Feeding habits of the otter and the American mink in Białowieża Primeval Forest (Poland) compared to other Eurasian populations

摘要: Diets of the otter Lutra lutra and American mink Mustela vison were studied by scat analysis on five woodland rivers streams in eastern Poland. Fish constituted 51% food biomass consumed otters spring-summer 40% autumn-winter, with common fish (perch Perca fluviatilis, pike Esox lucius, roach Rutilus rutilus) being captured most frequently otters. Amphibians (mainly Rana temporaria, which also dominated living community) made up 34% otters’ 58% autumn-winter. relied three prey groups: (40% spring-summer, 10% autumn-winter), frogs (32% 51%, respectively), small mammals (21% 36%). Out available Micromammalia, strongly selected root vole Microtus oeconomus. The cold season diet both depended river size. On forested valleys, fed nearly exclusively amphibians (72–90% biomass). With size a increasing riverside habitat becoming more open (sedge reed marshes instead forests), shifted to catching predominantly (up 76% diet) preying 65% diet). Review literature Eurasia showed that their diets did not change latitude (as indicators climate severity duration water freezing) but they habitats. In diet, mean share declined from 94% (SE 1.7) sea shores, 71% 2.9) lakes ponds, 64% 2.8) streams. roles crustaceans increased same gradient (from 0 15%, 3 7%, respectively). inland waters, abundance crayfish was essential factor differentiating composition. Eurasia, staple types (on average, 27% SE 3.9), (30%, 5.0), (17%, 4.8), whereas ponds birds 33% 10.1) (28%, 9.5). Palaearctic region, over wide habitats, appeared specialised taken water, typical generalist capable utilising several groups originating land.