WHY IS THE EUROPEAN MINK (MUSTELA-LUTREOLA) DISAPPEARING - A REVIEW OF THE PROCESS AND HYPOTHESES

The historical range of Mustela lutreola extended from Finland to east of Ural Mountains, to northern Spain and Caucasian Mountains. The spe cies went extinct in some parts of Central Europe already a hundred ye ars ago. During this century, populations have declined almost everywh ere. Several hypotheses have been put forward to explain the disappear ance of the species. These include climatic change, competition with t he American mink M. vison, destruction of the habitat, disease transmi tted by the introduced American mink, crash of the favored food item, crayfish Astacus astacus, hybridization with the European polecat M. p utorius, etc. It is very clear, however, that none of the hypothesized factors alone could explain the events in various place at different times. The early declines in Central Europe and later in Finland took place before the spread of the American mink. On the other hand, the p resent decline of M. lutreola in Estonia seems to coincide well with t he spread of M. vison. The early declines in Central Europe could have been caused by destruction of the natural river ecosystems, especiall y river banks. Still, in Finland the major disappearance happened well before the major environmental change of natural small river ecosyste ms due to modern forestry. Even if the detailed explanations seem to v ary, there is an underlying theme: environmental change. The European mink seems to be a much more specialized species than the American min k. Before the arrival of M. vison, the change in the preferred habitat , small sandy brooks, or the crash of the food source, could have been the underlying cause. With the arrival of the American mink, the Euro pean one loses even without the environmental change.