Summary
The management of rare species is a conservation priority worldwide, but this task is made difficult by detection errors in population surveys. Both false positive (misidentification) and false negative (missed detection) errors are prevalent in surveys for rare species and can lead to incorrect inferences about their population status or distribution. Environmental DNA (eDNA), which is DNA shed from an organism in its environment, coupled with quantitative polymerase chain reaction (qPCR) analyses, has become a reliable and extremely sensitive means for identifying rare species in aquatic systems. Due to the demonstrated effectiveness of these methods, USDA Forest Service scientists tested their efficacy in surveys for rare species in terrestrial settings to reduce detection errors for three rare forest carnivores of conservation concern: Canada lynx (Lynx canadensis), fisher (Pekania pennanti), and wolverine (Gulo gulo). The scientists investigated their ability to reliably identify species directly from snow samples collected within tracks, identify species by collecting snow samples in locations where an animal had been photographed months earlier, and identify species from old hair samples collected during the summer after being deployed the prior fall (i.e., overwinter surveys). The scientists found that their species-specific assays could effectively detect DNA of all three species, including from snow-track surveys, snow collected at camera stations, and overwinter samples that failed to amplify with conventional lab techniques. All results indicate that the sources of targeted eDNA collection provided adequate quantities of DNA for robust species detection. The scientists suggest that using qPCR methods to detect DNA has the potential to revolutionize winter surveys for rare species in terrestrial settings by reducing or eliminating misidentifications and missed detections and allowing surveys in areas where winter access is not feasible such as wildernesses. Detecting DNA from rare carnivores snow track samples and old hair samples was highly successful. Detection was enabled by adapting environmental DNA methods used in aquatic surveys. This cost-effective method can revolutionize winter rare carnivore surveys by providing highly specific and sensitive results.
