"Flies, the wedge tired" - this line from the poem by Rasoul Gamzatov "Cranes" written under an impression of a beautiful and sad show – autumn flight of birds flies on the sky. The question "Where Do Birds Depart to Winter?" was answered by scientists-ornithologists (researchers of birds) long ago.
Birds are beings warm-blooded. Temperature of their body about 41 degree, and at small reaches 45. It means that birds quite could not fly away on a wintering, and remain in places of constant dwelling. However every fall many bird species leave familiar spots. It is connected not only with the coming cold weather, but also with sharp reduction of a forage which cannot almost be got in the winter.
The birds making regular seasonal movements are called migratory. Cranes, swallows, wagtails, orioles, larks, lapwings, song thrushes and many others treat them. Some bird species in one region can belong to flying, and in another to be settled. For example, rooks in a northern part of an area are flying, and in southern – settled.
The majority of birds move to a wintering packs, but is also such which go to distant flight by small groups and even one by one. At some bird species the first leave familiar spots of a female, and at some the baby birds who grew up during the summer fly away in the beginning. Instincts and heredity prompt to young growth the necessary road. The trajectory of flight of birds repeats every year. They move on the same favourite ways. Ducks wild ducks winter in Western Europe. On the way to the place of a wintering they cross Belarus and Ukraine, reach Germany, Holland, Denmark, Great Britain and the North of Italy. And the duck-shilokhvost goes to winter to the western coast of the Caspian Sea, to lower reaches of Kuban and to the Mediterranean countries. Usually birds fly away and come back annually to one and too time. Though weather in the form of a sharp cold snap can influence the term of flying away of birds. Birds fly to a wintering to places close to their ordinary habitat. Steppe types move to steppe zones with warmer climate, and forest birds go to the places rich with the woods. In the spring the first the birds wintering nearby fly back. After others the types departing on a wintering on a long distance return. But, as a rule, all of them find former places of nesting and settle in the nests. Why birds do not remain in the warm regions, and come back – there is no definite answer. Scientists assume that to all fault the hormones pushing to reproduction therefore birds after the wintering fly to native places year after year.