How to Follow a Scent Trail
Copyright © June 1, 2024 by Robert Wayne Atkins, P.E.
All Rights Reserved.
Introduction
If an odor is only a few feet away from a person then almost anyone can determine exactly were the smell is coming from.
However, being able to successfully follow a weak scent trail a long ways back to its source is a skill that very few people have in the twenty-first century.
This article will describe an easy way to follow a smell back to its source.
Just for the record, I have a lot of wilderness survival books and many of those books explain how to follow a fresh blood trail. This is not difficult to do if the animal is losing blood from some type of wound, and the blood is visible, and the blood is not dripping onto a surface that can absorb or hide the small drops of blood.
However, none of my wilderness survival books contain any information on how to follow a scent trail.
Therefore on June 1, 2024 I did an internet search on this topic and the only articles I could find on the internet where the following:
1. How to train a dog to follow a scent trail.
2. How to find the source of an odor inside your home.
The reason I am mentioning this is to let you know that the information you are about to read is based on what I have learned by taking long walks in the forests for more than 60 years.
Discussion
The five senses are the abilities to see, hear, smell, taste, and feel.
The nose of an animal is soft and most animals can detect smells that a person cannot detect. However, people can still detect smells but our ability to detect odors is not as good as most animals.
A person's ability to follow a scent trail depends on three important factors: our sense of smell, the intensity of the odor, and the speed of the wind.
- Sense of Smell:
It is not unusual for a person to need eyeglasses to see, or a hearing aid to hear. These two senses enable us to successfully interface with the rest of the world.
However, most of us do not give any thought to our sense of smell because our sense of smell does not significantly impact our ability to enjoy our lives. Therefore there is no device that people can wear to enhance their sense of smell in the same way they can enhance their ability to see or hear.
We do not all have the same sensitivity to smells and most of us do not know if our sense of smell is average, above average, or below average.
Some of us can easily detect and identify faint odors that other people cannot detect. My wife is one of those people. She can smell things that nobody else in our family can smell. However, when she takes us to the source of the smell, then we can all smell it.
You may or may not be a person who has an enhanced ability to detect and identify odors. If your natural sense of smell is below average then you may not be able to follow a "scent trail."
- Odor Intensity:
The intensity of the odor will be in direct proportion to the chance of locating the source of the odor.
For example, if a person enters a kitchen and either bacon or coffee is being prepared, then the person will usually be able to detect and identify those very distinct aromas without actually having to see the bacon or the coffee.
However, if a person enters a kitchen and the only thing that is being cooked is white rice on top of the stove, then the person will usually not be able to smell the cooking rice and the person will have to visually see the rice to know that rice is being cooked in the kitchen.
The same concept applies to things in nature. Foul odors usually become stronger as you get closer to the origin of the odor. And pleasant odors usually become stronger as you get closer to the origin of the odor.
But most odors are not intense. And some things do not emit any noticeable type of odor.
Not all smells need to be followed. Some smells are disgusting, such as the decaying body of a dead animal and there is no reason to try to find the dead animal.
Some smells are pleasant and they may lead you to a food source.
You will have to make the decision on whether or not you will invest the time to locate the source of something that you can smell.
- Wind Speed:
The wind speed will determine whether or not a scent trail can be followed:
- No Wind: If the air is stagnant and there is no breeze, then there will be no scent trail to follow because the smell will simply ascend straight up into the air.
- Strong Wind: If the wind is blowing hard enough so you can easily feel the wind on your face, then the wind will disperse an odor before the odor has traveled very far on the wind.
- Gentle Breeze: If a gentle breeze is blowing then it may be possible to follow a scent trail.
If you are outdoors and if you can detect a scent with your nose, and if you are interested in where that smell is coming from, then the first thing you should do is determine the current direction of the wind. The easiest and most reliable way to do this is to drop a very, very lightweight object down to the ground. A small dry leaf, or a very small piece of paper, are good choices. Or you could cut off a very short piece of one strand of your hair. Watch the object as it gradually makes its way to the ground and its "flight path" will be the direction in which the wind is blowing towards. Look in the opposite direction and that is the direction from which the wind is blowing from, and that will be the direction from which the smell is coming.
