Question

what is migration and define migration

Answer 1

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.

Answer 2

1. The movement of organisms in large numbers from one place to another place is termed as migration.

2.Human migration is defined as the relatively permanent movement of people across territorial boundaries. It is also known as immigration and emigration when they cross the international boundaries.

3.Many factors play their role in the initiation of migration. 
a) External factors like climate, natural disasters, drought, shelter, food shortage, etc may cause animals to migrate to seek better conditions.
=>For example –
Consider a species of the deer that live in a certain park. They would migrate to warmer places during winter if the park they reside is harsh for them to survive. But, if they are living near the hot spring, where they can graze throughout the year, then there is no need for their migration.

4.Bird migration is the natural seasonal movement, often south and north along a flyway, in between the breeding grounds and wintering grounds. 

5.World Migratory Bird Day is celebrated on 13th May!