Any information presented here about the phenomenon of scent and the ability of whitetail deer to detect and respond to it is strictly anecdotal, a compilation of my observations and conjecture, not the result of a disciplined scientific study.
The vagaries of scent
At the end of a late afternoon bow hunt for whitetail deer with my father in a scrub-wood flood plain of the Missouri River, I was forced to admit my abysmal ignorance about the mysteries of scent and scenting in the animal world. Scent is a huge factor in a bow hunter’s success, or lack of success, and that after that weird hunt I vowed I would learn all I could about it.
Forty years later I am not sure I have made a lot of progress.
That Missouri bottoms hunt was a good one. The rut was at peak, and my father took a nice buck, shooting from a low tree stand with a borrowed recurve bow the day after a cable on his new-fangled compound bow snapped. It was his first bow-killed deer, and we were giddy with excitement over his good shot, but the most fascinating part of the story was the seemingly suicidal behavior of the buck.
The tree stand was about a hundred yards from Bazile Creek near its confluence with the Missouri. I had hung the stand as best I could in a misshapen cottonwood tree above a trail that I knew several does were using as the main route from their bedding places in the impenetrable brush on the opposite side of the creek to the edge of a 20-acre cornfield where several rows of standing corn had been left as a food plot for wildlife.
We had seen scrapes and rubs at places along the trail but had not seen the buck himself, so we assumed he as a nocturnal critter and would not appear while we were on stand. That was okay; we would have been happy to take a nice doe.
Unexpectedly, the buck came striding along the trail well before dark and slowed for a broadside shot 15 yards from the cottonwood tree. Unfamiliar with the bow, and maybe suffering from a touch of buck fever, my father took a shot that went a foot over the buck’s back. It wheeled and ran back down the trail toward the creek crossing.
Disgusted with himself – and the sport of bow hunting in general – my father sat down, hung his bow on a branch, took out his pipe and tobacco pouch (Half & Half brand), and settled back for a consoling smoke. There was a light wind from the northwest, and he watched the pipe smoke drift toward the creek. What happened next was a violation of everything we thought we knew about bow hunting.
Within 10 minutes of the time he lit his pipe he heard a rustling in the brush, looked several yards down the trail, and caught a glimpse of the buck once again walking boldly toward the cornfield. He snuffed the pipe, stood up, slowly lifted the bow from its hanging place, drew an arrow from the quiver, and set himself for another shot. The buck obligingly paused at the same place along the trail, and my father put an arrow through him. It dashed off about 50 yards before dropping stone dead.
My father told the whole story three times as we dressed out the buck, and I was dumbfounded. How could this buck walk right across the scent line of tobacco smoke and not be spooked? I considered asking my father to climb back into the tree and fire up his pipe again so I could walk the trail and check it out, but it was now well past dark and our immediate plan was to drag this buck a half mile to the pickup, drive home, open a couple beers and start bragging.
The only conclusions I could draw were: 1) whitetail deer are attracted by the scent of Half & Half tobacco smoke and I should puff on a pipe every time I was in a tree stand, or 2) scent is affected by wind, air temperature, ground temperature, humidity, and other conditions in the wild in ways that we humans cannot comprehend because our own sense of smell is so limited. Pipe smoking is a nuisance, so I went with the second assumption.
The next summer, when I was sure no one would see me, I took a charcoal briquette out of the barbecue grill one windless afternoon, dropped it into a weedy spot in our backyard, and lay on my stomach to watch the trail of smoke. Okay, I admit I went into the garage for my oil can and squirted a few drops of 30-weight motor oil onto it to increase the plumes of smoke.
The directions and intensity of the several fingers of smoke that went meandering away from the smoldering lump were a surprise. Down at ground level, and I mean in the four of five inches immediately above the ground, there are currents, cross currents, eddies, and pools of flowing air that take the smoke – and hence its scent – along paths you would never expect. Yes, when a 15 mile-per-hour wind is blowing, the stream of scent is fairly predictable and steady in the downwind direction, but lesser wind velocities play strange tricks with scent.
I have done the smoldering-wood experiment several times and in many different places since that first test, and the scent-flow images it impressed on my mid have been an overlay for my evaluation of scenting conditions each time I climb into a tree stand. Preventing and/or eliminating human scent is the most important factor in bow hunting, I have come to believe, and a hunter is wise to make careful observation of the vagaries of scent whenever he is afield.
My own observations have led me to the following list of conclusions. Any information presented here about the phenomenon of scent and the ability of whitetail deer to detect and respond to it is strictly anecdotal, a compilation of my observations and conjecture, not the result of a disciplined scientific study. These “facts” are dependent on common bow hunting conditions: hunting from a stand that is 10-12 feet above ground level, use of “scent-killer” soaps and/or sprays for both body and clothing, air temperature of about 20 to 60 degrees, rural hunting area.
- Unless your scent is exceptionally strong (cigarette smoke or engine exhaust fumes or pungent gun oil, for example), deer can detect and will react to human scent at a distance of about 40 to 50 yards.
- Deer detect scent in a narrow vertical band of air current, from ground level to about six feet above the ground. Scent flowing above that level can pass over a deer and go unnoticed.
- Deer detect scent in a somewhat broader horizontal band that expands gradually as the distance from you to the deer increases. The band may be only three feet wide at the base of your tree, and may increase to 50 feet at a distance of about 30 yards from your tree. Even in very light winds, your scent is a stream, not a pool.
- A wind velocity of five miles-per-hour is sufficient to carry your scent in a consistent downwind direction, and you can focus all your attention on approaches from the upwind side.
- A wind velocity of more than 10 miles-per-hour will cause your scent to disperse and diminish within 50 yards, and so on these more windy days you must be alert for deer approaching unexpectedly from downwind.
- The commercial “scent killer” sprays really do work, and combined with the normal precautions a bow hunter takes to reduce his odor they can make you “unscentable” to deer until they are within five or six yards distance.
- Any “masking scent” lotion or spray (skunk scent, apple scent, juniper scent, etc.) is counter-productive; its odor alerts deer that something is unnatural and makes them more wary, not less.
- The “lure” scent formulas, such as doe urine, sometimes attract deer, sometimes do not, and sometimes repel them, depending on many factors in the estrous cycle and the day’s weather and feeding conditions. They are generally not worth the expense or effort.
- Does are more aware and responsive to scent than are bucks, especially, of course, during the peak of the rut when bucks can be totally oblivious to scent warnings.
- Each woods, and each section of a woods, has its own prevailing air currents. Observe, study, interpret, and apply those to your hunting set-up; think like a deer.
Finally, do not smoke your pipe while you are sitting in your tree stand. That trick made for a great story that has lasted more than 40 years, but one aberrant success in four decades of bow hunting is a low percentage strategy for overcoming the challenge of scent.
More stories about hunting and life in the North Country are published in my collection of essays, Crazy Old Coot, and my novel, Hunting Birds. Both are available in Kindle and paperback editions at Amazon.com.