Migration is characteristic of many living creatures. In long passages of seasonal travel many animals migrating fish. Some birds fly South in connection with the change of season. But why do they do it?
With the same salmon are relatively clear – red fish out of the rivers into the sea for feeding, and returns to breed. In the river there is not sufficient food for larger fish and in the sea there are no conditions for spawning. But why do birds fly? Why do some of them live sedentary in their territories, while others can cover vast distances?
This is mainly due to food supply and climate.
Is it only cold stimulates the flights?
Many ordinary people believe that birds fly away from the cold. Indeed, in autumn the temperature plummeted, and people have to get out of the cabinets warm things. But do birds get cold? This point is highly questionable, as the plumage of the vast majority of them are very warm. The winter cold is quite able to carry even a homemade parrot. And largest specimens, the same cranes that are leaving North latitude beautiful wedges should not freeze completely. Under the feathers of each bird is a layer of fluff that provides reliable insulation even at temperatures down to -45 degrees. What drives them in flight?
The situation becomes clearer if a closer look at the diet of migratory birds and their flying counterparts. The winter easily transferred to omnivorous birds, which can easily find their own food in any season, especially near human. Sparrows, crows, pigeons – all they can find enough food. If we consider storks, cranes – with the advent of cold weather they lose access to food. Freeze ponds, they can hunt for frogs and lizards. Insectivorous birds also remain without food – in winter, insects disappear, part of them dies, the other part is in hibernation.
Why did the birds return?
In the southern edges of the birds find their food, can survive the winter. But what drives them back, because they could stay there forever? It turns out that this point is associated with the reproduction of fish. With the approach of the breeding season in the organisms of birds begins to produce adequate hormones and other active substances increase in the blood of birds return to where they themselves once came to light. They come North to give birth to a new generation that by the autumn will fly South with their parents, then to return home to the North.
Where is the birthplace of migratory birds?
Such an incredible passion to the Homeland lies in the birds instinctively, they breed only where they themselves once hatched from the egg. To the South they fly temporarily, as their Homeland can be considered the Northern region. Birds strongly, firmly remember all of what was seen, felt them immediately after hatching. It is worth remembering that even the ducks believe their mother, whom the first saw after birth, and can be hard to follow, not only for his true mother-duck, but the dog, man.
Interesting fact: the mystery of bird flight have been studied by ancient scholars of more than 3,000 years ago. On this subject, thought Aristotle, Homer. But the exact answer is not today.
The Director of the bird flights?
It’s still unclear what exactly is the mechanism of bird migration to the South. Many researchers believe that this mechanism starts with the decrease in daylight, but this information is not proven. In any case, it is a vital mechanism, as staying in the North, migratory birds would not be able to survive the winter. Individuals with damaged wings, not having the opportunity to go to the South, surviving only with the help of man.
Those birds who could not fly from South to North successfully through the period of the absence brethren, but the majority are unable to participate in reproduction. In order to find a mate and to make the eggs, the bird must return to a familiar place where she returns each year. Many birds, choosing a partner for life, will fly in pairs, but part of a large pack. Pack flights safer and the building in the form of a wedge allows you to save energy due to the aerodynamic properties of such a construction. The head bird is the leader, she’s the strongest, accounting for the maximum resistance of the air, as if she “cuts up” airspace for other individuals. The leader periodically replaced other strong, healthy individuals. For those who are in the middle and at the end of the wedge, we have less load.
Thus, the birds leave their Northern Home, not to stay without food for the winter. They return to breed. Many of these mechanisms still remain a mystery to scientists who monitor the migration and behavior of birds. Ornithologists are still a lot of arguing around this issue.