Lessons from the use of non-invasive genetic sampling as a way to estimate Eurasian otter population size and sex ratio

摘要: Given the difficulties in establishing population parameters of elusive animals wild by traditional methods, such as trapping, much attention has been given recent years to non-invasive genetic sampling. Our work compared estimates size and sex ratio derived from sampling with known number released during an otter reintroduction reports on pitfalls opportunities that may be encountered studies this kind. This study makes use 121 samples spraints (faeces) collected over 7 months a Upper Thames (UK) where total 17 otters was two consecutive phases. Spraints were processed multiple tubes approach seven microsatellites used. Of all samples, 19 % complete for at least five loci, minimum required discrimination between individuals. Six out nine first phase detected, four males females, while none second detected probably due combination behaviour. In particular, specific (mostly females) dominance composition (lower) individuals release group explain our failure detect group. Taken together, results add further evidence approaches represent potentially accurate route census populations but design should take into account factors like order maximise detection minimise error.