Most of us have seen search and rescue dogs locating lost children on television shows. On TV, dogs use any means possible to find a lost person, from sniffing for human scent in the air to sniffing an article of clothing and tracking that individual’s unique scent.
While search and rescue dogs are capable, in principle, of being trained as both air scent and trailing dogs, most dog handlers train their dogs to perform only one of these disciplines. Therefore, the most valuable dog team, in terms of obtaining a high probability of detection, is one with a dog that can switch back and forth between air scenting and trailing as conditions dictate.
All humans, alive or dead, constantly emit microscopic particles bearing human scent. Millions of these are airborne and are carried by the wind for considerable distances.
AIR SCENT DOGS
The air scent dog is the type most frequently encountered. This dog finds lost people by picking up traces of human scent that are drifting in the air, and looks for the “cone” of scent where it is most concentrated. This dog will not normally discriminate scents, so there is the possibility of a “false alarm” if other people (searchers, citizens) are nearby. Air scent dogs work best in situations such as large parks or private lands that are closed at the time, since the dog will home in on any human scent. The success of an air scent dog will be affected by a number of factors, including wind conditions, air temperature, time of day, terrain, and presence or absence of contamination (auto exhaust, smoke, etc.). The best conditions for air scent dogs to work are early mornings or late afternoons on cool, cloudy days when there is a light wind.
The trailing dog is often referred to as a “tracking” dog, although “tracking” and “trailing” are not the same to the purist. The trailing dog is directed to find a specific person by following minute particles of human tissue or skin cells cast off by the person as he or she travels. These heavier-than-air particles, which contain this person’s scent, will normally be close to the ground or on nearby foliage, so the trailing dog will frequently have its “nose to the ground,” unlike the air scent dog.
A Bloodhound is typically trained for scent discrimination. Each dog is usually worked in a harness, on a leash, and given an uncontaminated scent article (such as a piece of clothing) belonging to the missing person. The dog follows that scent and no other. At times, the dog may track, following the person’s footsteps, or air scent, and home in on the subject’s scent.
Field contamination (scent of others) should not affect his work. He should be able to trail scents on pavements, streets, grass, water, etc. If there is a good scent article and a point where the person was last seen, a trailing dog can be the fastest way to find the victim. Without the scent article and a point where the person was last seen, these dogs cannot work effectively.
While those are the two standard types of search and rescue dogs, there are also other dogs trained to find lost people.
Read more of the article about the following types of search and rescue dogs and what to do if you are lost:
- Water Search
Article sourced from http://www.ussartf.org