Migration Birds’ Navigation Secrets
Researchers at Bonn University discovered that iron-rich liver cells in birds act as biological compasses, detecting Earth’s magnetic field to aid navigation during storms, at night, or in fog. Experiments with homing pigeons showed that suppressing liver iron activity disrupted their ability to find their way under overcast skies but not in sunlight.
A team from Bonn University has identified a new biological mechanism explaining how migratory birds like pigeons and storks navigate accurately in conditions where visual cues are absent. Their research reveals that iron-rich liver cells function as internal magnetic sensors, responding to Earth’s magnetic field and relaying signals to the brain. These cells, loaded with magnetite, generate electrical currents when exposed to magnetic stimuli, providing a reliable navigational tool in darkness or dense fog. The study involved 34 homing pigeons divided into two groups: one with normal liver function and another with temporarily suppressed liver iron activity. Birds in the control group successfully navigated back to their home lofts from a 19-kilometer release point under overcast skies, while those with suppressed liver iron activity displayed disoriented flight paths. However, both groups performed equally well under bright sunlight, confirming that the liver’s magnetic sensing is critical only in low-visibility conditions. Lead researcher Clivia Lisowski explained that these iron-loaded immune cells in the liver act as tiny magnetic sensors, offering a consistent navigational method independent of external cues. The discovery challenges previous theories that focused on the beak, eyes, or nerve cells as the primary magnetic sensing organs. This finding could extend beyond birds, suggesting similar liver-based magnetism may aid navigation in other species like bats or marine animals. Scientists are now investigating how magnetic information is transmitted to the brain and whether environmental factors could disrupt this mechanism. The research also highlights a distributed magnetic sensing system, where multiple organs contribute to an animal’s orientation.
This content was automatically generated and/or translated by AI. It may contain inaccuracies. Please refer to the original sources for verification.