Feathers are not only decoration for birds. They give warmth, the ability to fly, find a mate during the mating season, hatch offspring and hide from predators. Consider the types of feathers and their structure.
Why does a bird need feathers?
Plumage is a trait unique to the class of birds. It is vital for birds and performs many functions. It is feathers that allow birds to fly, creating a streamlined body shape, and most importantly, the bearing surface of the wing and tail. The feather protects the body of the animal from damage and injury. The waterproof function is effective - the tops of the feathers fit snugly against each other and prevent getting wet. The lower part of the contour feathers, down feathers and down are closely intertwined, forming a kind of air cushion near the surface of the skin, protecting the body of the bird from hypothermia.
The plumage has a different color and shape and carries information not only about the species, but also often about the sex of the bird. Appearance plays a big role in both intraspecies and interspecies communication.
General structure of the pen
Plumage performs many functions, and each of its individual elementsmay differ in appearance. Next, we will look at what bird feathers are. The structure and composition of the plumage have much in common, regardless of the purpose. The feather is made up of the protein keratin. Made from the same material as our nails and hair.
The structure of a bird's feather is as follows: rod, chin, beards, beards, hooks. The basis of each pen is the central core. It ends with a hollow opening, which is attached to a feather bag in the skin. This name appeared even at the time when goose quills were used for writing. Their tips were sharpened, that is, sharpened.
The upper part of the pen, on which the barbs are located, is called the trunk. Elastic filamentous formations are attached to the trunk at an angle of 45 ° - first-order beards. They have even thinner and smaller threads - beards (they are also called second-order beards).
Hooks are located on the beards, with the help of which the beards are fastened together and form an elastic and dense fan that can resist air pressure during flight. If the hooks are disengaged, then the bird corrects them with the help of its beak. The mechanism is often compared to a zipper. The beards at the bottom of the fan do not have hooks and make up its downy part.
Feather types
The structure and function of pens can be divided into several types:
- outline;
- helmsmen;
- wing;
- downy;
- fluff.
Despite the fact that outwardly feathers seem quite simple, in structure theyare complex and ordered structures and consist of many tiny elements. The structure of the pen depends on the functions it performs.
Outline feathers
Contour feathers are so named because they form the contour of the bird's body and give it a streamlined shape. They are the main type of plumage and cover the entire body. The structure of the contour feather of a bird is as follows: the rod is rigid, the beards are elastic and interlocked. These feathers are not evenly distributed on the body, but are tiled, which makes it possible to cover a large surface of the body. They are attached to pterylia, special areas of the skin. The structure of the contour feather of a bird forms a dense fan, which almost does not let air through.
Steering and flight feathers
The tail feathers are on the bird's tail. They are long and strong, attached to the coccygeal bone and help to change the direction of flight.
Flight feathers are strong, they form the plane of the wing and are designed to provide flight. They are located along the edge of the wing and provide the bird with the necessary lift and thrust. The lower part of the bird's wing is covered by one of the varieties of contour feathers - coverts.
Down feathers and down
Down feathers are located near the surface of the body, under the contour ones. The structure of the downy feather of a bird has its own characteristics: the rod is very thin, there are no hooks on the beards. These feathers are soft and airy. They are located between down and contour feathers. The structure of the downy feather of a bird allows for thermal insulation.
Down resembles a downy feather, but withstrongly shortened stem. The beards also do not have hooks, they are soft and tuft away from the apex.
Other types of feathers
The structure of feathers can be very interesting. There are many birds, or rather their species, and they may have their own characteristics. For example, some species have thread-like feathers. They are very thin formations with a long shaft and only a few beards at the very end. Scientists still do not know exactly what their function is. Presumably, the thread-like feathers are related to the sense organs and help determine the position of the flight feathers.
The structure of feathers (of birds of some species), related to the sense organs, is always specific. For example, bristles that perform both sensitive and protective functions have a soft shaft and several barbs at the base. They are located on the head.
There are also decorating feathers - modified contour feathers. They have a variety of shapes and colors and serve to attract females. An example is the rich peacock tail.
Most species of birds have a special gland that produces a secret with which animals lubricate their feathers. This prevents them from getting wet, making them more elastic. But there are birds that do not have such a gland, and its function is performed by powder feathers. In this case, the structure of the bird's feather is simple - it consists of one trunk, which breaks as it grows and crumbles into tiny particles, forming a kind of powder that protects the plumage from getting wet and sticking together.
Feather growth
The structure of a bird's feather can be very complex, and it is just as difficult to develop. Like hair, feathers grow from the follicle. Each new feather at the beginning of development has an artery and a vein in the rod, which feed its growth. The trunk of a developing feather in the eye is dark, it is called blood. After the growth is completed, the pore becomes transparent, the blood no longer flows.
The nascent feather is protected by a waxy keratin sheath. At a certain stage of development, the cover is removed by the bird during feather cleaning. One, two, less often three times a year, the bird completely changes its plumage. Old feathers fall out on their own, new ones take their place. This process is called molting. Most birds shed gradually, without losing their ability to fly. However, there are species that lose all flight feathers and cannot fly. For example ducks, swans.
Coloring
The structure of a bird's feather also affects its color. We can divide the factors that affect the color of the pen into two groups: physical and chemical. Chemical factors include the presence of various pigments in feathers. Linochromes in various concentrations provide yellow, light green and red, melanins - brown and black.
Physical factors include the refraction of light in the cells of the pen and the angle of incidence of the rays. This produces green, blue, purple hues and a metallic sheen.
