Magneto reception

Birds need a good sense of direction and a map. Birds have a substance called biological magnitude in their head`s. They also have a really sensitive compass in their head as well. They also have a substance called cryptocrome, Just above their beak as well. When the two substances are energised by blue light they can see the earths magnetic field, Enabling them to plan their journey. How do they know where the right spot is? When young birds run out of energy, They can then learn the environment. They do this by looking at features on their journey like road`s and bridges etc.