Migratory birds can 'see' the earth's magnetic field

It is known that birds use the compass to orient themselves when flying away. But how exactly that system works is still a mystery. Now, German scientists reveal: The key of the mechanism is in the eyes.

The team of Dominik Heyers and colleagues, Oldenburg University found birds using specialized neurons in the eye - sensitive to the direction of the magnetic field - as a compass that guided them around the world.

For the first time, they found these neurons, through a special path, connected to a region of the brain responsible for vision. It seems that depending on the direction of the magnetic field, the molecules that sense the magnetic field in the eye (called cryptochrome) will activate the strong or weak light receptor.

"It's a pity that we can't ask them, but we imagine it is like a dark spot or a bright spot in the bird's usual vision," Dr. Heyers said. This further confirmed that migratory birds recognize the magnetic field as a visual form, the researchers said.

The research team looked at warblers garden, a migratory bird. They breed in northern Europe and migrate to Africa to avoid winter colds.

Heavenly ducks migrate. (Photo: sciam.com)

T. An