |
| Skeleton | The appearance of pneumatic bones (bones with air cavities). This ensures the relief of the skeleton while maintaining its strength, while the limbs themselves are lengthening, which greatly facilitates the flight |
| Muscles | developed on the chest, which leads to the movement of the wings Digestive system: without teeth, quick digestion, frequent monitoring of the intestines, etc.D. |
| Digestive system | The digestive intensity in birds is very high. A high metabolic level is associated with the processing of a large amount of food |
| Respiratory system | Air bags contribute to an increase in the volume of inhaled air, participate in the mechanism of double breathing, contribute to heat transfer, protecting the body from overheating, facilitate the weight of the body of the poultry |
| The system of reproduction organs | The females have one left ovary and one left egg |
| Circulatory system | Large size of the heart, the presence of 4 chambers, thanks to which the body tissues receive arterial blood rich in oxygen |
| Nervous system | the presence of relatively large visual shares, which is associated with a more complex structure of the organs of vision |
Features of the breathing system
The respiratory system also had a serious influence by the adaptation of birds to flight possibilities. To be able to work intensively in flight, the muscle system of the bird needs constant supply of oxygen of all tissues and organs. And for this purpose, birds have formed special organs, air bags, t.e. peculiar cylinders with air, and thanks to them, birds have double breathing.
Adaptation of birds to the environment
The characteristics of the external and internal organization of the body of the bird can change in direct dependence on the environment of its habitat. So, the woodpecker living in the forest is equipped with claws for the possibility of moving along the branches. The inhabitants of the reservoirs have their own devices they have short limbs equipped with membranes, and thick feathers with grease. If we talk about coastal birds, they are real masters of planning and have strong wings, but significantly shortened tail (seagulls, albatrosses), which makes it possible to catch fish directly during the flight.
Bird birds are able to make out prey at a distance of up to a thousand meters: hawk, falcon and other predators are well adapted to this.
Not all representatives of birds are capable of flight. For example, penguins are adapted to spend most of their lives in cold water, and their limbs were transformed into fins. In the same way, ostriches, chicken and some other birds do not fly, which is reflected in their systems and structure.
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