Interspecific Relations between Otter Lutra Lutra and Mink Mustella Vison in Sweden

Food spectrum, food competition, habitat selection and distribution of otter and mink were investigated in a water system in southern Sweden. Frequency of scats showed an inverse correlation between the density of otter and that of mink due to habitat preference and specific interference. A dense otter population kept the population density of mink low in restricted areas. The mink had a negative influence on the population size of the otter because of food competition in winter, causing a restriction of the otter to optimal habitats. The pattern of coexistence is discussed.