TAKING songbirds on an excursion to a planetarium has revealed how they
navigate during migration.
Birds migrate overnight using the stars, but how they do this has been
unclear. They could use the stars as a compass, pinpointing the Pole Star by the
way the other stars rotate around it. The height of that star would tell them
their latitude. If they had a good sense of time passing, they could also
navigate by judging their longitude from the positions of the constellations and
work out the exact route to their destination.
To test these ideas, Henrik Mouritsen and Ole…
