Bird Migration is the regular seasonal journey undertaken by many species of birds. At a particular season thousands of birds travel from one place to another. One of the greatest mysteries of bird life is migration or travelling. Every year, during autumn and early winter, birds travel from their 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 the 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 movements, 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 travelling 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 they drown in the wild waves. Sometimes 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 km per hour. 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 km per hour. Migrants generally fly at a distance under 900 meters, but some travellers 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 birds speed across the sky. Swallows, flycatchers, warblers, shore birds and water birds begin 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.
Birds were seen moving from one place to another with the change in seasons from the earliest times, but people had strange ideas as to why the birds travelled 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 placing on 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 a clue to the direction and locality to which the bird has migrated.
Ringing has proved that birds cover large distances. There is some evidenceto believe that the woodcock on its winter movements flies from the Himalayas to the Nilgiris without a pause, a distance of 2,400 km. The wild duck comes to our lakes from Central Asia and Siberia flying 3,200 to 4,800 km over the Himalayas. The rosy pastor comes from Eastern Europe or Central Asia. The wagtail, about the size of a sparrow, comes from the Himalayan regions and Central Asia to the plains. Smallest of all, the willow warbler, half the size of a sparrow, covers as many as 3,200 km to reach us every winter!
Why do birds migrate in spite of heavy loss of life on the way?
Primarily to escape the bitter cold and a restricted food supply. In the case of waterbirds, the food supply disappears altogether, when the water freezes and the fish and other seafood are difficult to obtain. The main reason for the spring movement is the availability of nesting sites and the need to escape summer heat.
The migration of birds is a fascinating study indeed, and there are many unsolved problems which lie ahead. For example, how do the birds know when to start? How do they know their way over the sea without any landmarks? How do they manage to return year after year to the same locality? How do the young cuckoos join the adult birds without previous experience, and without any guidance from adult cuckoos which fly to India and Africa several weeks before the young cuckoos are ready to leave their foster parents? These and many more such interesting questions lie ahead of you to solve!
A Flight with the moon on their wings
– Rob Reilly
Bird Migration is the regular seasonal journey undertaken by many species of birds. At a particular season thousands of birds travel from one place to another. One of the greatest mysteries of bird life is migration or travelling. Every year, during autumn and early winter, birds travel from their 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 the 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 movements, 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 travelling 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 they drown in the wild waves. Sometimes 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 km per hour. 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 km per hour. Migrants generally fly at a distance under 900 meters, but some travellers 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 birds speed across the sky. Swallows, flycatchers, warblers, shore birds and water birds begin 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.
Birds were seen moving from one place to another with the change in seasons from the earliest times, but people had strange ideas as to why the birds travelled 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 placing on 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 a clue to the direction and locality to which the bird has migrated.
Ringing has proved that birds cover large distances. There is some evidenceto believe that the woodcock on its winter movements flies from the Himalayas to the Nilgiris without a pause, a distance of 2,400 km. The wild duck comes to our lakes from Central Asia and Siberia flying 3,200 to 4,800 km over the Himalayas. The rosy pastor comes from Eastern Europe or Central Asia. The wagtail, about the size of a sparrow, comes from the Himalayan regions and Central Asia to the plains. Smallest of all, the willow warbler, half the size of a sparrow, covers as many as 3,200 km to reach us every winter!
Why do birds migrate in spite of heavy loss of life on the way?
Primarily to escape the bitter cold and a restricted food supply. In the case of waterbirds, the food supply disappears altogether, when the water freezes and the fish and other seafood are difficult to obtain. The main reason for the spring movement is the availability of nesting sites and the need to escape summer heat.
The migration of birds is a fascinating study indeed, and there are many unsolved problems which lie ahead. For example, how do the birds know when to start? How do they know their way over the sea without any landmarks? How do they manage to return year after year to the same locality? How do the young cuckoos join the adult birds without previous experience, and without any guidance from adult cuckoos which fly to India and Africa several weeks before the young cuckoos are ready to leave their foster parents? These and many more such interesting questions lie ahead of you to solve!
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