Straight from the Coyote’s Mouth: Genetic Identification of Prey through Oral Swabs of Predators

Human-carnivore conflicts often involve the depredation of domestic livestock. These depredation events are rarely observed, yet mitigation typically involves identifying the species or individual involved for removal or relocation. We tested a molecular method to identify individuals involved in depredation events using mouth swabs to determine if prey DNA could be detected, and for how long. We fed mule deer Odocoileus hemionus meat to captive coyotes Canis latrans and swabbed their mouths at five predetermined intervals between 2–72 h after consumption of the deer meat. We assessed two different molecular forensic methods to analyze the saliva swabs: qPCR for species identification and microsatellites for individual prey identification. We found that qPCR analysis was highly effective, detecting the deer DNA in the coyote saliva for up to 72 h post-deer consumption. Our results suggest that if an individual carnivore suspected of livestock depredation is captured within 72 h of a depredation incident, it is possible to confirm their potential involvement with a buccal swab and qPCR analysis. Utilizing this method could aid in more targeted and effective removal of individual problem carnivores as opposed to widespread removal of involved species.