Come September, you will see several exotic birds migrate into India. Have you ever wondered how these birds find their way from really far-flung places like Russia and Japan, navigating across vast continents and oceans?
How do they maintain their sense of direction in these long fights that they take every year? Scientists have long wondered about the reason for the birds’ accurate sense of direction.
A recent study published by Oxford University may have solved the mystery. It found a possible connection between the migratory birds’ biology and their ability to fly in the right direction.
The biological connection
Researchers from the University of Oxford and the University of Oldenburg in Germany studied robins and analysed the in-built “living compass” that they use to navigate.
The European robin and other migratory birds have some chemicals in their body that help them see the earth’s magnetic field. The researchers – professor Peter J Hore and his team – have developed a theory that birds may use magnetically sensitive proteins in their body that enable them to fly thousands of kilometres to migrate.
Sounds like Superman’s X-ray vision while flying, right?
Actually, it’s a chemical in the eye that is sensitive to magnetism that helps birds to see the Earth’s magnetic field.
They are called cryptochromes, which are located in the retinas. These cryptochromes enable sensing and help them in navigating these long distances.
This piece of information brings the scientific community closer to the mystery behind how birds decide to take a specific route when the weather changes.
“We think we may have identified the molecule that allows small migratory songbirds to detect the direction of the Earth’s magnetic field, which they undoubtedly can do, and use that information to help them navigate when they migrate thousands of kilometres,” Professor Hore told BBC News.
The research process
Scientists observed a purified form of the cryptochrome molecule in the lab to see whether it can act as a magnetic sensor. They inferred that it could form pairs of ‘radicals’ that have high magnetic sensitivity. Radicals are atoms or molecules that have free electrons, thereby making them very reactive.
And here’s how they believe that it works in a bird : light striking the retina causes electrons to move within the cryptochrome molecule. This produces a pair of short-lived high energy radicals that act like microscopic magnets. And these magnets could help the birds fly in the right direction.
These magnetically-sensitive chemicals are more found in robins than in birds such as chickens, that don’t migrate.
Besides, as the migratory season approaches, these migratory birds get more receptive to the magnetic field.
What are the other theories?
We already mentioned that the finding about cryptochromes is a development after years of research. Scientists are now getting closer to detecting the inbuilt GPS in birds, but there have been other hypotheses over the years.
One of them is pretty exciting. It says that a chemical compound works with the magnetic field of the earth. It is said that an oxidized-iron compound located in the body of the birds is in tune with the magnetic field and creates a rotational force. This force, called torque, leads to changes in signals in body alignment and directs the movement.
What are the other possible explanations for the amazing sense of direction that these migratory birds have? Share your answers with us in the comments..
Liked this? Read more here
Aparna is a mom, singer and dreamer. At BYJU\'S, she writes stories about learning for children. She believes in the power of music, especially ghazal, the magic of the universe and happy learners. When not writing or singing, you will find her intensely engaged in conversations about life and the power of words.