Cloacal swab sampling is a reliable and harmless source of DNA for population and forensic genetics in tortoises

Testudo graeca, Testudo hermanni and Testudo marginata are endangered species listed in the IUCN Red List and Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Correct identification of species and distinct population units can support sound conservation projects and forensic applications. However, the collection of biological samples is not always easy or harmless. Blood sampling is usually invasive and risky. Salivary swab sampling is commonly used in other reptiles but can be unsafe for tortoises by the reason of their head retraction escape response. Cloacal swab sampling should be easier and less risky. In this study, we genotyped 37 tortoises at eight microsatellite loci and compared the reliability of individual genotypes obtained from blood, cloacal and buccal swabs. Results showed that performances of cloacal samples are comparable with those of buccal and blood samples, and proved that cloacal sampling is an alternative and reliable source of DNA for tortoise genotyping.