An evaluation of non-invasive sampling for genetic analysis in northern European reptiles

Genetic studies of native herpetofauna populations are important for the conservation of European biodiversity, but previous studies have been largely dependent on invasive sample collection. Here we explore the efficiency of non-invasive sampling (NIS) for molecular studies and review the various potential sources of such samples. Snakes produce a multitude of by-products, such as sloughed skin, faeces and eggs or embryos, that, along with road kills, predated specimens and museum samples, could potentially be used in molecular studies. We describe a new method for obtaining snake faeces in the field and, using mitochondrial cytochrome b primers, we successfully amplified 500 and 758 bp sequences from a variety of tissues collected by NIS. The availability and degradation of such material differed greatly, and both DNA extraction and PCR success appeared dependent upon sample origin and storage. Nevertheless, for the first time we demonstrate that faecal, egg and foetal tissues, as well as sloughed skin and carcasses, represent valuable NIS source material permitting genetic studies with minimal disturbance to the individual and its population.