A method of genetic identification of pine marten (Martes martes) and stone marten (Martes foina) and its application to faecal samples

Reliable identification of species occurring in a given area is a basis of effective wildlife management and conservation. However, discrimination of species is often difficult, especially if two morphologically similar, rare and elusive species occur sympatrically. This is the case with pine marten Martes martes and stone marten Martes foina, two closely related mustelids that have overlapping ranges throughout central Europe. Here we describe a genetic method that allows for distinguishing non-invasively collected samples (faeces or remotely plucked hair) derived from pine martens or stone martens. On the basis of the analysis of tissue samples of 31 pine martens and 26 stone martens, we found that the microsatellite locus Ma18 - developed in another study for American marten Martes americana - differs substantially in allele lengths between pine martens and stone martens, thereby allowing a genetic distinction of these species. We propose combining the use of the locus Ma18 with the second one described in the literature as having the same properties. The simultaneous application of these two markers allows for unequivocal species identification. To test the practical use of this method, we analysed 365 faecal samples collected in the vicinity of the town Rogow (51 degrees 48'N, 19 degrees 53'E) in central Poland, where pine martens and stone martens occur sympatrically. We successfully identified 78 scats of stone martens and 155 of pine martens. We found that the faeces of both martens occurred inside forest complexes of the study area. Thus, it is impossible to draw any inferences on the marten species solely from the type of habitat where the faeces were found. Genetic identification of faeces or hair provides a reliable and relatively cheap method of determining the presence of two species of European martens. Its application enables the monitoring of changes in their distribution, which is important because of their different demographic trends and conservation status.