When an American battalion was trapped behind enemy lines in World War I, a pigeon delivered the coordinates that helped save the soldiers when no human messenger could. Later, pigeons carried financial news and stock prices across a 76-mile gap in Europe’s telegraph network. During the Cold War, the CIA strapped tiny cameras to pigeons to snap aerial reconnaissance photographs.But how did these birds navigate their journeys? Scientists have uncovered a new mechanism of their uncanny precision, especially in overcast conditions. It turns out, they follow their gut instincts — literally.Through a series of flight and lab experiments, researchers found pigeons can use special cells in their liver as an internal compass. These iron-rich cells displayed intriguing quantum properties that allowed the pigeons to sense Earth’s magnetic field for direction, according to a study published Thursday in Science. Without the cells, the pigeons became lost under certain weather conditions.AdvertisementAdvertisement“It is a big riddle in the field of how birds use the magnetic field to find directions,” said Christian Kurts, a senior co-author and immunologist at the University Hospital Bonn in Germany. “Magnetic fields — no one would ever have estimated that immune cells can also sense that. This is a new function of the immune system.”Pigeons, as well as many birds, use several tactics to traverse terrain, including tracking the position of the sun, smells, landmarks and, most mysteriously, the magnetic field — which they especially rely on when the other cues aren’t available. One leading idea for how birds sense magnetic fields propose …
