Study Overview:

This study assessed the efficacy of using ecological scent detection dogs to survey for the endangered Pima pineapple cactus (Coryphantha scheeri var. robustispina). To achieve the overall research goal, two scent-detection dogs were trained to recognize the scent of  and to discriminate the scent from that of sympatric cactus species. A trial phase was conducted with two detection dog teams, each consisting of one detection dog and one handler, to quantify the accuracy, sensitivity, and specificity in finding Pima pineapple cactus.

Pima pineapple cactus is listed as an endangered species by the U.S. Fish and Wildlife Service (USFWS) and as a highly safeguarded species by the State of Arizona. It grows on gently sloping alluvial fans, ridgetops, and basins of the Sonoran Desert scrub and semidesert grasslands of southern Arizona and northern Mexico (USFWS 1993). This cactus has proved difficult to detect during traditional transect surveys because it is sparsely distributed within its range and habitat and is small and often camouflaged by tall grasses or other vegetation.

The results of this pilot study suggest that detection dogs can potentially offer a method of survey that is more efficient than traditional transect surveys for the species. Two detection dogs were successfully trained to recognize the scent of PPC and to discriminate the scent from the scent of sympatric and related plant species. Through rigorous training and testing, the detection dogs demonstrated that they recognized the target scent when PPC was hidden in a container among control containers and when it was well camouflaged in a field setting. This target recognition remained strong even when the type of container and the location of the search area was manipulated and when potentially confusing nontarget odors were added to the training and trials.