Specially-trained dogs are used in many applications, including sniffing out drugs or contraband in oversea shipments, guiding the blind and providing therapy to invalids or the mentally ill. In the Delta, dogs with particular sniffing skills are being cued up to help protect a threatened species during annual levee maintenance.
The giant garter snake inhabits agricultural wetlands and waterways such as irrigation and drainage canals, ponds and streams throughout the Central Valley. Levee maintenance activities such as mowing, excavating, and filling small burrows can impact the snakes, which make their homes in and around levees. Because the giant garter snake is a threatened species under the U. S. Endangered Species and California Endangered Species Acts, activities that can disrupt these snakes are subject to guidelines to minimize adverse impacts. Since the snakes hibernate in borrowed rodent burrows from October to April, and their presence is difficult to detect, needed levee maintenance has to be deferred in areas that may be harboring the reptiles.
Enter the “Harvey Dogs”. H. T. Harvey & Associates, a California-based ecological consulting firm, has been training dogs to detect several species and to give their handlers a cue when the species is present. Using their superb noses, dogs can detect a target species from smelling the live animal or particles such as scat, skin casings, or feathers.
The Harvey Dog team recently completed a pilot study to determine if scent-detection dogs can be trained to recognize giant garter snake residual odor and distinguish it from that of similar snake species, and the answer was a resounding Yes: scent-detection dogs may be able to survey for snakes not only sheltering in burrows, but also in water! After the study, the Harvey Dogs were used to survey for snakes in partnership with giant garter snake expert (and UC Davis graduate) Eric Hansen. Both atop kayaks in sloughs and on foot on levee roads, the dogs detected the snakes and their findings were corroborated by environmental DNA analysis. As an added bonus, the surveys are noninvasive to the species.
When the dogs are working, they wear special vests and a bell to indicate they are “on-duty.” The vests allow the handlers better visual contact with the dogs and are also handy to hold the dogs’ GPS units which record their tracks while they work. The bells on the vests serve two purposes; they help to alert wildlife to the presence of the dogs and allow the handlers to have audio contact with their dogs while working over long distances. The ultimate goal is to deploy dogs so giant garter snake surveys can be done any time of year, clearing the way for needed levee maintenance. Finding species using scent detection dogs is truly a team effort, and for future work along levees, the Delta maintenance teams and the Harvey Dogs are aiming to build a winning partnership.
About The Dogs: Many of the dogs brought into the Harvey Dogs program are rescues. Others are dogs that did not pass search and rescue standards but are good at searching for and locating specific scents. In addition to Giant garter snakes, Harvey dogs have been trained to detect San Joaquin kit fox, California tiger salamander, blunt-nosed leopard lizard, and Morro Bay kangaroo rat, as well as to detect bird and bat fatalities at wind power sites. On their downtime, the dogs enjoy many activities including hiking, swimming, running, agility training and sometimes just relaxing in the sun. Meet the Harvey Dogs:
- Bolt: Border Collie/Australian Cattle Dog Cross
- George: German Shepherd/ Rottweiler Cross
- Gunny: Belgian Malinois Harleigh: Labrador retriever
- Kaia: Belgian Malinois mix (trained on GGS)
- Lithium: Patterdale Terrier mix (trained on GGS)
- Luna: Border Collie/Retriever mix
- Vector: Dutch Shepherd Zorro: German Shepherd
From the Delta Voice – a publication of the Delta Protection Commission