The Eye of the Avian
By Dave Hanks
The EYE of the AVIAN is upon you;
Bold and bright, regally shining –
An entrée into the soul of each creature.
To be close-up and personal is but a hope,
Because their extraordinary sight prevents it,
And the ornithological world
Will retain much of its mystery and richness!
Vision is the most important sense for birds; in fact it is superior to almost all
other vertebrates. Good eye sight is essential for flight. A secondary eye lid
(nictitating membrane) gives extra protection and aids vision in less than favorable
atmospheric conditions. Bird eyes also have ciliary muscles that can change the shape
of the lens for a greater advantage. Bird eyes are the largest, in relation to their
size, when compared with other animals.
Migrating birds can spot unused nests, or sources of food, from aloft and descend
to feed or bed down for the night. Predatory birds such as hawks, eagles, and
vultures have vision powers that are 3 – 4 times sharper than ours. Vultures and
hawks can spot rodents from heights of 10 – 15,000 feet, and then dive at over 100 mph
and still keep their target in focus. Eagles have tremendous vision. They can spot a
rabbit that is several miles away.
There is a saying: “When entering the forest, the deer will hear you, the bear will
smell you, and the bird will see you.”
(A Short-Eared Owl keeps me at a distance with his incredible vision)
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