Birds Can See Earth’s Magnetic Fields

Birds can see Earth’s magnetic fields

The mystery behind how birds navigate might finally be solved: it’s not the iron in their beaks providing a magnetic compass, but a newly discovered protein in their eyes that lets them ‘see’ Earth’s magnetic fields. These findings come courtesy of two new papers – one studying robins, the other zebra finches. The fancy eye protein is called Cry4, and it’s part of a class of proteins called cryptochromes – photoreceptors sensitive to blue light, found in both plants and animals.

These proteins play a role in regulating circadian rhythms.