Adaptation of birds to flight: signs. How birds adapted to the flight

Most representatives of the bird class have mastered the land-air habitat. The adaptation of birds to flight is due to the peculiarities of their external and internal structure. In this article, we will discuss these aspects in more detail.

Signs of the adaptation of birds to flight

The main features that allow feathers to master the air environment are:

- feather cover;

- modification of the forelimbs in the wings;

- warm-bloodedness;

- light skeleton;

- the presence of a special bone - keel;

- double breath ;

- a shortened intestine;

- absence of one ovary in females;

A well developed nervous system.

These structural features illustrate how birds are adapted to flight.

Structure of the skeleton

With the ease of climbing upwards for birds it becomes possible, above all, thanks to the light skeleton. It is formed by bones, inside of which are air-bearing cavities. The main parts of the skeleton of birds are the skull, spine, upper and lower extremity belts and free limbs themselves. Many bones coalesce with each other, providing the strength of the whole "construction". A distinctive feature of the bird's skeleton is the presence of the keel. This is a special bone, to which the muscles are attached, which move the wings. It is characteristic only of birds.

Covers

The features of adaptation of birds to flight are in many respects connected with the features of the covers. Feathered are the only group of animals whose body is covered with feathers. They can be grouped into three groups. The first is called "contour". Thanks to them, the body of the bird acquires a streamlined shape. Depending on the location on the body and the functions performed, the outline wings are covering, flapping and steering. They cover the body, forming the contours of the wings and tail. Regardless of the species, each wing consists of a central part - a rod, on which most part there are puffers, formed by first and second-order beards with hooks. The lower denuded portion of the pen is called the ocher.

The second group is represented by down feathers. Their beards are devoid of hooks, so they are not linked, but are free. The third type is fluff. A characteristic feature of its structure are fluffy beards, which are located at the end of a strongly shortened beam at one end.

Using the example of feathering, it is easy to see how the birds adapted to the flight. It provides thermoregulation, determines the color, the ability to move in airspace. By the way, the color of birds can serve as a disguise from predators, and one of the forms of manifestation of demonstrative behavior.

Warmth-keeping

This adaptation of birds to the flight is very important. Warmthreading implies the presence of a constant body temperature that does not depend on the environment. After all, as is known, with altitude the air temperature drops significantly. And if the birds were cold-blooded, like fish or amphibians, they would just freeze during the flight. Such a feature is inherent in this group of organisms due to the progressive structure of the circulatory system. It is represented by a four-chambered heart and two circles of blood circulation. Therefore, venous and arterial blood do not mix, the exchange of gases and substances occurs very intensively.

External structure

The body of birds is divided into the following parts: the head, the mobile neck, the trunk, the tail and the limbs. On the head are the eyes, nostrils and a beak covered with horny covers. Absence of teeth makes the skull even easier. The eyelids are still, the cornea is moistened with the help of blinking membranes.

The main adaptation of birds to flight, Certainly, Is also in the modification of the upper limbs. They are transformed into wings. Legs are lower limbs, often covered with horny scales. This feature of the structure has remained in birds from their ancestors - reptiles. The claws on the toes help the birds to rest on the supporting surface.

Internal structure of birds

The adaptation of birds to flight is reflected in the peculiarities of the structure of most internal organs.

The digestive system is represented by the oral cavity, the esophagus, which forms the expansion - goiter. In it, the food is subjected to additional enzymatic processing, becomes soft and is quickly digested. Further, the food enters the stomach, which consists of two parts: glandular and muscular, and then into the intestine. It opens outward with a cloaca. The intestine of birds is shortened in comparison with other animals. Such a structure also makes their body easier. Undigested food remains do not stay long in the intestines and can be released through the cloaca even during the flight.

Adaptation of birds to flight is also traced in the structure of the nervous system. Due to its development, animals have a sufficiently clear color vision, which makes it easy to navigate in the air even at a sufficiently high altitude. Well functioning and hearing. And thanks to the developed cerebellum, the coordination of movements is at a high level . Birds react quickly during an approaching danger or hunting.

Compactness is a characteristic feature of the reproductive system. Testes of males of small size, bean-shaped. They open their ducts directly to the cloaca. The females have only one ovary. Such a structure makes the weight of birds significantly smaller. The egg from the reproductive gland moves along the oviduct, where the fertilization process takes place, the egg is covered with shells and calcareous shell. Then through the cloaca comes out.

Features of breathing

Adaptations of birds to the flight also affect the respiratory system. After all, intensive work of the muscular system requires continuous supply of tissues and organs with oxygen. Therefore, along with pulmonary respiration, birds have additional organs - air sacs. These are additional air tanks with a sufficiently large volume. Therefore, the breathing of birds is also called double.

Adaptation of birds to their habitat

The features of the external structure often change depending on the habitat. For example, a woodpecker living in a forest has sharp claws. With their help, he moves along the branches of the trees, leaning on the tail with stiff feathers. The beak of this bird is like a chisel. Using it, and also with the help of a long sticky tongue, he takes out insects and larvae from the bark, seeds from cones.

Birds - inhabitants of reservoirs, also have a number of important adaptations. These are short lower limbs with swimming membranes, a dense feather cover, lubricated with the water-repellent secret of special glands. "Get out of the water" - this proverb, known to everyone, came about thanks to the peculiarities of the life of waterfowl.

Inhabitants of open spaces - steppes and deserts, have protective coloring of feathers, very powerful legs and excellent vision.

Birds of the coast are masters of the planning flight. Albatrosses, gulls and petrels are characterized by the presence of strong and long wings. But their tail is short. All this allows coastal inhabitants to fish right from the air.

Is it possible to see the prey at a distance of up to a thousand meters? For birds of prey this is not difficult. Falcon, hawk, eagle - bright representatives of this group. They have a large, curved beak, which they grab and tear food. And powerful sharp claws do not leave a chance for salvation. Predators can fly for a long time in the air thanks to very wide wings. And those of them that hunt at night, additionally have sharp eyesight and perfect hearing. For example, owls and owls.

Do all birds fly

Not all representatives of this class are able to fly. For example, penguins are excellent swimmers, their upper limbs are modified into fins. But these birds do not know how to fly. They have a keel, but the big weight does not allow them to soar into the air. A thick fat layer and thick plumage are simply necessary for life in the harsh conditions of the north.

The ostrich family includes emu, kiwi, cassowaries, and nandu. These feathered keels are absent. And the inability to fly is compensated by a quick run. This skill rescues birds in the conditions of a plain Africa.

The vast majority of modern birds are perfectly adapted to the flight and habitat. They live in the forest, on ponds and their coasts, steppes and deserts.

Representatives of a class of birds amaze with the variety, have an important value in the nature and human life, and the characteristic features of a structure determine the ability to fly.