Characterisation of den sites of American mink Neovison vison in central Spain

The American mink Neovison vison is a widely distributed species in Spain, for which important basic ecological data are lacking. We studied mink den site selection in a location in central Spain during the winter of 2008/09 using snow-tracking and direct observation. Dens were located more frequently in tree roots (51.9%; N = 79) inside emergent vegetation (15.2%) and on human-created enbankments (15.2%). Human buildings and burrows were scarcely used (< 10%). The logistic regressions we carried out supported that minks used secondary river beds for shelter more often than their availability in the environment should predict. These secondary areas are characterised by their low width and the frequent presence of small streams (of < 1m width). In rough terms, this pattern could be a way of avoiding potential interactions with other animals sharing the same habitat; and also for thermoregulation while resting. On the basis of the wide habitat niche, ecosystem management as a measure of mink control appears to be ineffective.