Nearly 20% of bird species are migratory, their seasonal movements radically changing avian community composition across the world. A global macroecological analysis of bird migration will be presented in this talk. The seminar will first cover mapping global patterns of the distribution of migratory birds, revealing strong spatial features. Secondly it will cover patterns to test hypotheses about the processes driving this phenomenon. The results paved the way for a mechanistic model which successfully explains the patterns previously described and has been used for reconstructing the global seasonal distribution of birds back to the last ice age.