Identification of mustelid species: otter (Lutra lutra), American mink (Mustela vison) and polecat (Mustela putorius), by analysis of DNA from faecalsamples

The abundance of mink, otter, and polecat may be inferred from records of t heir seats, and the feeding biology of the species is often studied by anal ysis of skeletal remains and other hard parts in faeces. However, in some s ituations it is difficult to distinguish between faeces from these three mu stelid species. A method is described for assigning faeces to these three m ustelid species, based on analysis of DNA extracted from their seats. Muste lid-specific primers were developed for PCR amplification of a part of the mitochondrial cytochrome b gene, and two restriction enzymes were found to detect species-specific sequence variation. Analysis of DNA from different faecal samples showed that the results were reproducible and that the appro ach provided an efficient method of species identification.