The Migration reference article from the English Wikipedia on 24-Jul-2004
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Migration

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Migration occurs when living things move from one biome to another. In most cases organisms migrate to avoid local shortages of food, usually caused by winter.

Birds often migrate (see bird migration for more details). The longest known migration is that of the Arctic Tern, which migrates from the Arctic to the Antarctic and back each year.

Whales, butterflies, moths, and lemmings are also known to migrate. The periodic migration of flocks of locusts is a phenomenon recorded since Biblical times.

Human migrations on the largest scale are discussed under two entries at Wikipedia:


See also: migrant, population transfer, population genetics. Try the list of peoples at Nomadic people or look under the specific migrating ethnicity that interests you.