  One of the greatest mysteries of bird life is migration or traveling. Every year, during autumn and early winter, birds travel from there breeding haunts in the northern regions of Asia, Europe and America to the southern, warmer lands. They make the return journey again during spring and early summer.
They are very punctual too, unless they are delayed by bad weather. We may calculate almost to a day when we may expect our bird friends to return, carrying winter on their backs.
Some species also move out of one area into another, not very far away. All birds have a certain amount of local movement, caused by the stresses of living and the variations in food supply. This kind of movement is particularly noticeable in North India where the seasons are well defined.
Birds, which spend the summer in the higher reaches of mountains, come down during the winter to the lower foothills or even the plains. This type is very common within India where the mighty Himalayas lie close to the Indo-Gangetic plain.
The brave little voyagers face many dangers and hardships, while traveling long, long distances through the air over hill, forest and plain and over large stretches of water. Sometimes sudden storms arise and drive them far out of their course; often they are blown right out to sea and drown in the wild waves. Then at night bright lights attract and confuse the birds.
 Migrating birds do not fly at their fastest. The migration speed is usually from 48 to 64 km an hour and rarely exceeds 80. Small birds seldom exceed 48 km per hour; most shore birds fly between 64 and 80 km per hour, while many ducks travel at 80 to 96. Migrants generally fly at under 900 meters, but some travelers have been found sometimes at greater heights.
Some birds make the long journey in easy stages, stopping to rest on the way. Others fly great distances without pausing to rest and feed. Some fly by day, some both by day and by night, but most of them speed on their way through darkness after the sun has set.
Birds usually travel in flocks. The V-shaped formation of cranes and geese attracts much attention as the bird's speed across the sky. Swallows, flycatchers, warblers, shore birds and water-birds being to gather in flocks- each with its own kind-and, after a great deal of excited fluttering, twittering and calling, they rise up into the air and away they go.
Usually the male birds go first to their breeding grounds in bachelor parties and the female birds follow them in a few days!
The movement of birds with the changing seasons was known from the earliest times, but people had strange ideas as to why the birds traveled, or where they went. To explain their absence from a place in a particular season, they said that the birds buried themselves in the mud and slept there throughout the winter!
Later, detailed studies of migration started. Information was gained by directly observing the habits of birds, and also by ringing. Bird movements are also studied by creating artificial conditions and studying their effects on birds.
Today, most of the information on migration has come from ringing young and adult birds. Ringing is done by capturing a bird and putting on to its leg a light band of metal or plastic. The band bears a number, date, identification mark, and the address to which the finder is requested to return the ring. The bird is then set free. The place where such a bird is shot captured or found dead gives clue to the direction and locality to which the bird has migrated.
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