Adaptable mechanisms of bones of a humeral belt in adaptation to flight at birds

We studied the bones of birds the shoulder girdle of orders Galliformes (chicken, guinea fowl silver), Anseriformes (goose and duck home), Owls (tawny owl, owl polar) and Falconiformes (Goshawk), which are represented by blades coracoid bones and collarbones. They are the safest place to attach and support the muscles of the shoulder girdle, so in the course of evolution they have become strong, elongated elements are fused with each other at right angles and are the intermediaries through which the load is transferred from the wing to the body. The clavicle connects between the sternum, coracoid bone and the shoulder joint. At Owl ordinary and goshawk are strong, arched and curved, flattened on the sides. In the polar owl collarbone a straight, thin, with deployed front lateral edges, laterally compressed. In waterfowl clavicle strongly curved arched in the middle part, in the cross-section are rounded, whereas Galliformes collarbone long, straight as a fork. The blade is located on the dorsal surface of the chest along the spinal column in the form of a long, slightly curved bone, in which is fixed a significant amount of muscle. Coracoid primary function is to hold the shoulder joint in a defined position relative to each other under the action of the aerodynamic forces created by the wings during flight. Shoul- der belt birds most pronounced along the outside of the chest at the penultimate level of the cervical vertebrae, thanks to this arrangement, the wing has a definite, stable position with respect to the center of gravity of the body, which is necessary for balance in flight. Evolutionary transformation birds locomotor apparatus are the result of the influence of external factors (traction muscles and ligaments, integration and differentiation of muscle) and external (effects of gravitational forces and aerodynamic drag forces during the flight).