Even when your world is full of light, it can be difficult to find your way. An impressive method of navigation, used by pigeons, is called magnetoreception. Homing pigeons can detect the earth’s magnetic field and use it as a map to find their way home using magnetoreceptors even if they are put in a cage and transported to a strange location.

In flight, there are three dimensions to account for: left and right, up and down, and forward and backward. Like other birds, pigeons are known for their excellent eyesight. Most of their navigation can be handled by landmarks and other visual cues. However, when they are put in a cage and transported to a strange location, how do they manage to find their way home?

Though scientists have yet to determine precisely how pigeons respond to the earth’s magnetic field, they have found many clues. The most promising hint is in their spectacular beaks. Along the skin lining of their upper beak are iron-containing particles called magnetite. The magnetite is attached to nerve endings arranged in a complex, three-dimensional pattern.

This three-dimensional spread is the key to creating a three-dimensional map of the world. The earth’s magnetic field moves in three dimensions, and the pigeon can detect it in all three directions. The details still are uncertain, but it is assumed that the sensory cells associated with the magnetite (called magnetoreceptors) sense slight changes in the angle of the magnetic field, enabling the pigeon to find its way home.