Trophic niche comparison of American mink and Eurasian otter under different winter conditions

Abstract

No abstract available

Using DNA metabarcoding to investigate diet and niche partitioning in the native European otter (Lutra lutra) and invasive American mink (Neovison vison)

“…This is consistent with many other morphological studies which conclude that the otter is a generalist (Prigioni et al 2006;Remonti et al 2010) or an opportunist, whose diet varies with prey availability and latitude (Clavero et al 2003;Almeida et al 2012Almeida et al , 2013Reid et al 2013;Alderton et al 2015), although it has also been called a specialist with respect to its diet being limited to aquatic prey, such as fish and amphibians (Sidorovich 2000;Bonesi et al 2004;Bonesi and Macdonald 2004b;Melero et al 2008;Skierczyński and Wiśniewska 2010;Krawczyk et al 2016). Conversely, the mink has been observed to utilise both aquatic and terrestrial resources (Sidorovich 2000;Jędrzejewska et al 2001;Bonesi et al 2004;Bonesi and Macdonald 2004b;McDonald et al 2007;Brzeziński et al 2008;Melero et al 2008;Skierczyński and Wiśniewska 2010). Results from previous morphological studies (Harrington et al 2009) and presented here suggest that the mink specialises on terrestrial prey when co-existing with the otter.…”

“…In Belarus, higher niche overlap was identified in spring and autumn than summer or winter due to greater availability and consumption of amphibians by both the otter and mink (Sidorovich 2000). In Poland, higher niche overlap was found in spring-summer than autumn-winter (Jędrzejewska et al 2001), in harsh winter conditions as opposed to mild winter conditions, and in a wetland complex compared to a river catchment (Skierczyński and Wiśniewska 2010). In the UK, Bonesi et al (2004) found niche overlap between the otter and mink decreased following an increase in otter density and establishment of a resident population, and niche overlap was lower in winter than spring possibly due to resource restrictions.…”

“…In our study, mink diet was dominated by birds (55.9%) and mammals (39.6%) with only a small component of fish (4.5%). A morphological study in the Biebrza Wetlands of Poland also observed that more mammals (43.7%), fish (32.9%) and birds (21.5%) than amphibians (1.9%) and invertebrates (0.1%) were consumed by the mink in a harsh winter, yet the importance of mammals (68.8%), amphibians (27.2%), birds (1.2%), fish (2.7%) and invertebrates (0.1%) shifted in a mild winter (Skierczyński and Wiśniewska 2010). These results and our own somewhat contrast with other estimates obtained using morphological analyses.…”

Diet of the Eurasian otter Lutra lutra on small watercourses in Western Poland

“…A small share of frogs in the winter diet of otters from the Barycz Valley indicated that in our study area amphibians do not constitute an alternative source of food, thus their biomass (1.2%) is very small in comparison with the biomass of fish. Similar findings were reported from Biebrza Wetlands, where amphibians never occurred in the diet of otters during harsh winter seasons, and even during mild conditions its share in the diet did not exceed 8% of biomass (Skierczyński and Wiśniewska 2010).…”

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

“…In addition, minks are riparian predators foraging both on terrestrial and aquatic food, and the proportion of these prey groups in the mink diet is expected to be variable (Macdonald & Strachan 1999). Similar to previous studies which have found pronounced intraspecific differences in diet composition between individuals, sexes, seasons, and even years , Macdonnald & Harrington 2003, Skierczyński & Wiśniewska 2010, Magnusdottir et al 2012, the diversity of taxa that we identified in the diet of minks differed across seasons. First, we found a decline of mammals in the summer diet of minks, in accordance with the findings of Bartoszewicz & Zalewski (2003), whom also described a high proportion of mammals in the mink diet, highest in autumn and winter and declining in spring when minks preyed mostly on birds and accessible fish (but see Brzeziński 2008 andZschille et al 2013).…”