The Migratory Urge of the Equinox

Almost the 21st September, the Autumn Equinox in the Northern Hemisphere.Being here in Scandinavia i detect the urge that all migratory birds must feel.That desire to leave their spring/summer residence and head south. Well south west for me, to the crystal clear warm waters of the Yucatan. To the beach and a 2nd life in the Caribbean until the Spring Equinox rolls around next March.I check the Met reports for the mission on Sat maps, National Hurricane Centre & on my Earth Desk. 2 days out and i think i can make landfall before anything Cyclonic develops. Still i am aware that the wings of a butterfly in Brazil could start a Cat 5. I should ask one of those little birds on a wire preparing their flight plan what the forecast is. How do they navigate?