Genetic homogeneity of Canadian mainland marten populations underscores the distinctiveness of Newfoundland pine martens (Martes americana atrata)

American pine martens (Martes americana) are mid-sized mustelids found in the boreal and taiga zones of North America that prefer late-successional coniferous forests. Studies have shown that tracts of treeless land and roads may impede marten dispersal and that fewer martens are captured or observed in clear-cut areas. If marten habitat is indeed fragmented by roads and treeless land, this may result in decreased gene flow between regions and therefore in increased levels of genetic structure and decreased genetic variation in regions where these potential barriers are present. In this study, we evaluate the genetic variation and connectivity of marten populations across Canada. Thirty-five regions from the Canadian provinces and territories were sampled, including 1262 individuals, genotyped at 11 microsatellite loci. As expected, and in agreement with previous studies, little genetic structure was observed in northern regions, where few barriers to marten dispersal are thought to exist. However, contrary to our expectations, no strong breaks in gene flow were observed between any of the 35 sampled regions with the exception of the insular Newfoundland population. The lack of genetic structure observed may suggest that, at a larger scale, marten dispersal is not as limited by some landscape features as was previously thought.