Tracking Vs Air Scenting
Tracking Vs Air Scenting
All humans constantly emit microscopic particles bearing human
scent. By the millions, these particles become airborne and can
be carried by the wind for considerable distances. Human scents
vary, reflecting each person's gender, race, hygiene, diet, toiletries
used and other factors, to a dog giving each a unique "signature".
Airborne scent is concentrated near its source, follows the air
currents, and becomes more dilute the further it travels.
Dogs have 40 times the number of olfactory cells than humans and
unlike humans, they do not become accustomed to scents. An air scenting
SAR dog is especially trained to locate the scent of any human in
a specific search area and close in on the source of the scent.
SAR dogs are not restricted to following the missing person's track
and can search long after the track is obliterated, zeroing on on
where the person is now, not how they got there.
While it is better if SAR dogs can search early on in a search
and in previously undisturbed areas, they can work effectively where
other searchers have been. All our dogs can work day or night, in
most kinds of weather, and are especially effective where human
sight is most limited -- in the dark or in dense bush or heavy undergrowth.
Our dogs do not require a scent article, although this may help
in some circumstances, especially in more populated areas.
How Our Dogs Work
Incredible but true ....
Did you know ?
- dogs are one million to one hundred million times more sensitive
to smells than humans
- a search dog has 44 times the number of olfactory cells in its
nose than a human!
- the total surface area of the olfactory lining inside a dog's
nose is larger than that of the dog's entire body surface!
- a dog's olfactory lobes take up one-eighth of its brain!
- a dog can detect a scent that is one part in ten quadrillion
(that's 10 to the power -15)!
Air Scenting Dogs
Our dogs are "air scenting" dogs and work off the lead
looking for any human scent. The handler generally creates a search
pattern across the wind. When the dog detects human scent they will
"alert" ... easily recognised by the handler and something
that is constantly being watching for. The "alert" is
something like a startle movement.
The dog will then try to follow the scent to its source. This is
done by detecting when the scent is weakening and turning back towards
the stronger scent. Scent normally forms a cone shape from the person.
The dog will swing back and forward as it determines the edges of
the cone and then work its way to the source. The beauty of this
method of searching is that you do not need to know where the person
started from and you do not need to follow their tracks if they
have walked in circles or over difficult terrain ... you go directly
to where they are now.
The diagram below might be helpful.
As soon as they find someone, the dogs are trained to return to
the handler, give a recognisable signal and then lead the handler
back to where that person is. Only once they have "refound"
the missing person are they rewarded by the handler. Dogs vary as
to their preferred reward ... some will respond best to food, others
to affection or to a game with a special toy.
Of course, the dogs may find someone other than the missing person
(eg. another searcher). To the dog, this is still a "find"
and they are rewarded just the same. They are then asked to continue
searching for the missing person and because they are able to discriminate
between individuals, by each person's unique scent, they will not
search again for the person they just found.
© 2003-2008 Search and Rescue Dogs of Tasmania
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