Marrett Grund, Ph.D., Minnesota Department of Natural Resources, Farmland Wildlife Populations and Research Group
When I grew up, my Dad taught me that deer were colorblind. Therefore, I could wear anything into the field and still be inconspicuous to deer—as long as I didn’t move. I wound up not being all that successful at hunting deer, so I decided to do some research on what deer could actually see. Here are some of the things that I learned.
Color vision is basically defined as the ability of an animal to distinguish light energy of different colors at the same light intensity. A small portion of the light energy spectrum is considered visible light. Within this visible spectrum, humans can see blue, green, and red colors. Different combinations of these colors produce white or any other color within the visible light spectrum.
Studies have shown that the retina in a white-tailed deer consists of cone receptors that allow deer to see blue and yellowish-green colors (this compares to human’s blue, green, and red colors). However, deer have only half the density of cone receptors in their retina as humans. In addition, deer also have a rod receptor in their retina that allows them to see blue to bluish-green colors in low light situations.
As is always the case, results from different studies have had slightly different conclusions. The one consistent finding among studies is that deer could distinguish blue from other colors. One study also concluded that deer were least able to distinguish colors along the orange and red colors—perhaps the most important finding for many hunters. However, another study showed that deer could differentiate reddish/orange colors from blue-green colors. This study indicated that deer may have had the capability detecting the orange colors against the blue-green colors due to light brightness, not because of light had a different color.
Undoubtedly, deer rely on their sense of smell and hearing to detect things that may present danger to them. However, their sense of sight is still quite important, particularly when the deer is attempting to confirm the threat of danger (after the deer smelled you, heard you, or detected your movement). Deer have excellent vision, both during the day and at night. During the day, deer can see blue to yellowish-green colors. Deer can also differentiate orange colors from blue-green colors. Furthermore, deer can see blue colors in low light situations.
Therefore, I no longer wear blue jeans when I am hunting deer because I know that deer can detect blue colors during day and at dawn/dusk. Instead, I wear orange coveralls during the firearms hunting season. I wear one solid color throughout my body so that deer cannot detect a contrasting color. Deer may be able to detect the brightness of the orange, but the safety and legality of that brightness clearly offsets the potential for being observed by a deer. I have greatly improved my deer hunting success since learning all this information about deer vision. But, I have also learned that I still need to abide by my Dad’s number one rule—Always Sit Still and Don’t Move!