Expand or disappear ? Why related Mustelid species follow different roads. Lessons from the genetic study of minks, polecat and otter

The present global changes have a strong impact on the survival of many species and on their demography and population dynamics. On one hand, some species undergo strong reduction of their populations due to the fragmentation of their habitats, the competition with other species, the pollution or degradation of their habitat or the appearance of new diseases. On the other hand, many species tend to expand their distribution range) and can even be considered as invasive species in some cases.
The aim of our presentation will be to better understand which biological factors could lead to decrease populations of a species until extinction or in contrast, could help a species exanding its population densities and distribution area.
These hypotheses will be illustrated by our recent results obtained through the genetic study of the European mink Mustela lutreola, the American mink Neovison vison, the polecat Mustela putorius and the European otter Lutra lutra (Cabria et al. 2011; Michaux et al. 2005; Pigneur et al., In Prep).