Pigeons rely on a liver-based compass to navigate cloudy skies
Scientists trained 34 pigeons to navigate a 12‑mile route and found iron‑rich immune cells in the liver may act as an internal magnetic compass, helping them sense Earth's magnetic field when visual cues are blocked by clouds. Pigeons depleted of these cells got lost under overcast skies, while birds with normal iron stores completed the route; after the cells naturally repopulated, navigation improved again. The cells display superparamagnetism and may relay directional information to the brain via nerves from the liver. While some scientists praise the possible new mechanism of magnetic perception, others call for more direct evidence before drawing firm conclusions. The research team plans to further investigate how immune cells communicate with the nervous system and to track pigeons globally to learn more about their navigation skills.
