Birds Have an 'Internal Compass' Protein Which Lets Them Sense Earth's Magnetic Field

Tuesday, 03 April 2018 - 8:17PM
Earth
Tuesday, 03 April 2018 - 8:17PM
Birds Have an 'Internal Compass' Protein Which Lets Them Sense Earth's Magnetic Field
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Flickr/Mike Baird
We take it for granted that various species of birds will "fly south for the winter", but how do they navigate over long journeys? Different migrating animals have lots of different methods, but the bird method seems to be cooler than we realized.

Scientists have suspected for some time that birds can sense and react to Earth's magnetic field, relying on an internal compass to navigate around the planet. But two new studies published in The Journal of the Royal Society Interface and Current Biology claims to have identified a specific protein in certain bird species (zebra finches in the former study, European robins in the latter) which serves as this magnetic-field-sensor.

The protein is the light-sensitive Cry4 (short for cryptochrome 4) found inside a bird's retina, and it appears to work loosely using a form of quantum mechanics.



In the field of quantum mechanics, electrons within atoms have a "spin" which can be considered "up" or "down", and this gives the electron some properties of a tiny magnet. If an electron goes unpaired within the atom, it can be receptive to outside magnetic fields like that of the Earth. Now just picture that process occurring inside of a bird, and you've got a general picture of how they navigate.

The evidence isn't conclusive just yet, but the fact that the same protein was identified in separate studies is a good sign until more research comes out. But both the zebra finches and the robins in the studies were found to produce Cry4 at all hours of the day, and in the case of the robins, even more Cry4 is produced during their migratory season.

In the future, birds will have to be observed more in regards to how they use this protein, and researchers might look for birds who don't have the protein as well.

But apparently, birds are naturally quite gifted quantum mechanics. They're more gifted than we are, at least.
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