The seasonal movement of a complete population of animals from one area to another. Migration is usually a response to changes in temperature, food supply, or the amount of daylight, and is often undertaken for the purpose of breeding. Mammals, insects, fish, and birds all migrate. The precise mechanism of navigation during migration is not fully understood, although for birds it is believed that sharp eyesight, sensibility to the Earth's magnetic field, and the positions of the Sun and other stars may play a role.
American Heritage Science
Other Word Forms of Migration
Migration Sentence Examples
The birds are currently beginning their large migration to the south.
This migration is usually accompanied by a more or less complete metamorphosis.
This was the largest migration in U.S. history.
The result of migration is that races of widely different origin and habit have had to adapt themselves to similar conditions.
After oil was found in an uninhabited region, there was a migration to that area.