Noninvasive saliva collection for DNA analyses from free-ranging Tibetan macaques (Macaca thibetana)

Cryptic and endangered fauna, including many primate taxa, pose challenges for noninvasive collection of biomaterials. As a result, application of noninvasive genotyping to primates has been limited to the use of samples such as feces and hair for the extraction of PCR-amplifiable DNA. We present a method for noninvasive collection of saliva from habituated, free-ranging monkeys. The method utilizes a low-cost apparatus that controls for contamination and is usable with individual, free-ranging primates. Saliva samples were collected from 18 individuals in a population of Tibetan macaques (Macaca thibetana) in the Valley of Wild Monkeys in Huangshan, People's Republic of China. DNA was extracted from these samples and PCR-amplified for both mitochondrial and nuclear genes, Cytochrome B and MHC-DR Beta 1, respectively. These results indicate this is an effective technique for the noninvasive collection of saliva across age and sex class, and dominance rank in a free-ranging, terrestrial primate species. This device could have wide application for obtaining high-quality saliva samples from free-ranging primate populations for use in epidemiological studies, hormonal analyses of HPA axis function, pathogen screening, noninvasive genotyping, and behavioral genetics.