Revealed: Birds navigate by being able to SEE Earth's magnetic field with their right eye
By Daily Mail Reporter
Last updated at 9:06 PM on 13th July 2010
Birds use their right eye to see the Earth’s magnetic field and use it to navigate, scientists have discovered.
鳥類使用牠們的右眼見到地球的磁場，並用它來導航，科學家們已發現。
German researchers found that if a bird’s right eye was covered by a frosted goggle, the birds could not navigate effectively, while they could navigate perfectly well if the left eye was covered instead.
德國研究人員發現，如果鳥的右眼被一磨砂護目鏡遮蓋，鳥類不能有效地導航，而牠們能完美地導航如果左眼代之被遮蓋。
It has long been known that birds are able to sense magnetic fields and use them to navigate, particularly when migrating south for the winter.
早就知道鳥類是能夠感覺到磁場，並使用它們去進行導航，特別是當移居到南方的冬天
Snow geese head off on the migratory journey: Scientists have found that birds can actually see magnetic fields
雪鵝投向遷徙旅途：科學家已發現鳥類可以實際地看到磁場
Now researchers have found that the bird actually sees the magnetic fields with their right eye giving information to the left side of their brain.
現在研究人員已發現，鳥類其實用牠們的右眼看到磁場，提供資料至大腦左側。
The magnetic images create light or dark shadings over what the bird usually sees with its normal vision.
磁影像創造光線或黑暗陰影，在鳥類通常以其正常視力見到的東西。
The shadings change as the bird turns its head, giving it a visual compass from the patterns of shading.
Scientists believe that the birds have molecules in their retina which shift into an active state when struck by blue light in which each molecule has an unpaired electron, creating a 'radical pair.'
The presence of magnetic fields affects the time it takes for the radical pair molecules to revert to their inactive state.
Both the visual and magnetic images involve variations in light and shade, but visual images tend to have sharp lines and edges, while the magnetic images have more gradual changes from light to dark.
Researchers led by Katrin Stapput of Goethe-Universitat in Frankfurt, Germany, discovered that when this magnetic sense is distorted the patterns of light and dark make little sense because the bird cannot separate the information from the visual and magnetic images.
Stapput decided to test the theories by fitting robins with goggles that were covered with clear foil on one side and frosted foil on the other.
Both sides of the goggles were equally translucent, allowing 70 percent of the light to get through, but on the frosted side the image was less clear. The birds were then kept in cages until it was time for them to migrate.
The birds were released into a funnel-shaped cage with its walls painted with fluid, which was scratched if the birds touched them.
The results were that birds with no eye coverings, and birds with the left eye covered set off in a northerly direction as expected, while those with the right eye covered were disoriented and headed in random directions.
http://www.dailymail.co.uk/sciencetech/article-1294303/Birds-navigate-able-SEE-Earths-magnetic-field-right-eye.html
美飛船拍到太陽磁力線清晰畫面
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