ScienceDaily: Do Migratory Birds 'See' The Magnetic Field?

ScienceDaily: Do Migratory Birds 'See' The Magnetic Field?: "These findings strongly support the hypothesis that migratory birds use their visual system to perceive the reference compass direction of the geomagnetic field and that migratory birds are thus likely to 'see' the geomagnetic field."

I bet they can see thermals too.