The “sixth sense” birds use to visualize Earth’s magnetic field has been demystified, as two teams of scientists claim to have identified the source of their powers.
Birds are known to navigate using magnetism, not only in their day-to day lives but also on long migrations that can cross entire continents.
This ability is referred to by scientists as “magnetoreception”, but how exactly birds are able to do it has remained the subject of much speculation.
Now, scientists have pinpointed a substance in birds’ eyes that gives them the ability to perceive magnetic fields – a protein called Cry4.
Two separate studies conducted in robins and zebra finches have described a role for Cry4 in the visualization of magnetic fields.
Previous work has suggested a group of proteins to which Cry4 belongs called cryptochromes – which are found in the eyes and are involved in regulating circadian rhythms – also have a role in magnetoreception.
To identify which cryptochrome was responsible for this sense, scientists at Lund University in Sweden examined the presence of three of them – Cry1, Cry2 and Cry4 – in the bodies of zebra finches.
They found that Cry1 and Cry2 did what would be expected of substances that regulate daily rhythms – their appearance in the finches fluctuated depending on the time of day.
Cry4, on the other hand, remained constant, suggesting this protein had another role that required it to be active regardless of time.
* This article was automatically syndicated and expanded from The Independent.