How birds can detect the Earth’s magnetic field

he receptors that sense the Earth’s magnetic field are probably located in the birds’ eyes. Now, researchers at Lund University have studied different proteins in the eyes of zebra finches and discovered that one of them differs from the others: only the Cry4 protein maintains a constant level throughout the day and in different lighting conditions. Cry4 belongs to a group of proteins called cryptochromes. Normally they regulate the biological clock, but have also been considered significant for the magnetic sense. With this study, we now know which of the birds’ cryptochromes do what. “Cry4 is an ideal magnetoreceptor as the level of the protein in the eyes is constant. This is something we expect from a receptor that is used regardless of the time of day”, explains Atticus Pinzón-Rodríguez, one of the researchers behind the study. The conclusion is […]