This past weekend, prior to heading into the timber to check trail cams and begin fall inventory of potential target bucks, I had a thought-provoking debate with a hunting buddy of mine; when is the best time to enter the woods to scout, hang stands, and check trail cameras?
For as long as I can remember, I have been a firm believer in entering the deer woods just before, or during, a substantial and soaking rainfall; both odor dispersal and sound reduction can be obtained by doing so. My hunting buddy enlightened me with his philosophy of entering the woods at precisely the opposite time when the air is dry, and relative humidity is low. In his mind, the potential problem that my current approach carries is that relative humidity tends to be rather high just prior to, and during rain showers; while in my defense, any scent that is left behind has a higher likelihood of being saturated and dispersed by the falling precipitation. When temperatures are cooler, and the air is dryer, the amount of human odor that can be picked up by the reduced moisture content in the air can also be beneficial by lessening the number of molecules that the wind can transport and disperse. So which is it? Which scenario offers the most advantageous outcome for us? Unfortunately, there is no concrete answer. While neither methodology provides a foolproof way to remain completely covert, both rain and low humidity have the ability to minimize the scent we leave behind. The timing of your entrance can be critical to reducing the likelihood of being detected.
Warm air tends to hold more water molecules than cool air. For each incremental 15 degree rise in air temperature, the number of water molecules being contained in the air nearly doubles. The incremental rise translates to increased odor dispersal through absorption in the water that is held in the air. On the contrary, as temps start to plummet during late fall and early winter, the molecules begin to freeze, and the air becomes much drier. Think about it, all of us have been in the woods on a cool, foggy morning where the relative humidity is high. If you pay close attention, you will notice that your sense of smell is greatly amplified by the high concentration of moisture molecules. Imagine what this does for a whitetail! Relative humidity is one more important factor to apply to whitetails and how we both scout and hunt them. It is wise to err on the side of caution during pre-season scouting trips and early season hunts when humidity is above 70%.
There have been numerous studies done with the assistance of dogs to determine the lingering effect that your scent leaves in the deer woods. It is believed that a whitetail can smell 1/3 better than your bird dog which means that they have approximately 300 million olfactory receptors vs. a dogs nose at 210 million. As humans, we are severely handicapped in the sense-of-smell department at approximately 5 million receptors. A deer’s scent receptors run through the nasal passage and into two olfactory bulbs in the brain that are devoted solely to distinguishing scents. The large bulbs are roughly five times the size of our own, and if you compare the size of a whitetail brain to a human brain, you can quickly discern that the percentage of brain space that is geared towards scent recognition is incredibly high. A deer’s nose can decipher six scents at one time, think about that for a second. A mature whitetail has the ability to pick up the sweat on your brow, the gas on your boot, the Gatorade in your pack, the wax on your string, and the faint remnants of your shaving cream all at the same time.
A whitetail’s sense of smell is his primary weapon of defense. A deer’s elongated nose is engineered with a sophisticated nasal structure that can detect the danger of an approaching predator from several hundred yards away. Moral of the story, you simply cannot cover or hide all your scent from the impeccable nose of a whitetail deer, it is not possible. Unless there is going to be a substantial rainfall, say half an inch or better, it may be best to scout and hang stands on cool, dry days. Hot and humid weather will increase the amount of sweat that you produce, and in turn, you will be leaving a lot more scent in the timber. What we as hunters can do is minimize the amount of scent that we leave behind by closely monitoring weather conditions and using scent eliminating sprays. Scrub down like a maniac, wear clean clothes, and try your best not to enter the deer woods unless conditions are in your favor.