Translated from a Chinese website (it's a bad automatic translation, but you'll understand):
Migratory birds rely on the body's "biological compass" to determine the direction is "open secret", but it is not clear how the perception of the magnetic field of birds.
"Nobody knows it (the magnetic induction system) to work," Patterson said Murray, "magnetic induction principle is that people understand the nature, at least so far the (principle)."
How long migratory birds perceive the magnetic field on two main points. One view is that the birds beak cells can sense the Earth's magnetic field and pass the message through the nervous system to the brain; another point of view, birds eye in the photoreceptor cells can "see" the magnetic field, and the information through another way to the brain is referred to as "N clusters" light processing area.
Specific proteins in migratory birds eye "cryptochrome" Maybe this is the light-dependent magnetic field sensing of the media. Light stimulation of this protein produced a pair of free radicals, free radicals can be carried by the electron spin may be able to perceive the special properties of Earth's magnetic field.
In general, the magnetic elements of change is very small, but with the solar activity and geomagnetic storms are closely related phenomena, but it happened very suddenly. This is because the intense sunspot activity, when the energy released is equivalent to some one hundred thousand hydrogen bomb blast, while a large number of charged particles ejected. These charged particles hitting the Earth forming a powerful magnetic field to the magnetic field superposition, so that under normal circumstances, the magnetic elements changed dramatically, causing "magnetic storms." Occurs when the magnetic storm on Earth many strange phenomena occur. Over the North Pole in the dark there will be a beautiful aurora. The compass will swing, short-wave radio broadcasts suddenly, relying on the magnetic field "navigation" will be lost pigeons, flying around. To cosmic rays and magnetic fields can stop high-energy charged particles from the sun is harmful organisms from the natural umbrella.
There may be and the polarity of the magnetic field changes related to conversion, according to Indian newspaper reports, Hyderabad (Hyderabad), a company in 2012, researchers predicted that the Earth and the Sun's magnetic poles will reverse. Earth's magnetic reversal Earth's magnetic field is the occurrence of the Arctic and Antarctic swap, in the course of the earth will experience at some point in time there is no magnetic field in the state.
Such a thing in human history not recorded, so only through computer simulation of its impact. Hyderabad model based on the Earth and the Sun's magnetic field in addition to the conversion