The origin, dispersal and distribution of the American mink Mustela vison in Poland

Poland, feral population of the American mink Mustela vison Schreber, 1777, originating from the immigrants from Belarus and Lithuania, as well as from Polish fur farm escapees, started to develop in the beginning of 1980s in the north-east and north-west of the country. According to questionnaires sent to hunters, up to the end of 1980s mink colonized 9 out of 16 Polish provinces. Within next decade mink were observed in next 6 provinces. In Warminsko-Mazurskie and Podlaskie provinces (north-eastern Poland) mink presence has been confirmed by over 90% of hunting units, whereas in the north-west of the country by over 50% of respondents. In southern provinces mink are still uncommon but they successfully enlarge geographical range. During the 20-year period, mink have colonized over half of the Polish territory. Colonization of particular regions was correlated in time with a decline of muskrat and waterfowl populations. From the beginning of 1980s to the half of 1990s, in north-eastern provinces hunting bag of muskrat decreased 10-fold, whereas in other parts of Poland the number of hunted muskrats was more or less stable. Despite the lack of complex ecological studies on the mink impact on their prey, it is highly probable that this introduced carnivore negatively affects populations of semi-aquatic birds and mammals.