A small brownish warbler has made scientists change their tune about how migrating birds know which way to fly.
Scientists have long thought migratory birds navigate by the stars. Although birds also can sense the Earth’s magnetic field, scientists had thought this was a backup used on cloudy nights.
But a laboratory experiment showed that a young garden warbler needs information from both the magnetic field and the stars to choose the right heading on its first migration. The stars alone are only good enough to send the bird generally south. The work was reported Thursday in the journal Nature.
