As a nice follow up to my first post on this subject, I thought I would share with you some interesting facts about the incredible olfactory system of Whitetail deer and why you can’t leave scent control up to a product you buy off the shelf. I’ve already shared this information on my Twitter feed by pointing to the original article on the IMB Monster Bucks website but I thought it would help to summarize some of the author’s key points here to give you an idea of just how difficult it is to fool the nose of a deer.
- Deer have seven glands that are used primarily for scent communication.
- The nose of a whitetail deer has up to 297 million olfactory receptors, dogs have 220 million with humans limiting out with just five million… [in other words] the whitetail deer’s sense of smell is nearly 1/3 greater than that of a canine [and unfathomably greater than ours].
- whitetail deer have two giant olfactory bulbs attached to the brain which decode every smell they encounter. The bulbs weigh around 60 grams, four times as much as human olfactory bulbs.
- In tests dogs have been able to pick up chemical solutions that form one or two parts in a trillion. That is the equivalent of smelling one bad apple in two billion barrels. This is relative to a whitetail deer’s sense of smell as [this part is important] some hunters believe they can cover their human scent with cover up scents. Wrong!
- Dogs can detect odors that are up to 40 feet underground, thus deer can detect them even deeper than that depth.
- Estimates state that a whitetail deer can detect human scent for up to 10 days after it’s left.
- As far as dogs and whitetail deer are concerned, all humans have a unique smell. They can pick people out according to body and other odors …Therefore, the deer your hunting may quite possibly know the difference between how the farmer smells that works in the field that is NOT a threat to them, and you the hunter–
- [another key point regarding cover scents] If you are the hunter that wears cover scents then know the whitetail deer are probably associating your cover scents with those of a predator. Cover scents will hurt you more than help you.
- …dogs can track human smells over long distances. Scientists think they can pick up on the difference in odors from different footprints to work out which direction their prey is headed. They can do this twenty minutes after a person has passed by, even though the footprints are made a single second apart. If this is accurate, then again with the whitetail deer having a keener sense of smell – it is very possible whitetail deer can smell which way you are headed and avoid you by going the other direction.
- Based on 42 trials it has been concluded that scent absorbing suits with carbon lining had little to no affect on a dog’s ability to track human beings. However environmental factors such as the wind did effect the dog’s ability to locate. This information suggests carbon lined clothing as odor absorbing suits may not keep a whitetail deer from detecting the hunter.
- It is a scientific fact that it takes 600 degree [heat] for carbon to reactivate, however the modern day clothing dryer averages 175 degrees maximum temperature. Thus you aren’t reactivating your carbon lined clothing whether or not you think you are.
There is no [scientifically proven] way to reduce human scent 100%. [This fact is especially true when dealing with whitetail deer.]
Here are some of options not based on marketing schemes and pseudoscience that the outfitter recommends;
- Silver Ion Clothing: suppresses most body odor molecules in fabrics, then releases the odors during traditional home-machine laundering with unscented detergents. The silver ion technology works wet or dry, garments can be drip-dried or tumble-dried, and the scent-control technology is effective for the life of the garment. Even towels are being advertised for post bathing to kill bacteria and fungus that causes human odor.
- Play the wind: The very best way to avoid the whitetail deer’s sense of smell is to “play the wind”. This means in a nutshell that the hunter always hunts and approaches a hunting area from a direction where the wind isn’t taking human scent into where he or she believes the deer are positioned.
- Hang-high: [another method for "playing the wind"] While most hunters won’t hang tree stands higher than 17 feet [with the proper safety precautions in place] hunting from very high tree stands (25 to 30 feet) is a better way to avoid scent detection. A minimum of 15 feet is recommended.