What You Didn’t Know About a Deer’s Sense of Smell
Bernie Barringer 11.12.14
Everyone knows the whitetail deer has an amazing sense of smell. But how good is it really, and what are the factors that deer rely on to know what’s going on in their environment? Here are a few things you probably didn’t know about a deer’s ability to smell.
I was situated 20 feet up in a tree nature had placed in a good spot for seeing deer. Less than 10 yards in front of me was the edge of a picked cornfield, and beside me ran a well-used deer tail leading to the field from a bedding area. It was early November, and the rut was heating up.
An hour before dark, a doe casually walked from behind, using the trail to enter the field. Over the next 20 minutes, she fed over a small hill and out of sight. Not long after that, a buck came trotting along the field’s edge right in front of me. He was obviously worked up about the rut, and he periodically put his nose to the ground, grunting as he came.
When he hit the trail where the doe had entered the field, he skidded to a stop and turned toward me, following the trail with his nose in the dirt. After about three steps, he spun around and ran the opposite way, trailing that doe. He was over the hill and out of sight in 15 seconds.
That event was an “Aha!” moment for me and it changed the way I viewed a deer’s ability to smell. By following the doe’s scent just a few yards, that buck knew which direction she was travelling by determining which way the scent was older. That’s absolutely shocking when you think about it. How can we ever think we could fool a nose that can work miracles like that?
I sat in a seminar in which a well-known hunter was talking about using a drag rag attached to your foot and saturated with buck lure. Drag the lure to your stand and the buck will follow. He stated that as the scent is deposited on the ground, you should replenish the lure often so the buck doesn’t follow the trail the wrong way. Sounds good on the surface, but that’s flawed logic. If the scent is getting weaker and weaker, wouldn’t the buck follow it the wrong way every time?
The truth is the buck will follow the scent the correct direction because he knows how long the scent has been there. The age of the scent is a totally different concept than the strength of the scent. When you understand that concept, you suddenly realize that complete “scent elimination” is impossible to attain. We can strive for scent control and scent reduction, but don’t get fooled into thinking that any product will allow you to ignore the wind. Let’s look at the physiology of the deer’s nose to help us better understand what we are up against.
It seems crazy to compare a deer’s ability to smell to our own, but that’s really the only benchmark we have to go on. We have a small patch of olfactory receptors in each nostril, they are connected to a part of the brain that we use to interpret the smells that pass over them.
A whitetail deer’s long nose offers a lot of room for scent interpretation, and the deer has olfactory receptors throughout both nasal cavities—more than 800 times as many olfactory receptors as a human has, in fact. There may be olfactory receptors on the outside of the deer’s nose as well. This may be why they tend to lick their noses to moisten them, which helps them pick up scents and smells.
But we’re not done, there’s more. The whitetail deer has an organ on the roof of the mouth that also interprets smells. It’s called the Jacobson’s organ and it can sort out smells that come through the mouth.
While a human’s brain is much larger than a deer’s, a comparatively small area of the human brain is dedicated to analyzing odors. The portion of the brain dedicated to analyzing odor in a whitetail’s brain is much larger than that of a human’s, despite the fact that the brain is much smaller. In a deer, more brain power is dedicated to analyzing odors than any other brain function.
In all, some studies have estimated that the whitetail deer’s ability to smell is about 10,000 times stronger than a human’s. And they are good at sorting out the odors, too. In one study, it was determined that deer could separate at least six different odors when they are mixed together. Think you are going to “cover” your odor with a dollop of skunk cover scent beside you? Nope.
Fortunately, we have products at our disposal that help reduce and control our odor. Scent Killer spray has been tested to significantly reduce human odor. Antibacterial soaps and laundry detergents have been shown to help reduce the bacteria that is responsible for most human odor. Activated carbon is very good at adsorbing odor, but it may not have the longevity that we once thought when added to clothing. Silver added to clothing has been shown to reduce odor. There are more products being developed all the time that seem to help reduce human odor.
Nothing we’ve come up with so far can reduce odor to the point that a deer cannot smell you if the wind carries your scent to it. Still that is no excuse to avoid cleanliness and use products that can help reduce your human odor, because less is better even if we cannot achieve total scent elimination.
Some scientists estimate that under perfect conditions, a buck can smell a doe’s sexual pheromones from a mile away. We would be a fool to think we could mask our scent to the point which that buck couldn’t smell us. The more we know about the power of a deer’s nose, the more we can use care to hunt them properly, and even more importantly, the more rewarding it is when we actually bag one.
Follow Bernie’s bowhunting adventures on his blog, bowhuntingroad.com.
