Evaluating the efficacy of non-invasive genetic sampling of the Northern Pacific rattlesnake with implications for other venomous squamates

Abstract

A common challenge for conservation genetic studies is finding minimally invasive sampling methods that maximize the quantity and quality of data produced. Conventional approaches rely on tissue or blood sampling, which typically require lengthy handling times, and can be hazardous for high-risk species, such as venomous snakes. Finding alternative, less invasive techniques is imperative in such circumstances. We compared DNA quantity and genotyping success of blood samples to those from buccal swabs, cloacal swabs, and scale clippings in the Northern Pacific rattlesnake (Crotalus oreganus oreganus). Buccal swabs and scales yielded significantly less DNA compared to blood, whereas cloacal samples were not significantly different. Cloacal swabs produced the highest PCR success and lowest genotyping errors commensurate to the blood samples, but differences were not significant between sample types. Our findings suggest cloacal swabbing as an efficient, less invasive alternative for providing high quality genotypic data for squamate reptiles (venomous or nonvenomous).