Understand Scent and How Conditions Will Affect It
Keep in mind, however, that even if the scent trail is too old for a search dog to track, a MAR Technician can POTENTIALLY HELP YOU find your lost pet using other methods, including using his or her dog to track a fresher scent trail from a viable sighting.
“The ideal working scent conditions for a trailing dog are cool, moist days with no wind. Scent will pool, cling, and survive in shady areas and areas with lush vegetation. The moisture provided by lush green grass, the shade of a front porch, or the damp surface of a gutter are all examples of places where residual scent could be present several days after the source of the scent has passed through an area. Scent survives longer in the cooler conditions found in the evening or early morning hours because lower temperatures will tend to bring the scent back down to ground level.
Hot and dry conditions have a negative impact on scent survival. In these conditions, scent is more easily dispersed and destroyed. Direct sunlight will dry out and quickly destroy scent vapors. In addition to the physical toll that it can take on a trailing dog, heat can also cause scent to rise above the level of where the dog is working. The key to working a search dog in hot temperatures is to avoid it if you can.
Wind can disperse scent great distances, minimizing a scent trail and making trailing difficult. In a case where a lost person walked down a sidewalk four days prior to a trailing dog starting to search, the trailing dog might very well work by dipping down into the driveways, up to front porches of homes rather than the spot where the person walked on the sidewalk four days before. If there is grass directly next to the sidewalk, then the trailing dog might work on the grass. The chances of any scent remaining directly on the pavement of the sidewalk are slim after a four-day period. But the chance of scent surviving by clinging to the moisture provided on the grass and in the shady areas is very likely. Scent needs moisture to survive which rain provides. Rain does not make scent mysteriously disappear. Rain will not destroy scent, but a heavy downpour on pavement can disperse it, making it difficult to follow a trail. In those cases, the scent will cling in gutters and puddles instead of being dispersed along a consistent path like a sidewalk.
So How Long Can Scent Survive?
The odor of decomposition has been known to change the composition of soil and can be detected by search dogs many years after the body decomposes down to skeletal remains. For obvious reasons, the longer you wait to have a search dog track a scent trail, the less likely that dog will be able to work the scent trail successfully. The longer you wait, the more likely the lost dog will have moved or been transported a great distance. Thus, the fact that the scent of the missing dog might still be present after seven days is sometimes a moot point if the dog has already traveled 20 miles and you aren’t able to catch up to him or her. This is why Missing Animal Response Network is pushing for community-based lost pet services. Ultimately, we want to see the rapid response of MAR trailing dogs who can respond within hours or a few days to search for lost dogs in their own community.
Keep in mind that a two-week-old scent trail laid in a residential area that is highly contaminated with other animal scents and dispersed with vehicular traffic is much more difficult to work than a two-week-old scent trail laid in the depths of a cool, damp forest thick with vegetation. Scent has a better chance of surviving in shady, damp, and cool areas than it does in open ground or pavement where it is easily moved by wind currents, swirled around by passing cars, and ultimately dried out and destroyed by direct sunlight. Although no one knows exactly how many days a scent trail will be viable, we can make estimates based on prior successes of cases worked by police Bloodhounds and search-and-rescue trailing dogs who have made actual walk-up finds. The majority of successful scent trails where these dogs actually found the lost person or criminal were basically hours or a few days old.
How Long Does Scent Last
The length of time a dog can follow a scent is highly dependent on how long the scent itself will last. This is dependent on a few factors including, weather conditions and the material in which it attaches. There is much debate around how long a dog can smell a scent and a common answer appears to be around 1 month. However this entirely depends on whether the material is still letting off gases, in particular, decomposing bodies will continue given scent off for many years.
Another factor influencing how long a dog can track someone or something is the material in which they stand on. Some believe that a scent trail will disappear quickly once a person walks on a road or pavement, as apposed to a wood area where scent can be more easily distributed.
A smell is formed through the release of gases into the air. These gases can be released through oils on the surface of a material. The amount a material smells is down to its ability to release gases into the air. Fabrics are generally good at holding smells, as the gases are released within the fibres of the material. Odours can linger in a certain place and the ability of a material to release a scent will help a dog to track it in a certain direction.
Tracking with dogs – the first lesson in following a scent
Police dogs are impressive pups with a list of incredible abilities. Not only are they extremely dedicated to their work, but they are one of the best scent trackers around. So how do police officers train their police dogs to track a scent?
In this article we’ll dive into the details of scent tracking in dogs, and how these working pups learn this impressive ability.