Friday, January 9, 2009

Butterfly Migration.
Generally people are more familiar with the bird migration, but at the same time very few people know about the migration of the butterflies. It is very amazing that such a delicate and tiny insect can do long journeys during migration. But often we can see the swarms of butterflies in a large numbers flying towards a particular direction. But still the butterfly migration is somewhat different from bird migration as their journeys are usually one-way and the flyers do not return to the place of their birth at all. The total distance traveled by a butterfly is its life time is known as life time track, which may vary from 2 km to as much as 3000 km.
In birds or animals it is easy to record their migration as they have longer life and often they return back to the same area. In butterflies the life span is very short, the generation which moves from north to south may die after laying eggs in south and it is the next generation which returns to north. The butterfly when flying between two habitats prefers to adapt a particular single direction. Most butterflies fly when the sunlight is bright, as they prefer to have the effect of thermal efficiency. It is still a mystery how butterflies assemble and decide in which directions they should fly, so that the new areas they reach will have plenty of food for their caterpillars.
In India, two types of migration have been observed. In one, at irregular intervals, many thousands of particular species or related species of butterflies seen flying in streams in a particular direction. These are particularly Milkweed butterflies and Yellows and Whites. The other type of migration takes place regularly, mainly to avoid unfavorable weather conditions, and it is common in those species that are found in hills. Such butterflies came down to avoid extreme cold or heavy rainfalls.
In India, these species have been reported as regular migrants; Lime, Common Emigrant, Mottled Emigrant, common albatross, Common Indian Crow, Dark Blue Tiger, Blue Tiger, Striped Tiger, Great Eggfly, Painted Lady, Pea Blue and there are about 60 other species recorded in India. But as there are very few butterfly observers and no fix method of migration study, very less is known about this. It is very important that if we collect such data or information and used it for study then we will certainly get some amazing fact about butterflies and their migration.
Yuwaraj Gurjar.

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