The study of the external structure of birds allowed scientists to establish the characteristic features, thanks to which they adapted to flight. It is their presence that makes these animals absolutely unique representatives of the chordate type.
Features of the structure of birds
The ancestors of birds are reptiles. And this is not just an assumption. The non-feathered part of the bird’s leg, called the tarsus, is devoid of feather cover and flakes. They have a similar structure with the same structures in lizards and snakes. During the evolution of birds, progressive structural features prevailed. This is the appearance of a four-chamber heart, in which there is a septum. Thanks to her, venous and arterial blood is completely divided. This change led to the appearance of warm-bloodedness. This is the ability to maintain a constant body temperature, which is independent of environmental conditions. Due to this, birds can be at high altitude for a long time at low temperatures.
The external structure of birds also determines their ability to fly.
Body parts
The body of birds consists of a head, neck, trunk and limbs. All of them have their own characteristics, often associated with living conditions. There are eyes on the head. Their size varies depending on how large the body is. Predators have the same volume eyes as humans. And in chicken, they are equal in mass to their brain. All birds are able to distinguish colors. And the visual acuity is simply amazing. For example, a Peregrine Falcon predator clearly sees prey at a distance of about 1 km.
The head of the birds is very mobile. Owls, looking for prey, are able to rotate it 270 degrees.
Features of the external structure of birds are determined not only by the ability to fly, but also by the nature of the food. First of all, this concerns the structure of the beak. It is the initial section of the digestive system that leads to the oral cavity.
Beak
Beak is the visiting card of every bird. It is formed by a solid horn substance. Its constituent parts are the supraquibulis. Beak will replace many organs for birds, performing the functions of the oral apparatus, nose and forelimbs.
The diversity of beaks is determined by the nature of the food. Herons, which prey on aquatic creatures, are long and sharp. With its help, these birds can easily catch a frog or pierce a fish through it. With a crossed beak, it is easy to gnaw cones and get seeds out of them.
Predators attack their prey. At the same time, with the help of a sharp bent beak, they easily tear it into pieces.
A woodpecker obtains food in another way: its beak looks like a chisel. The bird makes holes in the wood from which it extracts insect larvae.
Limb features
The external structure of birds is also due to the structure of the limbs. Upper turned into wings. Their skeleton consists of a shoulder, forearm and hand. Covering feathers are attached to the covers of the wings. This structure makes birds capable of flying. The wings set in motion specialized muscles that attach to the flat bone, the keel.
With the help of the lower extremities, the bird lands and pushes off the ground, moves on the surface. Flexible toes allow you to hold on to any surface. They end with sharp claws, which are especially well developed among predators. They falcons, golden eagles and peregrine falcons dig into the victim, not giving her the slightest chance.
Integument
The skin of these animals is dry and devoid of glands, like reptiles. However, waterfowl have a coccygeal gland. With secretions of its fat-like secret, they smear feathers. As a result, they do not absorb moisture.
The unique external structure of the birds is due to the presence of feather cover. It is a derivative of the skin.
Depending on the structural features and functions performed, several types of feathers are distinguished. Contouring are divided into flywheels, coverts and steering. The first are located on the wings and provide the ability to fly. Hiding materials are similar in location and function. And the helmsmen are concentrated on the tail, act as a helm during the flight, helping the birds to carry out rather complicated maneuvers. The contour pen is based on a horn rod surrounded by a wearer. It, in turn, consists of beards of several orders, tightly connected by hooks. The part of the rod, deprived of the fan and immersed in the skin, is called ochin.
The next variety of feathers are down. They are located under the contour. Their functions are to maintain heat and heat insulation of the body. A similar function is performed by fluff, in which the barbs extend in a bundle in the form of a brush.
Some bird species have specialized threadlike feathers. Located in the corners of the mouth, they perform the function of the organs of touch.
External structure of birds and habitat
Features of the morphological structure of birds largely determine the conditions of their habitat.
A bright representative of rat-free African ostrich is not capable of flying. Therefore, it has high powerful legs, on which there are only two fingers. All this contributes to a quick run and makes it the largest bird on the planet. And thanks to their long necks, they can look out for the small terrestrial animals they feed on.
Penguins, despite the presence of a keel, are also not capable of flying. A large fat layer, which is necessary for life in harsh northern conditions, does not allow them to soar into the air. This is offset by their ability to swim perfectly. This is possible due to the fact that the forelimbs are modified into elastic fins. So the penguins fly in the water.
The life of the representatives of the Anseriformes is closely connected with water. That is why they have an elongated body, shortened and backward-shifted legs. This makes it easier for birds to dive under water for food. Between the toes are swimming membranes. An interesting structure has a beak. It is wide and flat in shape, and a system of horn plates is located inside its upper part. With their help, swans, mallards and eiders filter out food.
Owls and owls have a hooked beak, powerful and bent claws on their fingers, long wings and a short tail. Such structural features allow them to be forest predators. A thick and soft plumage provides a quiet flight.
Features of the external structure of birds: table
Birds are a group of warm-blooded animals adapted for flight. The table shows the main features of their morphology.
| Sign | Characteristic |
| Parts of the body, especially the skeleton | Head, neck, torso. The upper limbs are turned into wings. In most, the sternum forms a flat outgrowth - the keel. The bones of the foot fuse together, forming a foregrip |
| Body shape | Streamlined, non-obstructing air movement |
| Cover | Kosh is dry, devoid of glands, covered with feathers (contour, down, down) |
Thus, we can draw the following conclusion. A study of the external structure of birds indicates that its main features make these animals capable of flying.