Question

what is migration and name some migratory birds.

Answer 1

a large number of birds migrate from one place to another place is called migration.Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. 
eg: Siberian crane
arctic tern

Answer 2

Seasonal movement of animals from one region to another is called migration.
e.g. :- Asiatic Sparrow-Hawk
          Harriers
          Peregrine Falcon
          Osprey
          Pacific Golden Plover
          Bluethroat
          Wagtails
          Eurasian Wigeon
          Greater Flamingo
          Starling