The main way of movement of the majority of birds – flight. Some birds are incapable of flight. Other ways are circulation and run on the ground, a lasagna on trees, swimming.
Instruction
1. The body of floating birds has the certain characteristics allowing to spend with comfort time on water. It has a little flattened form, plumage dense, the down layer is more plentiful. Between fingers there are leathery membranes which increase force of a grebk. In the course of swimming of a leg belong a little back. Many birds, besides, are able also to dive: some plunge into the water from dive, others dive really deeply.
2. Dive from dive as the birds able to swim who are not able. They are enough production then their body is thrown out on a surface at once. Such birds have some special devices, density of plumage is a little increased. Other birds can dive on considerable depth and move in the thickness of water. They have in bones few cavities with air, the high density of plumage, the shortened wings, is more than hemoglobin in blood. The femoral joint is shifted back. On the land these fowls are kept clumsily. Scuba diving is carried out by means of legs and wings.
3. In branches of trees of a bird move jumps, helping themselves periodic waves of wings. Three fingers of a back extremity are directed forward, one – back. Such building allows a paw to clasp a branch strongly. At some of the climbing birds two fingers are directed back and two forward. Many have also a powerful beak helping to catch. Muscles of legs are strongly developed, claws sharp, durability of a tail helps to keep. These factors allowed many birds to succeed in a lasagna on steep surfaces. The big percent of birds freely moves jumps on the ground or rearranging legs. Fingers at such birds are shortened. Practically some flying and floating birds do not go: swallows, martins, Gagra.
4. Birds can fly thanks to difficult physiology of a body. The wing from above is a little convex, from below – is bent, its first line is thickened. Over a wing the area of the lowered pressure due to flow with air is formed, and it rises up. When lowering a wing there is traction force pushing a bird forward and the carrying power overcoming attraction force. An important role in flight control is played by the straightened tail. Polet is swing and soaring.
5. Swing flight – a rhythmical raising and lowering of a wing. The bird can change the frequency of waves, an inclination of wings that in many respects depends on the structure of a body of a concrete look. Some birds wave occasionally, the trembling flight is peculiar to others. At the soaring flight the bird moves due to energy of air flows.