to Avalanche Rescue Dogs
By Kim Gilmore
1st Special Response
Purpose: To provide a brief history of, reasons for and effectiveness of trained dogs in Emergency Rescue Services involving the public in a snow and avalanche context.
For years, snow related rescue operations were best described as chaotic and it wasnt until the late 1930s that the Swiss Army started training search dogs in Avalanche Rescue. Since that time trainers have refined their training techniques and now many avalanche victims can owe their lives to dogs trained in avalanche rescue.
Victims buried in snow as a result of an avalanche are but one class of snow rescues. Youth and elderly that have fallen due to injury or hypothermia and as a result are covered by snowfall as well as the healthy well-prepared hiker and skier who hole up in a snow cave after having become lost or exhausted constitute another class of Avalanche Rescue. Once buried, detection by the naked eye is impossible.
SAR dog Merak (Belgian Shepherd), pinpoints human scent buried
at approximately 2 meters during training. SAR dogs must have the persistence
to keep working through even the most inhospitable weather.
The trained search dog works a snowfield rapidly, searching for pools of human scent rising up through the snow pack. When the dog finds a potential scent source he will bury his head into the snow trying to locate the source. If the human smell intensifies, he begins to dig trying to get closer to the source. If the scent becomes weaker, a trained dog will start to work outwards from the area to attempt to either pinpoint an area of stronger buried source or rule the scent out as surface odor left by human searchers.
Nine month old SAR Trainee Mickey (Belgian Shepherd),
locates his handler during a training exercise.
Dogs are introduced to the concept of human scent
under the snow by first finding their owners.
When someone is buried in an avalanche, speed in locating the individual is of the essence. A Swiss study on avalanche mortality published in 1992 indicates that approximately 90 percent of persons buried in avalanches survive if recovered in the first 15 minutes. Chances for a live recovery at the 35-minute mark fall to 30 percent and after two hours the survival rate is three percent. However, there are exceptions to every statistic and people have been found alive in certain circumstances 5-6 hours after being buried and in a few documented cases people have been recovered still alive after 24 hours.
SAR dog, Zenobia (left, Border Collie) and
SAR Trainee, Harlan (right, mixed breed), patiently await
their turn to search. Avalanche dogs must be
social, obedient and a have a good temperament with
both people and other dogs.
A well-trained avalanche rescue dog is a model of efficiency in that one dog is equivalent to approximately 20-foot searchers and can search the same area in an eighth of the time. The following graph illustrates the ability of an Avalanche Search Dog Team and was taken from the National Research Council Canada Associate Committee on Geotechnical Research Avalanche Control, Forecasting and Safety manual (1976). During a Coarse search (Hasty search), the graph shows that a trained Avalanche Dog can search one hectare in approximately 30 minutes, where it takes 20 foot searchers 4 hours to search the same area with probe poles (covering about 2.5% of the total area that the dog could cover). During a Fine search, one dog can cover the same hectare in 1-2 hours where it would take 20 searchers 20 hours to cover the same area (only accomplishing 10% of what a dog could cover).
In an emergent situation, a dog, its handler and a few back-up people can be airlifted into the search area to conduct a Hasty search as the rest of the foot searcher make their way to the scene. Remember, speed = increased chance of a viable victim.
Although efficient, trained dogs are not infallible. Surface conditions, snow conditions, capabilities of the particular dog and scent diffusion all play an important role in how deep the victim can actually be buried and still be located. There have been confirmed reports, in optimal conditions, of a dog in Austria locating a body at approximately 12 meters. In the U.S. there has been a confirmed find at 10 meters. However, this type of success is few and far between. Realistically one can expect an experienced dog to be able to locate victims between 2-4 meters without a lot of difficulty in most scenting conditions.
Four month old SAR Trainee, Ellie Mae (Border Collie),
investigates the burial site of her owner during
a puppy training problem.
Speed, efficiency and a nose capable of detecting human scent deep beneath the surface of the snow has allowed the Avalanche Rescue Dog to earn itself the reputation of becoming an invaluable asset in the context of snow and avalanche rescue. Studies have proven the capabilities of dogs in the avalanche setting and in turn trained dogs have proven their abilities worldwide.
Zenobia and Merak, doing what they like to do best!