The Scent Factor
September 28, 2010
A technological revolution is changing the way we hunt whitetails, mule deer and blacktails. Science is giving smart hunters an olfactory edge. Are you among them?
When a deer inhales, it is able to identify and sort a complex array of odors, including those of hunters and cover scents.
Photo by Ron Sinfelt.
A good olfactory sense is a deer's best defense. Hunters have known this for thousands of years, but for the last two decades, a revolution led by science has changed the way we hunt deer from coast to coast.
Hunters see only a fraction of the deer around them. Odor lingers long after a hunter has passed. Deer that cross his trail are alerted. The hunter might hear the warning blows or snorts that are the signals that a deer has caught his scent, but by then it is too late.
When a deer inhales, it can identify and sort a complex array of odors. Some are food or herd smells; some are warnings. Deer also communicate by means of scent signals that include pheromones.
Tarsal, metatarsal, preorbital, interdigital, forehead, nasal, preputial and caudal glands secrete scent information. A specialized organ in the roof of the deer's mouth is believed to help a buck determine a doe's timing and may synchronize the reproductive physiology of the buck.
Does can pick out their fawns by scent. Bucks stake out territory and advertise for does during the rut, and the readiness of the doe is activated by scent detection.
Jim Heffelfinger, regional game specialist with the Arizona Game and Fish Department and adjunct professor with the University of Arizona at Tucson, has made a living out of studying ungulates and game birds. In his book, Deer of the Southwest, he described a deer's olfactory attributes. A deer's nasal passages "are lined with a tissue (epithelium) that contains mucus-producing cells. These cells maintain a moist environment in the nasal cavity to aid in the collection of scent. When a deer inhales, it draws in airborne molecules that land on an area of moist nasal lining, and through a chemical reaction, messages are sent to the brain for identification of the scent."
Temperature and humidity also play a role. Cool weather and the increased humidity of autumn improve a deer's sense of smell and make a finely tuned scent detection system even better.
Our challenge in October is to beat a deer's defenses, and we have varying degrees of success based on our implementation of strategy and tactics. We succeed more often when we employ a holistic, no-nonsense approach to scents.
We may never completely control the scent we bring to the woods, but the more we reduce our own odor, the better our odds are of seeing deer.
Scent can be covered up to some degree, confusing a deer's ability to sort through other odors and detect the human threat, but a better approach is to control human scent before the application of covers and attractants.
Studies have indicated that deer can process up to seven different smells at the same time. That means a deer can smell you as well as the product you trust to cover your scent. By eliminating degrees of human odor, we diminish the scent carried downwind and spread through swirling breezes.
Human scent is carried on clothing and equipment. It emanates from gun oils and fabrics; it is manifested on hatbands and the soles of our feet. Every step we take to block or eliminate scent is a small victory.
The battle begins with the body. A daily shower or a simple sponge bath with unscented soap makes a big difference.
Cooking smoke is another hazard. In our camp, we change clothes before we make dinner. The next day's garments are kept in bags where they don't pick up camp smells.
Odors cling to clothing from the inside as well. Scientists have engineered fabrics that block odors or stop them from forming. One approach is the use of nanotechnology.
In the past, clothing companies treated textiles after they were woven. Today, they can introduce treatment elements much earlier in the process. Some companies are using silver to fight odor, and they're able to embed the element at the primary level.
The process infuses a silver ceramic polymer in their soft, breathable base-layer fabric that binds to the bacteria in perspiration. With the fabric close to the skin, backcountry hunters can limit the odors they exude even after long, sweaty hikes.
Scent-controlling outerwear has been available for a few years, but technology is improving fast and new fabrics are more breathable and flexible than activated carbon-containing gear. Another process bonds a dandelion-shaped odor-adsorbing polymer to the fabric surface. Odor molecules bond to the fabric instead of wandering around to spook deer and elk.
Monte McDowell's company, Dead DownWind (www.deaddownwind. com), employs an enzymatic prevention method. The enzymes, which McDowell calls "a factor of nature, Mother Nature's cleaning tool," can be targeted. "If I engineer an enzyme to eat pizza and I put it in the refrigerator and close the door and open it again later, the only thing that will have changed will be that there is no pizza left."
The enzymes in McDowell's products attack a broad spectrum of bacteria in three categories: laundry products, body products and products for use in the field.
Scent elimination is the first step. By removing a high percentage of human smell from the mix, the hunter makes cover scents and attractants much more effective.
Cover scents are intended to confuse and distract the prey from the scent of the predator. Employ skunk or fox scent to cover the human scent with the strong odor of a small varmint. Confuse with fresh earth fumes or the scent of a food source like apples or acorns.
Cedar, juniper and pine are good cover scents to use anytime of year. Muscadine (wild grapes), crab apples, corn, persimmons and honeysuckle are best timed to the season.
Scents come in amber glass, spray bottles, wafers, smoke sticks that burn like incense, soaps, shampoos, breath mints and chewing gum. They can be applied to wicks, posted surrounding stands, tied to shoes and dragged on the trail behind a hunter.
Allan Sanford, owner of Blend'n In (www.blend-n-in.com) and a traveling bowhunter from Bend, Oregon, wanted to be able to mix scents from t
he plants he found in each new area. Rather than rely on someone else's juniper blend, perhaps taken from junipers in another state, he wants the confidence he gets from gathering the vegetation himself, mixing it with water from a pond or mud puddle. He invented a portable electric blender. At the beginning of each hunt, he grinds local vegetation to cover his scent and pours it in a bottle for use throughout the week.
