Some birds can literally see magnetic fields. The ability to visualize the Earth’s magnetic field is believed to be linked to the availability of light and it is thought that specialized molecules in the birds’ retinas allow them to literally see the magnetic fields, which appear as patterns of light and shade superimposed over the regular image from light. A new study shows that the internal compass also depends on the birds having clear vision in their right eyes.
Some birds can sense the Earth’s magnetic field and orientate themselves with the ease of a compass needle. This ability is a massive boon for migrating birds, keeping frequent flyers on the straight and narrow. But this incredible sense is closely tied to a more mundane one – vision. Thanks to special molecules in their retinas, birds like the European robins can literally see magnetic fields. The fields appear as patterns of light and shade, or even colour, superimposed onto what they normally see.
Below is what is suspected it would look like to be a robin flying over Frankfurt, Germany at a flight altitude of 200 m above the ground.
Image via Theoretical and Computational Physics Group