Dichromaticity And How It Affects Your Hunting | News, Sports, Jobs

Many years back I was invited to take part in a hunt that would forever change my life. But, like most things that happen to me throughout my life, it would take me years to figure out the importance of said hunt. RJ calls it the 10-penny nail in the 2×4 theory. It seems that only when I am cracked along the head with a 2×4 with 10-penny nails in it, do I pay attention. Stubbornness is a Robbins family tradition/trait.

The hunt in question was a goose hunt. It was back before we had geese in every pothole, field and golf course in our part of Goose Country. The chance to take part in the hunt was exciting because at the time I had never gone and paid to hunt anything.

As we checked in with our guides for the morning of the hunt, I noticed something unusual about our guide, who happened to be the owner of the guide service — he wasn’t wearing any camo. Now I had just purchased a brand-new Carhart camo jacket, hat, facemask and gloves for this very morning.

The reason I spent the money, which at the time we didn’t have, was because all the successful goose pictures and stories I saw have had camo clad hunters. So, this is what we all did.

As we took our places in the standing corn field at O’dark 30, to discover there was a line of 5-gallon buckets spread out about 20 yards apart, I chose the end bucket. This was another decision that would stick with me.

As luck would have it, our guide was positioned next to me.

Now, here’s a little bit about our guide. He came across as a grumpy old man, sporting a long gray beard covering a weather-beaten face that made him feel he had seen more bad days than good ones. In his red/black fennel coat and blue hat, he called out to hundreds of geese that flew over our ambush.

After several flocks came in, we were just a little short of our limit for the day, but the old guide still kept working the birds, to little avail.

During the downtime when he wasn’t working his weathered wooden goose call, I would ask questions. I kept peppering him with what I’m sure to be the dumbest questions I had ever heard about geese and goose hunting.

It was the one answer to my question I finally had the courage to ask that would change the way I hunt. My question was, “We are all dressed in camo, but you are the guide and you have a red and black coat and blue hat and no face mask. Why is that?”

As he stroked his beard and tilted his head to one side he said, Geese don’t see colors. You see, in the wild ducks and turkeys, for example, can see colors, geese and deer can’t.”

I was taken back. Everything I had learned about wildlife was wrong? Has everything I ever read to that point a lie? Do all the folks I looked up to really didn’t know what they were talking about?

I was floored, to say the least. My follow-up question was, “Why would you say that?” The old guide tilted his head to the other side and said, “Because it’s true, and let me tell you why I know this.”

He continued with this simple, but very understandable, explanation.

“It’s basic woodmanship,” he said. “If the opposite sex of any given species is a different color than their mates, that species can see color. Various colors in wild animals are for breeding purposes, identification only.”

The wild turkey has different color variations in each sex. Ducks are the same — a hen mallard isn’t as colorful as a drake mallard. Geese? You can’t tell the difference in sex by looking at them and so on.

This brings us to the world of the whitetail, their vision and dichromaticity and how it affects hunting.

The camouflage of animals is dominated by browns, tans and blacks. The reason for this is that humans and animals see differently. For years some thought that deer “see in black and white.”

This isn’t quite true. Deer see “dichromatic,” or being able to see bluer, and hardly any red.

What researchers have found is that deer can see colors, though they don’t experience them in the same way we do. They can pick out short — blue — and middle — green — wavelength colors, but they’re less sensitive to long wavelength colors such as red and orange.

Deer can only see green and blue, so they are “dichromatic”. So, deer are essentially red-green colorblind, specifically, they have protanopia. They would see reds and oranges as shades of green. In humans, this is a problem when driving because you can’t see red car lights and traffic lights.

Under normal conditions, a deer can smell a human that is not making any attempt to hide its odor at least a quarter-mile away. If the scenting conditions are perfect — humid with a light breeze — it can even be farther.

Over the last few years, more and more research has been done on how deer actually see color. Obviously, this has been closely followed by hunters, as this research has a direct impact on the camouflage they use.

Let’s for the heck of it and for those that understand, ask the question, “How exactly do you see color?”

There has been an increasing amount of research, but let’s pick out two of the more important ones.

In the landmark 1992 study, the scientists sedated deer and shone different wavelengths of light in the deer’s eye and recorded the electrical response from the eye. Apparently, “subsequent recovery of each animal was unventful.”

In the 2014 study, a behavioral approach was taken and trained scientists deer using various color lights at various intensities. They then measured responses across these wavelengths to determine which ones the deer were most sensitive to.

Other adaptations in a deer’s eye enable it to see the smallest motions. Wider pupils, wider set eyes and a “tapetum” allow it to be highly sensitive to any kind of motion. They also have a lower concentration of cone cells over a wider horizontal area. Weirdly, this means that although they have amazing motion detection, they can’t see detail. Ever wondered why a deer sits staring at you for minutes on end? That’s because he can’t really see you well enough to figure out what you are. From a perspective of seeing details, deer would be legally blind if they were human. The other aspect of this amazing motion peepers is that they see more horizontally and less vertically. Thank goodness for tree stands.

The researchers found that as well as having only two types of cones, deer also had a lesser concentration of them. This was, however, made up by a greater concentration of rods. Rods are the photoreceptor cells that work in less intense light, or, as we light to call it, nighttime. They also had pupils that could let more light in, making their night vision even better.

Another adaptation resulting in only having two cones is that the spectral range into the blue end of the deer’s vision is increased. While probably not quite as impressive as the black light used by CSI to detect what’s been going on in that bed, it’s safe to assume that deer have increased sensitivity to ultraviolet light. The implication for hunters is a concern when washing their clothes. It’s common for detergents to have UV Brighteners in them to make washed clothes look whiter and brighter. It’s probable that this would be more noticeable to deer. There is a growing market in “UV Killer” washing agents for hunters, but you are probably OK with a) using a normal detergent that doesn’t have brighteners, and b) checking your camo with a UV blacklight.

We didn’t look at the other important senses of deer — smell and hearing. Let’s just say that they can probably smell you from a mile away and hear you rustling the bag of potato chips you are munching on for lunch while hunting. All things considered, vision is the last of the four of the whitetail senses we need to worry about after you have made sure you have dealt with the other three.

Next week we will discuss the sense of smell and how it affects whitetail hunting.

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