With that process in mind, let us back up one step. For the live find/human scent imprinting process, let’s eliminate the need to have a reward system established, or lets just make this reward a secondary reward, and the source of the scent the primary reward. Finding this person should be the ultimate reward. Regardless of whether this person that the canine finds has anything of value to offer, the human is the reward. They are a high value reward! What this equates to is a dog that is motivated to follow human scent because the human scent source is the ultimate! This goes back to the concept of an intrinsic reward…one that doesn’t require training to have significance. It is naturally rewarding to the dog. How do we do that with humans. Plain and simple…select for high social skills with humans and build on that. Any contact with humans should be positive. Entice play behaviors, up close contact, encourage with treats, anything that the canine views as enjoyable. The canine should go crazy when it comes in contact with humans, just as it would if presented with a high value toy reward. The secondary reward system can be built at this point as well. Imprinting the significance of the reward starts with the handler but is quickly transferred to other humans. By the time the scent imprinting training process has begun, the canine has learned two things: 1) Humans are really fun to interact with and 2) The humans, who are high value to begin with, are a source of a second high value reward, for instance a kong toy, bite roll, or treats.
When that part of the process is well established, then the actual process of rewarding the scent recognition by the canine can begin. Lets see, critical factor. To eliminate the ‘visual’ stimulus, the human must be concealed. This is no different than the other scent sources being concealed.
There are many ways to conceal a person for this exercise, but I have the advantage of having access to large boxes (approximately 4 ft. W x L x H) that have doors on them for concealing people on the inside. I train with local LE on a regular basis, and these boxes are utilized to build hunt drive for building searches for patrol canines. There are 6 boxes spread out over the area the size of a soccer field. The process can be done with as few as three, but if you have access to a USPCA regulation training field, then you will have 6 to use.
I start out by having a person hide in the box with my secondary reward with them. There are vent slots cut into the bottom sides of the boxes, so there is a scent source down low. It is important that the victim be allowed to occupy the box for a short period of time to allow the scent to build up inside of the box, especially in the early stage of the process. The longer this person can stay in there, the stronger the scent. The canine is walked past each box on lead. It is important to know which box the victim is in, so that you will be prepared to observe subtle behavior changes when the canine recognizes the scent.
The instant that a behavior change is observed, the victim pops the door open (it is important that the handler approach the front of the box where the door is, and from the side opposite of the hinges to ensure that when the door opens, the canine can associate the source of the scent with the victim) and immediately rewards the canine with the secondary reinforcer and lots of play. The handler allows the victim to take the lead and run a short distance away to encourage the canine to focus on the victim and not the handler. This builds victim loyalty. In other words, there is scent commitment. Over a period of time, the length of time may be extended between the dog initially recognizing and going to the source and actually getting the reward. This victim loyalty exercise will prompt the dog to stay with the source (victim) until the behavior is reinforced. For a disaster K9, this is crucial, since many a victim will be concealed in rubble and debris and it will be necessary for the canine to stay with the scent source until the handler safely negotiates the hazards of a debris pile and marks the location for rescuers. It is not uncommon to see the canine attempt to penetrate the barrier between it and the victim or begin to vocalize out of barrier frustration. One should be careful not to overly frustrate the canine to the point that it gives up and walks away. Mild frustration will intensify the desire to access the scent source.
As the training progresses, then the introduction of the verbal cue or search command comes into play, followed by the indication. I train the indication separate from the search behavior. This is a trained indication, so it needs to be solid prior to introducing it in association with finding the victim. The indication needs to be reliable and on cue. Eventually the verbal cue will be eliminated once the association is made between the victim, reward, and the indication.