When birds are migrating, they always know exactly where they are going, unlike us, when were driving, we need a Sat-Nav. Their sense of direction is dependent on a combination of three ‘maps’ of their own.
Birds have a substance called magnetite, which is located just above their beaks. This is a mineral that the birds use to help them determine Earth’s magnetic field, so they can navigate using true north.
We know that sunrise and sunset will indicate east and west. Birds that migrate during the day time can navigate themselves by the position of the sun. Even in the middle of the day birds can ascertain where they are by the sun’s position in the sky.
Finally, birds that travel at night use not only the moon, but they learn the constellations and navigate by them. The North Star is the most important as it’s in a fixed location, but all the constellations are useful in figuring out time and location.
Birds also have very keen eyesight and will use landmarks like mountains, rivers, even buildings and roads to help them find their way.