27th Annual Meeting and Symposium of the
Desert Tortoise Council, March 22-24, 2002
Abstracts

Search Dogs May Prove A Vital Tool in the Monitoring and Recovery of the Desert Tortoise

Curtis D. Bjurlin¹ and Deborah A. Smith^2
1Endangered Species Recovery Program, Fresno, CA 93727; 
²Department of Ecosystem Sciences, University of Washington, Seattle, WA 98195

Desert tortoises and their sign (scat, burrows, bone fragments) can be notoriously difficult to locate, especially with respect to young age classes. Low numbers, cryptic coloration and dense vegetation can lead to detection difficulties, and in experimental trials, have caused human observers to display variable search aptitudes. We propose that professionally trained search dogs may be a more effective method for locating tortoises and their sign. The scent discrimination ability of dogs is well documented from their use in law-enforcement and search and rescue missions. Moreover, dogs have been known to improve search efforts in wildlife research, successfully locating wildlife sign (e.g. bird nests and carcasses, ringed seal lairs, urine marks, scats) and wildlife (e.g. brown tree snakes, box turtles). During a recent trial, dogs trained to detect species-specific fecal samples, recovered 9 times more kit fox scat in dense vegetation than human observers. The use of detection dogs may greatly enhance current techniques used for tortoise population surveys and provide unambiguous presence/absence data at proposed construction sites. Furthermore, scent-following dogs may significantly increase detection probability of small tortoises, yielding new information on little studied early life stages.