Why some species disappear and other expand? The example of the minks (M. lutreola and N. vison) and the European otter (Lutra lutra

The present global changes have a strong impact on the survival of many species and on their demography and population dynamics. Some species have a strong reduction of their populations, following the fragmentation of their habitats, the competition with other species, different pollutions or the appearance of new diseases. In contrast, several other species tend to expand their distributions areas and can even be considered as invasive species in some cases. The aim of my presentation will be to better understand which biological factors, including genetics, could lead to decrease populations of a species until extinction or in contrast, to help a species to expand its population densities and its distribution area.
These hypotheses will be illustrated by our recent genetic results obtained on the European mink (Mustela lutreola), the American mink (Neovison vison) and the European otter (Lutra lutra).