Two new studies have revealed that birds actually have a special protein in their eyes which lets them perceive the Earth’s magnetic fields. This is how they are able to navigate so well and not the iron in their beaks. These interesting findings are courtesy of a study on the zebra finch, which the Journal of the Royal Society Interface published, and another one on robins, which the journal Current Biology published. This special eye protein is called Cry4, and it is actually part of another class of proteins called cryptochromes.
These are photoreceptors that are sensitive to blue light which can be found in both animals and plants. They are very important when it comes to regulating circadian rhythms. There has actually been some evidence over the years regarding the presence of this protein in birds’ eyes. This is what provides them with the ability to orient themselves and navigate by perceiving the Earth’s magnetic fields. The scientific name of this special sense is magnetoreception. Scientists know that birds can sense magnetic fields only if special wavelengths of blue light are present. Now, everything seems to point to the fact that the avian magnetoreception is actually a visual one. The cryptochromes are able to detect magnetic fields because of quantum coherence.
The secret behind birds’ navigational abilities
So, in order to make sure that is indeed the case, two separate teams of scientists began conducting two separate studies, one on zebra finches and one on robins. The zebra finches study reached the conclusion that while the Cry 1 and Cry2 proteins fluctuated daily, Cry4 was constant. When the robin study was conducted, the researchers found the exact same thing.
However, the teams have agreed that they need to conduct more research to find out whether the Cry4 protein is the one responsible for magnetoreception. Until now, everything seems to point to that being the truth.
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