Birds can see Earth's magnetic fields because of cryptochromes in their eyes
Is there practical expirementsl evidence demonstrating birds can sense magnetic fields? That is, can you train a bird to select between two boxes, one of which contains a strong magnet?<p>Just wondering. I'd read about theories regarding iron in the beaks and whatnot. Sounds cruel, but why not (a) train the bird to select the magnet, then (b) remove beak and check if it can still do the trick, or (c) remove eyes and see if it can still do the trick.<p>I'm not entirely sure, though, that (a) has been accomplished. Can't find anything on it.