Muskrat (Ondatra zibethicus) decline after the expansion of American mink (Neovison vison) in Poland

Abstract

Field survey data in Central Poland revealed that the proportion of sites inhabited by muskrats decreased from 44% to 7% over one decade. This corresponded to the decline in hunting bags of muskrat over the whole of Poland. The largest hunting harvest of muskrat was recorded in 1987/1988 (66,416 individuals), the smallest in 2007/2008 (4,567 individuals). The decline in hunting bags occurred in all regions analysed; however, it was most rapid in the north and north-east. Before the expansion of mink, which started in northern Poland at the beginning of the 1980s, muskrat densities in particular regions depended on the availability of aquatic habitats. A comparison of hunting bags of muskrat and American mink in years 2002-2008 indicated a significant negative correlation between the numbers of these two species harvested in seven regions of Poland. The negative correlation between numbers of muskrat and mink suggests that mink predation is one of the most important factors in the decline of the muskrat population in Poland.

A historical perspective on the effects of trapping and controlling the muskrat (Ondatra zibethicus) in the Netherlands

“…the province of Groningen) or indications of high population size (the nature reserve Oostvaardersplassen), even in the presence of all or most of these predators, and Bos and Ydenberg argue that the role of predation in the population regulation of muskrat in the Netherlands is small in comparison with the effects of trapping. This is in contrast to findings in Poland (see below). It seems that the intense control measures are most likely responsible for the population decline.…”

“…Further, there may be alternatives to trapping that could mitigate or prevent damage. Finally, one can imagine scenarios in which an invasive population, such as that of the muskrat, would decline over time regardless of trapping effort, owing to changes in the predator community, vegetation (cf. Danell) or disease .…”

Human–wildlife conflicts at pond fisheries in eastern Poland: perceptions and management of wildlife damage

“…Mink were more likely to be observed at farms visited by otters, indicating that otter impact on mink was insignificant in pond culture areas (see also Jędrzejewska et al 2001), but mink was also believed to decrease at some farms visited by otters. Also, the present results confirm that mink may be an agent of muskrat decline (Erb et al 2001;Brzeziński et al 2009). The observations and accompanying complaints about great white egret, a species absent from Poland for over a century, but recently rapidly expanding (Tomiałojć and Stawarczyk 2003), may portend an emerging conflict.…”

“…GDA was also performed for mink and muskrat, with their presence/absence as the categorical grouping variable. In mink and muskrat models, otter and mink presence/absence were added, respectively, as categorical predictors, on the assumption of strong trophic interactions between these species (Bonesi and Macdonald 2004;McDonald et al 2007;Brzeziński et al 2009). Continuous variables were log-transformed.…”

Diet of the American minkNeovison visonin an agricultural landscape in western Poland

“…al. 2003, Brzeziński et al 2010. There is also some evidence that minks can significantly affect species from other systematic groups, such as crustaceans (Previtali et al 1998, Fischer et al 2009).…”