What causes a Bird to start migration? The Germans call it “zugunruhe” or migratory restlessness. There are several factors that influence the beginning of migration, including the amount of daylight.
How birds find their way is a trickier manner. A researcher at Cornell University used Indigo Buntings to study the migration urge and migration direction. The buntings were exposed to a normal night sky and their behavior studied. The birds headed south. The night sky was then rotated. In response the birds started moving in the direction of the “new north.” It seems Indigo Buntings and other species use the stars to navigate. Pretty smart, huh?