How many times have you heard this story. The hunter walks to his tree stand before daylight on a cold November morning. He sees a few deer, but nothing close enough for a shot. But he knows there is a big buck in the area, so he hangs in there till noon. It�s cold and he is tired and hungry so he departs and doesn�t return to that stand until the following evening.
Knowing that deer have great noses, he notes the wind and enters the stand on a different path than the one he took the morning before. With great anticipation he settles in for the wait. An hour before dark he hears a deer walking in the leaves. It is a dandy buck and headed right for him.
Just out of range, the buck stops, and puts his nose to the ground. He doesn�t blow out of there, but just turns and quickly walks away. The wind was perfect, yet the deer never got closer than sixty or seventy yards. The hunter grudgingly gets down from the stand and walks to the spot where the deer turned away. He discovers that the buck had just intersected the trail he�d walked in on the day before. Whoa. A deer�s nose knows.
There have been estimates that a deer can smell as much as 10,000 times better than we can. Others say it is less than that, but what really matters, and what every hunter knows, is that they can definitely smell better than we can. By a long shot.
Deer use their nose to survive. Their sense of smell is the major way deer detect predators, find food, and it helps them �talk� to other deer during breeding season. They use their nose at scrapes, overhanging limbs, at buck rubs, and around does to help them cue to what is happening before and during the rut. In essence, a deer survives by its nose and they rely on their sense of smell for everything.
We will never fully understand how a deer uses its sense of smell, but there is new research on how mice and humans process odors and it may give us some real clues as to how deer smell as well. Knowing how deer use their highly tuned sense of smell will show you why it is so important to stay as scent free as possible. If you aren�t sure about this, then read on. What follows should convince you that being able to detect your odor is something that deer can do extremely well.
In 2004 two researchers got the Nobel Prize in Physiology for their work on how humans detect odors. What they learned was most interesting. Humans have a small patch of odor receptor cells inside the nose. (This gets a bit complex, but don�t go away). These odor receptor cells make proteins that allow the detection of different odors. What determines the proteins that these cells make? Genes. Genes code these proteins, so the ability for all mammals including humans and deer, to smell, is tied to genes. Each protein in each odor receptor cell can allow mice to smell between one and three different odors. Since mice have at least 1000 of these genes, they can potentially smell as many as 3,000 different odors.
Humans have only 300 of these genes, meaning they can smell as many as 900 odors. We don�t know how many genes deer have, but they definitely have way more than we do. One would guess that deer have at least 500 proteins and the genes to create them, and if each allows them to smell between one and three odors, they could potentially smell 1,500 different odors.
Though that is important, the next finding by these scientists is the kicker. These different odor receptor cells take in various odors, send that information to the brain where patterns are formed.
Here is what the scientific research report quoted on this formation of patterns by inhaling different odors, �we (meaning humans)can consciously experience the smell of a lilac flower in the spring and recall this olfactory memory at other times.� �A unique odor can trigger distinct memories....�
So, �a unique odor can trigger distinct memories.� Let�s put this in deer language. We have odors coming into the deer�s nose, hitting the receptor cells that have these proteins created by genes that allow odors to go to the brain. There the deer forms patterns based on everything that was going on when it smelled a certain odor or odors. Now how does this all work to a deer�s advantage?
Let�s say a deer walks into an alfalfa field. Of course the deer sees the field, and it smells the alfalfa. That deer has been to the field many times before, so there is a pattern already in the brain that says, �I see the field and I smell alfalfa, so it is time to chow down.� Odors create patterns and these patterns determine where a deer will eat. If the deer walks in a certain direction and smells an odor that is part of a pattern created a month before, then that tells him to continue in that direction and he/she will find food. It might be alfalfa, it might be acorns, it might be brassica. The pattern was created and the deer reacts.
What if a buck runs into a dog and that dog chases him? The deer smelled the dog and then gets chased, and that is now a pattern in the deer�s brain. Next time he smells a dog, he will run away. If he is a young buck, then he might stand around a few seconds after seeing the second dog, and he may then get chased. Aha, the pattern is reinforced, so the third time he sees a dog, he is gone. Someone once told me that a buck isn�t all that smart, he just has great reaction time. True, and he is reacting to learned patterns in the brain tied to odors.
This whole pattern thing works the same when deer have encounters with hunters. What odors might a deer get around a human? Cigarettes, perspiration, clothes, gasoline, after shave, you name it. If a deer encounters those odors while living in a state park where there is no hunting, then it may not form a negative pattern. In fact, the deer may form a neutral pattern. Nothing bad happened when he smelled those odors, so the deer �became accustomed� to the presence of humans. The odors are part of a pattern that did not result in anything negative for the deer, so they do not react. In essence they became relatively tame.
But if there is a negative human encounter, associated with perspiration odor, or cigarette odor, or any human odor, that deer forms a pattern. The older the deer, the more reinforcement he/she got, so the reaction may well be instant.
Let�s go back to the buck that smelled the hunters boots or shoes on the trail he took to the tree stand. Apparently that buck had an earlier negative encounter with a human. He got the odor, something negative happened, and a pattern was formed. That pattern was there when he got a whiff of humans, so he left in a hurry.
So, all human-related odors are stored away in a deer�s brain and the patterns generated by odors are there as long as that deer lives. If deer are around farms, people, with no negative encounters (i.e. no dogs chase them, no hunters, etc.), then the patterns they store won�t result in flight. However, in most deer country, those human-related odors are negative for the deer, and they react by fleeing.
Deer will lick their noses all the time, especially bucks during the rut, because odor particles stick to a deer�s nose better when it is wet. So wet weather may also enhance the ability of a deer to recognize an odor. I love to bowhunt on mornings when there is a mist in the air. But be aware that a deer�s sense of smell may well be enhanced at such a time.
We�ve just learned that deer smell better than we thought, and we now know that they put things that happen to them, plus the odors, into patterns that determine their behavior. The question then is what can we do about it? The answer is simple. Reduce your odor any way possible. There are all kinds of products out there that can help reduce odor; scent-free soaps, deodorants, scent-reducing clothes, scent-reducing sprays, etc. You can also keep your odors from clothing by keeping them clean, placing them in scent-proof bags or containers, putting your hunting clothes on outside, and do not get overheated while going to your stand.
Why is it that the best chance to take a big buck is often the first time you sit in a new stand? Odor. Reusing a stand means more odor in the area. Let�s say you sat a stand three evenings in a row. If an older buck comes in downwind, and gets your odor, you may never see him. Many of our best hunters will tell you that controlling scent and watching the wind is critical. This is especially true for bowhunters who have to get close to harvest a deer.
A guide I hunted with in Montana many years ago told me that deer are not smart, they just have great reaction time. I never fully understood that until I found the above research. That reaction time is all about odor and patterns formed in reaction to odors. Deer can react to those patterns in milliseconds. The older the deer, the more those patterns are reinforced and the better the reaction time.
The bottom line here is that you need to take all the steps possible to eliminate your odor, because a buck�s nose knows.
........"This is a chapter of Dr. Samuel's book, Whitetail Advantage, published here with permission of published with permission of Krause Publications, 700 East State Steet, Iowa WI 54990. Copies available at most national bookstore chains such as Barnes and Noble, or at www.knowhunting.com.