The bird is recognized by feathers. It is quite fair as from all living beings only birds have feathers what they are called birds for. Among birds males have the richest and bright appearance usually, pursuing the obvious aim - to become the most attractive to gray, ineprimetny the self-check.
For appearance and not only
Certainly, not only the decorative aims were pursued by birds, in the course of evolution acquiring feathers of the most fantastic coloring. Though it is an important factor first of all as it is surprising at feathers the main function – protection, no, not from teeth of a predator, and from the adverse atmospheric phenomena. The feather of a bird rather reliably protects her from excessive moisture, a heat, cold and many other.
In turn, the bird as far as possible cares for feathers, diligently cleaning them from dirt and regularly greasing with special fat to which allocate her near-tail glands.
It is natural that the bulk of birds is able to fly also in this process, the help of feathers is simply invaluable. Not only that the pen-type covering gives to a bird a streamline shape, optimum in terms of aerodynamics, but also thanks to grooves on swing feathers, to their special characteristics and arrangement substantially increase carrying power in flight.
How did feathers appear?
Thus, need of presence at birds of feathers is not even challenged. Other question what is represented by feathers and from where they undertook? The first why it is necessary to make a start, so it from direct ancestors of modern birds, namely from various dinosaurs and other lizards. As their present feathery lineal descendants. However, it is worth remembering also close relatives of birds – reptiles. Feathers of birds nothing else as modified scales also consist they of the same substance – a keratin. The keratin – is the strong and resistant material created from special cages. The feather, in turn, consists of a core and the acting small beards from it. Depending on purpose of a feather and its arrangement on a body of a bird, it can be planimetric, swing, down, threadlike and so on. Different feathers perform the special functions which, in turn, depend a genus of a bird and her way of life. As well quantity of feathers in various birds a miscellaneous. Least of all them at a humming-bird. It is more at a tundra swan. However, this circumstance is quite explainable as dwelling in severe conditions demanded creation big quantity of down feathers. A variety of coloring of opereniye of birds is simply amazing, without speaking about the main color scale, just right to be surprised to quantity of various shades and half tones that it, certainly, provides to birds due appeal, in particular during the marriage period.