Earth Cycles and Scenting
Temperature and Scent
|working a pup|
With practice these natural influences can be used to your dog’s advantage or disadvantage depending on the following aspects that are related to how the wind, rain and air temperature transports the scent your dog follows.
The Science of Scent can be quite complex and for easier understanding I’m going to stay away from the scientific side of scent and discuss, in layman terms, how scent is affected by the weather. This can be a confusing but interesting topic.
To begin with, Earth cycles influence the air temperature of day and night, the speed of the wind and how rain storms are formed, which in turn, affect the scent particles your dog will follow.
Air temperature affects the work of a search dog in more ways than only the dog’s performance when it is to hot or cold outside. We all know the heat of the day can make us feel less active or and more active. The hotter the temperature the less we want to work. The same is true of our dogs.
Day and Night Tempertures
The earth breaths in a regular cycle each day as the sun heats the day beginning with a cool crisp morning then warms to high temperatures in midafternoon and decreases to cool again at dusk.
This earth cycle is extremely important to a serious mantrailing dog handler or air scenting dog because as the earth cycle repeats day after day, the scent particles and surfaces all around us dry up and loose the freshness of dawn heating throughout the day then cooling to remoisten and expand overnight.
Throughout the increasing heat of the day, water and moisture in the scent particles evaporate. The surfaces and the scent become dry. Similar to how a surface will become dry in the sunshine so does the scent particles on the surface of everything around us.
Moisture and scent particles are absorbed by surfaces and objects during this drying out period of the day then later released or replenished with moisture when the sun begins to go down and the day cools off.
This means during certain times of the day, the particles of scent will be more difficult to detect due to the loss of moisture in everything. Scent particles are still there but shrunk in a sense and can be detected under certain circumstances.
This aspect is naturally adjusted in the dog by increased panting and the production of more saliva and a wetter nose.
This is why search dogs and tracking dogs should be kept hydrated at all times and well watered in order to produce a wet nose. Always carry water and wet your dog’s nose for better scenting ability in hot dry weather.
Mild temperatures will affect the dog’s nose less but more with distance. For instance, when a dog begins to dehydrate after tracking for several miles the nose will dry up and scenting ability begins to drop.
At this point a dog may lose the scent, go off track or stop trailing or tracking the trail or scent not because the trail has disappeared but because their nose is dry.
As the Earth breathes in this natural cycle every day, and scent dries up, the particles are absorbed inward on surfaces. When the temperature cools, the scent particles are released.
This is why wild animals are not as likely to hunt or seek food during the heat of the day; they lay and wait for the cooling cycle to begin in the late afternoon. When the day starts to cool off moisture is released from the earth and all surfaces expand releasing scent particles giving them help in the hunt.
As the day temperature cool and night falls, you can feel the moisture come out of forest and grasslands, and see it in gardens and lawns as dew in the morning.
The ground outside actually inhauls all day in one long breath then exhales overnight in oxygen. Just like we and our dogs breaths so does Mother Earth.
Trees and plants absorb the air around us during the day and release oxygen at night replenishing the earth as part of the earth’s cycle. Scent particles are in the air, trees and plants.
The day’s temperature plays a role in how quickly the scent particles will be released or if they stay dry making them move more easily on the wind. The surface comes into play when the surface changes from grass, dirt, pavement or a table top.
Each surface will absorb or reflect different amounts of scent particles and other microscopic particles, such as bacteria, dust and other contaminates. As the day turns to night and continues to cool more and more surface particles are moistened, expanded and released as the pores everywhere open giving wild animals trails to follow and hunt.
Overnight the earth is refreshed as moisture inhaled during the day is exhaled and condensed again into night dew and fog holding scent particles. This is the best time to work a scenting dog.
Winter temperatures slow the day heat cycle until the moisture in the air reaches the freezing point at which time the scent particles become frozen in place and dogs are able to detect the person’s trail because as the dog breathes on the frozen scent pool and moves through the trail the ice thaws out under the dog releasing scent for the dog to smell.
I use this natural earth cycle to my advantage when working dogs by starting sessions or lost person trails as the day starts to cool off.
If the heat of the day is going to be over 85f degrees it’s best to Wait to work a scenting dog until the afternoon begins to cool, usually between 3 and 4 pm.
I’ll work a Bloodhound all night with lights, taking a rest break every 2 hours for 20 minutes on long trails or difficult incidents. I stop working the dog on very warm days when the day begins to warm in the morning (10-11am) then wait, rest, sleep until afternoon (3-4pm) when the day starts to cool. We start all over searching again until we finish and make the find.
If we work all night then we’ll sleep and rest in the heat of the day.
All of a sudden she would turn off the path we would be working and jump into the brush where a creek or spring would be. There she would stick her whole nose and muzzle deep in the water and blow bubbles. She’d pull her head out of the water, shake, splash a little on her belly with her front paws then go back to work on the path we were on.
Bloodhounds love to wet the nose. All of my Bloodhounds would put their whole muzzle into the water up to eyes, nose, lips and all then they blow bubbles. It’s great fun to watch in a lake when the dog goes under water walking on the bottom, ear floating and nose blowing bubbles. They can go quite a long way under water this way.
Sue taught me to always keep your scenting dog’s nose wet on the trail by watering your dog often or wetting your hand then patting the dog's nose with the wet hand. A hot dog will not and should not drink very much water until they cool off or they can colic.
I only give a hot dog a few drinks of water from the palm of my hand until they cool down and are not panting hard. If I have extra water I’ll put handfuls of water under the dog’s front legs and on the stomach to cool them off quicker. Behind the ears and inside the hind legs are other good cooling spots.
Next week I'll be posting about how the wind affects scent on the trail.