How Well do Raptors See?
This page is under construction. Please be patient while we get it up and running.Hawks have some of the most highly developed visual capacities. Comparisons of vision between hawks and people has been that raptors can see as well as someone with 8 power binoculars. However hawks do not have highly magnified vision, but do have small depressions on the retina that create a slight magnification. From an abundance of receptor cells in the retina, hawks are able to discriminate fine details at a much greater distance and in much less time than we are. While some species of hawks have up to 8 times the receptor cells that we do scientists consider the degree of visual acuity of hawks to us to be about 2.5 or 3 times.
Hawks have a bony "brow" above the eye known as a supraorbital ridge believed to offer shading from glare and even protection when flying through dense cover and a kind of wind and dust deflector.
Raptors including owls have a "third eyelid" known as a nictitating membrane which is used to moisten the eye, but also shut at the moment of attack, flying though brush, or even when feeding young-anytime there is a change of the eye being scratched or damaged.
Owl eyes are so large that they are immobile in their sockets and the owl has to turn his entire head to bring objects into focus.
Information coming soon
Most raptors do not have a well developed sense of smell. The exception are New World Vultures.
Turkey Vultures have been used to detect leaks in natural gas pipelines. A rotten meat odor is added to the gas and if there is a leak the vultures will start circling and then the leak can be repaired. There have also been studies demonstrating that Turkey Vultures can distinguish between just dead (at least 12 hours) and rancid which even Turkey Vulture's stomachs can not handle.