Birds can feel Earth's magnetic fields? Yeah, that might fly. Bioboffins find vital sense proteins

Birds can fly, sing, and, er, detect the Earth’s magnetic field behind their eyes, according to a recent paper published in the Journal of the Royal Society Interface.

Eggheads have long suggested birds use some sort of internal compass to sense the Earth’s magnetic field, as they navigate their way on long migrations, often flying thousands of miles.

Now egg-sperts at Lund University, Sweden, have found some evidence that that may be true. It boils down to a group of proteins nicknamed Cry4 that were found in the eyes of zebra finches.

The proteins called cryptochromes are mostly known for controlling the biological circadian rhythm or body clock, but it has also been linked to magnetoreception – a mysterious ability some organisms have that allow them to feel a magnetic field.

Atticus Pinzón-Rodríguez, coauthor of the paper and a postgraduate student at Lund University, said: "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".

It makes sense that the receptor should be active, since birds use it not only for migration, but also for “spatial orientation tasks in their daily life,” the paper stated. The results seem to be in agreement with a previous study Pinzón-Rodríguez was also involved. He discovered that for some species of birds that don’t migrate, they still used some sort of magnetic sensing to function.

"This and last year's results indicate that other animals, perhaps all of them, have magnetic receptors and can pick up on magnetic fields."

The same proteins have also been found in a number of animals and insects from pigeons, fruit flies, butterflies, to whales, salmon, and even mole rats. ®