To migrate is to move ones home or place of living from one region or country to another.
When birds fly South for the winter it is called migration.
The birds flew South for their migration in the Winter.
If what you really mean is, "How does the suffix -tion change the meaning of the base word migrate in the word migration, then I have an answer. -tion is "the act of", and instead of "The birds migrate.", as a verb, it turns into "The birds migration is very long.", and it's a noun.
Differential migration is simply a phenomenon especially found in birds where different sexes of birds migrate different distances.
E.P Ramsay has written: 'Notices on the migration of birds in Australia' -- subject(s): Birds, Migration
Janice M. Hughes has written: 'The migration of birds' -- subject(s): Migration, Oiseaux, Birds
6000000...0000000milllion trillion birds
flying with birds
Phenology
It could mean that the birds are nesting on your home. It could mean your home is on a route they use for migration. It could mean that you live in an area where hunting is not allowed (most people do) and the birds feel safe at your home. It could mean there are no predatory birds around such as hawks and no cats (who like to eat birds) around either. It could mean that the birds have found a source of food and/or water near your home. It might also mean that the birds have found a source of shelter from bad weather at your home.
H . Elliott McClure has written: 'Migration and survival of the birds of Asia' -- subject(s): Birds, Migration, Parasites
use it as the first word e.g. migration is what birds do to survive