noun
ADJECTIVE
▪ seasonal
▪
the seasonal ~ of birds
▪ autumn ( esp. BrE ), fall ( AmE ), spring
▪ annual
▪ internal , inward ( esp. BrE )
▪ urban
▪
The decline of the rural economy has caused urban ~.
▪ international
▪ large-scale , mass
▪ bird
▪ northward , southward , etc.
▪ forced
▪
the forced ~ of African slaves
▪ illegal
… OF MIGRATION
▪ wave
▪
the great waves of ~ that took Europeans to the New World
MIGRATION + VERB
▪ occur , take place
▪ increase
▪ begin
MIGRATION + NOUN
▪ path , pattern , route
▪
changes in the ~ routes of reindeer
PREPOSITION
▪ ~ from , ~ to
▪
~ from rural to urban areas