Scientists may have confirmed the theory that birds see magnetic fields, as the protein in birds' eyes that gives them this ability has apparently been identified.
The built-in magnetic sensor among birds is what helps them navigate long distances during migratory patterns, allowing them to fly toward a specific destination.
Birds See Magnetic Fields, Confirmed
Scientists have long believed that birds are able to sense and react to the magnetic field of the Earth. Two separate studies, with the one published in the Journal of the Royal Society Interface studying zebra finches and the other published in the Current Biology journal investigating European robins, look to have confirmed that theory.
The two studies have identified a protein in the retina of the eyes of birds named Cry4. If the researchers are correct, this is the first known molecule found in animals that enables the detection of magnetic fields. Through Cry4, birds are believed to see magnetic fields like they had access to a heads-up display.
Humans and birds might share some proteins, such as one found in both humans and woodpeckers that signal brain damage, but Cry4 is unique to birds. The evidence on the existence of Cry4 is not conclusive, with the next step possibly to study birds that do not have Cry4. However, because the protein was discovered in separate studies, there are fewer reasons to question the legitimacy of the findings.
How Birds Use Magnetic Fields To Navigate
On both the zebra finches and the European robins, the researchers discovered that Cry4 was produced throughout the day. However, for the European robins, more of the protein was produced during the migration season. In addition, Cry4 was located in the part of the retina that receives significant amounts of light.
With all these things considered, it is believed that birds use the magnetic fields that they see like a compass, allowing them to keep moving toward a certain direction in long, migratory flights.
But what does the bird actually see? The answer to that question is likely something we may never know in the near future. However, one of the theories is that Cry4 applies a "filter" that shows the constant magnetic field of the Earth. By keeping their flight pattern toward a certain point of the visible magnetic field, birds can stay on course to their preferred destination.
The discovery might mean that birds are more adept at quantum physics better than most humans, as the ability to see and harness magnetic fields come to them innately.