Pigeon liver cells sense magnetic fields

A new study published in Science (journal) reveals that homing pigeons may use specialized immune cells called macrophages in their livers to detect Earth's magnetic field for navigation. Researchers from the University of Bonn, University Hospital Bonn, University of Duisburg-Essen, and Max Planck Institute of Animal Behavior found that these iron-rich macrophages possess superparamagnetic properties, allowing them to respond to magnetic fields. Experiments showed that pigeons with removed liver macrophages struggled to navigate on overcast days, indicating a reliance on this magnetic sense when visual cues are absent. The study, co-authored by Christianna and Martin Wikelski, and led by Clivia Lisowski, suggests a previously unknown mechanism for magnetic perception in animals, with potential implications for understanding navigation in other species like sharks and for developing bio-inspired engineering solutions.