Immediately put something bigger on the ground, such as a stick, that points in the direction from which the smell is coming from. This will not only mark the direction of the wind but it will also mark the exact spot where you first detected the odor.
Resist the temptation to immediately begin traveling in the direction of the smell. A better option is to first travel to the right and left to determine if the smell is stronger in either of those two directions.
At the spot where you first detected the smell, carefully sniff the air to determine the strength of the smell. Then walk about 10 or 20 feet at a 90 degree angle to the wind, either to the right or left, and stop. Sniff the air a few times and make a decision if the smell is increasing or decreasing in strength.
- Increasing Strength of Smell: If the strength of the smell is increasing the continue another 10 or 20 feet in the same direction and stop and stiff again. If the smell is still stronger then continue moving in the same direction until the smell begins to decrease. Then return to the position where the smell was the strongest and clearly mark the spot and the direction from which the wind is blowing from.
- Decreasing Strength of Smell: If the strength of the smell is less then return to your starting position and walk 90 degrees in the other direction for about 10 or 20 feet, and then stop and stiff. If the smell is increasing then continue in this direction. If the smell is decreasing then return to the spot where the smell was the strongest.
The objective of moving right and left instead of straight ahead is to determine where the smell is the strongest based on the direction of the wind. The further the smell travels on the wind, the more the smell will spread out to the right and left. What you are trying to determine is where the smell is the strongest because the smell will be coming from that direction.
Note: If the smell disappears while you are doing the above, then the smell was not a "lingering" smell and the smell would have disappeared even if you had begun to walk in the direction of the smell when you first noticed it.
If you have a compass then note the direction from which the smell is coming from.
Now you can begin walking in a straight line towards the origin of the smell.
Depending on what the smell is, and the origin of the smell, the smell may become stronger as you get closer and closer to the smell.
However, many odors do not linger for a long time and it is not unusual for the smell to gradually become weaker as you approach its source. If you are aware of this then you will not become discouraged and you will not begin to wonder if you may be going in the wrong direction.
Explanation of the Above Method
Instead of immediately traveling in the direction of the wind, the above method suggests moving to the right and left to find the strongest presence of the odor.
Consider the illustration on the right. The source of the odor is at the top center of the illustration. And the wind is blowing from the top to the bottom.
As the scent travels on the wind, the scent will very gradually disperse to the right and left on the wind. As the scent disperses to the right and left, the intensity of the scent will gradually become less when compared to the intensity of the scent directly below the source of the scent. In other words, the scent will have the strongest smell at location "C because it will be in the direct path of the wind away from the scent.
If you can find location "C" using your sense of smell, and if you travel in the direction from which the wind is blowing, then you will have a very good chance of finding the source of the smell.
However, if you first notice the smell at location "A" and if you immediately begin traveling in the direction from which the wind is blowing, then you will arrive at position "X". Position "X" is to the left of the source of the smell and this means you will not have found the source. If you continue walking in the direction of the wind you will get even further away from the source of the smell.
The same problem will happen at locations B, D, and E.
For example, if you originally detected the smell at "E" and you immediately began walking in the direction from which the wind was blowing then you would arrive at position "Y" which is off to the right of the source of the smell.
However, if you originally detected the smell at "E" and you walk to the right then the smell will become weaker. If you then begin walking to the left you should eventually be able to find "C". But you will have to walk past "C" to the left to determine that the smell is becoming weaker at position "B." Then you could return to position "C."
Therefore your best chance of finding the source of the smell is to find position "C" and then begin walking in the direction from which the wind is blowing.
Conclusion
Even if you do everything right, you may not be able to find the source of the smell.
But sometimes you will be successful and you will be pleased with what you find.
Knowing how to follow a scent trail is a piece of survival knowledge that may, or may not, be useful to you one day in the future. Only time will tell.
Respectfully,
Grandpappy.
Grandpappy's e-mail address is: RobertWayneAtkins@hotmail.com