Overview
- An international team led by the Max Planck Institute and the University of Bonn published a Science paper reporting that pigeons have iron‑laden liver macrophages that form magnetic nanoparticles located close to nerve fibers.
- The authors report that temporarily removing those iron‑rich liver cells impaired the birds’ ability to orient and return home, with the effect strongest on cloudy days when the sun could not be used for navigation.
- The finding is based on a mix of techniques including magnetometry, cell separation and electron microscopy that showed iron crystallized into oxide nanoparticles in macrophages and anatomical proximity to hepatic nerve endings.
- The study’s authors and outside experts stress that key gaps remain: the exact neural pathway to the brain has not been traced, causal mechanisms need replication, and other sensory systems may also guide navigation.
- If confirmed, the result would introduce a new class of biological magnetoreceptors with possible analogues in other organs and species and could change how scientists study long‑distance animal navigation.