What is a migratory bird?
Migratory birds are birds known to travel periodically from one place to another in search of food and place and a favorable climate to live.
Once in a year several kinds of birds in the northern hemisphere have been abandoning their houses in autumn and return to their houses in spring to breed again.
India has been the preferred destination for as many as 2500 spectacular migratory bird species from various parts of the world.
Siberian birds spend their winter in and around the Bharatpur Bird Sanctuary, Rajasthan in India and spend their entire summer in Siberia.
Lets walk through some of the beautiful migratory birds in India that visit India Every year.
Similarly more than two third of the species breeding in the northern United States move south in winter, making trips up to 6000 Km. each way. Most birds do not cover more than 40 km to 100 km, but some may make long distance flight of 3218 km or more.
Some shore birds such as Arctictern and Greater Shearwater migrate for more than 10,000 km in each direction between breeding grounds in the Arctic and Wintering area in the Southern Hemisphere.
It is calculated that 5000 million land birds migrate from Europe to Africa each autumn and half of them succeed in returning next spring.
Cohn explained about the bird migration as “A periodic passing of animals from one place to another”. The word migration has been derived from the Latin word “Migare” which means to travel.
It is different from unidirectional movements and those in which animals are helplessly carried by some other agency. Bird migration is a two way journey in which some birds moving from nesting place to other places in search of food and soothing climate.
Migration gives them a maximum daylight at all times and helps them not only to survive the extremes of temperature but gives them longer period for feeding because birds feed only in light and goes to a place of resting during darkness.
In India alone there are about 2500 species of migratory birds, Most of them remain in India but some of them cross the Indian borders and migrate to other countries.
The cuckoo is a well known example of a migratory bird. It arrives in Uttar pradesh in the beginning of March and breeds there. During the month of August, it leaves this place and migrates to south India and Srilanka to spend winter there.
The wagtails appear in India in the beginning of winter season and at its end they leave this place, migrate to Siberia and Manchuria to spend summer and lay eggs.
The Rofous turtle dove breeds in central Siberia, Japan, North and central China, Tibet and Nepal. In winter it migrates southward all over Eastern India and as far south as Deccan.
The central starling is found in thousands in the North western part of India and becomes a serious pest of wheat fields. In summer, It migrates to Turkistan and Tianshian mountains to breed.
The White Wagtail breeds in Eastern Siberia from the lake Baikal to Machuko. It spends winter in Eastern Assam, Kashmir and Afghanistan
The Brown Shrike breeds in Eastern Siberia in summer. In winter it migrates to India and Srilanka two to three thousands miles away.
Many Kinds of geese, ringed and released in Madhya Pradesh were spotted in Siberia which is 2000 miles away. The recorded speed of Migration was 1325 miles in 64 days. The Glossy Ibis ringed and released on July 7th 1931, at Astrakhan in the Volga Delta at the head of Caspian sea was recorded at Nashik on 14th March, 1934.
Parties of swallows returning to Britain from south Africa may cover 9650 kms in six weeks, often flying back to their old nests.
Some birds fly alone and achieve astonishing speed . A tiny Wheatear weighing less than 30 gm, was ringed in Walesand covered 965 km away on the French Mediterranean cost, only 43 hours later.
Marine Birds also makes extensive migration. The great Shear water breeds on Tristan da cunha but comes to Greenland in May returning again after months of wandering at sea, apparently without a landfall.