Physiological mechanisms
According toPhases
Tracking behaviour in dogs is exhibited through three separate phases.Searching Phase
* Initial period in which dogs attempt to find a track. Dogs sniff very quickly ten to twenty times between inhalations of breath.Thesen, A., Steen, J. B., & Doving, K. B. (1993). Behaviour of dogs during olfactory tracking. Journal of Experimental Biology, 180(1), 247–251. Sniff frequency is usually 6 Hz and occurs while the dog is in motion looking for a trail.Deciding Phase
* Track identification is apparent when the dog halts and then proceeds to take smaller step and the sniffing frequency of the dog becomes much longer. * Period usually lasts 3–5sTracking Phase
* Similar to the searching phase. Sniffing behaviour and walking behaviour become quicker.Methods
Although dogs use physiological methods to detect scent trails, they apply these methods differently depending on the environments in which they are tracking. A scent results from the individual odour of a person being tracked or through an environmental disturbance odour that results from the physical movements of the person being tracked. The ways in which dogs track an individual, vegetative and track scent can vary depending on circumstances. Specifically, scent tracking ability of a dog depends on whether or not an individual deposits their scent in the air or on the ground. An air scent is when human odours of sweat, cells, gland secretions, or toiletries circulate freely in the open air. The bacteria attached to fallen skin cells provide dogs with odorous by-products that enhance the individuality of a trail. While an initial air scent is much stronger than a ground scent, a ground scent remains detectable for a longer period of time. A ground scent is the combined permeations of trampled vegetation, bugs, mud, and soil disturbed by an individuals footprints. The disturbed soil releases moisture and kills plant life which results in a different odorous by-product. Each footprint releases a new odour more potent than the ones of the undisturbed vegetation surrounding it. A track scent is often a mixture of both the air scent and the ground scent being left behind by an individual. Dogs are able to determine a track scent by identifying a combination of both human odours and environmental odours released by an individual. They then use the strength of this overall scent to determine the directionality of a trail and track along that route. Since an initial footstep is much less potent than the last footstep taken by an individual, dogs move in the direction where the scent seems to become stronger. Additionally, dogs have been observed to alternate between visual tracking and scent tracking depending on the circumstances of their environment. For the most part dogs prefer to use olfactory cues even when the target or visual cues are within their line of sight.Gazit, I., & Terkel, J. (2003). Domination of olfaction over vision in explosives detection by dogs. Applied Animal Behaviour Science, 82(1), 65–73. However, there has been research conducted where dogs have been shown to rely on visual, social or cognitive cues to identify the tracks of an individual.Factors that influence tracking ability
There are many different factors which influence a dogs ability to successfully determine the directionality of a track. The age, sex, and even personalitySvartberg, K. (2002). Shyness–boldness predicts performance in working dogs. Applied Animal Behaviour Science, 79(2), 157–174. of a dog can greatly influence tracking behaviour. Male dogs have been described to more accurately determine the direction of a trail than female dogs. It is hypothesized that this is due to the evolutionary history of male dogs. Male olfactory ability of canines is superior to that of females because historically it was their duty to find mates and mark territory. Canine olfactory sensitivity is also found to diminish, therefore younger dogs tend to have superior tracking than older dogs. Personality traits of dogs affect both their ability to be successfully trained and their ability to successfully track. Dogs that are more active and confident tend to perform better during training activities and tracking activities. The mannerisms of the handler working with the dog can also affect tracking ability. It has been discovered that humans and animals share very specific social skills that enable them to bond and work together effectively.Miklósi, Á., & Topál, J. (2013). What does it take to become ‘best friends’? Evolutionary changes in canine social competence. Trends in cognitive sciences, 17(6), 287–294 Adaptations of social tolerance and attentiveness has enabled dogs to participate in cooperative problem solving with their human counterparts. Social attentiveness refers to an animals ability to pay attention to their partners actions and behave accordingly.Range, F., & Virányi, Z. (2015). Tracking the evolutionary origins of dog-human cooperation: the “Canine Cooperation Hypothesis”. Frontiers in psychology, 5, 1582. It is this factor that explains how dogs are capable of interpreting and reacting to cues from their handler. Pointing, gaze shifting, and facial expressions demonstrated by the handler can be used by the canine to locate objects and follow a certain direction. Although usually purposeful, unconscious signals are also capable of being interpreted by canines while working with humans. Therefore, handlers are trained to be cautious of their actions when working with their canine in order to ensure their demands are being properly perceived by the dog.Human uses of tracking dogs
Human uses for tracking dogs are dependent on many different factors. Specifically, the demands of a job often influence which kind of dog humans choose to train and employ. There are three different types of scenting dogs based on their affinity for air scents, ground scents and tracking scents. Described as a tracking dog, trailing dog, and point source dogs each one specializes in a different method of tracking.Tracking dogs
Tracking dogs are known for their ability to detect and follow the vegetative vapours released from disturbances of plant life They stay very close to foot paths and are able to follow considerably aged tracks.Trailing dogs
Trailing dogs have a stronger affiliation for proponents of human scent near the trail they are tracking. They can be observed deviating slightly from or crossing over the trail they are tracking. Trailing dogs heavily rely on scent because the trails in which they follow often don't have any visual cues for tracking. Tracking and trailing dogs are often used interchangeably for police aid in human, suspect and victim searches.Point source dogs
Point source dogs are specialized in air scent tracking and tend to ignore ground scents. They utilize increasing intensity of specific odours to identify and track a trail to a certain target object. There are two separate classifications of point source dogs: detector dogs and discrimination dogs. Detection dogs are most often used to identify both non-biological and biological scents of a target object while ignoring other non-target environmental scentsBrowne, C., Stafford, K., & Fordham, R. (2006). The use of scent-detection dogs. Irish Veterinary Journal, 59(2), 97. Discrimination dogs are most often employed by police forces to identify the scent of a specific individual being tracked. This differs from detection dogs because they are required to react to a scent that matches or differentiates between other ones instead of identifying that a certain scent is present. Specific uses of detection dogs * Explosive and mine identification * Bacteria detection in buildings and homes * Detection of human waste materials in storm drains * Search and rescue missions, recovering evidence from a crime scene,Baldwin, H. B., & Puskarich May, C. (2000). CRIME-SCENE INVESTIGATION AND EXAMINATION , recovery of human remains. In Editor-in-Chief: Jay A. Siegel (Ed.), Encyclopedia of forensic sciences (pp. 447–457). Oxford: Elsevier. and locating drugs and explosives Specific uses of discrimination dogs * Finding dead or aliveFurton, K. G., & Myers, L. J. (2001). The scientific foundation and efficacy of the use of canines as chemical detectors for explosives. Talanta, 54(3), 487–500. police suspects * Distinguishing between different forms of narcotics and reacting to the presence of a specific narcoticTracking trials
A Tracking trial is an event to encourage dogs to make use of their strongest facility, the ability to follow aSee also
*References
{{Dog sports Dog sports Olfaction