What Whitetails See

What Whitetails See.


Job one for a white tails eyes is detecting movement day or night. The sooner, and farther away, the better. A deer's chief predators have historically attacked from the ground, often from dusk to dawn when color often isn't detectable; as a result color vision hasn't been a priority for whitetails. Deer require a wide field of view that operates at peak deficiency from the ground to the horizon.

 Nearly 20 years ago, researchers at the University of Georgia began studying the whitetail's eye in physiological detail. Their analysis concluded that a deer's color vision is limited to the blue and green wavelengths. This means deer can likely distinguish blue from red. The researchers reported that whitetails probably see blaze orange as some shade of gray or brown.

The university took its research to a new level in 2009 when graduate student Bradley Cohen built a device to test the colors whitetails can detect. When the lights activate and bins open the deer must choose the color light that indicates accessible food. If they choose the wrong bin, a small door seals off the food. By day 28 of the training, the seven adult does chose the correct lights and food bins 88 percent of the time. Cohen concluded deer could see a bit further into the red and blue, and possibly ultraviolet, spectrums than previous research indicated, but the increases weren't "biologically significant."

Cohen's Professor, Karl V. Miller said he'd worry more about the deer's ability to see shades of blue than shades of red, like blaze orange. " Deer see blues fairly well, maybe better than we can," he said.

because deer's eyes are mounted on both sides of their head, deer have nearly 300-degree vision, including about 65 degrees of binocular vision to the front. The only area they can't see is the 60 degrees directly behind them. A deer's pupils are more of a horizontal and oval shape, which allows decent vision fore and aft from the ground to the horizon. However, deer vision isn't so good above the horizon, making it difficult for deer to spot movement above them. That's why hunters can often make moves in a tree stand that would get them spotted at ground level.

For instance, University of Georgia research in 2007 estimated that deer have about 20/100 vision in daylight, whereas normal human vision is 20/20 (five times better). "When you see all these fine detailed cam prints with leaves and twigs, that's not important to deer," Miller said. "You'd probably do just as well with a blurred cam.


Information gathered from: American Hunter, December 2011 issue.