Ever used the term “eagle eye”? The eye of an eagle is one of the most sensitive in the animal kingdom, and its size can cause it to weigh more than the eagle’s brain. The secret to the bird’s exceptional vision is the density of visual cells, the rods and cones of its retina.



Look at the back of your hand: your rods register the overall shape, the cones register details such as contour and color. The density of rods and cones within a raptor’s eye may be five times more than in your own eye.



So when hunting in open country, the Golden Eagle uses its seven-foot wingspan to ride thermals high into the air. There, it spots the minute movement of its favorite prey, a rabbit, over a mile away. That's like you driving at forty miles an hour, and being able to look back to where you were when this BirdNote started and see a jack rabbit.



So the next time you give the “eagle eye” to a raptor, chances are, it saw you first.

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Credits:



Written by Adam Sedgley



Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Call of Golden Eagle recorded by A.L. Priori



Ambient track recorded by C. Peterson



Producer: John Kessler



Executive Producer: Dominic Black



Narrator: Michael Stein

© 2014 Tune In to Nature.org November 2016