Dynamics in space use of American mink (Neovison vison) in a fishpond area in Northern Germany

Telemetry of American mink Neovison vison revealed seasonal and sexual variations in home-range size, intersexual- and partially intrasexual range overlaps and spatial dynamic of territorial system. From 2003 to 2006, 14 mink (nine males and five females) were radio-tracked in a fishpond area in northern Germany. We observed comparatively large home ranges. Both sexes reduced their large summer home ranges to smaller ones in the winter period. In both seasons, male mink used significantly larger areas than female mink. During the mating season, males considerably enlarged their home ranges and roamed nearly through the entire study area. These variations and diversity of range size were discussed in connection with thermoregulatory behaviour, prey availability and distribution, population density and stability of the social system. Analysing intraspecific static interactions, we observed high intersexual overlapping rates in both the summer and winter periods. But there were no or rather very low levels of intrasexual overlapping. However, in the summer period, large home ranges of neighbouring males also overlapped to some extent, but temporal avoidance of adjacent territory holders was observed. Consequently, our results reveal intrasexual territoriality, with males having larger territories, overlapping those of females. The shifting of stable temporary home ranges observed within one season or between the same seasons of consecutive years demonstrates the highly dynamic nature of spatial behaviour among American mink. All these recorded characteristic features of spatial behaviour should be considered when planning mink control projects and measures for the management of this invasive carnivore.