Reprinted from my May 2008 Know Whitetails column in Whitetail Journal
Does Camouflage Keep You Hidden?
Years ago when state agencies began to make fluorescent orange clothing mandatory during gun seasons, hunters became alarmed. They worried that the bright orange color would make them more visible to deer, but subsequent research showed that deer did not see orange as we do. Around that same time a young bowhunter from Virginia named Jim Crumley came out with Trebark camo. No more solid brown hunting coats. Trebark opened a flood gate that made our old hunting clothing obsolete.
In a few short years we had Realtree and Mossy Oak, and the camo crunch was on. Today we find camo for all habitats, from hardwoods to wetlands, from snow to the desert. And we find camo everywhere, from flashlights to fanny packs, arrows to ATV’s, boots to bows. You name it, and we camo it.
The hype sounds great, but the real question is, does camouflage keep you hidden? There is some new research on how deer see that provides an answer to this question. But before getting to that, let’s look at what we know about deer vision. We know that deer don’t see longer wavelengths well at all and reds and orange colors (which are in the longer wavelengths) are seen as shades of gray or yellow. We also know that deer have various adaptations that allow them to see extremely well at night. They have more rods in their retina, they have a tapetum lucidum behind the retina that reflects light thru the retina, and they have a pupil three times wider than ours. Add these all up and its scary how well deer see in low light.
As an aside let me comment on how the full moon affects deer feeding. The thing I hear all the time is that hunting during a full moon is difficult because this allows the deer to feed more at night (and thus move less in day light), because they can see better. Think about that for a moment. When it is totally dark, with no moon at all, deer do very well at night. They aren’t out there stumbling around, walking into trees, because they see extremely well in low light. When you walk to your tree stand and it is totally dark, and you bump a deer, it runs off with no problem. No stumbling around, just gone.
Bottom line is that deer do not need the moon to see at night. This isn’t to say that the moon doesn’t affect deer movements, but such movements aren’t related to a deer’s vision at night.
Some other things about deer vision. The eyes of deer are further apart, giving them the ability to cover a lot of ground with their eyes. But there is a weakness. New research done at the University of Georgia shows that deer have 80 percent less acuity than we do. We have sharp central vision, deer do not. When we focus on one spot (as you are now, reading these words), things in the periphery are blurred. Stop reading and focus on this word. Note, the further from the focused word, the blurrier the image. Being able to see that word very clearly is called visual acuity. In fact, when you go to the eye doctor and look at those "E" charts, they are really testing your visual acuity.
When we focus on one spot, we see that spot very clearly. Deer don’t. The reason is that we have an optic fovea that is located in the center of the retina and it is packed with many, many cones. On the other hand, deer have a band of photo receptors across the retina, rather than one central spot. This allows a deer to scan a wide field of view all at once, without moving their eyes. Thus, when you have a deer standing at 80 yards facing in your direction, but not looking at you, they will difficulty seeing you if you do not move.
But if you move, they gotcha. Aha, finally we get to the need for camo clothes. The added rods they have plus this band of photo receptors spread across the eye rather than in one spot, give deer an extraordinary ability to detect movement. It is movement that does the hunter in, and it is camo that allows you to move and get away with it.
OK, not totally. Movement even when wearing camo, will get the attention of deer. We all know that. If you flip up your arm, even in camo, you enhance the chance of being seen by a deer, even one that is not looking directly at you. But, since deer have poor visual acuity, slow movements are harder for them to detect, and wearing camo helps.
Camo also reduced what I call the "blob phenomenon." That 200 square inches of fluorescent orange that you are required to wear in gun season is a gray "blob" to deer. Large blobs of gray are not common to the woods, and when that "blob" moves, they pick it up. So, camo helps to eliminate that because of the way it is designed. No big blobs of color.
So, there you have it. Camo helps keep you hidden from deer, especially when you move. Consider this question. Do you think a deer has a better chance of seeing you move your hands if you are wearing camo gloves or if you are not wearing gloves? The defense rests its case.