Sometimes, finding fresh elk or deer urine, he scoops up the soil, mixes it with water and sprays it on his boots, hat and pant legs. He makes good use of cover scents throughout the pre-season as well, while checking trail cameras. And he doesn't walk on deer trails.
"I scent myself and my boots, and when I get to my camera, I pull my card and then spray my camera down and get out of there as soon as possible."
The cover scent program ramps up on opening day. "From my camp, I scent down with whatever is the local vegetation. I'm hunting out of a tree stand, so early season I'm scenting down before I leave my bivy site. I scent the tree down and then spray my lower torso. Once I'm up in the tree, I don't worry too much about it, but sometimes I spray from the tree down to the ground to cover my scent."
Scent elimination and cover scents are two legs of the stool. The third leg is the attractant.
Hunting with my daughter at Rio Bonito Ranch, north of San Antonio, we saw the best attractant of all. The doe fed out into a clearing. After 10 minutes, another deer appeared. The spike buck was legal, but Tiffany wanted a mature buck for her first deer.
The doe would not let the little buck approach closer than 25 feet. She bolted. For 20 minutes, the little buck chased. They vanished into the oaks for a few minutes and then the doe emerged again and began to feed, 100 yards away. We saw her look up at the spot from where she had come. A big whitetail buck stepped into the open, following the exact trail that the spike had traveled minutes before. The buck rubbed his antlers on the same bushes and then stood to look at the doe for a moment. I counted 8 points.
Tiffany leaned into the scope, finger on the trigger. "How big is he, Dad?" she asked.
"He's big enough," I said.
She took the slack out of the trigger and rocked with the recoil. The buck humped at the shot, bolted straight toward us, then veered off into the trees. My 14-year-old daughter had just taken her first buck.
Pheromones are components of scents that all animals use to send behavior signals to other animals of the same species. Secreted by forehead, tarsal, metatarsal, interdigital and other glands, they are used in combination during marking, rubbing and rub-urination and are interpreted by individual deer according to sex, age and social rank. Both does and bucks will investigate the scent of new deer that enter their core areas.
Bucks recognize the odor of other bucks through scent "signposts" left at rubbed trees. Estrogen in doe urine signals breeding readiness. High testosterone in buck urine signals a buck's readiness.
That means that hunters can employ buck-in-rut urine to attract deer of both sexes. The scent of a hot buck attracts hot does, which brings in the bucks.
Most attractants on the market focus on deer urine. It can be administered in a variety of ways.
Another approach involves the use of vaginal secretions from does at the peak of estrus. The VS-1 Deer Scent from Border Crossing (www.bordercrossingscents.com) can be used with scent sponges or wicks around tree stands and at scrapes, rubs and other high-traffic areas.
There is no doubt that urine- and sex-based attractants can be powerful tools, but food scents are effective as well. Remember that deer are thought to be able to differentiate up to seven different smells simultaneously. When used in combination with urine or sex scents, food odors might change the equation enough to get a buck to commit to dinner and a date.
Disappear Hunting Products uses this approach (www.disappearhp. com). The Disappear Cover Scent is a blend of natural whitetail deer tarsal gland extract and food scents. It can be applied to boots to leave a scent trail. At the stand, soak some cotton balls with the product and place them upwind and downwind.
Darren Brown, vice president of Buck Bomb (www.buckbomb.com), recommends a unique attractant process when combined with a baiting program. "Our new Vanilla Curiosity is really good in places you're allowed to bait. When you go to re-bait your site, spray down the bait." The odor of vanilla drifts downwind. "Every time you do that, you educate the deer that there is bait on the ground and when you come in to hunt, you can spray a little vanilla and wait."
The Buck Bomb in all its iterations employs a premise of the atomization of food-grade scents, attractants or urine. "The nozzle can contain one drop of urine and turn it into 3,000 particles. We use a propellant to push it up through the nozzle at a speed that atomizes it. When it is atomized, it drifts and it sticks to whatever it comes in contact with and leaves a nice scent trail back to the source, which is you with a can in your hand or with the can on the ground in front of your stand."
For 2009, the Buck Bomb released Acorn Rage Bomb, developed in concert with WildGame Innovations, a product that smells like acorns and molasses. Other new products are Bone Collector Doe in Estrus and Buck Bomb Fuse, a scent canister with a 1-inch-wide, 12-inch-long wick that comes with a bottle of doe estrous urine.
Brown believes that their Young Buck product is one of the best attractants throughout the season. The scent of a young buck is a curiosity to both does and older bucks.
For mule deer (and blacktail) hunters, Muley Bomb Doe in Estrus is a good attractant and cover scent.
Last October, a buddy and I spotted a blacktail buck feeding in a clearing. My friend was unable to convert him to useable protein, so we emptied a can of Muley Bomb Doe in Estrus on a bush and returned the next morning at first light.Tracks told the tale. Two bucks had found the scent. We followed the trail and, 10 minutes later, spotted both bucks at the edge of the timber. We notched our tags at the same time and helped each other pack the meat to the road.
Every scent-elimination, cover and attractant strategy represents a degree of compromise based on time, availability, comfort and budget, but today's hunter has more options than ever.
A high degree of confidence comes with the knowledge of how to beat a buck's best defense. And a holistic approach to scent control and attraction can pay off with more big bucks that feed into shooting lanes, calm and unaware of our presence.
(Editor's Note: To order a signed copy of Gary Lewis' Deer Hunting: Tacti
cs for Today's Big-Game Hunter, send $24.95 (includes S&H) to Gary Lewis Outdoors, P.O. Box 1364, Bend, OR 97709.)