Carrots, Fluorescent Orange and A Whitetail’s Eye

Posted on August 21, 2012

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What can a deer really see?

I’m not a big fan of fluorescent orange, in fact I really dislike it and only wear it where the law requires. For years I have held to the belief that by having to adorn this article of clothing my chances at a clever buck was somewhat compromised. I still find the notion that some lawmaker gets to delegate legislation on how best to keep me safe an infringement on my common sense. After all, the whitetail I hunt for has no such safeguards nor does any other wild thing. As the prolific writer, Archibald Rutledge penned,

“I often think that wild things are compelled to use all the senses God gave them. We sometimes use a few, but we have lost so much native alertness that even at so palpably dangerous a place as a railway crossing, a sign has to be erected reminding us to stop, look, and listen. The children of nature are forever stopping, looking, listening; but you will search their haunts in vain to discover any signs warning them to exercise so simple a precaution.”

Although it would make great conversation fodder to debate the merits of wearing a piece of wardrobe that can be seen for miles, that is not the trail that this piece is to go down.

What can a whitetail really see?

For years, it has been debated as to a whitetail’s ability to see color, at least the same way that humans do. It has long been my belief, unsubstantiated as it was, that God would not have created such a magnificent animal as the whitetail and not provided it with color vision. In 1993 noted deer biologists Dr. Larry Marchinton and Dr. Karl Miller from the University of Georgia conducted research that accurately defined the range of color vision in whitetails. Their findings were: (1) deer should be relatively less sensitive to long wavelength lights than many other mammals (e.g., humans), and (2) white-tailed deer would be expected to have dichromatic color vision.

 

What does that mean in layman’s terms? Deer, like humans, have two types of photoreceptors: rods and cones. The difference is that they have far more rods than cones, which is responsible for their great vision in low light conditions. Due to the fact that a deer’s eye has no yellow pigment covering the central region of the retina and far less cones, their ability to see in a broad wavelength of color with visual acuity is seriously compromised. They see or are sensitive to violet, blue and some green on the color spectrum, but when it comes to green and shades of red it doesn’t register. Traffic lights would pose quite a problem for a whitetail. Deer have two cones in limited concentration. These give them limited dichromatic color vision similar to a human with protanopia; red-green color blindness. Deer perceive blues and yellows, but are unable to distinguish green, yellow, orange, red, tan, brown, and gray from different shades and intensities of yellow. In simple terms, deer see their world during daylight hours as shades of yellows, except for blue.

According to vision scientist Dr. Jay Neitz’s interpretation of the study, “Human sensitivity is highest in the green-yellow region of the spectrum and for equal intensities, these wavelengths are perceived as brightest. Humans are relatively insensitive throughout the short-wavelengths (blue and violet). Sensitivity also drops off rapidly in the very long wavelengths; we are relatively insensitive to deep reds. Humans can distinguish four basic colors; blue, green, yellow and red. We also distinguish dozens of intermediate colors, e.g., violet, blue-green, yellow-green, orange etc. Humans can make subtle color discriminations across the visible spectrum.

 

The region of highest sensitivity for the deer is at a shorter wavelength than that of humans. The relative sensitivity of deer to short-wavelength light is dramatically higher than human sensitivity to those wavelengths…Because of the absence of red cones, the drop off in sensitivity at the long-wavelength end of the spectrum occurs at shorter wavelengths for deer. They are less sensitive in the spectral region that appears orange to humans and are virtually insensitive to deep reds.”

Dangling the carrot

A few years ago I ran my own test with red and green apples (an experiment that I have written about previously) to prove that whitetails cannot see these colors, but have to smell the apple to locate. This fall I conducted a similar study using carrots. I set up in a suburban area where I regularly photograph whitetails, a location where backyard gardens yielding carrots and other vegetable treats are a common delicacy for the resident deer. I carefully placed several carrots atop the leaf litter just off trails regularly utilized by whitetails and waited within my photo blind. When the first deer appeared – a 1 ½ – year old spike horn – it was interesting to watch him stop and begin sniffing around until he located one of the carrots. The next deer was a mature buck sporting nine points and despite the carrots being a mere step away from him, it took a couple of minutes for him to locate them; even I could see the orange veggie from my vantage point. Three more deer appeared in succession, all exhibiting similar difficulties in seeing the carrots, but had no trouble when it came to smelling their presence.

 

Despite having read the research, I was astounded with what I had witnessed. In order for me to be completely convinced, I went back and ran the experiment again a few days later with the same exact results.

Anxiety over wardrobe diminished

Holding a carrot next to my hunting coat I realized that the coloration of the fluorescent sown onto the upper part was precisely the same. For the first time in my hunting career I felt a bit at ease regarding this colored fabric that has become mandatory in most states when pursuing whitetails. Beliefs die as hard as traditions and I’m not sure that I will ever get to the place where beyond compliance I’d choose to wear this color if given the choice, but knowing that a whitetail doesn’t see this color any better than my standard green & black attire makes it that much more tolerable to wear.

 

All images on this site are copyright protected and the property of R.G. Bernier

© 2012 R.G. Bernier Nature Photography – All rights reserved.

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Posted in: Whitetail Deer