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"How Search and Rescue Dogs Work"
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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.


What Then?

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.


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