Abstract
Unambiguous evidence for the effectiveness of muskrat (Ondatra zibethicus L.) control in well-established populations in mainland Europe is lacking. Yet, this evidence is important given ongoing public challenges to the need for muskrat control and the expressed political aim of the European Union to eradicate invasive alien species, including the muskrat. In this study, indices of muskrat abundance based on livetrapping were compared among (i) sites at which muskrat control had been suspended for 3 years (suspended trapping), (ii) sites with ongoing control by kill trapping (ongoing trapping) and (iii) a site at which control efforts had ceased more than 8 years previously (no trapping). In the no trapping site, the muskrat abundance index was variable but consistently high, while in the ongoing trapping sites, the muskrat abundance index was consistently low. In the suspended trapping sites, the index of muskrat abundance increased from a level near that of the ongoing trapping sites to that of the no trapping sites. The findings are corroborated by population estimates based on data from robust design mark-recapture models and data from kill trapping. The results are interpreted as compelling proof for an effect of control on muskrat numbers, a basic premise of the control programme.
Highlights
Invasive alien species (IAS) are a worldwide issue and in many cases demand some form of population management.Electronic supplementary material The online version of this article contains supplementary material, which is available to authorized users.GA Nijmegen, Netherlands 5 Resource Ecology Group, Wageningen University, P.O
Its habit of excavating extensive burrow systems in earthen dams, banks and other water retaining structures is considered dangerous, especially in regions below sea level that would be flooded if these structures were damaged (BCM 2006; Bayoumi and Meguid 2011). To minimise these and other negative effects, muskrat populations are actively controlled in some of these countries. The efficacy of this population management has been challenged (Pelz 1996; Zandberg et al 2011), and in this paper, we report a study designed to compare the growth of muskrat populations with and without a control programme
The predictions are that (1) the muskrat abundance index will be higher in sites without muskrat control than in sites with control and (2) the muskrat abundance index will increase after trapping is suspended, altering the index values resembling the ‘ongoing trapping’ situation to those resembling the ‘no trapping’ situation
Summary
Invasive alien species (IAS) are a worldwide issue and in many cases demand some form of population management. The muskrat (Ondatra zibethicus L.) is invasive in Europe and is for important reasons considered a serious threat to human safety, economy and biodiversity in several countries (EU Deputy Direction of Nature 2015). Its habit of excavating extensive burrow systems in earthen dams (levees), banks and other water retaining structures is considered dangerous, especially in regions below sea level that would be flooded if these structures were damaged (BCM 2006; Bayoumi and Meguid 2011). To minimise these and other negative effects, muskrat populations are actively controlled in some of these countries. Muskrat populations are present in large parts of NW Europe, following introduction in 1905 (Artimo 1960; Long 2003; Le Louarn and Quéré 2011)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
